I was surprised this past weekend when one of my patients presented with a splint on her hind leg. I was not surprised that a splint had occurred, but surprised that my client had no idea what a splint was! Most learning in the horse world seems to take place in the School of Hard Knocks; therefore each horse owner’s education is drastically different depending on the various lumps that each of us has taken during our horsey adventures. For some of us, the lump that makes up a splint is something new.
Splints can occur in the cannon bone region of all four limbs, on both the outside and the inside of the leg. Remember, the cannon bones are the ones between the carpus (a.k.a “knee”) and the fetlock on the front leg and between the hock and the fetlock on the hind leg. The splint itself is actually a result of damage to a non-essential ligament called the interosseous ligament. These ligaments glue the splint bones to the sides of the cannon bone. If the horse has an excessive impact such as kicking a fence or landing hard on the leg, the ligament can tear. The body addresses this by filling the torn area in with calcium mineralization. Once this hardens, it becomes a sort of cement patch to stabilize the area. We call these “splints.”
Mature splints are hard, irregular lumps that protrude off the sides of the cannon bone. They are generally unchanging and non-reactive when touched. It is quite common for horses to get splints on the inside of their front cannon bone regions, but as mentioned, they can occur on both sides of any of the cannon bones. Very few middle-aged/ geriatric horses have legs that are entirely free of splints.
In the early stages when a horse first “pops” a splint - the area will be soft, fluctuant (movable and compressible), hot and painful. It is crucial at this stage to identify the problem as a splint, since failure to treat splints can result in longer term lameness and more serious issues. In general, treatment of a splint involves the cornerstones of anti-inflammatory therapy:
1. Rest: The horse should be stall rested/hand walked for about 10 to 14 days to give the splint a chance to calcify. Sometimes it takes longer, depending on the size of the interosseous ligament tear. Your veterinarian can direct you on an exact course.
2. Ice: Cold therapy helps to reduce inflammation and sooth pain.
3. Anti-inflammatory therapy: Feeding bute or firocoxib for 5 to 7 days is often recommended by veterinarians. Anti-inflammatory medications help to reduce swelling, edema, heat and pain. Many have also used topical Surpass (diclofenac) cream to assist in reducing inflammation. Another popular treatment is DMSO gel applied topically- but beware since it can cause skin reactions in some horses!
In addition to these hallmark therapies, folks will often wrap the leg with a standing wrap to help reduce swelling and shield the splint from any further injury.
By and large, splints really are not considered to be a big deal. They are usually noted as incidental findings on prepurchase exams, and rarely do they result in ongoing lameness.
Bottom line: Correct detection and early intervention keep splints from becoming major issues. If you suspect your horse may have popped a splint- rest, ice and anti-inflammatories given at the direction of your veterinarian should solve the problem within a couple of weeks.