Tritrichomonas foetus' is a single celled flagellated protozoan parasite that is known to be a pathogen of the bovine reproductive tract as well as the intestinal tract of cats. In cattle, the organism is transmitted to the female vagina and uterus from the foreskin of the bull where the parasite is known to reside. It causes infertility, and, at times, has caused spontaneous abortions in the first trimester. Cases of infection in cattle have declined due to the use of artificial insemination. In the last ten years, there have been reports of Tritrichomonas foetus in the feces of young cats that have diarrhea and live in households with multiple cats.
Tritrichomonas foetus in the genus Tritrichomonas within the order Trichomonadida in the Kingdom Protoctista. The parasite is 5-25 µm in size and is spindle shaped with four flagella which are whiplike projections and an undulating or wavy membrane. Their movement is jerky and in a forward direction. Tritrichomonas foetus looks like small tadpoles with small tails when viewed microscopically. The parasite interacts with bacteria that normally reside in the intestinal tract by adhering to the intestinal epithelium of the host.
Tritrichomonas foetus in cats is characterized by diarrhea that comes and goes and may contain blood and mucus at times. The diarrhea is semi formed in a cow pie consistency. In most cases it affects cats of 12 months of age or younger and cats from rescue shelters and homes with multiple cats. Close and direct contact appears to be the mode in which the parasite is transmitted. Tritrichomonas foetus is most common in purebred felines, breeds like bengals, persians, etc. Since catteries tend to trade queens and studs to provide greater genetic diversity the parasite is spread from one cattery to another. One easy way Tritrichomonas foetus can be differentiated from other common diarrhea is that is extremely maladorous. The smell is so awful it can trigger a gag reflex in people.
Diagnostically, Tritrichomonas foetus can be detected by two methods:
Treatment of the infection is difficult due to drug resistance. Traditional antiprotozoal drugs such as fenbendazole and metronidazole do not alleviate the symptoms. Some antimicrobial drugs have been shown to improve symptoms but do not eradicate the parasite.
Dr. Jody Gookin at North Carolina State University, College of Veterinary Medicine, has published research on the effectiveness of the drug ronidazole . The Owners Guide contains valuable information on diagnosis and treatment with the drug. Currently there is no drug specifically indicated for t. foetus in felines, and ronidazole treatment is considered off-label usage. Ronidazole has had good efficacy in eradiation of the parasite in felines. Care should be used when administering the drug. Exact dosing is essential, and caplets are recommended over suspension to increase dose accuracy. Additionally, ronidazole has the potential for a variety of side effects, most importantly, neuroligical side effects. During treatment, the cat should be engaged in play activity regularly to ensure they are not experiencing neuroligical side effects, or motor skills impairment. Two weeks of ronidazole, 30 mg/kg, twice daily, is currently the recommended dosage. NOTE: AS THIS TREATMENT IS CURRENTLY OFF-LABEL USAGE IT SHOULD ONLY BE PRESCRIBED, AND TREATMENT MONITORED, BY A LICENSED VETERINARIAN.
Care should be exercised while handling ronidazole, which is toxic to humans.
During treatment, the feline should be keep isolated from other cats as to prevent the spread to another cat (typically transmitted by an infected cat sharing the same litter box as other cats). The cat should be fed a veterinarian prescribed dry-food diet, preferrably of high fiber content. Wet food should be avoided. A common GI diet remedy in cats (boiled chicken breast, white rice, and pumpkin) may be highly beneficial during and after treatment.
It has been shown that most cats show improvement and no signs of infection within 2 years of onset. It appears that over time the parasite dies off and the infection is remedied on its own. In some cases, the symptoms may improve over time, but the animal is likely to still be a carrier of the parasite, capable of transmitting it to another cat.
Treatment with ronidazole has shown good efficicy, and some positive results may be achieved after just 2–3 days of treatment. Ensure that you complete the 2 week cycle of drugs. If even one t. foetus organism remains there could be a recurrance. It is essential that a PCR test be conducted after treatment to verify that the organism has been completely eradicated. It is also recommended that a followup test be performed a few months after the first.
During and after treatment a special diet may be required. Since the organism resides in the colon of the feline, long-term infection may cause excessive damage to the colon. Do no dispair if you cat still has diarrhea after treatment. If the foul smell is gone, and its a slightly different fecal consistency then you may indeed have eradicated the parasite, but now have to deal with the colon damage.
A common feline diarrhea remedy is a home-made diet of: boiled chicken breast, steamed white rice, and canned pumpkin. Simply mix up the ingredients and serve. Start out with a small amount of pumpkin (1 tbsp is recommended by most veterinarians for an average sized cat), and increase as needed. DO NOT give the cat too much pumpkin or he/she may become constipated. Make sure the canned pumpkin does not contain any additives - the only ingredient should be pumpkin.
Try to use foods that are high in solulable fiber, 8% or greater. You may also try adding psyllium husk (as directed by your veterinarian) to the regular diet. There are very few cat foods on the market with such a high amount of fiber. One suggestion is Royal Canin Indoor Light 40. Another is Royal Canin Intense Hairball 34, both with >8% fiber. This particular food actually has psyllium husk in the food, put in during manufacturing.
The special diet may be required for several months, depending on the length and severity of infection.