Short Takes: 09/03

Indoor versus outdoor cats; Giardia vaccine for cats is of minimal value

Who Let the Cats Out?
These days, most veterinarians urge cat owners to keep their pets indoors, for reasons of health, safety and population control. They know from experience that indoor cats are less likely to contract infectious disease, be hurt by cars and other animals, or play the mating game with strangers.

So researchers at the Tufts University School of Veterinary Medicine and the University of Massachusetts School of Public Health wondered: Why dont more cat owners listen to the advice of veterinarians? Partial answers were reported in the Journal of the American Veterinary Medical Association (Vol. 222, No.11) in the article, Evaluation of cat and owner characteristics and their relationships to outdoor access of owned cats.

The study of New England cat owners found 60 percent keeping cats strictly indoors and 40 percent allowing some outdoor access, although 97.1 percent of all cats in the study were called inside at night. Statistical analyses found no significant differences in some factors considered in the survey: The age of the cat, reproductive status or whether they had been declawed, for example, didnt matter. Rural cat owners were somewhat more likely to let their cats out, while more city dwellers and suburbanites keep their kitties inside.

Also more likely to be allowed to outdoors were cats acquired from animal shelters, which is where they might end up again if they roam. Researchers did note the presence of a dog in the household was significantly associated with outdoor access of owned cats.

Sure, blame it on the dog.


Giardia Vaccine Hardly Helps Cats
Speaking of the perils of outdoor life, one nasty infection for cats (and dogs and people, too) is giardiasis, from the flagellate organism in contaminated water and animal feces, Giardia lamblia. Trouble starts brewing in the small intestine and severe diarrhea can be one result of the zoonotic disease, which perhaps can pass among animals and humans.

A Giardia vaccine for cats was tested and reported on in a recent Journal of the American Veterinary Medical Association (Vol. 222, No. 11) by researchers at the Colorado State University College of Veterinary Medicine and Biomedical Sciences.

Results of their study, Efficacy of Giardia vaccination in the treatment of giardiasis in cats, are not encouraging. They began with 16 cats, kept in laboratory conditions and experimentally infected with Giardia cysts, the stage of the organism usually encountered in water or feces. Half the cats received regular doses of vaccine and the control cats got none. After 28 weeks, seven of the eight control cats had giardiasis, but so did five of the eight vaccinated cats.

The researchers noted that Giardia lamblia can assume somewhat different forms, depending on its host species, and that might account for problems with the vaccine. They concluded: Whether Giardia vaccination is an effective treatment for giardiasis in naturally infected cats remains to be determined.