what doespinfiring in the legs mean?

l found this on Google.

http://horse-injuries-and-therapy.com/blisteringandpinfiring.html

Used to be often seen on racehorse is front legs, especially in Ireland:
Vets use local anaesthetic to numb the legs, then use a 'gadget' that produces tissue damage at regular intervals along the lower legs. Reason for this is that it is supposed to promote healthy alignment of tissue fibres alongside the leg & tendon - when there is a problem, such as a strain. Tendons often heal in a 'lumpy' manner - pin firing is said to avoid this.
Both legs r normally done because pin firing only one leg would make the horse shift weight onto it is 'good' leg - which could result in strain, or laminitis in the good leg.
The technique of pin firing has been used for a long time but is very controversial, l believe it was banned in England but is now allowed again, if nothing else helps.
Normally by the time the pin fired legs have healed, the tendon strain is probably better anyway. Hope this explains it a bit - u can find articles if u google 'pin firing'.

It is an antiquated procedure that was used as others have described. The good news is that in most cases if you have a horse that was pinfired in the past, most of them go on to do fine in later life.

Pinfiring is a (thankfully) obsolete procedure that used to be done to treat a variety of problems that were typical of racehorses: bucked shins, bowed tendons, & other soft-tissue injuries of the lower leg. (Bar firing & caustic blistering were also remedies used.)

The theory was that counter-irritation caused by the infliction of burns or caustic irritation to the area would increase the amount of blood flow to an injured area, turning a chronic injury into an acute injury, & thus increasing the chance of complete healing.

Barbaric. BUT-- in a lot of cases, it actually worked.

Not because of the applicsation of counter-irritation, but because while the pin firing or blistering healed, the poor horse got what he REALLY needed for the injury to heal: REST! Elliot Burch, a hall of fame trainer from the era when pin-firing was common, used to say that if u pin-fired the horse is back, you'd get the same effect: the horse would be laid up & given time to heal.

If u can find a good picture of the Thoroughbred Three Bars, who was so influential in the Quarter Horse breed, u will see the typical pattern of scarring that occurred with pin firing. Pictures of race horses taken during the 30's, 40's, 50 is & 60's, u will see a lot horses have the scars from pin firing.

For more current information on treatment of tendon injuries & bucked shins:

http://thehorse.com/ViewArticle.aspx?ID=2783
http://thoroughbredtimes.com/horse-health/2006/November/21/Pinfiring-proves-obsolete.aspx

Absolutely barbaric procedure. l am glad it is no longer recommended.