Equine sarcoid

Equine Sarcoids or Sarcoids are common, usually benign, skin tumours of horses and other equidae which have several different forms.

Aetiology

The cause is not fully understood but a viral cause is suspected.

Typical Appearance

They typically occur from the tail under the back legs, along the ventral midline to the chest and the head.

Occult Sarcoids

These are flat, hairless, lichen-like, slightly crusting, dark patches. They often have a smooth, dark hairless area around them.

Verrucose Sarcoids

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

Nodular Sarcoids

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

Fibroblastic Sarcoids

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

Mixed Sarcoids

Sarcoids are commonly a mixture of two or more of the forms described above.

Malevolent Sarcoids

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

Very often warts in the girth area can be mistaken for sacroids and also match the discriptions above. However, these can be treated much more easily and a cause found quickly too. It is still important to contact your vet for advice too though. Often they can be caused by sweat and dirt etc, so a warm "newmarket" scrub should do the trick. Anther common cause can be a fungil infection on the skin. Contact your vet for a simple treatmeant if you suspect this may be the case.

Diagnosis

A positive diagnosis can only be made using histopathology of a biopsy, however in most cases the location and character of the lesions is so suggestive of equine sarcoid that a diagnosis can be made and a biopsy may be contraindicated as it can awaken an otherwise slow growing lesion.

Treatment

Treatments may include banding with rubber rings, surgical excision, cryosurgery, injection with Bacillus Calmette-Guérin as an immunomodulator, radioactivity and topical or injected chemotherapy agents. No one treatment is suitable for all sarcoids and it is essential that individual cases are assessed by a veterinarian to ensure that the best treatment is selected. Sarcoids can be difficult to treat and this has encouraged many bogus treatments to be put forward.

Prognosis

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.

External links

Twenty facts you need to know about sarcoids, A guide for vets, owners and trainers by DC Knottenbelt BVM&S, DVM&S, MRCVS