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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2 Comments

Filed under immunology, preventive care

2 responses to “Canine Vaccines

  1. Leptosporosis is zoonotic as well.

  2. That’s correct!

    In order to get lepto directly from a dog, that dog’s urine would have to come into contact with mucous membranes or open cuts/sores on the owner.

    However, lepto is a danger to people that come into contact with the same environmental contamination as pets — lakes, puddles, in the yard, etc.

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