Tritrichomonas foetus in cats – signs and treatment

Updated 2026-09-30 · 1 sources

Based on: International Cat Care (iCatCare)

Book a vet visit

Book a vet appointment if you think your cat has this – a vet needs to confirm it and plan the treatment. It is an infectious condition in cats that can cause diarrhoea.

What to do now

What you can do now

  1. Contact your vet
  2. Note when it started, how often it happens and what else you see
  3. Take a photo or short video to show the vet
  4. Keep fresh water available
  5. Let your cat rest somewhere calm

Don't

  • Do not give any human medicine
  • Do not wait if it gets worse

What it is

Tritrichomonas foetus infection can cause diarrhoea in cats.[1] It is more commonly seen in young cats and kittens, and most affected cats come from rescue shelters, pedigree breeding colonies and multi-cat households.[1]

Signs

  • Passing faeces more often than usual, often in small amounts
  • Fresh blood or mucous in the faeces
  • An inflamed, painful anus with severe diarrhoea
  • Faecal incontinence, meaning loss of control when holding in faeces

Causes and risk factors

  • Young cats and kittens
  • Rescue shelters
  • Pedigree breeding colonies
  • Multi-cat households
  • Young pedigree cats, particularly Bengals and Siamese

How a vet finds out

  • Physical examination
  • Blood tests
  • X-rays
  • Ultrasound
  • Faecal test, including testing a fresh faecal sample
  • Culture

How vets treat it

  • Antibiotics
  • Diet change
  • Antiparasitic treatment

Breeds prone to this

Veterinary charities list these breeds as more likely than others to get this condition. Each breed page lists the inherited conditions documented in the breed.

Bengal catSiamese

What the experts say

“Your vet will need to test a fresh faecal sample to diagnose T. foetus infection. There are three tests commonly used: Faecal or rectal smear – your vet will examine your cat’s faeces under a microscope to look for evidence of the parasite.”

— International Cat Care (iCatCare) [1]
If your pet is struggling to breathe, has collapsed, is having a seizure or can't stand up: go to the nearest vet now.

Not sure how serious it is?

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Common questions

How will a vet find out if my cat has this?

Your vet will need to test a fresh faecal sample; a faecal or rectal smear may be examined under a microscope for evidence of the infection.[1]

Does every cat need treatment?

It may not be necessary to treat all cats because the diarrhoea usually resolves over time and is often more of an inconvenience than a cause of significant illness.[1]

Which cats are more likely to be affected?

It is more commonly seen in young cats and kittens, and most affected cats come from rescue shelters, pedigree breeding colonies and multi-cat households.[1]

Sources

  1. International Cat Care (iCatCare)

How this page was made: written with the help of AI from the sources below, then checked claim by claim against those sources. Urgency levels follow OkPaw’s fixed safety rules. It is guidance, not a diagnosis. How we write our pages

Other conditions in cats

Urethral ObstructionWormsAnaemiaAnaphylaxisAntifreeze poisoningArthritisAsthmaAtopic DermatitisBladder infectionBlindnessBordetella Bronchiseptica InfectionCardiomyopathy