Last week it was brought to my attention that the Food and Drug Administration recalled a blistering compound, Miracle Leg Paint, due to the potential for human and horse poisoning.Last week it was brought to my attention that the Food and Drug Administration recalled a blistering compound, Miracle Leg Paint, due to the potential for human and horse poisoning.
Last week it was brought to my attention that the Food and Drug Administration recalled a blistering compound, Miracle Leg Paint, due to the potential for human and horse poisoning.
This product contains mercuric chloride, a type of mercury, which has the potential to be toxic in high doses or with prolonged exposure. Even brief exposure to mucous membranes can be very serious due to the severe ulceration that follows.
Why are blistering agents used? Blistering agents are counter-irritants, which are believed by some to increase the blood flow to inflamed area, which expedites the healing process.
The indications for a blistering compound (according to the O.R. Adams ‘Lameness In Horses’ (3rd Ed) include:
1. Joints that are chronically inflamed
2. Chronic bone conditions such as ringbone, sidebone, bone spavins, etc.
4. Tendonitis and tendosynovitis
6. Drawing of abscesses
Contraindications for blistering agents include the following:
1. Acute inflammation
2. Open wounds
3. Most flexor surfaces
4. Anywhere near a mucous membrane (most are very caustic)
5. In horses that are weak or emaciated
It should be noted that most blistering is done in performance horses, e.g., racetrack and barrel racers and is not common among show horses. This is due to the fact that some blistering agents are very strong, and their severe irritation of the skin will cause the hair in the affected areas to grow back white.
Most cases of mercury poisoning (mercurialism) in horses have been reported to be due to ingestion of grains treated with fungicidal alkylmercury compounds.
I did find one case report of horses that got mercury poisoning via a mercuric blister that was applied with dimethyl sulphoxide (DMSO) which enhanced the absorption of the mercury and one case where poisoning was due to the direct application of a mercuric blister.
Ms. Georgia Brown, the owner of the Equine Miracle Corp., the company that manufactures the Miracle Leg Paint, expresses concern for the product being pulled from the market.
Ms. Brown stated that the product has been sold for some 25 years, and to her knowledge, there have not been any cases of mercury toxicity involving her product. Additionally, Miracle Leg Paint had passed through the proper channels for patenting in 1998, and no problems were encountered at that time.
She said that the company is actively working with the FDA to generate control studies and to reintroduce the product back on the market as a number of her clients were concerned and felt that they had no replacement for the product.
The real question to be addressed is the effectiveness of any blistering agent. It is generally agreed now among veterinarians that blistering basically causes irritation and scuffing of the skin. The only benefits derived from the agents are due to the enforced rest that is given to the horse after blistering.
Will the FDA decide if the drug is safe? Only time and control studies will tell. In the meantime, don’t blister your horse’s legs. Horsemen that have the product should contact their local waste-management authorities to determine how to destroy the product.
For a look at the Federal Drug Administration press release, dated May 10, 2002, please click here. THIS IS A CLASS I RECALL.