Q: Miso, our 3-year-old pit bull mix, had diarrhea for almost 14 months after we adopted him from the shelter. For 6 months he did OK on a special diet and only occasionally had severe problems. We stopped all of his chew toys and tried several doses of different antibiotics — everything works well for awhile, and then he relapses.
Our veterinarian suggested a biopsy which we are considering. He is currently on Flagyl and doing well, but now our veterinarian wants to switch him to Tylan that we mix with his food. We aren’t sure what to do at this point. Suggestions?
A: Chronic diarrhea can have multiple causes and an ever-increasing number of treatments. Viral and bacterial infections, dietary allergies or intolerances, cancer, parasites and intestinal motility disorders are just a few of the broad categories that can cause this problem in dogs. Your veterinarian may have already ruled out many of these as potential contributors to Miso’s issues, but some diseases require a more invasive test that requires a tissue sample or biopsy to make an accurate diagnosis. You should pursue the biopsy on the advice of your veterinarian if at all possible.
In some situations, medications such as Flagyl or Tylan can be helpful. Tylan is especially useful in dogs that require long-term management and, as a powder, it is relatively convenient to use when sprinkled on your dog's daily food. It historically was prescribed only to large animals and chickens, but with a wide margin of safety and high success rate, it is often the drug of choice for chronic diarrheas in canines even if a dog is being successfully managed on another drug.