Tritrichomonas foetus (T. foetus) is increasingly recognized in cattery environments. As a result, it is pertinent that cat owners be aware of this parasite and what it means for the multi-cat environment. Let’s go over some of the most common questions associated with T. foetus.


What is Tritrichomonas foetus?

T. foetus is a relatively newly discovered single-celled parasite in cats. The parasite was identified in the United States in 1996, when it was isolated from cats with chronic diarrhea. 

In catteries, T. foetus appears to be a fairly common parasite, where it is associated with diarrhea in especially young animals.

T. foetus "lives" in the large intestine, whose main function is to absorb liquid from the digested food; therefore, nutrient absorption, which takes place in the small intestine, is not affected, and does not result in delayed growth in kittens or emaciation in adult animals.

What are the symptoms of Tritrichomonas?

It is not unusual for T. foetus to be detected in adult, healthy animals without manifesting as a clinical problem.Occasionally, however, foul-smelling diarrhea is seen that resembles cow poo and may be mixed with blood and/or mucus.
The symptoms occur intermittently, and in more severe cases, can cause anal incontinence. The cats are often alert despite showing symptoms.

The older cats usually seem healthy and sound, apart from the cow-poop-like diarrhea, which tends to have slimy streaks. The diarrhea comes in periods and smells very bad, and some individuals leak diarrhea from a severely inflamed rectum.
T. foetus is most concerning in kittens, where symptoms vary. Some kittens get really sick and die from dehydration, while others stay healthy as long as they stay with their mothers, but only get sick when they move.

Survival in the environment: What kills Tritrichomonas?

T. foetus  doesn't survive long outside the cat's body;therefore, infection does not build up in the environment in the same way as Giardia.

The organism survives up to a week in wet faeces at room temperature.

Survival for Tritrichomonas is:

  • Water 30-60 minutes
  • Urine >3 hours
  • Dry food 30 minutes
  • Wet food 2-3 hours
  • Dry cat litter 0 minutes
  • Filter paper 5 minutes


Is Tritrichomonas contagious to other cats?

Yes, T. foetus is very effectively transmitted via faeces, so it can be assumed that cats that share a box with one or more infected individuals are also/become infected; however, it does not live as long in the environment as e.g. giardia, thus is not as easily transmitted.


Can cats give humans Tritrichomonas?

T. foetus does not infect humans.


What percentage of cats have Tritrichomonas?

Studies show that T. foetus occurs in all types of cats.

The parasite has been detected in the USA (study 31 percent of cats at an exhibition),

Switzerland (20 percent of healthy cross-section), and Norway (21 percent of healthy show cats).


How is Tritrichomonas treated?

As far as it's known, there is currently no drug registered for treatment against T. foetus.

Ronidazole, which is available as a licensed preparation, often has a good effect.

However, due to the risk of side effects and potential neurotoxic and teratogenic effects in humans, ronidazole should be used with caution.The powder form of the drug should be avoided.

Treatment with diet and probiotics can have a positive effect on the symptoms.

Even treatment with metronidazole can provide a temporary improvement clinically.

In groups where the organism has been identified, consideration should be given to reducing the group as diarrhea that occurs with T.foetus infection appears to be clearly related to stress. 

From the point of view of the spread of infection, it may be of value to investigate the effect of treatment with breath sampling.

Untreated cats usually become symptom-free within six months to two years but can continue to be chronic carriers and pass the infection on.

It is suspected that the presence of the organism for an extended period of time in the intestine paves the way for inflammatory bowel diseases.


What is recommended for remediation of the environment in connection with Tritrichomonas?

Since Tritrichomonas is sensitive to oxygen and dryness, today no special measures beyond normal surface cleaning are considered necessary in the cat's immediate environment.
However, you should clean the litter boxes thoroughly daily and preferably spray them and surfaces where the cats stay.

Textiles are washed at 60° C. 

How can I prevent Tritrichomonas?

The three most important points to protect cats from infection:

  1. Establish quarantine for new cats entering the cattery.
  2. Limit the total number of cats in the cattery and establish smaller groups of cats without mutual contact.
  3. Have many litter boxes. According to the Swedish Agricultural Agency's animal welfare regulations, there must be at least one litter box per two cats. Clean them daily.

Does Tritrichomonas affect fertility?

There are indications that treatment with Ronidazole may have an impact on the animal's fertility for a longer period of time after treatment.
There are also studies that show that Tritrichomonas can occur in the uterus of females in cases where the cat is infected with the parasite, which can lead to difficulty getting the female pregnant and stillbirth.



T. foetus is a parasite that needs to be diagnosed and treated in a cattery environment, where it is most likely to adversely affect kittens. Cattery protocols should involve testing cats, quarantining, and regularly sanitizing surfaces and litter boxes. T. foetus treatment requires Ronidazole in compounded or tablet form, carefully administered due to the seriousness of the drug’s potential long-term effects. 


Interesting discovery
A cattery sold a young cat, and when the new owner tested the cat who was quarantined in the new home, it was discovered that this cat had T.foetus.
The breeder who sold the cat then started testing all cats to see who was infected and who was not infected.

Worth mentioning is that cats F and G have been tested several times during a two-year period. Cat F has been tested free 5 times and Cat G has been tested free 4 times.
T - This means they met, and they have been living together either as adults or as kittens.
P - Means those cats have been mated with each other.

A "-" Means that those cats never met at all.

Red cat means that this cat tested positive for T.foetus.
Green cat means this cat is tested free, and no T.foetus has been found in the sample.

Green cell means there is no contamination either because the cats have not met each other or because both cats are free and are therefore not able to contaminate each other.
Blue cell means those cats have met, one is affected and still, the other cat has not been affected.
Red cell means that both cats are affected and they met.

The conclusion when all cats have been tested is that the source of the infection is Cat A and the only logical explanation is that Cat A been infected before arrival and has been carrying this since the arrival 4 years ago. For some reason, this cat did not get rid of the infection herself, which might happen in some cases.

Also worth mentioning is that none of those cats have any form of symptoms, they never had a loose stool, and they never had any particular smell, when collecting poop however a smell could be felt from one of the collections.



By:Malin Sundqvist