Feline vaccine-associated sarcoma (FVAS) confronts cat owners and their veterinarians with an aching dilemma: Inject cats with all of the best-available vaccines and take the slight – but significant – risk that cancer might grow at the vaccination sites. Or, skip some vaccines and risk one cats life – and many more if an epidemic spreads. Now, a nationwide 1,347-cat study, reported in the Journal of the Veterinary Medical Association (JAVMA Vol. 223, No. 9), could make vaccination decisions a little easier.
The multicenter case-control study said probably not guilty to six possible causes of FVAS: Specific brands of vaccines do not seem to be associated with FVAS, the study found, and neither do cats places of residence, history of traumatic injury, viruses, or most vaccination practices, such as reusing syringes. Rather, the researchers pointed a tentative finger of suspicion at and called for more research into two classes of injectable medications and one vaccination practice.
The corticosteroid, methyl prednisolone acetate, and long-acting penicillin did appear to be found more frequently among cats with sarcomas, the researchers said, emphasizing the difference between medications and vaccines. And whether veterinarians warm the vaccines – or use them straight from the refrigerator – also might matter.
Administration of cold vaccines was associated with a higher risk of sarcoma, they concluded.
Whatever the cause of FVAS turns out to be, the report noted, the condition is relatively rare: Among the tens of millions of cats in the United States, only thousands of new cases will develop each year.
In Britain, where traffic accidents are the fourth most common cause of death among cats, veterinary researchers wondered why. Their report, Study of factors that may predispose domestic cats to road traffic accidents in Veterinary Record (Vol. 153, Issue 18) showed which cats unsuccessfully cross the road – in one English county, at least – and partially disproved the black-cat myth.
Comparing characteristics of cats that were seen by veterinarians for traffic injuries against control cats that were allowed outdoors but had never been hit, the study reached this precise conclusion: Young cats (particularly those between seven months and two years of age), male cats (entire or neutered), and non-pedigreed cats were most at risk of being in a road accident in Cambridgeshire between March 2000 and February 2001. The careful scientists made no claims that their study sample was typical of any place on earth except Cambridgeshire, U.K., but they noted similar findings in a 1981 study in the Maryland (U.S.A.) city of Baltimore.
Regarding the apparent bad luck of non-pedigreed cats in traffic, the researchers said owners of pedigreed cats might spend more time training their expensive pets while limiting their outdoor hours.
And if a black cat crosses, is it unlucky for the cat? Color and visibility have little to do with whether a cat is hit by a car, the researchers said. Although 44 percent of the road-traffic-accident cats were totally or mainly black, and 35 percent of control cats that hadnt been hit (yet) were black, the difference was ruled not statistically significant.