Founder or Laminitis?

All horse people shudder at the mention of founder. Some of us really don't have a clear picture of what it is, what causes it or what the connection is with laminitis. For all practical purposes, it's the same thing, with founder being more of a layman's term and laminitis a medical term.

Normally horses and ponies have a smooth, springy, regular gait moving freely, easily, and gracefully. Watching a fine horse move through its paces is a beautiful picture.

One of the most common ailments that can change this picture rapidly is laminitis. Laminitis is caused by an alteration in the blood supply to the foot that results in damage to the sensitive laminae where the hoof is attached to the foot. The disease may be acute or chronic and may affect one or all four feet at any one time. The forefeet are affected more frequently.

There are many factors that can cause laminitis. Some of the more common are unintentional or accidental overfeeding, overweight animals lacking exercise, retained placenta and cold water intake by an overheated animal (metabolic laminitis). Other factors such as metritis (parturient laminitis), local infections, excess weight bearing on one or more legs, running on hard surfaces (traumatic laminitis), and standing for long time periods in transport are other causes. Ponies appear to be more susceptible to laminitis than horses. Also, horses between the ages of four and ten years appear to be more susceptible than other horses.

Acute laminitis has a sudden onset. Horses apparently normal in their movement one night may be in severe pain and reluctant to move the following morning. The animal may be standing with all four feet close together, if all four feet are affected, with its head low and its back arched. If only the front feet are affected, the horse will shift the hind legs underneath it to try to put most of its weight on the back feet and vice versa. Also, the animal may be exhibiting an expression of pain and anxiety. In some cases, the pain may be so severe as to cause muscle spasms and profuse sweating. If the horse can be persuaded to move, the gait will be painful and stiff but may improve slightly as the horse "warms up." Acute laminitis is a medical emergency and when a horse shows these signs, a veterinarian should be consulted immediately.

In mildly acute cases, the horse may respond to treatment by a veterinarian if therapy is initiated early. In severe cases, or in cases with improper or delayed treatment, chronic laminitis is likely to result. In chronic cases, your veterinarian may be able to obtain relief from pain but not effect an immediate cure of the laminitis. The chronic condition may result in the separation of the hoof wall from the sensitive laminae of the foot. When this happens the third phalanx (coffin bone) may rotate downward. It is then possible for it to penetrate the sole of the hoof and/or produce overgrown feet.

Decrease the chances of laminitis:

• Make gradual changes in feed
• Monitor grazing on lush spring pastures (especially ponies and any horse who has foundered in the past)
• Avoid rapid increase in grain feeding - always store grain in containers that are "horse-proof"
• Avoid working a horse heavily or for prolonged periods on hard ground or roads
• Be alert for signs of laminitis in any horse who is ill or has a digestive system problem
• Inspect placentas carefully after a mare has foaled to make sure there are no pieces missing