Horses come up with ingenious ways of hurting themselves, mainly due to social friction, fright/flight reactions or run-ins with seemingly benign objects or conditions. Environment conditions, such as muddy or rocky footing, can lead to injuries such as falls or stone bruises, whereas puncture wounds can also be caused by scuffles with herdmates. Although your first priority is caring for the wound, reconstructing the accident can help identify the cause of the puncture and prevent it from happening again.
The signs: Punctures, also called stake wounds, occur when a sharp object pierces the skin to inflict a wound that is deeper than it is wide at the surface. Some blood or serum may ooze from the opening, but the surface may seal over quickly and stop the flow.
If you're lucky, the entire puncturing object may remain inside, with or without an end protruding from the wound, showing you the exact extent of the injury. You're in worse shape, diagnostically, if the horse has pulled free of the object or broken off the penetrant below skin level, leaving you without a visible clue to the depth or cause of this threatening injury. Punctures of a joint or foot are almost certain to cause lameness, if not immediately, then as swelling over the next hours and days increases the painful pressure.
The source: Stake wounds can occur anywhere on the body but are most common in the sole of the foot, the legs and the chest, and most impalements occur when horses are running. High-speed contact with a seemingly benign object, such as a downed branch or corn stubble, can drive it deeply into the flesh. Puncture possibilities abound around horses: splintered fence rails, broken wire, T-posts, protruding or fallen nails, rigid plant stubble, ice shards, sharp shoe studs on other horses, branches and thorny brush.
First aid: Call your veterinarian to examine and thoroughly clean all puncture wounds that break through the skin or hoof. Bacterial infection is likely, and pieces of the puncturing object may remain imbedded in the wound to cause much swelling and pus formation. Tetanus is a lethal infection that thrives in the oxygen-free atmosphere of closed puncture wounds.
If the puncturing object is visible in the wound, consult with your veterinarian before removing it; he may want to perform the removal himself to be sure that nothing is left behind. Additionally, inexpert removal of the object could do further tissue damage and cause more bleeding.
Antibiotics and anti-tetanus treatment are usually administered following debridement of a puncture wound. Punctures near joints or tendons are most urgently in need of medical care because the by-products of infection can irreversibly damage cartilage and tendon sheaths.
"If the wound penetrates the joint, assume you've got a joint infection and call your veterinarian," says Jerry Black, DVM. "The knee and fetlock in particular have no significant soft-tissue cover, so it doesn't take a lot of penetration. Even a quarter-inch puncture in the fetlock is serious. It needs to be tended to within a matter of hours."
Examine any near-joint puncture very closely to see if fluid is escaping from the wound. "Joint fluid is a clear, yellowish fluid," says Michael Foss, DVM, "but because serum oozes out of most any wound, it's sometimes hard to tell the difference."
Rub the fluid between your thumb and finger to test its consistency: Joint fluid is thicker, viscous and more mucuslike than serum, which is thin, runny and possibly tinged with blood. If the puncture is near a joint and there's the least suspicion that joint fluid is leaking from the wound, contact your veterinarian immediately and keep your horse as immobile as possible to prevent further contamination.
Follow-up: If the penetrating object is not in the wound, check the turnout area for possible causes. Look carefully at your fence line for blood or hair and along well-traveled paths for potential penetrants. Regularly patrol turnout areas, particularly those bordering roads, for trash, debris and deteriorating fencing or buildings that could wound horses. Avoid using T-posts in horse fencing, but if they are already in place, cap the ends with plastic covers. Repair broken fence boards and protruding wire/nails immediately. Finally, keep your horses' tetanus vaccinations up-to-date.
This article is excerpted from "Triage for Turnout Injuries" that originally appeared in the June 2001 issue of EQUUS magazine.