Linear Keratosis

Recently, one of our horses was diagnosed with the dermatological condition of equine linear keratosis. It was with great difficulty that the condition was properly diagnosed. That’s why, I thought it might be helpful to share our experience, in case there are other horse owners out there who are baffled by the same equine skin disorder.

Our mare is a 2007 model which we purchased from a reputable breeder. Upon picking her up, we discovered a fungus-like patch extending from her right wither down to her right gaskin. The condition did not seem to be bothering her (it wasn’t itchy), however if it was a fungus that could be transferred to another animal, this was a concern to us. Therefore, following several veterinarian examinations and various topical anti-fungal preparations, one of our vets suggested that we do a skin biopsy. This test produced accurate results. And while knowing what we were dealing with was a huge relief, we couldn’t help but feel slightly forlorn when we finally did get a proper diagnosis.


Equine Linear Keratosis occurs as vertical linear areas of alopecia (or near alopecia), scaling and crust formation on the sides of the horse’s neck, or shoulder or chest. The condition is characterized by the gradual development of annular areas of alopecia, usually in a linear, vertically oriented configuration. In our mare’s case, her shoulder looked as though someone had spilled a chemical down her body – a scenario we even considered for a while. The lesions are usually 2 to 10mm wide by a few cm to more than 1m in length. The lesions are neither painful nor pruritic. Our horse isn’t itchy and the skin seems healthy otherwise. Linear keratosis accounts for 0.67 per cent of the equine dermatology cases seen at the Cornell University College of Veterinary Medicine. Meaning, the condition is very rare.


Since the diagnosis, we have learned that it is possibly a hereditary condition and it may never disappear. However, linear keratosis is not contagious and luckily, it cannot pass from our mare to her stable mate or any other horses she may come into contact with. And aside from its blemish appearance, our mare’s skin disorder really doesn’t affect her. She is not sore in that area and it had never affected her training.

Linear keratosis is something I will continue to investigate and as I learn more, I’ll keep you posted!


3 thoughts on “Linear Keratosis”

  1. My gelding also has this, however his progressed differently and his does itch him. We are still in the recovery process, but he is slowly getting better.

  2. I have a young thoroughbred filly who developed this problem since I purchased her. Definitely it is itchy for her and by biting at the lesions she makes a more pronounced scab. What a mess – if anyone has any proven remedies I am most interested to hear of them.

Leave a Comment

Your email address will not be published. Required fields are marked *

Shopping Cart