Sarcoids in Horses: What Owners Should Know

A practical guide for recognising and managing equine sarcoids

Sarcoids are one of the most common skin tumours seen in horses. While they’re not life-threatening, they can be persistent, tricky to treat, and frustrating for both owners and horses alike. Understanding what they are and how to manage them can make a big difference in your horse’s comfort and long-term wellbeing.

What Are Sarcoids?

Sarcoids are a type of skin tumour unique to horses, donkeys, and mules. They are believed to be caused by a virus called bovine papillomavirus (BPV) and can appear anywhere on the body. They’re not contagious between horses, but some horses may be genetically more prone to developing them.

Common Types of Sarcoids

Sarcoids can vary in appearance. The main types include:

• Occult – Flat, hairless patches that may look like ringworm.

• Verrucous – Wart-like growths with a dry, scaly surface.

• Nodular – Firm, round lumps under the skin, often in the armpit or groin.

• Fibroblastic – Aggressive, fleshy growths that can ulcerate or bleed.

• Mixed – A combination of the above types.

• Malevolent – Rare, rapidly spreading sarcoids that follow lymph vessels.

Where Do Sarcoids Usually Appear?

Sarcoids can develop anywhere, but they’re most commonly found:

• Around the eyes and ears

• On the chest and groin

• In the armpits

• On the legs or inner thighs

• Near previous wounds or scars

They often show up in areas prone to rubbing or moisture.

Are Sarcoids Dangerous?

Sarcoids do not spread internally like cancer in humans, but they can:

• Grow and multiply

• Cause irritation or discomfort

• Become infected or bleed

• Interfere with tack or rugs

• Lower the horse’s value or suitability for sale

For these reasons, early identification and management are essential.

Treatment Options

There is no one-size-fits-all approach, and not all sarcoids need immediate treatment. However, some common options include:

• Surgical removal

• Laser treatment

• Cryotherapy (freezing)

• Topical creams

• Immunotherapy or chemotherapy agents

Every case is different, so it’s important to monitor growths and seek advice before attempting treatment. Inappropriate handling or trauma can make them worse.

Can Sarcoids Come Back?

Yes. Even after successful treatment, sarcoids can recur, especially if the area is re-traumatised or if other sarcoids are present. Some horses may go on to develop multiple sarcoids over their lifetime.

Tips for Owners

• Check your horse regularly for new lumps or changes in existing ones

• Avoid picking or rubbing sarcoids, as this can aggravate them

• Be cautious with rugs or tack that may rub against affected areas

• Seek professional advice before beginning treatment

Final Thoughts

Sarcoids can be challenging, but many horses live full, active lives with them. By staying vigilant and working with your vet, you can keep your horse comfortable and manage sarcoids effectively.