E465
Laminitis (Founder)

* Ponies, mares, and overweight animals are at an increased risk.

* Each of these conditions causes inflammation and pressure within the hoof wall and constriction of the blood vessels, preventing adequate blood flow to the hoof. This constriction may be severe enough to cause permanent tissue damage and necrosis (death of the tissue).

Clinical Signs: The horse is often reluctant to move, or may move with very stiff front legs. The horse may go off feed and be lethargic. The animal will often shift weight back and forth from one leg to another, and be very sensitive to hoof testers over the toe area (see page B885). With experience and practice, the digital pulses of the feet can be felt and noted to be pounding in horses with laminitis (see page B150). The front legs are usually more involved than the hind; therefore, the animal may stand with the front legs forward and the hind legs tucked in underneath. In severe cases, the hoof may actually slough off, and/or the coffin bone of the foot can rotate downward into the bottom of the sole (see fig. 1 & 2 below). A horse with chronic laminitis will usually have thick rings in the hoof wall, parallel to the coronary band, and may have areas of hemorrhage or bleeding in the white line area.

Diagnosis: In many cases, laminitis can be diagnosed based on a physical exam and history. If this is not sufficient, a veterinarian can take a radiograph (X-ray) of the foot. The veterinarian can tell if there is any rotation of the coffin bone. See figures 1 and 2 below.

* See the anatomy portion of Section A for questions on anatomy.

Treatment: This involves four major areas.

1. Remove the problem causing the laminitis.

1. If grain overload is suspected, the horse should be given fluids, mineral oil, and Banamine. See page E285 for additional information.
2. If an infection is suspected, treat the infection.
3. Heavy horses should be placed on a weight loss program.

2. Reduce the inflammation.

1. Nonsteroidal anti-inflammatory drugs (NSAIDS) are essential (see bute and/or Banamine). Do not give corticosteroids, and be cautious regarding the duration and amounts of NSAIDS used.

3. Reduce the pressure placed on the hoof wall.

4. Increasing the blood flow to the foot.

1. Ace, given 4 times a day, will help increase the circulation.
2. Some researchers suggest walking a horse wearing frog support pads over soft ground for 5-10 minutes every 3-4 hours. Be careful not to overdo the exercise, since this may prolong the problem.

Prognosis: The prognosis will be determined by the animal’s response to treatment and the degree of rotation of the coffin bone. See figures 1 and 2.

1. If the horse recovers in 24-48 hours and no rotation has occurred, the prognosis is excellent and the animal can usually return to work in 10 days.
2. If the horse has 2-5 degrees of rotation within the first month after the problem begins, but has no continued rotation thereafter, the animal has a good prognosis. However, the horse should be rested for an additional 45 days and not over-used for several more months.
3. If there is 5-10 degrees of rotation in the first 45 days, and there is no additional rotation, the horse should be placed out to pasture for 12 months. This horse will probably not return to peak performance.
4. If there is 10-15 degrees of rotation, in the first month, the prognosis is poor. These animals often have the coffin bone penetrate through the bottom of the sole and usually never have a full recovery.