Resources for information on Canine Circovirus

Many of our clients have called and sent email to ask about Canine Circovirus. The news has picked up the stories of dogs in Ohio, California, and Michigan. New information is somewhat hard to come by. The virus isn’t thoroughly understood at this point in time. Investigators are working hard to bring us more information. In the meantime, here are a few links that lead to more info on Circovirus.

Circovirus FAQ from the AVMA

Guidance for Veterinarians about Circovirus

Information from Michigan State University’s Diagnostic Center for Population and Animal Health:

LANSING, MI – Based on recent cases in California and Ohio that may indicate the emergence of a new canine circovirus, the Diagnostic Center for Population and Animal Health (DCPAH) at the Michigan State University College of Veterinary Medicine has added two real time PCR assays for canine circovirus to its test catalog. Running two PCRs for this virus is important as the initial research on the virus indicates some genetic variation. The PCR assay can be run on fresh or formalin-fixed tissue. DCPAH has received requests for canine circovirus testing from Michigan clients and two positive results have been found. However, both animals also had simultaneous infections with other organisms; therefore identification of the circovirus was not necessarily linked to the cause of the disease shown by the animals. DCPAH is currently working on an in situ hybridization (ISH) technique which is a crucial next step. ISH is a method that uses DNA or RNA probes to detect virus in microscopic lesions.

“It is important to note that circovirus has been found in the feces of healthy dogs. Also, the initial research shows that nearly 70% of dogs showing clinical signs of illness and found positive for circovirus were also infected with other viruses or bacteria known to cause disease. Currently, circovirus by itself is not associated with a specific disease process. However, coinfection with canine circovirus and other pathogens may have the potential to cause disease as has been demonstrated in other species, for example pigs,” says DCPAH acting director Thomas Mullaney.

Matti Kiupel, section chief for DCPAH’s pathology laboratory adds, “In order to link circovirus to the cause of a disease process, a full diagnostic work-up (including a postmortem in the case of deceased animals) is essential. This also allows diagnosticians and pathologists to identify the full spectrum of infections and/or diseases that are present in a specific case.”
Recent publicity about circovirus in Michigan dogs is not cause for panic. Veterinarians should consider possible circovirus infection in animals showing clinical signs including vomiting, diarrhea (possibly hemorrhagic) only after other more common causes have been diagnostically excluded. Ascites, pleural effusion, hypovolemic shock, bicavitary hemorrhage, and disseminated intravascular coagulation may also be present, but as with gastrointestinal symptoms, more common causes should be excluded. According to the early research by Li et al, circovirus “should be considered in cases of unexplained vasculitis in dogs.”

Dog owners whose pets show signs of illness, including vomiting, diarrhea, lethargy, should contact their veterinarian and seek diagnosis and treatment. There is no evidence to-date that canine circovirus can be transmitted to humans or cause human disease. Since many pathogens are transmitted from animals to humans (zoonotic diseases such as rabies, leptospirosis, salmonellosis) thorough hand-washing should be standard practice after handling animals, especially those showing signs of illness, or animal waste.

Additional information on circovirus developed by the American Veterinary Medical Association (AVMA) for veterinarians and the general public is available on the DCPAH website at animalhealth.msu.edu.

Emerging Viral Disease (Maybe)

The news has been active over the last week or so due to the possibility of a new, emerging viral infection in Ohio. Some dogs have been sick, and a number have died, from what may be circovirus. This would be a new finding in dogs, and the State Veterinarian in Ohio is working with regulatory agencies and veterinary schools to try and figure things out.

Here’s a link to an article in an Ohio newspaper.

Thursday News

Treating infections is one of the most widely known aspects of medical practice. Humans and other animals are in a constant and highly variable relationship with the microscopic world inside and outside our bodies. Bacteria help us digest and use our food, but they can also cause life-threatening infections. Dealing with the bad bugs often requires an antibiotic, a chemical that kills the bacteria. Finding new antibiotics that can be brought to the market as a safe, effective treatment is a long, expensive, arduous process. As a result, we don’t see too many new antibiotics.

Scientists have discovered a small molecule in the bloodstream of the giant panda that has antibacterial properties. The pandas make this small chain of amino acids (a peptide) naturally and it circulates in their body. Interestingly, it kills bacteria very quickly — more quickly than the drugs and molecules we already know about. The hope, of course, is that we can find a way to make this available to help humans and other animals. Scientists are working on making this peptide in the lab so that wild pandas can be protected.

This is another example of why research into the natural world is far, far more important than it might at first seem. Nature has a great deal to share with us about elegant solutions.

Here’s the link to the article. (It’s pretty short.)

Itch, Itch, Itch : Seasonal Allergies

Spring is here, more or less. We got an early preview a while back that threw off the usual calendar, but the plants and trees have inched their way through colder temps since then. Early in the warm season, trees in particular are throwing pollen into the air. Other plants do as well, and depending on the month, different types of plans will release pollen throughout the growing season. Mid-summer tends to be a mix from grasses, with trees and weeds as well. Late summer and early fall are mainly weeds. All of this pollen is a bane for anyone with hayfever or asthma. (Believe me, I know this wholeheartedly — my hayfever gradually gets worse each year.) Itchy eyes, congestion, a sore throat — all of it’s part and parcel for breathing in the pollens carried around by the wind outside. Without the help of antihistamines, steroid nasal sprays, inhalers, and allergy shots, people would be utterly miserable. Pollen.com has a nice daily map for allergen counts.

