Tag Archives: preventive medicine

Shortage vs Planning

Back in 2011, the company that manufactures the drug we use to treat a heartworm infection in dogs stopped making the product.  The factory was old and couldn’t meet quality standards, so the FDA stepped in and recommended shutdown.  I found out from an interesting article that the factory is owned by a different pharmaceutical company than the one that owns the rights to the drug.

The resulting shortage led to a situation where veterinarians have to call the company that markets the drug (Merial) if we diagnose a dog with heartworm disease.  They determine if that patient is eligible for treatment with the medication.  A very small supply of the drug is being imported from Europe with FDA consent.  Yes, you read that properly.  Our federal regulatory agency is allowing a small amount of the drug to be imported by the company for sale here in the US so that we can treat the dogs that come up positive for heartworm.

A few reasonably obvious questions come up when we consider this situation.
Why are so many companies failing to produce the medications we need?
Why are many of these drugs produced in only ONE facility in the whole country?
Why is the FDA apparently cracking down on these factories?
Why can’t we import more of the drug?
What alternatives do we have?

Truth be told, I’m not certain of the FDA’s grounds for cracking down on these companies.  I’d think it was with the intent of keeping the safety and efficacy of our drugs intact.  That’s a good thing.  It’s also scary.  How long has substandard production been going on?  I can only suppose the reasons for one facility being the sole production site.

This whole situation is a real bear.  We’ve struggled at Pet Authority to keep stock of some of our most important drugs so we can treat our patients.  I can think of four drugs in addition to the heartworm treatment medication that have simply been unavailable at some point in the last 2 years.  It’s maddening.  There’s nothing we can do about it.

Well, that may not be entirely true.  There’s one drug shortage that wouldn’t affect our clients and patients much at all.  How much need would there be for the medication used to treat a full heartworm infection if pets were protected by monthly prevention?  Almost none.

Year-round prevention is the best way to keep your pet from ever needing to be treated for heartworm disease.  There are enough products out there with nearly 100% efficacy that even if one or more becomes unavailable, there are alternatives that will get you through.

Stated more simply:  heartworm disease is preventable.

I’ve lectured and guilt-tripped and begged and advised, but still, owners simply choose to stop giving prevention.  I see at least one dog every day that I practice that has not been given prevention monthly.  Often, missed doses are during the height of the summertime mosquitos; the highest risk.  I just don’t get it.

The mystery of drug shortages is an opportunity to look at how our behavior influences the lives of our pets.  The choices we make are a much more direct way to influence wellness.

Prevention over cure.

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Cold Weather Doesn’t Mean Bugs Are Dead!

The incredibly warm winter we had last year, coupled with the high heat this summer, has created a bumper crop of bugs for Fall 2012. We’re finally getting some relief from the heat, but that’s not exactly the best news for pets and parasites.

It’s tempting now that the weather is cooler, especially at night, to assume that the risk for fleas, ticks, mosquitos, and other parasites is over with. This is absolutely not the case! It’s still vitally important that pets continue their parasite prevention products. Here’s why:

Fleas start looking for warm bodies when the weather gets colder. They don’t survive in cold temperatures if they’re exposed, but they can easily overwinter on animals. They can also survive in cool temperatures in the house for long periods of time. Once we’ve had a couple of good, hard frosts, it’s safe to assume that the flea population outside has -decreased-, but it’s not safe to say it’s eliminated. Contact with pets, wild animals, or infested houses/buildings can allow fleas to get a foothold on your pet and house in the wintertime. We advise staying on topical flea/tick prevention year-round exactly for that reason. Frontline Plus and K9 Advantix II provide great protection against fleas and ticks.

Mosquitos can also be found indoors as the weather cools off. I’ve killed two in my own house in the last few days. Mosquitos put dogs and cats at risk of getting heartworm disease. Heartworm disease can be fatal in both dogs and cats. Cats are especially hurt as we don’t have an effective way to treat heartworm if a cat contracts the disease. The risk of transmitting West Nile Virus is also a human health risk. Be sure to have your screens in good repair and be watchful for mosquitos in the house. Heartgard Plus, Triheart Plus, and Advantage Multi all protect pets from heartworm disease.

Some intestinal worms can survive in colder temperatures, though most are killed by freezing. The eggs, however, can survive winter conditions outside. When the weather isn’t cold enough to have the ground frozen, dogs are at a much higher risk of exposure by getting mud on their feet. They may lick their feet, which inadvertently allows them to ingest the eggs found in soil. There’s always the risk of contracting parasites from another animal’s feces, too. Yes, that’s a disgusting thought, but dogs eat a lot of disgusting things. Keeping your pet on monthly heartworm prevention also provides protection against various internal parasites. Heartgard Plus and Triheart Plus both protect dogs from hookworm and roundworm infections. Topical Advantage Multi protects dogs from hooks, rounds, and whipworms.

Colder weather isn’t a good justification for slacking off on parasite prevention. Pets and people are still at risk of infections and infestations by parasites and the diseases they can carry. It’s far better to stay on the prevention than to try to fix a problem after it shows up.

Snow dog

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Chronic Kidney Disease – A Case for Early Detection

Chronic kidney disease is a common diagnosis in veterinary medicine. It’s a disease for which we have no cure, only the ability to slow it down and manage the other symptoms. Ultimately, it’s fatal. The really nasty part is that we have a hard time finding it before a vast amount of irreversible damage is already done. I’ll give a little background into what’s happening with kidney disease, then talk about what we can do to treat it.

The kidney is a remarkable organ. It filters waste products out of our blood so that they can be excreted in the urine. They manage the balance of water and electrolytes (salts) in our bodies. They also make a hormone that tells the bone marrow to produce red blood cells. (Red blood cells carry oxygen throughout our bodies.) The kidneys you’re born with are the kidneys you have for the rest of your life. They don’t regrow, and “healing” is a limited ability for this important organ.

On a microscopic level, the kidney is quite complex. The illustration below shows the arrangement of blood flow and filtering in the functional unit of the kidney: the nephron (neff-ron). Tiny little arteries carry blood into a tangled ball of blood vessels called the glomerulus. Around that ball is a cup-like structure called Bowman’s Capsule. The vessels in the glomerulus are designed so that waste products and water are leaked out. Some other things the body prefers to keep are also filtered out. These wastes and other things are then collected by the Bowman’s Capsule. Bowman’s Capsule is connected to a big U-shaped tube (cut off in this illustration) that gives the kidney a chance to recollect the good things that were leaked out of the glomerulus. Those things are reabsorbed or transported back into the blood. Some new things are excreted, while others are traded out and sent into this U-shaped tube. Eventually, the U-shaped tube hooks up with a bigger tube that travels to the middle of the kidney. In the middle of the kidney, all of this waste material and whatever water the body is getting rid of is collected, then piped down to the bladder. Of course, this waste fluid is urine.
500px Physiology of Nephron svg

In chronic kidney disease, a variety of different things can go wrong, but in the end, it’s the nephrons that are destroyed. As nephrons are destroyed, the kidney begins to lose its ability to do the work it needs to do. This can be a very slow process, taking years in some cases. As with most things in the body, there’s some redundancy in the kidney to allow for a certain amount of damage without the body suffering for it. The kidneys can do their job well enough even with some loss of nephrons. Eventually, there’s a threshold after which the kidneys can’t keep up and things start to go very wrong. We can’t easily detect a problem until things start to go wrong, which is why this is such a nasty diagnosis to make.

Perfect kidneys are at 100% function. As we talk about percent damage, keep in mind that we’re referring to the grand total sum of both kidneys. It’s possible that one kidney can be damaged more than the other, or undamaged, but we aren’t distinguishing for the purposes of this post. The end result of damage to the kidneys is that the nephrons are destroyed, leaving scar tissue where functioning kidney used to be.

Chronic renal disease en

When 2/3 of the kidneys’ functional capacity is gone, leaving only 33% working, the kidneys lose their ability to manage water balance in the body. Water is allowed to leave the bloodstream at a rate that will dehydrate the animal. This is the earliest sign of chronic kidney disease. It can be subtle. The urine will seem more dilute. Pets will begin to drink more water and pass more urine. In truth, the urine production goes up because of the inappropriate loss of water, so pets drink more to remain well-hydrated. We can detect this low urine concentration when we run a urinalysis. Sometimes, we can detect protein loss in the urine, too, which is a sign of trouble. A pet may begin losing weight.

