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An Ounce of Prevention . . . Is Worth a Vaccine!

Published 9 years ago9y ago • Bookmarks: 72

March 5, 2015

| by Dr. Brian J. Green, DVM — Sleepy Hollow Animal Hospital |

In this age of vaccine hysteria brought about by the recent measles outbreak, a review of what is known, what is fact, what is feeling, what is faith, and what is incontrovertible is important. As it relates to our pets, however, dogs and cats do not claim religious exemptions, and feeling is usually less an issue since their pet parents don’t get the needle, so fact and fear is probably what we as veterinarians need to focus on most when discussing what measures are best for protecting our pets from some really, really nasty diseases.

Not wanting to immerse myself too deeply into the controversy on the human side, I will merely state that vaccines have a proven safety and efficacy profile based on millions of doses, hundreds of studies, and the fact that people who are not immunocompromised (defective immune system due to existing disease, genetics, chemotherapy, AIDs, etc.) will not contract an infectious disease that they have been properly vaccinated against. Further disclaimer: I do not work for the pharmaceutical industry, nor am I likely to unless offered a cozy place to work on a Caribbean Island, in which case we can talk about it over lunch – your treat.

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What we do know on the pet side, is that in rare instances, certain vaccines have had side effects that make caution in their use tantamount. Cats receiving certain vaccines containing adjuvants (additives that increase the immunity in a killed vaccine) have been known to develop an aggressive cancerous growth at the injection site. In particular, the previously available 3-year rabies vaccines and some of the feline leukemia virus vaccinations that were adjuvanted were the most implicated. (As an aside, we at my animal hospital have never used an adjuvanted leukemia vaccine, and have not used the mentioned rabies vaccine since the first report came out). And occasional immune mediated diseases have been thought to have been vaccine induced, but most of the efforts to prove causality have been (as usual) in an extremely vocal minority.

So what is currently recommended for our pets?

The first question pet owners should ask themselves is has their veterinarian established the possibility of exposure to the disease? Some vaccines are mandated, but at what frequency? Should I vaccinate against a deadly disease if my pet is unlikely to encounter it just to be safe?

The answer to those questions is important, and the following recommendations are based on safety, exposure considerations, possible consequences of not vaccinating, and consequences of vaccinating needlessly.

‘Core vaccines’ are the vaccines that nearly every veterinarian will tell you are important. They include canine distemper/parvovirus (usually given in combination with several other components) and Rabies.

The former, though, much to the manufacturers disappointment, has been found to last 3-5 years (and sometimes beyond). Because of this, the more conservative among veterinarians, me included, recommend blood titers (levels) to measure protection until the vaccine is no longer protective, and only then revaccinating. This markedly decreases any chance of an adverse reaction to these ‘live, attenuated (weakened) vaccines’. The same is true of the feline distemper vaccine, the virus of which is, in fact, genetically similar (and might have originally mutated) to the canine parvovirus, both diseases being dramatically deadly when contracted. Blood titers of the feline vaccine are also advised in the same way.

Rabies vaccination is typically given as a 3-year killed vaccine to dogs, and until recently a 1-year (non-adjuvanted) vaccine in cats. Even indoor cats are required by law to receive this vaccine. A recent 3-year non-adjuvanted feline vaccine has been introduced, and may eventually replace the 1-year if safety proves equivalent.

So what are non-core vaccines, and when are they needed?

For cats, the only non-core vaccine currently recommended for potentially exposed cats is the feline leukemia virus vaccine. This disease is only transmitted cat to cat, usually via bite wounds and sexual contact, so strictly indoor cats need not apply. No other non-core vaccine is recommended by the American Veterinary Medical Association (AVMA) or the American Animal Hospital Association (AAHA).

In dogs, lyme vaccine is highly effective if hiking in woods, parks, aqueducts, etc. is a regular part of the dog’s life. Otherwise, good flea and tick control is probably adequate. The same exposure type applies to a disease called leptospirosis, which dogs contract by drinking from puddles contaminated by wildlife urine. This is an extremely deadly disease, contagious to people, that an effective vaccine can prevent if exposure is likely. Bordetella (kennel cough) is recommended for boarding and grooming sites, and canine influenza is advised for boarding and daycare facilities with high populations or rapid turnover. Corona virus is never indicated for any reason, and in this area, vaccines against rattlesnake venom is not given.

When all is said and done, your veterinarian is probably best positioned to guide you through the myriad of information and misinformation available on the internet. The fact that there is a potential conflict because he or she may profit from administering the vaccine should not come into it if the above guidelines are rigorously followed. If you are unsure, you may need to discuss your concerns with your vet, but it is far more difficult and much more expensive to cure some of these diseases than prevent them. And for the record, while breeders of dogs and cats are usually quite knowledgeable about pet care, they should not be your prime source for medical advice. And live pet retailers should be avoided completely, but that is an article for another day.