Dogs and cats suffer from this type of allergy, too. There’s really no difference in how the immune system is behaving in response to exposure to all of this pollen. The unique part about allergies in dogs and cats is that they do a majority of the immune-related chemistry in their skin. Instead of the respiratory problems that people get, dogs and cats will get itchy, inflamed skin. When the allergy is to the things in the environment, it’s officially called “atopy.” On a quick side note, cats can get plain old asthma; and dogs can get allergic airway disease, too. I’m not going to cover those today, as they’re separate enough as topics to make up a whole other post.

When we are exposed to things that are not from our own body, the immune system has to identify these ‘foreign’ things and decide how to respond to them. This is the basic principle we discussed way, way back in the vaccine posts. (Immune Basics & Immune Responses) You’ll remember that we have to stimulate the immune system more than once in order for it to produce a good response from vaccination. The seasonal changes in pollen end up working much the same way. In this case, it’s an unfortunate turn of events. Young animals are exposed to all of these pollens during the first year of their life. This is a lot like the first vaccination. The immune system catalogs and learns the foreign material (pollens). Then, we go through winter with relatively low exposure. The next year, when the growing season begins, the immune system once again is exposed to these foreign materials. The problem is that the immune system often overreacts to this second exposure, and releases all kinds of pro-inflammatory chemicals that lead to redness and itching. The things that follow for allergy-suffering pets stem from that overreaction. Just as not all people suffer from allergies, not all dogs and cats do. We believe there is some genetic component, but the real reason for allergies developing isn’t understood.

Usually, I see a gradually increasing severity of signs and symptoms in dogs and cats. The first ‘bad’ year is just a little itching and licking here and there. Each year, the allergies get progressively worse, with more licking and itching, maybe a hot spot. Things get ugly from there: large hot spots, skin infections, hair loss, claw/toenail infections, and ear infections. It’s shocking sometimes to see how bad something as simple as a little pollen allergy can get.

Common clinical signs and history that we see include:
•Licking the feet or chewing the feet
•Redness of the feet, belly, and ears
•Licking/chewing/scratching at various areas on the skin
•Hair loss
•Flaking/peeling skin
•Hotspots – areas of moist, red, gooey skin and partial hair loss; these are painful
•Ear infections (not as common with this type of allergy but sometimes seen)

When I first see a pet with mild signs, I will go over with the owner when the problems first started. Usually, owners will realize that there was a -little- itchiness in the prior summer. “This year it’s a lot worse” is something I commonly hear. We have to rule OUT a couple of other problems as we work on finding out about environmental allergies. Allergy to food ingredients and allergy to flea bites can also cause similar signs in pets. I’ll discuss those another time. Once we rule those out, or if the history suggests that the problem is very obviously seasonal, we have a preliminary diagnosis of Atopy — Environmental Allergies. One last quick note on the source of allergens: indoor allergens can cause atopy, too. Things like dust, dust mites, dander, etc. I’m focusing on the outdoor stuff because it’s seasonal.

Treatment for allergies is two-fold. First, I generally have to apply a set of band-aids in the form of treating the symptoms of the allergy. I have to help stop the itching, calm down the redness and inflammation, treat infections, and make sure that all external parasites have been ruled out or treated. These things don’t treat the underlying cause of the allergy, though. They help treat the symptoms. For some patients, this is “good enough” for that first couple of years. We give an antihistamine in almost all cases. Supplementing omega fatty acids helps. Sometimes, medicated shampoos or conditioners are useful. We have sprays for the skin, as well as antibiotics and – if things are really ugly – glucocorticoid steroids.

Ultimately, these bandaids aren’t enough. We have to treat the underlying cause of all of these secondary problems. Treating the allergy itself means we have to outsmart the immune system. The immune system produces a specific type of antibody that hooks up to a specific type of cell in the tissue. When allergens like pollen come in contact with these antibodies, the cells burst and release inflammatory chemicals. Repetitive low-level exposure to pollens makes more and more of these little grenade cells ready to respond at the next exposure. Left on its own, the immune system is hoist by its own petard.

What’s needed is a way to stop the pollen from ever contacting the explosive cells. This is done with allergy shots. Technically, this is called hyposensitization therapy. We allergy test dogs/cats with blood or by intradermal skin testing. Most people are familiar with the little tiny injections that the dermatologist gives you to see how big of a welt your skin makes. This allows us to put together a custom cocktail of allergens that are then made into a vaccine of sorts. The pets are treated with a series of injections of the things they’re allergic to, which creates a LOT of antibodies that circulate in the blood and tissue. What this does is create a massive standing army of antibodies that are ready to all pile onto pollen before it can contact those grenade cells and make them pop. We’ve used the immune system’s response to the allergy-causing pollen to create a defense against the pollen, which protects the pet from the inappropriate overreaction of the immune system. Neat, huh? Simply put, ‘allergy shot’ are a vaccine for allergies.

We also have a medication available for treating allergies that takes the opposite approach. Instead of using the immune system and provoking a bigger response, this drug suppresses the immune system and stops the bad chemistry from happening to begin with. This drug is a specially altered version of cyclosporine that makes the drug go to the skin more readily. The only drawbacks are that this drug is quite expensive, and many animals vomit while on it. Still, for owners that don’t feel comfortable with the allergy shots, it’s a good option. The few times I’ve used it, it’s been very helpful.

The take-home message for the day is: if it’s itchy, treat the -underlying cause- instead of just using bandaids. Thanks for reading!

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!

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!

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!

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.”

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.

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