When 3/4 of the kidneys’ functional capacity is gone, leaving only 255 working, the kidneys can no longer keep up with the removal of waste products from the blood. Byproducts of metabolism begin to build up in the bloodstream. We can detect these rising values on bloodwork, namely the serum chemistry. As these waste products rise, we begin to see effects in the animal. Appetite drops because of nausea and irritation of the stomach lining, followed by vomiting. Dehydration and weight loss occur, as well as significant loss of muscle mass. At very high levels, these wastes can directly impair brain function, too. Other effects of advancing kidney disease can include high blood pressure and anemia. Sadly, many of the pets we diagnose arrive with lots of these clinical signs.

There are lots of treatments available for renal disease, but remember that none of them are a cure. Chronic kidney disease is managed, not fixed. We lower the protein intake of a pet’s diet to decrease the waste-filtering workload of the kidney. We also keep the phosphorus low in the foods we feed to help prevent some other complex but highly damaging changes in calcium and phosphorus levels in the blood and bone. There’s an oral medicine to help with that problem as well. We can give injections of the hormone that makes red blood cells be produced. We can give fluids under the skin to help flush the wastes out through what’s left of the kidney. Some animals respond very well to these treatments. Cats tend to do better for longer periods of time than dogs. Each patient is different in terms of response to treatment and the rate the disease progresses. Some patients survive only a few months. Others can go years before we lose the fight. We manage the patient, not the numbers on the lab work, with the goal being good quality of life. The sooner we start treatment, the better most animals do!

Running lab work is the ONLY way we have to watch for the emergence of chronic kidney disease. The clinical signs that owners see are present early on, too, but they start out subtly. Most of us don’t notice a gradual change like this until it’s further along. Annual urinalysis helps us detect the changes that signal early kidney disease. Bloodwork may also show subtle signs earlier in the process, so that’s also a valuable tool.

The take home message here is this: RUN ANNUAL LABWORK ON YOUR PETS! It’s the best way we have to watch for early signs so we can begin treatment early.

Please ask questions. This is a complex disease that I could talk about for pages and pages, so I simplified the basic discussion for today. I’m happy to expand on any aspect if there’s interest!

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Lifestyle Evaluation

Flying Dog

We’ve talked pretty extensively about vaccinations and other preventive healthcare recommendations. For both dogs and cats, the list of things available to help care for them on a daily basis is huge. Not every pet needs everything we have to offer, however, so many of these recommendations are based on an evaluation of a pet’s lifestyle. We try to determine exactly what risks each pet faces based on how they live their lives with their owners. From there, we’re able to select the essential parts of that pet’s care plan. This way, we’re addressing the actual risks for that pet without giving things that aren’t needed. Medications and vaccines are two very specific things that we don’t want to overdo. I’d like to take some time today to talk about the risk factors that we evaluate for each pet.

Indoor or Outdoor Living

Almost all dogs go outside. The cats we see are generally indoor-only, though we do see indoor-outdoor or outdoor-only cats once in a while. The outdoors is a high-risk place for many reasons. Parasites (hookworm, roundworm, fleas, ticks, toxins, heartworm), physical dangers (cars, sharp objects, bodies of water, predators, wild animals), and environmental risks (heat, cold) are all found outside the house. Infectious diseases like distemper, parvo, rabies, leukemia, feline respiratory disease, and FIV are all out there lurking in the environment. Depending on a pet’s time spent outside, we will determine which vaccines and parasite prevention products are needed. Sometimes, outdoor living indicates a need for additional blood testing. This is primarily for cats as we test for Feline Leukemia and FIV.

As a reminder: ALL pets, dogs and cats, indoor or outdoor, are at risk for heartworm disease and should be on monthly prevention.

Social Activity

Pets that have social contact with other pets are at risk for sharing infectious diseases and parasites. There is also the risk of fights. Wild animals are another risk for pets that are out and about, especially at night. Going to the groomer, boarding, obedience or recreational classes, dog parks, or nose to nose contact at a fence or window screen are all ‘social’ activities that bring along the risk of disease transmission. Additional vaccines such as Bordetella and Feline Leukemia are indicated for pets that have social activity.

Travel

Owners that take pets along with them on vacations have a unique set of challenges to overcome. Pets may get carsick. Traveling to other countries requires very, very specific procedures for having the Rabies vaccine up to date. Certain areas of the country put pets at risk for contacting diseases or dangers not found here in Michigan. Rattlesnakes, poisonous toads, plants, tick-carried diseases, toxic plants, and exposure to extremes of heat/cold all come into play when pets travel. Even going “Up North” here in Michigan presents additional risks (ticks and wildlife, primarily). Pets traveling to the ocean can become very sick if they drink too much saltwater.

Diet

It’s important for us to know what a pet is eating. This means that owners need to be honest and fully disclose all of the things a pet is eating. Often, owners are embarrassed to tell us that a pet eats people food or gets a lot of treats. They don’t want to be “in trouble” with the vet. It’s far more important to speak up so that we can come to a plan together that will fit that pet’s life. Treats aren’t all bad, and not all people food is bad. We do have to be very careful about things like onions, garlic, grapes, and raisins. Cats have special dietary requirements, too. Both dogs and cats can benefit from an individualized nutritional plan, so it’s in their best interest to have open and honest owners!

Exercise

This is another topic with a heavy guilt attachment. Most of us should be more active for our own health. The same goes for our pets. We’ve got a little sign in our break room that says, “If your dog is too fat you’re not getting enough exercise!” As we learned with the recent news post on exercise regimens, it’s important to ease pets into more activity.

Other Illnesses & Age

Not every pet is in perfect health. Just as in people with chronic problems, pets that have diabetes, abnormal thyroid function, cancer, digestive problems, allergies, and so on all need to have those problems taken into account as we choose a preventive health care plan for them. Pets with cancer should be vaccinated less or not at all. Pets with diabetes have to have a very specific diet. Environmental allergies are aggravated by being outside more. Arthritis can be a bigger problem for pets that are active. Aging pets need to have more testing of their organ health.

As you can see, there are many factors that are evaluated to help us choose a preventive care plan. The questions may seem tedious and overly long for owners when they come in, but the truth is that without that information, we can’t offer our best possible care. The more we know, the better we can serve the unique needs of your pet.

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Quality of Life

Last week, I talked about pain in our veterinary patients. I’m going to expand on that topic today by discussing how we evaluate “Quality of Life.”

Whenever we see a patient for an appointment (for any reason, well or sick), we perform a physical examination. We also ask for an extensive history about food intake, weight gain/loss, activity level, general attitude, and any concerns the owner may have. An assessment of a pet’s level of pain is also included in the examination and history.

Once we have all of our information organized, we have a good idea about whether a pet is healthy and doing well, or not. For the pets that are doing well, there’s not much that we need to do beyond routine preventive care with vaccination, parasite prevention, bloodwork and stool checks. However, many of our patients will have a problem that needs to be addressed. We spend time talking with the owner about what’s wrong and what can be done about it. We put a plan into action to help the pet, then re-evaluate at some point in the future to reassess the situation.

Some conditions can’t be cured, only managed. They become an ongoing part of our evaluations and plans. As patients age, we see problems begin to arise that are simply consequences of being older. Arthritis, loss of sight, lumps bumps and tumors, dental disease, mental decline… these are just a few of the chronic issues we deal with on a daily basis with our older pets.

It rapidly becomes very important to look at the big picture. We understand that older pets or certain illnesses are going to mean that a pet isn’t “100% healthy and problem-free.” Bearing that in mind, we ned a way to evaluate whether a patient is living a good life. We need to know if the treatment we’re providing is good enough that we aren’t being unfair to our pets by asking them to suffer. These are difficult subjective questions to talk over with owners. Each pet requires an assessment based on a smaller number of very specific guidelines which help us decide if a patient is doing well enough or needs more intervention.

