Standard testing may overlook intestinal parasite in cats

Q:My kitten had chronic diarrhea, despite negative fecal testing and several deworming treatments. Finally, the veterinarian diagnosed Tritrichomonas and started medication that seems to be working. What is Tritrichomonas?

A:Tritrichomonas, nicknamed “tri-trick,” is a one-celled protozoal parasite that spreads among cats by fecal-oral transmission. Most often, a cat acquires the parasite by licking its paws after using a contaminated litter box or by grooming or nursing from an infected cat.

Tritrichomonas causes intermittent or chronic diarrhea. The stool may be watery to semi-formed, and it may contain blood or mucus. The anus may be red, and the cat may defecate frequently, strain in the litter box or exhibit fecal incontinence. Some affected cats vomit, show no interest in food and lose weight.

Standard fecal testing does not detect this parasite, so special fecal tests are required. The most sensitive of these is the PCR test. All of your cats should be tested, because carriers that appear healthy can still spread the parasite.

The treatment of choice is a medication called ronidazole, given once daily for two weeks, plus a probiotic. Testing is repeated after treatment to be sure the Tritrichomonas has been eliminated.

Fortunately, most disinfectants kill Tritrichomonas, so frequent litter box cleaning helps control an outbreak. It's always good to be prepared with cat insurance!

Lee Pickett, V.M.D. practices companion animal medicine in Pennsylvania. Contact her at askdrlee@insurefigo.com.