Scabs with hair loss on body.

My mare is 4 years old almost 5. I live in Oregon. She is stabled indoors and gets to go out in an indoor arena only when it is raining like it is right now. My problem with her is that she has small scabs about the size of a large pin head coming off her skin with the hair attached to it. You can feel the bumps and as soon as you run your nail over them the scab and hair comes off.My mare is 4 years old almost 5. I live in Oregon. She is stabled indoors and gets to go out in an indoor arena only when it is raining like it is right now. My problem with her is that she has small scabs about the size of a large pin head coming off her skin with the hair attached to it. You can feel the bumps and as soon as you run your nail over them the scab and hair comes off.

Story originally posted by: Michael Lowder, DVM, MS

Dr. Lowder,

My mare is 4 years old almost 5. I live in Oregon. She is stabled indoors and gets to go out in an indoor arena only when it is raining like it is right now. My problem with her is that she has small scabs about the size of a large pin head coming off her skin with the hair attached to it. You can feel the bumps and as soon as you run your nail over them the scab and hair comes off.

They are all over her right side with just a few on her left side. I have tried using everything I can think of to clear it up and can find nothing that works. She has also got a new problem that I do not know if it is connected to the other problem or not. She scraped her leg a little about a month ago and it has never really healed just scabbed over. I noticed yesterday that her whole leg is all swoolen and a little bit warm. but not in the hoof.

I tried to pick off the scabs on her leg yesterday and it was like real sticky in the fur and kind of grainy. And the hair just peels off where there is no scab. It is not proud flesh. Please could you give me any advice at all.

Thank you,
Jean

Jean,

The condition you describe sounds most like a disease called dermatophilosis caused by a bacteria (Dermatophilus congolensis). This disease is also known as "rain scald", "rain rot", and "lumpy wool" (in sheep). Factors that predispose animals to this condition are wetting of the skin and trauma. The crusts with hair that you describe are shed into the environment and harbor the bacteria that can then re-infect your horse or infect other horses.

To treat this condition, you must remove these crusts using a special shampoo. Do not put the crusts into the environment or your horse may become re-infected. Either a chlorhexidine or povidone iodine shampoo will be effective. Scrub the hair (entire coat, including legs) very thoroughly with the shampoo. Let the shampoo sit on your horse for 5-10 minutes before rinsing off.

Use the shampoo daily until the lesions are gone and then 2-3 times a week for 1 more week after the lesions are gone. Systemic antibiotics may be needed in severe cases (see your veterinarian if the infection does not clear up). This condition is most often seen over the back, sides, and on the extremities of horses so it may be contributing to the problem on your horse’s leg.

One of the most common clinical signs of this condition is that the hair comes off easily, so it sounds as if the bacteria may have infected the leg as well. Antibiotics may be needed in your horse’s case.

Thanks,
Dr. Lowder