One of the least specific questions we ask is, “Are there more good days or bad days?” This one’s tough for the veterinary team but great for owners. You know your pets better than anyone, so you’ll know if they’re having a bad day. You’ll recognize subtle changes in personality, activity level, enjoyment of toys/treats/activities, and sleeping patterns. Many older pets do have some days that are worse than others, and we have to be lenient about that. Things aren’t going to be perfect. That being said, a pet that’s having more bad days than good ones needs help to get back to more good days than bad.

Back in 1993, the United Kingdom’s Farm Animal Welfare Council developed a way to evaluate living conditions for farm animals. They’re quite easy to adapt to companion animals, too. They utilized a concept called “The Five Freedoms.”

1. Freedom from Hunger and Thirst
2. Freedom from Discomfort
3. Freedom from Pain, Injury, and Disease
4. Freedom from Fear and Distress
5. Freedom to Express Normal Behavior

These five criteria touch on the most basic parts of a life that we could consider ‘good.’ The most basic things — eating, for example — MUST be present for that animal’s life to be considered good. Without those, we’re doing any animal a disservice by continuing without changes to improve the animal’s status.

A veterinarian named Dr. Villalobos created a Quality of Life Scale that can be used to evaluate domestic pets. Each of the following criteria is evaluated on a 0-10 scale, with 0 being worst and 10 being best. It’s useful for both the veterinary team and the owner to fill this out for patients who need evaluation. We each have unique insights that, when combined, provide the most accurate assessment of quality.

HURT – Adequate pain control, including breathing ability, is first and foremost on the scale. Is the pet’s pain successfully managed? Is oxygen necessary?

HUNGER – Is the pet eating enough? Does hand feeding help? Does the patient require a feeding tube?

HYDRATION – Is the patient dehydrated? For patients not drinking enough, use subcutaneous fluids once or twice daily to supplement fluid intake.

HYGIENE – The patient should be brushed and cleaned, particularly after elmination. Avoid pressure sores and keep all wounds clean.

HAPPINESS – Does the pet express joy and interest? Is the pet responsive to things around him or her (family, toys, etc.)? Is the pet depressed, lonely, anxious, bored or afraid? Can the pet’s bed be close to the family activities and not be isolated?

MOBILITY – Can the patient get up without assistance? Does the pet need human or mechanical help (e.g. a cart)? Does the pet feel like going for a walk? Is the pet having seizures or stumbling? (Some caregivers feel euthanasia is preferable to amputation, yet an animal who has limited mobility but is still alert and responsive can have a good quality of life as long as caregivers are committed to helping the pet.)

MORE GOOD DAYS THAN BAD – When bad days outnumber good days, quality of life might be compromised. When a healthy human-animal bond is no longer possible, the caregiver must be made aware the end is near. The decision needs to be made if the pet is suffering. If death comes peacefully and painlessly, that is okay.

A score over 35 is considered an “acceptable” quality of life. Download a nice PDF of the assessment sheet here.

This is always a touchy area with owners. I believe the most owners know in their hearts when quality of life isn’t good enough. However, acknowledging that means that we have to accept the fact that a pet is in trouble and needs help, or will need to be put to sleep. If the condition that is causing life to be poor is easily addressed, the pet gains tremendous benefit and can have quality go way up. Sometimes, though, the harsh reality is that there will be a limit to what can be done. We have to be fair, we have to be selfless, and we have to be realistic. Letting go is insanely difficult, a fact that -any- pet owner understands. From my side of the table, I have seen clients make poor decisions about quality of life that they ultimately regret. I don’t say this to be judgmental or to preach. Seeing the truth is difficult at best, not to mention emotionally painful in many ways.

The Quality of Life assessments, when started -early- and used often, can help us identify small problems before we’re trying to push a boulder up a hill. All too often, I see pets that have had declining quality of life that the owner overlooked until it’s so bad that the pet is in horrible shape. In some cases, the owners elect to euthanize. In others, they ask, “What can we do to save him?” That second question is guaranteed to bring about an extremely difficult answer. Whether it’s the high financial cost to try to get a pet with lots of problems back on its feet, or a disease we simply can’t do anything about at that point, the pet is the one who has suffered its way to that point in time.

We can do so much better than that. Every single one of the quality criteria in that list can be worked on and improved. “Pawspice” care can be a wonderful way to ease pets through their golden years, but only if we have the courage and dedication to acknowledge that it’s needed.

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Obesity

CDC Overweight and Obesity map3

This map details the increasing proportion of our own human population classified as overweight or obese. It’s a frightening statistic, given the knowledge we have that being overweight causes many, many dangerous diseases. Diabetes, heart disease, high blood pressure, arthritis… it’s not a pretty list! Even so, our public perception of what an acceptable body looks like has shifted toward being overweight. It’s beyond the scope of this blog to discuss the human portion of this problem in-depth. Suffice to say that I think it’s important not only for our own lives, but for those of our pets.

What does normal body weight look like on a dog or cat? Have a look at the chart below. We score body condition in dogs and cats on either a 5 or 9 point scale. Pet Authority uses a 5-point scale similar to the chart. The “3” is ideal. There is an hourglass-shaped figure at the waistline (between hips and last rib), you can feel the ribs when you rub back and forth on the chest, and the belly curves up toward the pelvis. Compared to the overweight and obese pets, many people feel that normal body condition is too skinny. Not the case!!
Bodyscore img assist custom

Studies have been done that describe the prevalence of overweight pets at about 50%. I believe that here in Michigan, it’s closer to 70%. Very few of the pets I see, dogs or cats, are a normal, healthy body weight. It’s just as important for pets to be a normal body weight as it is for people. We’ve proven that diabetes, arthritis, heart and lung disease, and liver problems in cats can all be tied to an above-normal body weight. The bottom line is this: overweight pets do not live as long as pets with normal body weight. One study showed that overweight Labrador Retrievers lived about 1.8 years less than their normal-weight counterparts.

Let me state that more clearly: You are taking almost 2 years off your pet’s life by allowing obesity!

Why are pets overweight? Because we, as humans, think that food is love. (These are my personal opinions, here; please feel free to debate or chime in with your own reasoning!) The simple truth is that we, as human caretakers, are the biggest factor in our pets’ body condition. WE control the amount of food and exercise they get. WE control our perception of what ‘fat’ and ‘ideal’ is. Pet obesity is, for the vast majority, our fault. We feel that dogs need to have lots of treats, a ‘little extra’ food, or to be rewarded with food items for good behavior. I’m not opposed to giving treats or rewards. I am opposed to giving so many that the dog is overweight. Dogs don’t seem to mind so much if it’s just one treat or twenty — they enjoy the interaction with the owner. They will also likely be just as excited to get a low-calorie treat as one of the high-calorie ones. I think there’s a big cultural influence at work in the Midwest, too. When we get together with family, friends, or coworkers, the events often center around food. Our weather is such that it’s hard to get enough exercise in the winter. These things contribute to difficulty keeping dogs skinny. However, we still control the food bowl! It’s one thing if we’re fatter in the winter. It’s a whole other thing if we allow our pets to eat the same amount when they’re not getting as much exercise. (Are you seeing a theme here? We’re the ones at fault.)

Please don’t get the idea that I’m immune to these problems. My own cat, when she was younger and healthy, got to be overweight. I ignored it for about six months before doing anything. I ended up having to buy her a low-calorie food to get her weight back to normal. I did it, though, and she’s now over 15 years old and doing remarkably well. I know for a fact that if I’d let her continue to get fatter and fatter, she wouldn’t be here today. This is something that *can* be fixed, that *is* a solvable problem.

I’ve stood on my soapbox plenty long, here. I’d like to finish out the post today by listing a few little tips on how you can reduce weight in your pets. They’re not meant to be condescending. Sometimes, the simple truth is quite hard for us to see until it’s pointed out.

A special note on cats: PLEASE come talk to us at an appointment or at least call to discuss weight reduction in cats. If it’s not done very very carefully, cats can become deathly ill with fatty liver disease. You need a careful plan for cat weight reduction!!!

•Increase exercise. Dogs and cats both need to have exercise daily. Running around on their own in the backyard isn’t usually enough. Walk dogs and get cats to play for 10-15 minutes a day, at least. Check out The Indoor Pet Initiative for great cat tips.

