Dear Dr. John,
My old German Shepherd is getting close to the end of his life. Our veterinarian has done a great job of keeping him going as his hind legs have continued to weaken over the last two years. We have put him on Rimadyl twice a day and we have used slings to get him up and laid down mats to help him get a grip on various floor surfaces.
He has also had occasional loose bowels for which we have given him metronidazole from time to time. It works very well. Is there any reason why we can’t keep him on it to prevent the loose bowels? Lately, he has had a few bouts of a little blood on his stool. Our vet he suggested the same medication which I had leftover and it worked. What could now be causing the bleeding, and should we have it checked out? W.W.
Dear W.W.,
It’s reassuring to know that your dog has continued to do reasonably well. The NSAID that you have been giving him, Rimadyl, is relatively safe to use long term with regular assessments of liver function by way of blood tests since that class of drugs can potentially cause liver issues. Metronidazole is a commonly used and effective drug for gastrointestinal issues since it fights bacteria and is anti-inflammatory. Its specific use is to treat giardia and a few other protozoal infections. It is typically given for a course of 5-7 days and should not be used long term as doing so could lead to serious adverse effects. These include liver failure with jaundice and neurological issues such as ataxia, weakness, disorientation, nystagmus of the eyes, and even seizures. Abnormal heart issues can also occur if used at too high a dose or for too long.
Speak with your veterinarian about options to treat the loose bowels such as bland diets, probiotics, etc. The recent blood seen in the stool could be due to many things. It could be a sign of some irritation or colitis, your dog may have eaten something that caused a little bleeding, or there could be something such as a polyp in the colon or rectum. If it continues, I would have it assessed by your veterinarian.
Dr. John de Jong owns and operates the Boston Mobile Veterinary Clinic. He can be reached at 781-899-9994.
