9539 Liberty Road, Frederick, MD 21701
Phone: 301-898-4009 ~ Fax: 240-668-3664
Gentle, complete veterinary care for the felines in your family
Link map for Frederick Cat Vet for directions, hours, bio of the veterinarian and staff, veterinary services offered and a tour of the veterinary practice

Zoonosis is any disease that is transmitted from animals to people. Below are the most common infectious organisms in cats that can cause zoonotic disease:


What is it?: The most common ones are roundworms and hookworms.

Where does it come from?: Cats can acquire these as nursing kittens, eating rodents and birds or by grooming contaminated soil from their paws. As with cats, ingestion of the microscopic parasite eggs will cause an infection in people.

What problems does it cause?: Cats usually develop vomiting or diarrhea. In people, the disease can be much worse as the parasites migrate throughout the body.

Take-home message: The Center for Disease Control (CDC) recommends at least annual testing for all cats by submitting a fecal sample to your veterinarian. Revolution ® is an effective topical monthly control against these parasites and should be given to at-risk cats.


What is it?: The three major zoonotic bacteria in cats are Campylobacter, Salmonella, and E-Coli. Giardia is a protozoal organism that also infects people.

Where does it come from?: Ingestion of contaminated food, soil or water.

What problems does it cause?: These usually cause severe diarrhea and sometimes vomiting, in both people and cats.

Take-home message: All cats have bacteria in their intestinal tracts, most of which are beneficial, so antibiotics are given only when needed. Routine sanitary methods including washing hands will prevent any transmission to people. Special care needs to be given with small children, especially when new cats are introduced into the household.


What is it?: Ringworm is not a worm at all but a fungal infection. The fungus lives in hair follicles.

Where does it come from?: Ringworm is acquired from direct contact of infected spores present in infected grooming equipment or brushes, contaminated boarding facility, or the outdoor environment.

What problems does it cause?: In animals the lesion looks like a dry scaly bald spot. In humans it makes the signature round red lesion with scales on the outside of the ring. The spores can live for 18 months in the environment, making it difficult to eradicate from an area. Some animal can be carriers and never show any signs but still transmit the disease.

Take-home message: Ringworm is not usually debilitating but can be quite a nuisance. Early detection of possible lesions are essential for good management. Treatment is very effective but takes 4-6 weeks.


What is it?: Toxoplasma gondii is a protozoa that lives in cats' intestinal tracts.

Where does it come from?: The two most common causes of exposure for people are from infectious eggs in raw vegetables and meats and through gardening. A cat's litter box is also a concern but of much less risk.

What problems does it cause?: It is of greatest concern to the human fetus and immunocompromised individuals. Human signs are fever, swollen lymph nodes, muscle stiffness, joint pain, swollen liver, and spleen. It can cause severe problems or death for a human fetus.

Take-home message: It is recommended by the CDC that at-risk people should wear gloves while gardening or changing the litter box, or this duty can be passed to another person. Good hand washing and thorough cooking of meat can prevent this problem in the kitchen. There is no reason to get rid of a cat because of the concern about toxoplasmosis. Studies have shown that cat ownership does not increase risk of acquired toxoplasmosis in HIV-infected people, for whom this disease is of great concern.


What is it?: Rabies is a deadly virus that affects all mammals.

Where does it come from?: It is carried in the saliva of infected animals, so bite wounds are the most common source of transmission.

What problems does it cause?: The virus is reproduced in the central nervous system, so it causes abnormal movements, weakness, limping, seizures and severe personality changes including aggression.

Take-home message: This disease is on the rise in the United States as new homes encroach on wildlife habitats. All cats should be vaccinated against this disease. An unvaccinated cat with possible exposure to a wild animal or with a bite wound of unknown origin is considered a rabies suspect, and this situation can result in a long quarantine or euthanasia for rabies testing.

-Rob Kirkpatrick, CVT and Mike Karg, DVM