•Decrease treats. You don’t have to eliminate treats completely. Just realize that milk bones, pig ears, rawhides, jerky treats, etc. are all adding calories to the daily diet. Break treats up or buy really tiny ones. Use green beans or carrots (cut into tiny pieces!) for treats.

•See if your chosen food brand includes a “Low Calorie” or “Weight Loss” formula to help you reduce calories. If not, we have some prescription weight loss foods available to help. For dogs, you can reduce the daily feeding amount by 5-7% every month until the body condition is ideal.

•Use non-food toys to encourage chewing and other play activities.

Good luck! Don’t let your pet become a statistic!!

AVMA collection of pet obesity research papers.

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Why Spay?

I hope everyone has had a chance to be outside this weekend to enjoy the unseasonably warm weather! I’ve still got a gut feeling that we’re going to pay for this later with bad weather but I’m not about to miss a chance to enjoy it.

I still want to cover a topic today that I believe isn’t as well explained as it should be: spay surgery. I always welcome respectful debate about topics I cover, so I hope to encourage readers to ask questions or offer opinions. I have to manually approve each comment that’s made, so it may take a day for them to appear on the blog.

Commonly called a “spay,” this surgery is actually an ovariohysterectomy (OVH or OHE). It’s performed under general anesthesia with the obvious intention of preventing pregnancy in a female dog. Female dogs that are going to be used for breeding can’t be spayed, of course. If an owner is absolutely certain that a dog will be having a litter of puppies, there’s really no discussion to have. In the US, veterinarians remove both ovaries and almost all of the uterus from a female dog. In other parts of the world, the surgery may be only an ovariectomy, with just the two ovaries removed.

Most veterinary hospitals recommend that all female dogs get spayed. The age at which the surgery is performed is variable and ranges from 16 weeks to 6 months. The procedure is extremely routine for veterinarians. That’s a good thing! Procedures we do frequently have better outcomes and fewer complications. Patients are usually recovered by 10 days post-operatively. In most cases, I don’t think clients are given enough information about the procedure, why it’s important, and what to expect during and after the surgery. Clients are left with questions and anxiety. I can talk more about the procedure itself at another time if anyone is interested.

Population control is one of the most commonly cited reasons for spaying. The harsh truth is that far, far too many dogs are put to sleep in the US each year because they do not have homes. Most families are utterly unprepared for the amount of work (and cost) involved with having a litter of puppies, especially if the dog becomes pregnant against the owner’s intentions. Please don’t misunderstand. Population control is good! It’s a social and ethical goal that is sometimes hard for clients to connect with.

There are other direct health benefits from a spay. First of all, we eliminate the risk for cancer in the ovaries. Removal of the ovaries also stops the dogs from having heat cycles (estrus cycles). If the uterus is removed, we drastically reduce the risk of future uterine infections. If a female dog is spayed before her first heat cycle, we reduce her risk of developing mammary (breast) cancer by about 90%. If she is spayed after her first heat, we only reduce the risk by about 70%. That may not sound like much, but if it’s YOUR dog at higher risk, it’s risk that’s directly tied to you and your pet’s well being. I have lots of owners tell me that they “just want to have one litter,” then spay the dog. I also hear frequently, “We think it will be good for the kids to see our dog have a litter.” The vast majority of these clients never do breed the dog, which puts her at risk for the problems just mentioned.

Let me be clear: not spaying your female dog puts her at higher risk for two types of cancer and/or a life-threatening uterine infection. I don’t say this to use fear as a tool or a weapon. I think it’s critical that owners understand what the consequences of their choices are. In the last 5 months at Pet Authority, we’ve had at least 4 uterine infections and three mammary tumors. All of these dogs were unspayed females between 5 and 10 years of age. These are very real consequences that we see in practice.

In order to be fair, I need to mention some of the possible complications of the spay surgery. We do have to open the abdomen during this procedure, so complications with the incision (hernias, the incision opening up, etc.) can occur. These things are very rare if the post-operative rules are followed closely. Spayed dogs do have a lower metabolism than unspayed dogs, so they will not need as much food. (Spaying doesn’t make dogs fat. Overfeeding does.) Some female dogs will develop urinary incontinence at some point after the spay. We believe that this is related to the lack of hormones that the ovaries would normally release. This incontinence is treatable and in almost all cases and will be controlled as long as the dog stays on the incontinence medication.

Each owner needs to weigh the benefits, disadvantages, and costs associated with doing or not doing the spay procedure. Having an adult female dog spayed because she has a uterine infection more than doubles the cost of the surgery. It’s a higher-risk procedure because the dogs are already sick. I’m aware that a spay is not a cheap procedure. I wish we could make the surgery less costly without sacrificing patient safety. I also don’t believe owners would be comfortable hearing from us that we can do something at less cost with “only a little more risk.”

The bottom line, in my opinion, is that we can do a female dog a lot more good by spaying her than by not. We can minimize risk during anesthesia with good, safe practices. We can eliminate or reduce some cancer risks. We can nearly eliminate the chances of a life-threatening infection occurring. I just don’t see where the drawbacks are.

Thanks for taking the time to read my perspective on a somewhat controversial topic. Please ask questions, share information, or offer your opinion. Respectful debate is a healthy, beneficial thing. 🙂

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Why do pets need examinations?

One of the most common areas of practice that clients question is the need for physical examination of pets by the veterinarian. I feel that there’s a lot of misunderstood reasoning on both sides of the question. I’d like to try to offer some clear, straight talk about why examinations are important and why they happen when they do.

There are legal requirements that come into play first. According to Michigan’s veterinary practice law, vets have to know a patient well enough to make a diagnosis and/or a plan for treatment and health care. Michigan does not state how often that has to be done. Nationally, veterinarians generally feel that a yearly exam is the minimum to satisfy this requirement. The knowledge of a patient’s medical status is called the “Veterinarian-Client-Patient Relationship.” The VCPR has to be current for veterinarians to legally prescribe medications of any kind or treatments.

We can now focus on the reasons pets need examinations. One of my professors in veterinary school said, “Nothing compares to the value of a good physical exam.” What he meant was that a ton of important information is gained from a thorough examination.

Our pets rely on us to know when something is wrong. They can’t talk, and instinct tells them to hide their illnesses. Pets can seem normal when they’re actually very sick. We have only history and examination to get us started on a path to healing.

A thorough physical exam will check an animal over from nose to tail. We evaluate eyes, ears, mouth, skin, body condition, heart, lungs, internal organs, muscles and bones, general attitude, hydration status, lymph nodes, and pain score. (Our clients have the exact list on the yellow carbon copy of the exam sheet. It’s the little numbered list on the right hand side.)

It’s common for us to find something out of the normal range. It might be body weight, or yucky ears, or bad teeth. We can find tumors in the belly, arthritis, cataracts, skin growths, heart problems, or fleas. I’ve found completely unnoticed problems that were very important to the health of the pet. Good physical exams let us identify problems when they are small and easier to fix. We can really make a difference when we know what’s happening with our patients BEFORE a crisis.

By far the hottest area of contention is the need to examine pets before vaccinating them. Most people understand the need for sick pet physical examinations, but when apparently healthy pets come in ‘for their shots’ it’s tougher to understand.

For way, way too long, veterinarians depended on vaccines to be the reason pets were brought to the hospital. The true reason was to be able to examine the pet, but we didn’t explain it that way. We now understand that vaccines shouldn’t be taken lightly, and the exams are more important than vaccines. Vaccines, like all medications or treatments, have potential side effects. These risks may be higher if a patient has another problem that the owner or the vet are unaware of.

This summer, I saw a patient for vaccines that was generally fine according to the owner. I found that all of her lymph nodes were enlarged on the physical exam, and that turned out to be cancer. It would have been wrong and potentially harmful to vaccinate that dog, and if I hadn’t examined her I wouldn’t have known that. It’s an extreme example, but it holds up.

Any pet with an infection (ears, dental, skin) may not be healthy enough for vaccines. Giving vaccines could cause harm, which violates the oath we took to help our patients. I’ll tell you bluntly: if I gave a vaccine to a sick pet, *my* butt would be on the line for causing harm. I’m not taking that risk, and I won’t play recklessly with your pet’s health. It’s not fair to the pet or clients.

