Are we over-vaccinating our pets?

Sun Journal
Lewiston, Maine

Sunday, August 8,2004

The state of Maine requires that owners of dogs vaccinate their pets, and only for rabies, as a condition of issuing a dog license. The law is silent on other vaccinations for dogs, and for any vaccinations for cats and other pets. Yet it is common practice in Maine to vaccinate pets annually for a range of diseases, and most pet owners wish to do the right thing for their companion and (in the case of diseases like rabies and kennel cough) for society at large.

It comes as a surprise, then, to learn that the frequency of vaccination is a controversial issue in both the scientific community and increasingly among veterinarians. The issue came to a head this spring in Maine when a campaign by pet owners, backed by recommendations from national veterinary groups but opposed by some veterinarians, persuaded the Maine Department of Agriculture to change the state's rabies vaccination requirement from every two years to every three years.

Maine's new three-year rabies rule brings us into line with the practice in most other states and with the recommendations of a 2003 task force by the American Animal Hospital Association. However, the AAHA task force went further than rabies vaccines. It pointed out that many vaccines have an effective life of five years or more, and that each time an animal receives vaccine shots, it runs some risk of adverse reaction. The AAHA recommended that vaccine booster shots for distemper, parvovirus and hepatitis should be administered no more frequently than at three-year intervals. More frequent shots literally do no good whatever - an animal is either immune or it is not - but they potentially can do harm because of the low, but real, risks of adverse reaction by the animal's immune system.

The AAHA's caution about over-vaccination resonates strongly with many pet owners who are concerned about reports of growing numbers of cancers in pets, tumors at vaccine injection sites and post-vaccination autoimmune disorders. The state only tracks illnesses in farm animals, not pets, so no clear pattern is visible through these anecdotal reports. But with pets' lives at stake, we should adhere to the guidelines of the national veterinary bodies.

Unfortunately, the three-year interval recommendation is controversial with some veterinarians. While some people resist any change in "the way it's always been done," there appears to be another factor in play. Veterinary schools teach business classes as well as medicine, as most vets seek to become independent business people running a profitable practice. Reading the debates over vaccination frequency in the veterinary profession's journals and online, it is evident that many vets feel their income is threatened by a move away from annual vaccinations.

Like dentists who build a practice on the basis of repeat visits for annual cleanings and checkups, veterinary practices need the steady flow of return customers. But the dentists' business model offers the solution for veterinarians - checkups, without vaccinations. Annual animal checkups are a healthy practice for every pet owner, and some veterinarians are building practices on the income stream from such checkups rather than on unnecessary vaccinations. We must work to persuade pet owners to think in terms of full annual checkups, while also informing them of the risks of over- and under-vaccination.

In the next Legislature, I intend to introduce a bill to require full disclosure, in plain English, of information about the risks, potential side effects and nationally recommended frequency of vaccine shots, in the same way that pharmacists are required to give out such information for prescription drugs. I will be working with members of the AAHA task force, nationally respected veterinary scientists, to develop such wording.

No one wants to add a layer of burdensome regulation to veterinary practice. But when pets' health is at stake, it is appropriate to give full information to an animal's owner and then let them decide. The best friend an animal can have is a fully informed owner.

Sen. Chris Hall, D-Lincoln County, is a dog owner who lives in Bristol, ME. He is Senate chair of the Utilities and Energy Committee and serves on the Legislature's Business, Research and Economic Development Committee.