Sarcoids

Sarcoids are one of the most common growths found on horses, the cause is not fully understood but a viral cause is suspected. Once a horse has developed one sarcoid that horse is predisposed to developing more sarcoids, however they are not known to be contagious. 

They typically occur in areas from the tail beneath the back legs, along the midline of the belly, between the front legs and around the head. These areas may be most affected because they are the most hairless. A definitive diagnosis can only be made by looking at a biopsy, or tissue sample, under the microscope. No one treatment is suitable for all sarcoids and it is essential that individual cases are assessed by a vet to ensure that the best treatment is selected. Various treatments are used by vets including banding with rubber rings, cream applied onto the sarcoid. drug therapy injected into the sarcoid, surgical excision and freezing. It is occasionally possible to successfully remove all of a horse's sarcoids but in many cases the treatment results in control rather than resolution of the lesions.

There are various types of sarcoids

Occult Sarcoids- These are flat, hairless, lichen-like, slightly dry and crusting, dark patches. They often have a smooth, dark hairless area around them. They are most common on the inside of the upper hind legs, the neck and around the eyes.

Verrucose - These are raised, knobbly, dark areas that often spread into poorly defined margins. They can also be ulcerated on occasions.

Nodular - These are firm and nodular skin lumps which may have normal skin over them.

Fibroblastic- These are often ulcerated, weeping, raised sore lesions that may develop a stalk and become cauliflower-like.

Ulcerated fibroblastic - on a horse's sheath

Mixed - a mixture of two or more of the forms described above.

Malevolent- These are rare, invasive sarcoids that invade deeper tissues beneath the skin