Problems have a starting point. People get colds at random times, or flu, or sick for other reasons. Pets are no different. We know that time moves more quickly for pets, especially as they get older (think ‘dog years’). It’s honestly just bad practice to skip the exam before vaccinating or treating a pet, even if there was an exam recently. We have to make sure that we know what’s happening today before administering vaccines or any other treatment.

Annual or twice-yearly exams are the best way you and your veterinarian have to know your pet’s true health status. The exam is the single most important thing you can have done to help your pet stay healthy and happy for as long as possible.

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Flea Alert!

The bugs are on the muscle! We’ve seen a huge surge in flea cases in the past few weeks. I’m not sure if that’s because of the cold snap or just normal seasonal changes, but yikes!

While fleas might seem like an annoyance at worst, they can actually cause a number of very serious problems. One of the most dangerous has to do with the fact that fleas drink blood.

If you recall from the entry about blood samples and labwork back here, blood is “soup.” The red blood cells comprise, on average, about 30-50% of the blood’s volume. It’s lower in puppies and kittens. Average adult dogs run between 37 and 55%, generally. This percentage is measured with something called a packed cell volume, or PCV. This diagram indicates that the PCV is simply a percentage of the amount of red cells compared to the full volume of blood. In this diagram, the PCV is 46% (0.46).

500px Packed cell volume diagram svg

In a heavy infestation, fleas can drain a smaller pet’s blood to the point that the number of red blood cells decreases to a dangerous level (anemia). The fleas are drinking down cells faster than the bone marrow can replace them, so the eventual result is that the anemic pet can’t carry enough oxygen in the blood to keep itself alive. Severe flea anemia can kill a pet!

There are also additional complications that can result from a heavy flea infestation: infection with blood parasites called hemobartonella and babesia, as well as autoimmune problems can all have a link to flea infestations.

Patients with flea anemia can be saved with aggressive care. Usually, a blood transfusion is given to replace the red blood cells. Transfusions tend to take the patients out of critical trouble, but of course longterm attention to flea control is needed or the newly replaced cells will be consumed by the fleas.

Topical products that safely kill fleas are the best way to go. Vectra 3D, K9 Advantix, Frontline Plus, and Advantage are all good products.

I do not recommend the store brand products, nor do I recommend Hartz or Sargents. Flea baths can be dangerous for a wide range of reasons. Some flea collars are alright, but unless they’re used correctly (which they usually aren’t), they’re not very successful.

Preventing flea infestations in pets and your home is easy to do and relatively low-cost. Given the trouble and expense of treating your home and sick pets, it’s a bargain to stop the parasites before they gain a foothold. Just remember that ALL pets in the household need to be protected with a flea-control product to stop a home infestation from occurring.

Here’s hoping we can keep a Flea-Free Fall in sight!

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Vaccines – Controversy and Facts

This week we’ll get to the real grit that inevitably comes up when vaccinations are discussed. I had hoped that the most current set of recommendations from one of our oversight committees would be published in time to include them in this post. Unfortunately, as far as I know, they’re not yet out in the wild. I’ll touch on that a little as we go along with the discussion.

I’ve got a number of specific things that I definitely want to bring up. I’ll be keeping a close watch on the comments, as always, so please ask questions! This is an opportunity for you to find out about the aspects of vaccination that we don’t often get to talk about during visits. I may even utilize questions in the comments for additional posts.

I want to state right up front that with each patient, we evaluate whether the benefits of vaccination outweigh the risks of vaccination. We don’t take vaccines lightly. They’re essentially a drug, and there are side effects and complications and potential adverse effects from administering a vaccine. While the rate of reactions is quite low for most vaccines out there on the market, the complications can be severe. For each patient, we determine the risks of the patient’s lifestyle and recommend appropriate vaccines. We strive to minimize the number of vaccines given to all patients.

Vaccinations are an area of medicine that is under intense scrutiny by veterinarians, human health professionals, pet owners and parents. This is a heated topic to say the least, but I’m thankful for any respectful debate. We can only learn more and try to apply that knowledge to better care for our patients. I hope that our clients feel that we aren’t just accepting old dogma for our recommendations. I was certainly proud to find out that we are in compliance with the most current recommendations for canine and feline vaccination according to the oversight groups.

Vaccine Reactions

Reactions to a vaccine are varied both in severity and frequency. They span the range of very mild problems like being sleepy for a day or being a little sore, on up to life-threatening anaphylactic reactions. The overall reaction rate for the vaccines we use is honestly really low. We used to see a lot more reactions — at least a few a month. Now, I’m surprised to see one every few months.

Pain and soreness are easily countered by giving a dose or two of an anti-inflammatory (an NSAID). Occasionally we’ll have a little inflammatory nodule under the skin that goes away within a few weeks. Those nodules are usually due to the Rabies vaccine, which has an adjuvant.

Severe reactions may include signs like vomiting, diarrhea, weakness, and shock. Pets have to be treated with an injection of Benadryl and a Glucocorticoid steroid, or in very severe cases, epinephrine. I’ve had to give IV fluids, epinephrine, and the benadryl and steroid to just a few patients in the 10 years I’ve been a practicing veterinarian. Even the animals that go into anaphylactic shock are relatively easy to save. They bounce back quickly once the medications are on board. In the future, these pets are given medication prior to the truly necessary vaccines to prevent a reaction. We stretch out the frequency of vaccines and try not to give too many in one visit. Most patients do really well, and we’ve been able to have the benefits of vaccination outweigh the risks so that patients are protected from deadly diseases without suffering the reactions from the vaccines.

Adjuvants, Vaccine-associated Sarcomas, and other Vaccine Complications

As we discussed in the earlier posts, some vaccines contain an additional ingredient with the sole purpose of increasing inflammation in the spot the vaccine is administered. This irritating substance causes white blood cells to move into that area and subsequently be exposed to the pathogen in the vaccine. The idea here is that for killed pathogen vaccinations, the dead virus/bacteria alone wouldn’t be enough to stimulate an adequate immune response. The adjuvant creates that immune response through irritation/inflammation. The trouble, of course, is that you’re injecting a lipid or a metallic substance that causes significant inflammation and tissue damage. It’s difficult to know how much is exactly enough, and the sweet spot between adequate response and an overblown response isn’t always easy to hit, either. The complications from this aren’t very common — 1 in 1000 to 1 in 10,000 for most — but they can be severe. If your pet happens to be that 1, it doesn’t matter how many did NOT have the problem.

One of the complications that can arise is an immune response that ends up attacking another part of the body. Usually, it’s the red blood cells or platelets. This is clearly a very serious disease (immune-mediated hemolytic anemia or immune mediated thrombocytopenia) that requires aggressive treatment. Patients can die from these complications. There is a theory that thyroid problems in dogs may be linked to overvaccination with the DHPP vaccine. There’s no conclusive proof published that I’m aware of. I’ve had one case of anemia that I know was associated with vaccination in the 7 years I’ve been at Pet Authority. That patient survived and is doing very well. She leads a normal life, but we don’t vaccinate her anymore for fear of triggering a relapse.

Cats can have a very unique and devastating reaction to some injections (including vaccines, or any other drug). About 1 in 1000 to 1 in 10,000 cats will develop a very serious cancerous tumor at the injection site. We believe that the adjuvant in the vaccine is a major component of developing these tumors. However, affected cats also seem to have a genetic predisposition to developing this cancer, too. It’s a multi-factor disease that nevertheless is often terminal for the cat. Recombinant, adjuvant-free vaccines are the best way to avoid this complication in cats. We have switched over to the recombinant vaccines whenever possible for the cats in our practice.

Duration of Immunity

This is probably one of the most-asked about aspects of vaccines and immunology. “How long are they good for?” It’s a topic that has been at the center of the most fierce debate between the veterinary community and everyone else. It has also been a source of debate within the veterinary community. I’m going to speak about what we know now, and how Pet Authority has put this knowledge to use.

