We just rescued some feral kittens and their mom after a recent blizzard which fortunately trapped them inside one of our outdoor shelters. The kittens all have the exact same missing hair on the tips of their ears and last half-inch of their tails. What could this be? There is a black sludge on the skin which I've scraped off. Underneath the skin seems healthy and the spots do not fluoresce under a black-light so I'm assuming it isn't Ringworm, right? Have you seen this before?
Hairless Ferals in Minnesota
First off, congratulation on your resourcefulness of getting the cats while they were in the shelter, and getting mom too! You are correct to be on the look-out for Ringworm but what you are describing sounds like frost-bite from my experience. The tips of the ears and tail get the most exposure to the cold due to minimal blood flow to those areas. The black sludge is probably dead skin since you say it looks healthy underneath. It sounds like they are on the road to recovery but by all means see a vet if the skin stops looking pink and healthy. Hopefully the hair will grow back and they should be ok. I'll bet mom and kittens are all happy to be inside and away from the Minnesota winter temps. All the best, Mike