Q: Dear Dr. Richards,
Have you ever heard of a cat's fur changing colors in isolated areas due to a medication, treatment or test being administered???
My grandmother is extremely concerned that her cat Eloise's fur has changed from black on her back to a reddish brown. This happened after a visit to UC Davis to determine if she might have inflammatory bowel disease. Eloise's brother - Peter - died a year ago, and my grandmother is quite distraught at the prospect of losing her other "child". She asked me to find out anything I could about it using the internet. Can you help?
It might be a good idea to have the cat's serum protein value checked. Inflammatory bowel disease can lead to difficulty absorbing protein or vitamins and low serum protein can cause a reddish discoloration of the haircoat.
It wouldn't surprise me if some medications can do this, too. I just don't know of any, offhand.
Mike Richards, DVM