What Causes Diarrhea of Unknown Origin in Cats?


green eyes catPaulo Brandao | more info (via: Wylio)
Dear Dr. Barchas,

I have a nine year old cat named Oscar. He’s had a problem with very loose stools for a while now. I’ve had him to the vet twice and both times analysis of his stools were negative.

The vet gave him a shot for the diarrhea and put him on metronidazole for 5 days. The diarrhea didn’t stop and the second time he was put on the metronidazole for 10 days. The diarrhea stopped for about a week, but now it’s back.

Do you have any suggestions before I bring him in for a third time. The vet says it may be “duo” diarrhea of unknown origins!!!

Thanks so much,

Scarsdale, NY

I think it may be a little bit premature to call Oscar’s problem diarrhea of unknown origin. Technically I suppose the term is correct at this point since the cause is not yet known, but I believe a bona fide attempt should be made to find out what is causing the problem before giving up on finding out what’s wrong.

Many things can cause diarrhea in cats. Common causes include parasites, glandular problems like hyperthyroidism, metabolic issues such as liver or kidney problems, inflammatory bowel disease, food intolerance, pancreatitis, medication reactions, and stress to name but a few.

I would not recommend another course of medication without first making a concerted effort to get to the bottom of the cause. Basic blood and urine tests will assess the function of the thyroid gland, liver, and kidneys. Slightly more advanced blood work (a combination of tests called fPLI, TLI, cobalamine, and folate) checks for pancreatitis and certain intestinal issues. DNA testing of the feces can check for hard-to-find parasites and pathogenic bacteria. X-rays and ultrasound of the abdomen can give a an indication of whether intestinal problems such as inflammatory bowel disease are at work.

In other words, there are many things that could be going on and many tests that have yet to be run. Until some of the tests have been run it is too soon to say that the origin of the diarrhea is unknown.

Be aware that diarrhea may be a symptom of certain diseases that can have other deleterious impacts on the body. If you treat the condition that is causing the diarrhea, rather than simply treating the diarrhea, you may spare Oscar from those impacts.

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