How well your horse's knees remain fully functional over his performance career or lifetime depends on several factors, with good conformation at the top of the list. Additional considerations are genetics, career type, injury, training practices and nutrition.. Even under the best of circumstances, the knees of your aging horse will likely succumb to degenerative joint disease -- a long-winded term for arthritis. Your options for horse knee care, from correcting lameness issues to managing or delaying arthritis, are constantly expanding.
Not every horse has the perfect body, any more than humans do. Understanding problems that can arise from specific physical blemishes can help you adjust training and performance schedules and proactively detect potential problems. Your horse's front end bears about 65 percent of his weight in his normal activities, and his knees in particular take the brunt of the concussion associated with many equine disciplines.
Seemingly insignificant physical faults affect how your horse's frame carries his weight. A long-backed horse has difficulty bringing his hind legs underneath for power; thus, he carries more weight on his front end and his knees. This is also true for a horse with a "downhill" build, in which his rump is higher than his withers.
Properly called carpal valgus, this horse's knees angle inward. Many newborn foals are born knock-kneed but typically grow out of it. Those that don't are prone to arthritis, as the inside of the knees bear additional stress.
Knock-kneed horses may also be more prone to bone chips as the stress causes bone fragments to break away from a knee bone.
A bow-legged horse, with knees angling to the outside, has carpal varus. Not surprisingly, this conformation flaw places additional stress on the outside of the knees.
Also referred to as bench knees, this is when the horse's cannon bone -- the large bone in each lower leg below the knee -- is offset to the outside of the leg, rather than centered directly below the knee. This adds stress to the inside of your horse's knee.
The calf-kneed horse looks like his knees are bent backwards in his normal, weight-bearing stance. His weight is distributed very unevenly throughout his legs, making any riding discipline difficult.
A horse with enlargement in the front of the knee along the front carpal joint is sometimes said to have a "popped knee." He may have a bone chip, an infection or other trauma, or has simply had it since birth.
Most equines progressively acquire arthritis as joints and cartilage wear. Any intensive performance career can hasten this progression, and knees take the brunt of many high-impact disciplines such as jumping. Once you detect early symptoms, such as minor inflammation in his knees or stiffness, you can manage it to alleviate your horse's pain and discomfort and avoid career-ending lameness. Many horses continue to perform for years with the help of oral or injected joint supplements, or compete at lower levels.
Many arthritic horses exhibit stiffness during the first few minutes of a ride, then loosen up, so proper warm-up is important before a more strenuous workout.
Septic arthritis in the knee is more serious and difficult to treat. It's also less common, as bacteria have to find a way into your horse's knee joint and cause an infection. This typically only occurs if your horse gets an injury close to the knee joint, such as a puncture wound. Any wound near a joint warrants a call to your veterinarian.
A bone chip in the knee joint is not necessarily a death knell for your horse's career; consider the careers of two successful racehorses, War Emblem, who competed with knee chips, and Grindstone, who continued his career after chip removal. Many chips are successfully removed through arthroscopic surgery, allowing the horse to return to its normal or near-normal career. Chips that are not continuously shedding irritating debris often remain in the joint or are treated with a joint supplement injection.
- Chip fractures are bone fragments that chip off the bone due to trauma or activity so repetitive that the subchondral bone can't keep up with its repair and remodeling tasks.
- Osteochondrosis or OCD is a bone development condition that may form lesions that weaken the bone and may later chip off as the horse goes into work. OCD may be caused by some or all of these factors: mineral balance and other nutritional and overfeeding problems; genetics or endocrine problems; mechanical stress and trauma; or rapid growth.