Why Does my Dog Have Patchy Bald Spots?
One of my Pit Bull rescues has patchy bald spots on his face. The vet has tested several spots on two separate occasions and consistently show negative for mange. Any ideas what else could be causing this?
You don't mention how old your dog is. If he is less than two years old, I am guessing that puppy mange is causing the bald spots.
Yes, I know, your dog twice tested negative for mange. But the test for puppy mange (which is caused by a mite called Demodex) occasionally yields false negatives. The test involves scraping the skin with a scalpel blade. This process harvests skin (and any parasites contained within the skin) from the affected area. The harvested sample is scanned under a microscope. If Demodex organisms are seen, the diagnosis is clear. If none are seen, then one of two things could be going on: either puppy mange isn't causing the spots, or no Demodex organisms happened to be present in the area that was scraped.
Puppy mange most commonly causes patchy baldness without skin irritation (the spots generally aren't red or itchy). The spots most commonly occur on the face. In my experience Pit Bulls are extremely susceptible to the syndrome.
If your dog's spots aren't bothering him and they aren't coalescing to take over his face, I recommend that you try to wait it out. Almost every dog outgrows the problem by two years of age.
For more information on the syndrome, go to my website:
Photo: no sign of puppy mange on Tank.