We know that recombinant vaccines and modified live vaccines are the best ways to develop a good, strong immune response in the safest way possible. We know that -viral- vaccines and recombinant vaccines stimulate a very good longterm (cell-mediated) response in patients. There also tends to be a very strong humoral response that produces a lot of antibodies. We know that puppies and kittens require a series, and then a booster 1 year later, to produce a response that gets both antibodies and cell-mediated immunity to an appropriate level. The question is, what happens after that 1 year booster?

For viral diseases, which are in vaccines like DHPP and FVRCP, the immunity produced lasts longer than 1 year. We no longer vaccinate for distemper annually. After that 1-year booster, we vaccinate every 3 years. It’s widely accepted that nearly all patients will be adequately protected for 3 years and do NOT need to be vaccinated annually for DHPP or FVRCP.

Rabies is a special case because of the public health aspects involved. The FDA and State laws usually determine how often a pet is vaccinated for rabies. Two factors are involved: how long the company says the vaccine is good for, and what the state laws demand for the number of years between vaccines. Dog rabies vaccines have adjuvant and are good for 3 years in almost all cases (so long as the vaccine label says 3 years). The only time you vaccinate more frequently is when laws say you have to. For cats, the vaccine is a recombinant canarypox vaccine, but the label is only good for 1 year. This annual revaccination is less dangerous for cats than giving the adjuvanted 3-year labeled vaccine. We utilize a recombinant feline rabies vaccine for almost every feline patient.

Feline leukemia is also currently an annual vaccine due to manufacturer label. We do utilize a recombinant leukemia vaccine. My hope is that eventually, the company will state their support of a 3-year interval here, too. Theory suggests it should be adequate, but we don’t have the testing to back that just yet.

Bacterial diseases such as leptospirosis and lyme don’t generate a very strong immune response. They’re killed bacteria or parts of bacteria, which doesn’t do a good job of stimulating cell-mediated immunity. Therefore, these vaccines are given annually. The one change we’re making is that for both diseases, a dog can be late by up to 12 months and NOT require a 2-vaccine series to reestablish immunity again. Please keep in mind that if your dog is overdue, it is NOT protected from lepto and lyme! Don’t be late for the vaccines! Bordetella is another vaccine that has to be boostered more frequently due to the killed bordetella portion of the vaccine. We recommend boostering the nasal bordetella vaccine every 6 months for at-risk patients.

Titers

Titers are hand and glove with Duration of Immunity. A titer is a measure of the amount of antibody circulating in the bloodstream that matches a particular disease. When we get a ‘distemper titer’ for example, we are measuring how much antibody a dog has in its bloodstream that will fight off distemper virus if the dog is exposed.

I’m of mixed feelings on titers. For some disease (canine distemper and rabies), there is a specific amount of antibody that is considered the minimum for protecting a pet from getting the disease. However, for many other diseases a titer may be misleading. We know that immune responses are composed of two parts: antibody and cell-mediated memory. A LOW titer means a patient has low levels of antibody. However, that patient may still be protected by its cell-mediated immune response. A HIGH titer may not be enough to protect a patient against some diseases. It’s very hard to imply protection from a titer level for most diseases. I don’t recommend titers to our clients unless they -really- want to stretch out those vaccine intervals beyond 3 years. The titers are expensive, may or may not be an accurate measurement of immunity, and the vaccine risks are generally low. I think that putting dogs on a 3-year interval and skipping the titers is the most practical option we have that doesn’t ignore current data.

I think that touches on the majority of the big points of contention in vaccine theory for dogs and cats. If I’ve missed something that you’d like me to comment on or explain, please leave a comment. This is one of my favorite areas of medicine, so I welcome discussion. I hope everyone has enjoyed the holiday weekend!

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Feline Vaccines

Cats finally have their turn this week as we look at vaccinations. I need to bring up a special concern that guides a lot of the decisions we make about vaccinating cats.

Some time ago, an association was found between vaccines and a very nasty kind of cancerous tumor in cats (fibrosarcoma). It was initially believed that adjuvanted vaccines (particularly rabies and leukemia) were directly causing these tumors in cats. What we’ve learned since then has indicated the following:
-Between 1 in 10,000 and 10 in 10,000 cats will develop a sarcoma
-There is a genetic predisposition for developing fibrosarcomas.
-Adjuvant plays a part in development of fibrosarcomas
-ANY injection can lead to a fibrosarcoma

These factors have led to some major changes in the way we vaccinate cats. It’s important to minimize the number of injections that we give cats. We also try to give non-adjuvanted vaccines whenever possible. Lastly, for vaccines that must still have an adjuvant, the type that is used creates the minimum amount of inflammation possible while still ensuring that the vaccine works.

Distemper

Just as the canine distemper vaccine contains several pathogens, the vaccine we refer to as ‘feline distemper’ also contains multiple portions. Feline Viral Rhinotracheitis, Calicivirus, and Panleukopenia are the components. It’s generally abbreviated as FVRCP.

FVR = Feline Viral Rhinotracheitis
FVR is a herpes virus. It causes respiratory and eye infections. It’s highly contagious by way of oral, nasal, or ocular discharge/contact. Sneezing, coughing, eye discharge, and nasal discharge are the clinical signs that we look for. Some patients will develop a fever, lethargic behavior, or stop eating. Treatment includes supportive care, and most cats recover without complications. Sometimes, a chronic infection results. Also, any cat that contracts FVR will always have the virus, which can flare up in times of stress or other illness. Think about it like cold sores in people (also caused by a herpes virus). This is a modified live vaccine.

C = Calicivirus
Calicivirus is another respiratory/ocular viral disease. It can also cause lameness/musculoskeletal pain and gastrointestinal disease. It’s a highly contagious disease that commonly causes persistent infections. When cats are affected by Calicivirus, they can have fever, lethargy, lack of appetite, ulcers on the tongue, lips and nose, pneumonia, or leg pain.

P = Panleukopenia
Feline Panleukopenia is the cat’s equivalent of canine parvovirus. In fact, feline panleukopenia mutated and became canine parvovirus. Panleuk attacks rapidly growing cells, especially in the bone marrow and gastrointestinal tract. This disease is often fatal. It’s highly contagious. Treatment is just supportive care – IV fluids, antibiotics, and nutritional support. This is a very, very nasty disease.

Some FVRCP vaccines also include a Chlamydia portion. This is a bacterial disease that causes an eye infection. We don’t see a lot of chlamydia cases at the hospital, so we don’t utilize a vaccine with this component

Rabies

Rabies virus behaves in cats the same way it does in dogs. We have something of a dilemma in cats with Rabies vaccines, though. The 3-year product has an adjuvant, which we know increases the risk of a sarcoma tumor. However, the safest Rabies vaccine out there (a recombinant vaccine) has to be given yearly – which means more frequent vaccination. It’s believed by most veterinary specialists that vaccinating more frequently with a non-adjuvanted vaccine is the least risky option.

Bordetella / Kennel Cough

Cats can catch the bacterial portion of this disease, which is caused by the Bordetella bronchioseptica bacteria. This is ONLY an intranasal vaccine in cats and contains killed bacteria.

Leukemia

Feline Leukemia is a viral disease easily transmitted by bites, casual contact, shared food dishes/litterpans, or transfer from a mother to kittens in the womb or through her milk. Some cats become sick right away. Others can completely clear the virus from their system. Others will have the virus hide in the body and show up again later as they cause severe disease or cancer. Anemia, immunosuppression, and nervous system disease can all result. The vaccine we use for Leukemia is a recombinant vaccine that doesn’t have an adjuvant.

There are two vaccines available for cats that aren’t used by our practice. One is for feline immunodeficiency virus (FIV). That vaccine often doesn’t work very well, and it causes cats have a false positive FIV test result. The other is for feline infectious peritonitis (FIP). That vaccine doesn’t seem to help much at all (and in some studies caused WORSE disease), so we don’t use it.

Kitten Vaccine Series

Maternal antibodies and an immature immune system can create a situation where a single vaccination may not generate a good immune response in a particular kitten, just as with puppies. Therefore, we initiate a series of vaccines that are administered on a regular schedule. This creates a response in the vast majority of patients that is sufficient to protect that kitten from the diseases it is likely to encounter.

