By Nancy S. Loving,
When offering arthritic horses relief, start from the ground up
The degenerative joint disease arthritis is all too common in active and aging horses. In an effort to slow the progressive deterioration of joint tissue, owners and veterinarians often reach for anti-inflammatory medications and/or regenerative therapies. After all, our goal is to keep these joints comfortable.
One often-overlooked strategy in this effort is hoof care. Certain trimming and shoeing techniques can alter a horse’s limb biomechanics—for better or worse. In this article we’ll discuss how to care for arthritic horses’ hooves for maximum comfort.
What Exacerbates Joint Pain?
Arthritic horses try to minimize their joint pain by reducing the load on the affected limb(s) and shortening stride length. “This suggests that pain is associated with the concussion of impact and extreme ranges in motion (ROM),” says Andrew Parks, DVM, Vet MB, MRCVS, Dipl. ACVS, a professor at the University of Georgia’s College of Veterinary Medicine, in Athens.
Force of impact
The limb’s loading rate (deceleration) when the foot lands affects the force of impact on that leg, as can footing type. “The impact of baked clay in summer or frozen ground in winter is quite different from a soft dirt paddock, bedded stall, or engineered arena,” says Parks. “Anything that slows down the rate of deceleration of the foot is likely to decrease the effect of impact. Materials that absorb energy on hoof landing—either from the ground surface or within the shoeing apparatus—also reduce impact.”
Range of motion
You’re probably already familiar with this concept: Your veterinarian maximizes a joint’s
range of motion when he or she performs a diagnostic flexion test to pinpoint soreness in a painful joint. Excessive flexion or extension/dorsiflexion (backward bending or bowing) can aggravate arthritis.
Owners and farriers should handle arthritic horses’ legs with care. “Check range of motion and flexion ability, and don’t force an arthritic horse to bend or flex its limbs beyond its comfort zone,” says Steve Kraus, CJF, resident farrier and instructor at Cornell University’s College of Veterinary Medicine, in Ithaca, New York. “Use of a foot stand (when trimming or shoeing) keeps hind limbs low and supports the front legs to provide better comfort for both horse and farrier.”
To modify or limit range of motion extremes in locomotion, Parks recommends farriers help the foot lift and roll over (called breakover) more easily. “This may mean not only rolling the toe but also the whole perimeter of the shoe and even the heels,” he says. The easier it is for the horse to lift his heels off the ground, the less dorsiflexion the foot will experience at breakover.
Hoof balance is key to keeping an arthritic horse comfortable. Create a more level landing surface by picking out gravel and other debris from hooves daily. Have the feet trimmed every four to seven weeks (depending on hoof growth rate) to help balance the hooves and reduce the horse’s risk of developing long toes and collapsed heels, which can make him more likely to stumble.
“Farriers can manage the hoof capsule with trimming and shoeing to provide proper limb alignment so that forces are distributed equally through the joints,” says Kraus.
If a foot is acutely imbalanced (say, for example, one side has been wedged or trimmed shorter than the other), the joint on the elevated side of the hoof will narrow—something that’s visible on radiographs (X rays) taken immediately following this practice. “However,” says Parks, “if you look at feet with obvious (chronic) coronary band asymmetry and hoof imbalance, an interesting finding is that the imbalance in the joint space usually is not evident on radiographic images.”
This compensatory phenomenon is related to the coffin bone’s movement relative to the hoof capsule. The hoof’s growth rate also changes, slowing on the side experiencing the greater load.
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