Pastern Dermatitis

The dog days of summer are upon us which bring heavy morning dews on the grass in our pastures and this dampness is prime for the development of pastern dermatitis in our horses.  Pastern dermatitis, also known as scratches, dew poisoning, or mud fever, is caused by a bacteria or fungi or the combination of both and can be difficult and painful to deal with. Scabs or crusty lesions form on the heels and pasterns and can sometimes go unnoticed until the horse begins to stock up. While more regularly seen on white legs, it can affect horses with dark legs as well but is not as easily noticed without regular inspection.          

     

Providing a clean, dry environment will best avoid this condition.  Keep your horses stalled or in a dry lot until the sun dries the dew off the grass will help, and dry their legs well if you bring them inside in the mornings. If your horses have longer hair of feathering on their pasterns, clipping that hair shorter will decrease the chance of development.  Also, make of practice of checking their heels daily to see if scab formation is beginning.

Prevention is ideal, but many horses develop dew poisoning “overnight” and we then have to focus on a treatment plan. First, clip the area to remove the excess hair, but do not shave down completely down to the skin. Wash the affected areas well with a medicated (antibacterial or antifungal) shampoo and allow to set for about ten minutes before rinsing.  Gently massage off the scabs that have been loosened, taking care not to pull or tear any stubborn scabs off. Dry the area well and apply an ointment with anti-bacterial or anti-fungal properties that will help the healing process. Zinc-oxide based ointments will help to soften the remaining scabs and protect the area from dampness when the horse is turned back out.

In mild cases where treatment begins in the early stages and is consistently followed-through with, the condition should completely clear in a week or two.  For more severe cases where cellulitis develops in the legs or lameness occurs, a more intensive treatment plan that includes systemic antibiotics may be required.  As with any health issue, having a strong client-patient relationship with your veterinarian is important in order to create the most effective plan of treatment when problems do arise.

 

References:

https://vet.purdue.edu/vth/large-animal/equine-health-tip-understanding-and-treating-scratches-in-horses.php

 

https://thehorse.com/14634/dew-poisoningscratches/