By Dr. I. Elizabeth Borgmann. Vaccines and vaccination of both people and pets has become a highly charged and controversial subject. As we have been able to control infectious disease, the terrible consequences of the illness they cause are no longer at the forefront of our minds. Instead we have started to fear the very thing that has saved us so much grief.
Consider the recent article in MacLeans Magazine (Jan 16, 2012) describing an outbreak of measles in Quebec. This was a disease that was eradicated in the Americas in 2002. But because the vaccinations rates have dropped to below 93% (95% is necessary to limit spread of a disease), a significant outbreak occurred. Closer to home, consider the recent spread of Whooping Cough (Pertussis) throughout the Fraser Valley.
In our pets, we cannot even begin to hope to eradicate the infectious diseases that plaque our furry family members. We will be unlikely to reach the 90-95% vaccination rates achieved in the human population. But we can protect our individual pets.
Vaccines do not prevent infection by the pathogenic organism in question. Rather, vaccination prepares the body for a quick and timely response that eliminates the organism before serious disease occurs. A great deal of research has gone into the development of vaccines and one must balance the risks and the benefits. Does the benefit outweigh the risk? Most often, the answer is yes.
So what does your dog need to be vaccinated against? This is dependent on your pet’s lifestyle and exposure risk. Obviously the indoor dog that lives in a gated complex and whose paws rarely touch the ground does not need the same degree of protection as the dog that goes to the dog park on a daily basis and hikes the mountains in the summer.
There are three viruses that are typically included in the core vaccine regime of all dogs: Parvovirus – a virus that attacks the rapidly dividing cells of the intestinal tract and the bone marrow; Distemper – a virus that starts with a runny green nasal discharge and progresses to pneumonia, vomiting, diarrhea and seizures; and Adenovirus – a virus that causes canine infectious hepatitis.
Vaccination against Parainfluenza and Coronovirus is no longer considered essential as the vaccines are minimally effective and the diseases are not debilitating. Parainfluenza is a component of the kennel cough complex and is now recommended to be included in the intra-nasal vaccine but not with the core injectable vaccine. Coronovirus virus infections, once believed to cause hemorrhagic enteritis, are now known to cause very few clinical signs. Diarrhea may appear in very young puppies.
There are optional vaccines available for pets with a higher risk of exposure based on their life styles. These include vaccination against Leptospirosis , Lyme, and Bordetella.
Leptospirosis is an organism passed through the urine of skunks, opossums and raccoons. It survives well in our damp climate. It attacks the kidneys primarily as well as the liver and can be passed on to people. Active outdoor dogs that like to walk the dyke trails and hills, dogs living next to a greenbelt and dogs living on the farm should be vaccinated against this. Vaccination against this reduces the severity of illness but dogs can still become carriers.
The lyme disease organism (Borrelia) is present in about 6-10% of the ticks in our region. Dogs that are very active in the woods and meadows are most likely to be exposed to ticks. Though not as likely to cause infection in dogs compared to people, it can cause arthritis in the joints and kidney damage. Approximately 5-10% of dogs that pick up the Borrelia organism will develop disease from it. (In other words, in our area, about 1 in 100 dogs that pick up ticks will get Lyme disease.)
Bordetella is one of several organisms that cause a very annoying upper respiratory cough. Kennel cough is a complex of several organisms that is easily spread from dog to dog through aerosolization (coughing). Therefore dogs with contact with other dogs through dog parks , doggy daycares and kennels are at greatest risk. How many dogs does your pet greet on their daily walk? Vaccinations will lessen the severity of clinical signs but will not necessarily prevent them.
How often should you vaccinate? All puppies should have 2-3 vaccinations with the final vaccine occurring after 12 weeks of age. Boosters are commonly given at one year of age to capture any dogs that did not seroconvert well (develop adequate immunity).
Subsequent boosters are dependent on the vaccine. Most vaccines against the viruses (the core vaccines) can be given every 3-4 years. Vaccines against bacteria (leptospirosis, lyme, bordetella) are not as effective and should be boostered on a yearly basis.
What about vaccine titres? Yes, these are a good option for the core viruses (distemper, parvovirus and adenovirus). Ideally, test the levels for all three organisms. My personal favourite laboratory for this type of analysis is Cornell University in the U.S. They have a large and broad data base and they are able to provide clear guidelines on when re-vaccination is indicated. Testing all three titres and having the samples go to the U.S. is more expensive than testing for only distemper and parvovirus with some of the local laboratories.
What about all the evil side effects of vaccines? Remember the fear regarding vaccinating children and the development of autism? Do you recall that it was proven that the data was fabricated? How solid is the data against vaccinating your dog?
What do I do for my own dog? He is vaccinated and I would never consider not vaccinating my own dog. My dog goes on walks in the woods with me and is vaccinated for the core vaccines every three years and for Leptosporosis and Lyme Disease yearly. He is also vaccinated against kennel cough because he loves to meet, greet and play with every dog along the way. For me, knowing and having seen the outcome of illness associated with these diseases, I could never live with myself if he developed such a preventable problem.
No treatment or prevention is benign and without risks. The question is – which is riskier? To me, the cost benefit analysis is clearly in favour of vaccinations.
Oh, and yes, my human children are vaccinated too!
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Dr. Borgmann lives in Chilliwack and has been practicing in the Fraser Valley for over 13 years and can be reached at the Whatcom Road Veterinary Clinic