Hair loss

I have a 1 year old colt that has developed hair loss on the face, neck and spots on the belly. It looks similar to mange that you would see on a dog. What would be the best way to treat this? Should I be ...I have a 1 year old colt that has developed hair loss on the face, neck and spots on the belly. It looks similar to mange that you would see on a dog. What would be the best way to treat this? Should I be ...

Story originally posted by: Michael Lowder, DVM, MS

Dr. Lowder,

I have a 1 year old colt that has developed hair loss on the face, neck and spots on the belly. It looks similar to mange that you would see on a dog. What would be the best way to treat this? Should I be concerned about the two other horses in the pasture with my colt getting this?

Any help would be greatly appreciated.

Sincerely,
Alice

Dear Alice,

Hair-loss (or alopecia) in horses can be a clinical sign of several skin diseases. Primary diseases to consider are ringworm (or dermatophytosis) that causes areas of hair-loss on the head, neck, and trunk (especially under saddles or bridles) and is more common in younger horses. This disease is zoonotic (can spread to other animals as well as people) so you should keep you colt isolated from other horses and wear gloves when working with him.

Another potential cause of the hair loss is 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). One of the most common clinical signs of this condition is that the hair comes off easily, usually in crusts with the hair attached. These crusts contain infectious bacteria that may be infectious to other horses. Factors that predispose animals to this condition are wetting of the skin and trauma.

To treat this condition or to treat ringworm, you must use a special shampoo. 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.

Other potential causes of the hair loss are folliculitis (a bacterial infection of the hair follicles), pemphigus foliaceus (an autoimmune disorder), and zinc-responsive dermatosis (a condition which responds to zinc treatment). Horses can get a condition similar to mange called acariasis. Typically, this condition is very itchy.

If your colt’s skin appears to be itchy, you should call your veterinarian for diagnosis and treatment. If your colt’s skin does not appear to be itchy, I would recommend using the special shampoo I mentioned for 3-4 weeks and if the skin condition does not resolve or worsens, have your veterinarian look at your colt.

Thank you,
Dr. Lowder