Horse Side Vet Guide ®

Equine Health Resource

Pin Firing or Thermocautery


Pin firing is an old veterinary treatment in which a hot metal tipped instrument (firing iron) is used to burn a pattern of small holes through the skin overlying an injury (usually lower limb injury). Different practitioners suggested that different depths and patterns of holes were needed to get the desired effect.

There are different theories as to why this treatment should work. The most common is that it causes the body to intensify healing efforts at the location (whether through increased circulation or other factors), thereby improving or speeding healing the original injury.

No mechanism has ever been proven, and the effectiveness of the treatment has also never been proven.

In this procedure, the skin is first clipped of hair. The skin is cleaned and disinfected, and anesthetized using nerve blocks or local anesthesia. Following the firing, most practitioners covered the area in what is known as a blister, a chemical compound that caused further irritation. This was usually covered in a tight wrap, and the horse was confined to a stall for a set period of time.

The conditions most commonly treated include dorsal metacarpal disease (bucked shins), splint exostoses, curb, and sometimes tendon injuries.

Pin Firing is not used frequently today, and has been (somewhat) replaced by freeze firing, a similar procedure using liquid nitrogen instead of a hot iron. Pin firing still has its practitioners though, especially at various racetracks.


In most cases today, your vet will not suggest a treatment like pin firing.


If pin firing is suggested as a treatment, you should question the logic of using this age-old treatment.

Surely there are other treatments that are superior and cause less pain and suffering to the horse.

Is It working? Timeframe for effect

Horses undergo days to weeks of inflammation - swelling, reddening and drainage from the wounds.

If the primary problem heals, the question is whether it would have healed as well without this treatment, or better with other less antiquated treatments.

Questions To Ask My Vet

  • Is this really the best treatment for this injury?

Helpful Outside ResourcesCredible Equine Health Information on the Internet

Author: Doug Thal DVM Dipl. ABVP

