The protozoan Tritrichomonas foetus (TF) is a common cause of chronic diarrhea in young cats. It is more common in cats that are housed together, such as those in shelters or catteries. For instance, a study published in 2004 found almost one-third of cats attending an international cat show were found to be infected with this organism.
Previously, there had been no effective treatment reported for T. foetus infections. Recently, veterinarians at North Carolina State University, College of Veterinary Medicine, Raleigh, NC evaluated the use of ronidazole (RDZ) for treatment of this infection in cats.
Ten 10-week-old neutered female cats who were infected with T. foetus and had signs of loose feces were randomly assigned to two groups. One group received a low dose of RDZ and the other group received a placebo for two weeks. The low dose treatment with RDZ caused initial improvement, but each treated cat relapsed after treatment was completed. Both groups then received a higher dose of ronidazole, and nine of the ten cats were cured.
-- Gookin, J; Copple, C; Papich, M; Poore, M; Levy, M. Efficacy of Ronidazole in vitro and in vivo for Treatment of Feline Tritrichomonas foetus Infection. Journal of Veterinary Internal Medicine 2005; 19(3):436.