You have various options on how to treat horse sarcoids, as they are notoriously difficult to treat.
The plain fact that numerous treatments are described below indicates that there is no single magical cure and no definitive treatment for horse sarcoids.
You should definitely avoid half-hearted attempts at treatment, as these are likely to lead to failure.
Ineffective treatment of a horse sarcoid can be worse than doing nothing at all. It can even make the sarcoid more aggressive and turn an occult or verrucous sarcoid into a fibroblastic one.
Experience has shown that certain methods can be more appropriate for different types or positions of sarcoid.
Horse Sarcoid treatment options include :
Do Nothing (watchful neglect):
A single sarcoid or a small group that is isolated and does not interfere with tack or riding can be left alone and in time, may resolve itself.
This is effective for smaller sarcoids with an obvious neck of normal skin. A length of nylon or elastic is tied around the neck, cutting off the blood supply. Rubber rings used for lamb castration work well. However, the sarcoids do tend to re-occur.
Surgical Excision :
This carries a considerable risk of re-occurrence, except in smaller isolated sarcoids. It is important to make sure that the incision is in healthy skin. This is especially so for occult sarcoids. If the wound can be closed after removing a wide margin of normal skin around the sarcoid it will probably heal satisfactorily.
Sarcoids may re-occur at the site of excision either soon or several years after removal. Especially where large margins cannot be taken and surgical excision is difficult on the lower limbs and face, because the skin is tighter, healing is slower and there is an increased chance of scarring.
Generally, excision is relatively quick, inexpensive and does not require repeated veterinary visits.
Laser (carbon dioxide – YAG) :
Like electrocautery, it may damage cells beyond the line of the incision and so reduce the risk of re-occurrence. It also reduces bleeding.
This is useful for smaller sarcoids. Liquid nitrogen is used to freeze the sarcoid which then dies and sloughs off. It may be that this provides some stimulus to the immune system – and may cause regression of other sarcoids in some cases.
It is difficult to apply to large lesions and on the eyelids. In larger masses the main bulk of the sarcoid may be cut off ("debulked") first, and the remnant frozen. Usually at least three freeze-thaw cycles are used. Sloughing of the dead tissue may take up to 2 months.
This is not widely used, and requires repeated application.
This technique can be used for removing sarcoids. It reduces bleeding by heating the edge of the wound and may reduce the risk of re-occurrence.
Using Chemotherapy to Treat Horse Sarcoids :
An anti-cancer agent is injected into the tumour site. The primary aim is to stop cell division (reproduction) and thus cause cell death. Multiple injections are required.
Cisplatin and 5-fluorouracil are the most commonly used chemotherapeutic agents.
This treatment can be expensive due to the cost of the drugs. Compounds containing heavy metals such as arsenic, antimony and mercury salts, may be applied to the sarcoid
One example is the cream used by the Liverpool vet school which also contains corticosteroids and cytotoxic drugs.
Cisplatin is a cytotoxic drug ( ie it kills cells.) It works well when injected into nodular or small fibroblastic sarcoids. One small study found it to be 100% effective.
Immunological Treatments for Horse Sarcoids:
Some people have advocated using sarcoids removed from the horse to produce a vaccine which is then injected back into the horse to stimulate resistance to the remaining sarcoids.
Vaccines do not usually work well. In some cases the remaining sarcoids get worse after autogenous vaccine treatment.
This was originally produced to protect people against tuberculosis.
It is injected into the sarcoid on 3 or 4 occasions at 2-3 week intervals.
It acts as an immune stimulant and works quite well for some nodular sarcoids and some fibroblastic sarcoids. Sarcoids around the eye seem to respond well to this treatment.
Radioactive Gold and Iridium implants:
These have been used successful especially around the eyes. But requirements for radiological protection of the operator make it an impractical treatment in most cases.