We start the series at 6-9 weeks of age with an FVRCP combo vaccine. We continue the distemper series with a vaccination every 3-4 weeks until the kitten is 16-17 weeks old. We try to schedule these so that the kitten doesn’t get more than 3 FVRCP vaccines in total. I personally try to ensure that kittens don’t get more than 2 vaccines at or after 12 weeks of age.

Rabies is given after 12 weeks of age and before 6 months of age. This vaccine’s administration is determined by laws in the particular state. In Michigan, The very first Rabies vaccine a cat gets is good for 1 year. On the next vaccination, if we use the safer recombinant Rabies vaccine, it will again be good for one year. Some clients elect to use the 3-year vaccine (which I do NOT recommend!).

Bordetella intranasal can be given once a kitten is 12 weeks old. Only a single vaccine is needed to produce adequate immunity. This is recommended for any kitten that is going to go outside or be boarded or groomed.

The Leukemia vaccine used to be recommended only for cats that go outside or have exposure to other cats outside the household. However, the new AAFP guidelines have advised that all kittens get vaccinated for Leukemia as part of their initial series. One year later, if the cats are definitely indoor only/low risk, the vaccine is not continued. If the cats have decided they’re going to be indoor-outdoor or have exposure to other cats, the vaccine can be continued. The Leukemia vaccine’s relative safety, we feel that protecting kittens from this dangerous disease is far more important than the risks from vaccination.

Nearly all kittens are finished with their vaccine series by 16 weeks of age. We need to see cats 1 year after the vaccines are completed. FVRCP is boostered at that time, as is Rabies. Depending on a cat’s exposures and lifestyle, we may booster the Bordetella and Leukemia. The final kitten visit and this 1-year booster are the two most important vaccinations in a kitten’s life. At that point in time, we begin to decide on the frequency of vaccinations by taking into account a pet’s lifestyle, exposure to pathogens, health status, and age. While there is a recommended schedule for cats in general, we make a point to administer only the vaccines that are needed by each individual patient.

With the use of non-adjuvanted and/or recombinant vaccines, we’re able to vaccinate cats with far less risk than previously. The number of sarcoma tumors is being watched closely and studied extensively. The need to protect cats is far more important than the risks of vaccination. We still try to minimize the number of injections (vaccines or medications) a cat gets.

You can read more about Feline Vaccine-Associated Sarcomas here.

Thanks for reading!

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Heartworm Treatment Shortage

I’m going to share a disturbing piece of news with you in the hope that you can help to inform your friends and family. We have known for some months about a severe shortage in the supply of the medication used to treat dogs that have contracted heartworm disease (adult heartworm infection in the heart and lung vessels). This week, we received notice that this drug (Immiticide) is essentially out of reach/unavailable for order from anyone anywhere. The factory that produced the drug was the only one and there are no other companies who produce the drug.

This means that it is more important than ever to have your pet on a monthly heartworm preventative year-round. Year-round administration is the best protection we currently have for patients.

We have an ample supply of heartworm prevention available at Pet Authority. We will, of course, continue to sell prevention in single doses, six packs, and twelve packs.

The American Heartworm Society has issued a set of guidelines for treating dogs that have heartworm infection/disease. Please bear in mind that these are last-choice options, ways to do something rather than nothing to try to help dogs that are infected.

I personally feel that we are on the edge of seeing a rise in the number of dogs with heartworm disease. The tough economy has caused many clients to be unable to provide prevention for their dogs, or to stop giving prevention year-round. These missed doses have put dogs at a much higher risk. Due to the fact that there is a 5-7 month space of time between a bite from an infected mosquito to a positive heartworm test, we won’t know how the missed doses this season (May – November 2011) will affect dogs until 2012.

Please, keep your dogs on heartworm prevention year-round. It’s more important now than ever!

For more information on heartworm prevention, please read the blog post on heartworm disease.

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Canine Vaccines

This week I’m going to cover canine vaccines. I’ll spend a little time talking about each of the vaccines that we offer at Pet Authority. I’m going to save the discussion about how often we vaccinate and how long immunity lasts for the final post. I’ll speak about immunity in relative terms with each of the vaccines.

Distemper

The canine distemper vaccine actually contains between 3 and 5 different pathogens in one injection. This “combination” vaccine is also known as DHPP, DA2PP, or DA2P. The acronyms are a list of the pathogens included in the vaccine. We utilize a 4-part vaccine that contains distemper, hepatitis, parainfluenza and parvovirus (DHPP).

D = Distemper
Distemper is a disease caused by a virus (Canine Distemper Virus, CDV). It affects the respiratory tract, intestinal tract, central nervous system, and the lymphatic system. Infected animals often display a fever, lethargy, vomiting/diarrhea, mucus discharge from the nose and eyes, and in some cases seizures/tremors. There is no direct treatment for this disease and the survival rate is about 50%. This portion of the vaccine is usually a modified live virus. It is also now offered as a recombinant vaccine.

H = Hepatitis / Adenovirus
Infectious canine hepatitis is actually caused by Adenovirus type 1. This is another severe infection that causes fever, vomiting/diarrhea, liver damage, tonsillitis, and kidney inflammation/damage. Dogs can recover from an infection, but in some cases it’s fatal, and often permanent damage results. Early vaccines that included a modified live type 1 virus caused problems with the eyes, so current vaccines contain adenovirus type 2. The type 2 virus causes an immune response that also protects against type 1 virus. This is called cross-protection.

P = Parainfluenza
This is a viral infection that causes respiratory disease in dogs. It’s one of the pathogens responsible for Kennel Cough (canine infectious tracheobronchitis). This is not a severe or fatal infection in most cases, but dogs can develop pneumonia or a chronic cough. The vaccine is a modified live virus.

P = Parvovirus
Canine parvovirus is a mutation of the feline panleukopenia virus that emerged in the late 70s. This virus infects rapidly dividing cells in the lining of the intestinal tract and bone marrow. This is a horrible, deadly disease that kills 30-50% of the dogs it infects. As dogs age, they become less susceptible to parvovirus. Puppies are often infected during the window of susceptibility between maternal antibody and vaccine induced immunity protections. The vaccine is a modified live virus.

Rabies

Rabies is a viral disease that is almost always fatal. There are a scant few humans who have survived infection, but they suffered severe brain damage. This virus affects the nervous system. It’s transmitted in the saliva of an infected animal. A bite allows the virus to get into the nerves. It follows the nerves up to the brain, where it causes extensive damage. This is a zoonotic disease, meaning people can be infected as well. This vaccine in dogs is an adjuvanted killed virus vaccine. (Adjuvant is extra stuff that causes immune cells to come to the area of the vaccine, which creates stronger immune response.)

Bordetella / Kennel Cough

This vaccine can include a combination of 3 different pathogens: parainfluenza virus, Bordetella bronchioseptica bacteria, and adenovirus type 2. The vaccine we use contains parainfluenza and Bordetella. The Bordetella is a killed bacteria. The parainfluenza is a modified live virus. We give this vaccine by squirting it into the nasal passages of the patient. This causes very strong IgA antibody production right on the nasal passages, which in turn helps the body prevent these pathogens from entering the body at all. There is some systemic response as well. An injectible version is available that contains only the Bordetella bacteria.

Leptospirosis

Lepto is a bacteria that is found in the environment (standing water, lakes, ponds, puddles). Wildlife carry and shed the bacteria into the environment. While there are over 200 types of lepto out there in the world, we only vaccinate dogs for 4 types that most commonly affect them. These strains are: ictohemorrhagiae, canicola, grippotyphosa, and pomona. (Great names, huh? So much fun to spell!) This is a killed bacteria vaccine.

Lyme

Lyme disease is caused by a bacteria (Borellia burgdorferi) that is carried by a particular type of tick (Ixodes dammini / deer tick). Dogs and people can be infected by this bacteria. However, dogs do not transmit the infection directly to people. Tick bites cause the infection. The vaccine is killed bacteria (or parts of it). The newest vaccines contain two different parts of the Borellia bacteria, which is supposed to provide the best protection available.

