Q. I’m having a disagreement with my veterinarian. The breeder of my new Maltese pup says that dogs as small as she is should only receive half of the volume of standard vaccine, but my vet says the shots won’t be as effective and she refuses to administer only half.
In contrast to almost all veterinary drugs, vaccines are prescribed on a one-dose-fits-all basis rather than by body weight. So whether we’re talking about a 2-pound terrier or a 200-pound mastiff, all dogs receive the same dose.
While I won’t go so far as to say a half dose of a vaccine won’t be as effective as a full dose, I will side with your veterinarian. The reason: We don’t know whether a half-volume vaccine is as effective as a full-volume vaccine.
There’s only so much testing a vaccine manufacturer can be reasonably expected to undertake, and most canine vaccines are tested on average-size dogs. Vaccines are rarely tested on small breeds.
That is perhaps why smaller dogs have historically suffered more than their share of adverse vaccine reactions. In fact, in an oft-cited 2002 study, the risk of reactions was significantly higher for toy breeds.
That said, the risk is small. In one 2005 study evaluating 3.5 million full doses administered to 1.2 million dogs of all sizes, only 38.2 adverse vaccine reactions were observed for every 10,000 dogs.
So while vaccine manufacturers haven’t necessarily studied the safety of their vaccines in every size of dog, studies like this serve as a powerful basis on which to assume safety even in toy dogs at the recommended dosage.
Dr. Patty Khuly has a veterinary practice in South Miami. Her website is drpattykuhly.com. Send questions to firstname.lastname@example.org, or Dr. Dolittler, Tropical Life, The Miami Herald, 3511 NW 91st Ave., Doral, FL 33172.