Sarcoids are the most common form of equine skin tumour, they can occur spontaneously or associated with wounds, scars or bites.

Sarcoid above a horse's eye
Sarcoid above a horse's eye

They are frequently benign however can cause irritation or interfere with tack due to them commonly occurring in these areas.

There are different types of sarcoid, including:

  • Occult – flat hairless scabby lesions
  • Verrucous – wart like lesions
  • Nodular – Well circumscribed circular swellings. Pictured
  • Fibroblastic – Fleshy and often ulcerated masses, often due to trauma
  • Mixed – a mix of different types of sarcoid

What to do if my horse has a Sarcoid?

Contact your vet who can then arrange a visit to check the mass.

Treatments Options for Sarcoids

  • Electrochemotherapy – recent studies show a 99% non-recurrence rate over 4 years
  • Cryosurgery – involves freezing the tumorous tissue, around an 80% non-recurrence rate. Can’t be performed in areas where freezing will damage normal tissues
  • Laser removal – using a diode laser with a non-recurrence rate of 83%. This is not appropriate around the eyes or for very large lesions
  • Immunotherapy – Injection of a BCG vaccine into the tumour, this has become very difficult to source
  • Brachytherapy – this is very successful and useful in sarcoids around the eye but is expensive.

What is Electrochemotherapy?

Treating the sarcoid with electrochemotherapy
The same horse undergoing electrochemotherapy treatment

Electrochemotherapy is a relatively new treatment available and involves injecting the sarcoid with a chemotherapeutic (anti-cancer) drug called Cisplatin.

A short, repeated electrical current is then passed around the area to increase the uptake of the drug. This procedure completed under a brief (usually 15 minute) general anaesthetic.

Typically three treatments are required two weeks apart.

Post-Operative Care

Your horse should be able to go home with you 24 hours after the procedure, to be able to continue as normal once home.

Electrochemotherapy is available at the RVC Equine Referral Hospital.

Please contact the reception team at the Royal Veterinary College on 01707 666297 or Andy Fiske-Jackson ( if you are interested in this treatment and you would like more information.

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