Influenza

Canine influenza is a completely different virus from parainfluenza. Canine Influenza virus was originally a horse influenza virus that mutated and began to infect dogs at a racetrack in Florida (roughly 7 years ago). The virus has since spread to many regions of the US. Michigan does NOT have reported cases at this time, but Ohio and Illinois do have cases on the books. Influenza is HIGHLY contagious. It’s a more severe respiratory infection that has a higher death rate than normal kennel cough. We vaccinated dogs that are social — groomer, boarding, dog parks, dog shows/events. This is a killed virus vaccine.

Puppy Vaccine Series

I wrote last week about the complications we have to overcome when we start to vaccinate puppies. Maternal antibodies and an immature immune system can create a situation where a single vaccination may not generate a good immune response in a particular puppy. Therefore, we initiate a series of vaccines that are administered on a regular schedule. This creates a response in the vast majority of patients that is sufficient to protect that dog from the diseases it is likely to encounter.

We start the series at 6-9 weeks of age with a Distemper combo vaccine. While many puppies will have maternal antibodies that block the vaccination from producing a response, some will have far less maternal antibody. The immune system may not have a complete response at this age, but some response is better than none. Therefore, we hedge our bets against leaving a puppy unprotected.

We continue the distemper series with a vaccination every 3-4 weeks until the puppy is 16-17 weeks old. We try to schedule these so that the puppy doesn’t get more than 3 Distemper vaccines in total.

Rabies is given after 12 weeks of age and before 6 months of age. This vaccine’s administration is determined by laws in the particular state. In Michigan, The very first Rabies vaccine a dog gets is good for 1 year. Subsequent vaccinations are good for 3 years.

Bordetella intranasal can be given once a puppy is 12 weeks old. Only a single vaccine is needed to produce adequate immunity. The intranasal vaccine creates such a good response that puppies are well-protected within 72 hours of the vaccine.

Lepto is given on the last two visits of the Distemper series. Two injections 3-4 weeks apart are necessary to produce adequate immunity. I believe that all dogs in Michigan should have the Lepto vaccine, so for me this is a very important standard part of the protocol.

Lyme and Influenza also require 2 vaccinations 3-4 weeks apart. Sometimes we include these with the final visits in the distemper series. In some patients, we push these vaccines out past the 16 week point so that a pet doesn’t have to process so many vaccines at once.

Nearly all puppies are finished with their vaccine series by 24 weeks of age. We need to see dogs 1 year after the vaccines are completed. Distemper is boostered at that time, as are Rabies, Lepto, Lyme, and Influenza. The final puppy visit and this 1-year booster are the two most important vaccinations in a dog’s life. At that point in time, we begin to decide on the frequency of vaccinations by taking into account a pet’s lifestyle, exposure to pathogens, health status, and age. While there is a recommended schedule for dogs in general, we make a point to administer only the vaccines that are needed by each individual patient.

There are vaccines out there that I haven’t covered: Giardia, Melanoma, Coronavirus, and Rattlesnake venom. There are various reasons for not using these (restricted use, unnecessary, ineffective). If anyone is curious about the vaccines, by all means, let me know! I can cover them in more depth if desired.

Thanks for reading!

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Vaccines – Immune System Responses

As I sat down to write this week, I looked over last week’s post. I had a good start on immune system function, but I’d like to dig a little deeper this week. I’ll try to keep things reasonably understandable. I’m also going to repeat some material so that I can expand the discussion. I will focus on two important things this week: how much vaccine we give pets, and the maternal antibody problem.

Activating the Immune System

When we physically inject a vaccine into a pet, we’ve placed a certain amount of viruses/bacteria/proteins into the body. This amount has to be enough to stimulate the immune system to fully respond to the vaccine. We need the various types of white blood cells to show up and process the pathogens/infected cells so that we get a robust humoral and cell-mediated response.

I frequently get asked about whether I give the ‘same amount’ of a vaccine to a small dog as I do to a big dog. Without a doubt, yes, we do give the same amount of vaccine to a Chihuahua as we do to a Great Dane. The reason is that the immune systems of both of those dogs work the same way. There is a minimum amount of pathogen required to generate a robust immune response. If we give less, the vaccine may not provoke the immune system enough, and we could leave that pet unprotected. Immune responses vary a little from individual to individual. Manufacturers have figured out how much pathogen we need for the vast majority of pets to respond, and that’s what’s put in the vaccines. If we gave less to a smaller dog, the response might not be enough to protect from disease. The one exception to this “rule” is the nasal bordetella vaccine. We’re able to lose/spill some of that and still get a robust response in the pet.

Antibodies

I mentioned last week that when we adequately stimulate the immune system, two pathways are activated. The two parts of the system are Humoral and Cell-Mediated. Humoral immunity is composed of antibodies circulating in the bloodstream or standing guard on surfaces such as the lining of the nasal passages. Some antibodies are attached to other immune cells and function as on/off switches for those cells’ functions. Antibodies are also known as immunoglobulins, abbreviated as “Ig.” Immunoglobulins have a neat structure that looks like a “Y.”

Antibody
The structure of the antibody molecule has a “socket” shape on the upper tips of the ‘Y’ shape. The socket fits a particular bump on a pathogen. So, there are antibodies with a socket that fits a protein that the Lepto bacteria wears on its surface. For each pathogen, the body makes several types of immunoglobulins (Ig): IgA, IgD, IgE, IgG, and IgM. For this part of the discussion, we’re going to focus on IgA, IgM, and IgG.

IgA is found on the surfaces in the nose, throat, intestinal tract, and urogenital tract. IgA functions on these surfaces to block pathogens from getting into these surface cells or tissues to cause an infection. Our Bordetella (Kennel Cough) nasal vaccine causes a high level of IgA to be produced on the respiratory tract surfaces.

IgM is an antibody secreted by certain types of white blood cell (B Cells), and it’s the first antibody produced when an animal is exposed to a pathogen. It’s a very large molecule, so it stays primarily in the bloodstream. IgM is very good at activating the Complement System, which is the chemical reaction that occurs when an Ig sticks to a pathogen. The Complement System functions to kill a pathogen by punching a hole in the pathogen.

IgG is found circulating in the bloodstream and in body tissues. IgG sticks to pathogens to stop them from getting deeper into the body and also aids other parts of the immune system in responding. IgG molecules can also cross the placenta and provide some immunity to a fetus. IgG is produced during later phases of the immune system’s response to a pathogen, or when the body is later exposed to a pathogen it has been previously exposed to. This is the antibody produced when we give a booster vaccination, and it’s what we count on to protect our pets.

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Vaccines – Introduction and Immune System Basics

I’m going to start tackling a fairly in-depth topic this week: vaccines. We attended a seminar last weekend that included an early look at the vaccinations guidelines published periodically by the American Animal Hospital Association and the American Association of Feline Practitioners. These guidelines are created by a group of veterinarians and other experts in vaccines/immunology. The guidelines issue suggested practices on selecting which vaccines to use, how to use them, and how often to use them. The official guide will be published later this summer/early fall.

The seminar covered ways to assess each patient’s risks so we can develop an individualized vaccination program. We also talked about the various types of vaccines available and how each type has strengths and weaknesses as we examine their efficacy. I learned a tremendous amount from the seminar.

I’m establishing the timeline so that those of you who are regular readers (thank you! 🙂 ) have some time to research on your own as well. I would like to have a constructive and informative dialogue about vaccines. I encourage you to ask questions by leaving comments. I will try to answer them promptly and thoroughly.

August 7 – Introduction, Immune System Basics, and Vaccine Types
August 14 – Immune System Responses
August 21 – Canine Vaccines
August 28 – Feline Vaccines
Sept 4 – Controversy, Facts and Fiction

I’m saving the really hot topics for the last post (Sept. 4th). I will write in an open manner what the controversies are regarding vaccines, how often we give them, what the most current thoughts are about safety, and some of the consequences of vaccination. I’m confident that at Pet Authority our current strategy is in line with the most current recommendations for safety and good practices. We’re putting the health of the pets first.

The only thing I will *NOT* do through these posts is discuss human vaccinations. There are tremendously emotional issues with human vaccination strategy that go beyond the scope of my training. I acknowledge the fact that there are serious concerns with *any* vaccine given to *any* species. Beyond that, I will stick to veterinary patients and vaccinations.

Click the numbers below to move through the pages of the post…

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