It’s something that even your vet may not know. A parasite that is common in cattle, Tritrichomonas foetus, has been causing a lot of problems in domestic cats. Because the parasite is hard to detect, many cats may be getting misdiagnosed, just like my own.
Tritrichomonas foetus, commonly referred to as either TF or Tritrich in cat circles, is a protozoan parasite that causes stinky gas and soft smelly stools in both kittens and cats. It can be a cause of feline diarrhea but soft cow pie-like stools with a bit of blood or mucus are more common.
TF is easily mistaken for Giardia, a similar protozoan with a different treatment protocol. Because TF is hard to find in stool samples, lab reports are frequently inconclusive. This means the condition could be easily misdiagnosed as probable food allergies or inflammatory bowel disease (IBD).
My own experience with TF came with an Abyssinian kitten I bought from an ethical breeder with a good reputation. The kitten, Nigel, had been examined by a vet and had a health certificate. His only issue was really foul gas. A month later I noticed that he sometimes had diarrhea too but it wasn’t ongoing, just intermittent.
But I did mention the diarrhea to my vet when I took the kitten in for a wellness check. The fecal sample was negative but the vet offered de-worming liquid anyway based on his symptoms. Otherwise, Nigel was found to be healthy. He had a good weight, appetite and coat condition.
As the kitten got bigger, he continued to have intermittent stool problems and bad gas. The smell was horrific. His stools were usually soft, not liquid. Sometimes he passed a bit of bloody mucous at the end of his bowel movement. My vet assumed the wormer hadn’t worked and offered a Drontal injection that he said would take care of it. It didn’t.
By the time Nigel was old enough for his neuter, my old vet had retired and I switched to new clinic. I mentioned his problems and they sent his stool to an outside lab for analysis. The results came back as Giardia. I didn’t have a clue where he could have picked up Giardia but I got the medication.
Nigel didn’t have any soft stools for about three weeks after the Giardia treatment then the soft smelly stools and foul farting started up again. You could smell it all over the house. The vet started talking about IBD and food allergies and recommended I begin some food trials.
About this time, I was looking into getting another kitten. My breeder had retired but recommended Tracy Fasciana of Abayomi Abyssinians. While googling Fasciana on the internet, I came across an article she had written on TF . There it was! That was what Nigel had. Fasciana gave a link to Dr. Jody L. Gookin’s website.
Gookin is an expert on Tritrichomonas foetus. In 2004, she co-authored a study on fecal samples taken at an international cat show. It revealed the shocking results that 31 percent of the cats studied were infected with TF. Some were symptomatic and some not. Further studies demonstrated that the only medication proven to resolve TF is Ronidazole but it is not FDA approved for this purpose.
I immediately took a fecal sample to my new vet and asked to have the lab test specifically for TF, something the vet was not very familiar with and did not know was becoming more prevalent in the feline population. The test took two weeks but came back positive. At least I knew what I was dealing with. But I immediately ran into problems arranging for the medication.
I knew from reading Gookin’s studies that Ronidazole was the only medication to be effective against TF but because it was not FDA approved, my vet wanted to prescribe a trial of Metronidazole first. He eventually agreed to order the Ronidazole but we then butted heads over the dosage.
High doses of Ronidazole can cause neurological problems, Gookin found. She originally recommended 30 mg per kg of cat body weight twice a day. A few years later, she later revised this down to just once a day. Both my vet and my compounding pharmacy insisted I use the original high dosage because it is currently listed in the Plum Veterinary Drug Handbook. Against their advice, I opted to give Nigel the revised lower dose.
I then had problems when my compounding pharmacy made up the medication as a liquid instead of capsules. This medication is so bitter that Nigel gagged the moment it touched his mouth. It was two weeks of hell getting it down his throat even with sardine flavoring added. If you ever have to do this, do not get liquid or try to mix the powder with food! Stick with gel caps.
The two long weeks of Ronidazole treatment passed. It has been several months now and Nigel hasn’t had a soft stool since the third day into his treatment. His gas disappeared. The vet ran a fecal sample later and it was clean. He no longer has TF.
If I hadn’t treated Nigel, Gookin’s research suggests his soft stools would likely have resolved after about two years. But he still could have carried that parasite and given it to the other cats in our family. He might also have developed intestinal scarring and other complications.
I contacted his breeder soon after the initial diagnosis and she was horrified. You see, Nigel’s father had been diagnosed with TF but the breeder had treated him and thought he was clean. She offered to pay for Nigel’s treatment but I declined. If I had just called and talked to her in the first place, she could have told me what was going on. But I wish one of my vets could have told me instead.