Laminitis or Founder is a lameness caused by pressure on the laminae of the Hoof. This happens when the laminae swell with blood in response to chemical changes in the body. Pressure increases because the outer layers of the hoof Wall and the inner structures of the hoof are not able to provide room for the expanding laminae.
Laminitis has a large number of causes. These are:
- Grain Founder - This is caused by the horse eating more grain then it is accustomed to. The feed may be due to an accidental excess (like getting into the grain bin) or the symptoms may suddenly appear in a horse that has been eating a large amount of grain everyday. The symptoms often do not show up for 12-18 hours after eating the grain. The symptoms are milder for oats than with other grains.
- Water Founder - This is caused by the horse drinking cold water when the horse is hot.
- Road Founder / Concussion - This is more common in horses with thin walled and soled feet. Working a horse fast or for a long time on a hard surface can cause road founder. The most problems are found in horses that are not physically conditioned before they are worked hard.
- Grass Founder - Grass founder is common in overweight horses and ponies kept on pasture. The chance of founder is increased if the roughage mixtures contain alfalfa and clovers.
- After Foaling - This laminitis is a secondary reaction by the body. The Mare will also have an infection caused by a retained placenta or a general uterine infection.
- Secondary Infection - In some cases the horse will founder if they are extremely sick with a virus or a systemic infection.
Laminitis can occur in two main forms. It can be acute or chronic.
A horse with
acute laminitis may have all four feet affected. If this happens, the horse may lie down for long periods of time to relieve the pressure. When the horse is standing it tries to reduce the amount of weight on its front legs. It does this by standing with its forelegs ahead of its body and the hind legs forward to support more weight. Their front legs may be close together and the weight will be on the heels.
Chronic laminitis is a long lasting case of laminitis lasting over one month. More deformities of the foot are noticeable. In most cases the
Sole of the foot drops and becomes flat and the coffin bone is visible. Because of this, the horse travels so that it lands on its heels where normally the horse lands first on the toes. Heavy horizontal rings can be seen around the hoof because the
Coronary Band has been affected. Without proper care the toe can curl up as it grow longer.
Laminitis should be treated by a veterinarian. Treatment is more successful if the problem is recognized in its early stages. As the laminae swell they produce heat over the hoof wall, sole and coronary band. The horse becomes less active and may drag its toes as it walks.
A major problem with laminitis is that it can cause structural changes in the foot. The hardness of the hoof wall prevents outward expansion of the laminae. The pressure pushes the front of the coffin bone down towards the sole. If this happens, the bone can be seen 10 days after the illness. Most veterinary and
Farrier care is done to try to prevent this.
In a severe case of laminitis the hoof wall may slough off.
Treatment of the horse is often as follows:
- Grain Founder - this is usually discovered because it is an accident. Your veterinarian will use oil or drugs to clean the grain out of the digestive system. The horse will be given antihistamines. Because circulation is a problem the horse should be walked and the legs will be helped by soaking the feet in hot water.
- Water Founder - treat with antihistamines and care for the feet by proper trimming.
- Road Founder - the horse is treated with antihistamines and may need shoeing with pads to protect the foot.
- Grass Founder - the horse is treated with antihistamines. Like grain founder, the horse should be walked. The feed intake of the horse should be reduced for at least three days and the horse fed dry hay or grass.
- After Foaling - the mare needs to be treated for the infection and laminitis. If the laminitis occurs once at foaling it is likely to occur each time the mare foals after that. Exercise is needed.
After a horse has foundered, you should consult with a veterinarian or farrier before you ride it again. If the horse did not founder too badly, pads and shoes can be put on the affected feet and be sure to ride in an area that has soft footing. Ride for about 15 minutes and see how the horse reacts. For more serious cases of founder a long rest period is advised.
