Enteric Zoonotic Agents
July 1, 2002 (published)
Susan Little DVM, DABVP (Feline)

Winn Feline Foundation Progress Report
By Susan Little DVM, Diplomate ABVP (Feline)

July 2002

Enteric Zoonotic Agents in Cats: How Common Are They?
Investigators: C.V. Spain, J.M. Scarlett, S.E. Wade, P. McDonough
College of Veterinary Medicine
Cornell University, Ithaca, NY

Funded 1998

In recent years, the benefits of pet ownership for both healthy and ill people of all ages have received recognition. While domestic cats in general are thought to be of low risk for transmitting zoonotic diseases of the intestinal tract, there has been little hard information in the veterinary literature that documents infection rates. Without any factual evidence about risk estimate, physicians often recommend that immunosuppressed people should not own pets, despite the very real benefits of pet companionship for reducing depression and loneliness and alleviating stress.

Several infectious agents are associated with zoonotic intestinal diseases in cats. The most serious include Salmonella, Campylobacter, and Cryptosporidium. Other agents include Giardia and Toxocara cati. The purpose of this study was to generate current data for the prevalence of these five agents in cats housed in humane shelters or presented to veterinarians in central New York State.

From June 1, 1998 to February 15, 1999, a total of 263 cats between 1 and 12 months old were enrolled in the study. Of these, 114 cats were privately owned and 149 cats were from humane shelters. For each privately owned cat, a questionnaire was completed and a fecal sample was submitted. For the shelter cats, fecal samples were collected from their cages and basic information, such as age, sex and reproductive status were recorded. The fecal samples were submitted for culture of Salmonella and Campylobacter jejuni and tested for the presence of the parasites Giardia, Toxocara cati, and Cryptosporidium.

The most common agent found in this group of cats was Toxocara cati (roundworm), with 32.7% of all cats infected. The next most common agents found were Giardia, with 7.2% of all cats infected, and Cryptosporidium with 3.8% of all cats infected. Toxoplasma gondii was found in only 1.1% of cats and Salmonella and Campylobacter were found in less than 1% of cats.

Overall, 40.7% of these young cats had at least one or more zoonotic agents. Interestingly, the rate of infection with zoonotic agents was similar among client-owned cats (35.1%) and shelter cats (44.2%). The results of the study show that zoonotic agents with serious consequences for humans including Salmonella, Campylobacter, and Cryptosporidium are rare in cats.

The study also showed that diarrhea cannot be used as a predictor of zoonotic infections, for cats without diarrhea were just as likely to be infected. Roundworms were shown to be very common in cats and this finding supports the recommendation that all newly adopted cats should be treated for this parasite regardless of whether they have diarrhea.

Immunocompromised people should be able to work with both their veterinarian and their physician to minimize the risks of transmission of a zoonotic disease. The information from this study should make it easier for professionals to estimate these risks for individuals. Guidelines for pet owners can be found on the Pets Are Wonderful Support (PAWS) website at http://www.pawssf.org. For caregiver guidelines, see the Centers for Disease Control website at http://www.cdc.gov/mmwr/PDF/RR/RR4810.pdf.

For further reading:

Spain, C., J. Scarlett, et al. (2001). Prevalence of enteric zoonotic agents in cats less than 1 year old in central New York State. J Vet Int Med 15(1): 33-38.