by Sara Jackson

Created on: July 01, 2009   Last Updated: July 02, 2009

Sarcoids are skin tumors found on horses that are usually benign. These tumors are quite common and can be found on the tail, under the back legs, along the horse's midline, chest and head. All breeds of horses can become affected with sarcoids at any age. Though most cases are first diagnosed or seen in horses between the ages of 2 and 10 years old.

Sarcoids have no known cause, but a viral infection is suspected, especially the bovine papillomavirus types 1 and 2. An individual horse can accumulate anywhere between one and several thousand sarcoids at a time. While it is not known whether or not sarcoids are transmittable between horses, but what is known is that sarcoids do not spread to the internal organs.

There are five different types of sarcoids:

1. Occult Sarcoids-

Characteristics include flat, hairless, lichen-like, and slightly crusty, with dark patches.

2. Verrucose Sarcoids-

Characterized as raised, knobby, dark areas that will often spread into poorly defined margins. They have a tendency to become ulcerated if irritated.

3. Nodular Sarcoids-

Skin lumps that are firm and nodular. They may have a normal covering of skin.

4. Fibroblastic Sarcoids-

These are sarcoids that are ulcerated, weeping, raised, sore lesions that could become pedunculated and cauliflower-like.

5. Malevolent Sarcoids-

These are rare, invasive sarcoids that affect the deeper tissues beneath the skin.

These different types of sarcoids can be found on areas with thin skin and areas with limited or no hair cover, especially in places where the horse tends to sweat. Be especially watchful of areas where flies prefer to feed.

A positive diagnosis of sarcoids can only be achieved by doing a biopsy. But since the location and characteristics is obvious enough to eliminate the need for a biopsy.

There are five different treatments available:

1. Banding with rubber rings

2. Surgical Removal-

Nodular sarcoid appearing in the groin and thighs, sometimes benefit from this treatment, only if the sarcoids have no skin involvement. Rate of recurrence is particularly high.

3. Cryosurgery (Freezing)-

This type of surgery is tedious and time consuming, with a high rate of recurrence. It is only effective with sarcoids of a limited size and depth.

4. Radiation-

Gives the best results, but is very expensive. It is only used for those sarcoids around the eyes or over the joints.

5. Bacillus Calmette-Gurin Injections-

Works only on nodular or fibroblastic sarcoids around the eyes. Will make sarcoids worse if used on those on the limbs.

It is sometimes possible to successfully remove all of your horse's sarcoids, but in most cases, treatment of sarcoids is done through maintaining care, rather than complete removal of all the sarcoids. Horses affected will return to their normal level of performance when all the lesions have been treated. Failure of any type of treatment will result in the reappearance of a more aggressive tumor, which will often increase in numbers.

Learn more about this author, Sara Jackson.
Click here to send this author comments or questions.