When your horse suffers a major injury, such as a severely broken bone in a leg, the last thing you might be thinking about is laminitis. But laminitis should certainly be on your radar, as many horses that suffer serious limb or hoof injuries develop supporting limb laminitis, a condition that can prove fatal even if the original injury is well on its way to healing.
During a presentation at the American Veterinary Medical Association Convention, held July 16-19 in St. Louis, Mo., Joanne Kramer, DVM, Dipl. ACVS, assistant teaching professor in the Department of Veterinary Medicine at the University of Missouri-Columbia, discussed why supporting limb laminitis prevention is so important to keeping injured horses on the road to recovery.
Kramer noted that according to a previous study, about half of all horses that develop supporting limb laminitis are euthanized for various reasons, including the cost of care and prognosis. Despite the preventive and treatment efforts of his veterinarians, supporting limb laminitis was the ultimate reason for the euthanasia of 2006 Kentucky Derby winner Barbaro, who shattered his right hind leg in the 2006 Preakness Stakes.
"Problems occur with the opposite limb, because the injured limb cannot be repaired fast enough to get the weight off the uninjured limb so it can share the load," said Kramer.
A healthy horse shifts his weight from limb to limb constantly throughout the day to relieve the pressure on his limbs. When a horse isn't able to relieve pressure from a foot, his body weight bears down on the coffin bone of the healthy limb, which causes stretching in the lamellar attachment and compresses the blood supply.
The supporting limb can develop laminitis at any time, but many times it goes unnoticed until the pain is greater than that of the primary injury. At that point, Kramer noted, it might be too late to help the horse.
Therefore, Kramer recommends veterinarians watch and manage the healthy limb closely from Day 1, even though that could increase treatment costs for the owner. The veterinarian should take periodic X rays of the supporting limb and perform venograms to check its blood supply and ensure laminitis has not started setting in.
Additionally, she suggests working with a farrier to provide mechanical support via trimming and shoeing that redistributes the weight from weaker points to stronger points in the hoof and decreases the tension in the deep digital flexor tendon.
"This is one of the things you can influence by trimming and shoeing, so it is important to keep that in mind," said Kramer.
She also recommends helping the horse keep his body weight off the supporting limb when possible. She suggested encouraging the horse to lie down (sedation often helps achieve this), or using an intermittent sling support, if the horse will tolerate it.
Kramer suggested a few easy ways to identify possible supporting limb laminitis:
- Evaluate the coronary band. In many healthy horses, it will sit flat against the hoof wall. If a significant depression is felt between the hoof wall and the skin at the coronary band, the coffin bone could be losing its attachment to the hoof wall and sinking into the sole;
- Look at the skin around the hoof to see if it starts to sink and stretch, also indicating coffin bone movement; and
- Ensure there is normal sole growth.
Once the horse develops supporting limb laminits, treatment is much like other forms of laminitis and includes non-steroidal anti-inflammatory drugs and cryotherapy (cold therapy) to keep the horse as comfortable as possible.
"We have to get to a point where we are catching them and seeing (the support limb problems) earlier," she said.
Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.