And The Vet Said...

Laminitis

There have been many great horses lost and many more that have faced life ending careers due to an all too common condition in the horse, known as laminitis. Many will recall the death of the beloved race horse "Barbaro" due to this condition. Some of us also remember the great horse "Secretariat" who was also euthanized when laminitis became too painful for him to bear. In many cases if proper treatment is initiated immediately, complete recovery and reversal can be achieved.

Acute laminitis is a severe debilitating, excruciatingly painful, and potentially career ending and life threatening disease of the equine foot. It can occur in adult horses and ponies of any breed or use. Laminitis often occurs secondary to other diseases, such as acute gastrointestinal tract disease, grain overload, over indulgence of lush pasture, retained fetal membranes with subsequent metritis, plural pneumonia, and other diseases accompanied by endotoxemia. It is also seen in horses with "Cushing's Syndrome" or horses that are insulin resistant. Laminitis can also affect horses with severe non-weight bearing lameness. This occurs commonly in the contra-lateral limb owing to overload or excessive weight bearing on the "good" leg. This was the case with "Barbaro".

In laminitis blood flow to the hoof is disrupted causing the laminae of the hoof to separate from underlying structures of the foot. Usually it is the front feet that are affected where 2/3 of the horse's weight is concentrated. For example, in a 1000 lb horse each front foot would bear approximately 350 lb of weight.

The laminitic horse will appear to walk stiff or gingerly, and as the condition becomes more advanced, they may stand in a "saw-horse" stance with the front feet stretched out front and the hind feet tucked underneath their body. Many times people see this and think the problem is in the rear limbs because the horse appears to be trying to take weight off the hind limbs by putting them underneath. This stance is due to pain in the front feet.

Horses that recover from acute laminitis can become candidates for chronic laminitis if proper treatment is not initiated early on or if the secondary disease that contributed to the laminitis is not properly treated or eliminated. Horses that are affected with chronic laminitis can suffer years of pain and be a very large drain on the "pocket book" many times ending in poor results for all those involved.

As a result of chronic laminitis, horses are often kept on anti-inflammatories, such as Phenylbutasone, for long periods of time. This long term use can result in digestive problems like perforating ulcers, which can lead to death in some cases.

One of the most important steps in treating a horse suspected of having laminitis is to take radiographs of the foot. Both a lateral and dorsal palmer view of the affected foot or feet should be taken. From these views, measurements can be taken to help, not only access the severity, but also to help with shoeing and treatment options. Sole depth is an important measurement that is taken of the foot. The dorsal horn lamillar zone, which will indicate coffin bone rotation, is also measured. The palmar angle which will show the relationship of the coffin bone to the ground surface is also very important. Finally the coronary extensor process distance which indicates if a horse is "sinking", is measured. "Sinking" is a term used to describe the coffin bone sinking within the hoof capsule. All of these measurements are very important in determining the situation that is occurring within the horse's foot.

With the advent of digital radiography, measurements can be quickly and accurately made and stored for future use and comparison as shoeing changes and treatment is initiated.

Another tool that can be used to help determine severity of laminitis is the "venogram". A venogram gives information about the vascular perfusion of the bone and soft-tissue structures. It gives an indication of the circulation that is occurring in the foot. The venogram can also be performed initially and re-performed following shoeing changes to re-evaluate circulation to the foot.

Mildly affected horses respond well to initial heel and sole support, using a variety of materials. Once the inflammation is decreased and the horse is walking comfortably a "rocker" shoe can be applied by an experienced farrier.

Severely affected horses respond well to an "ultimate" shoe applied initially which will dramatically increase the palmer angle. When the horse is comfortable a "rocker" shoe can then be used.

A "rocker" shoe benefits the horse because it helps get the break-over point to just distal to the tip of the coffin bone, where it should be in these horses. It should be applied only be an experienced farrier and relief should be seen immediately or follow up radiographs and the treatment plan may need to be adjusted.

If improvements are not seen in the foot following changes in shoeing it may be time to consider a deep digital flexor tenotomy to help save the life of the horse. This procedure severs the deep ditigal flexor tendon. It will release the tension the deep digital flexor tendon has on the coffin bone. This surgery generally will NOT return a horse to its original performance use, but if it is a breeding animal it can be a life-saving procedure and it may result in a light trail riding animal.

Other treatments for laminitis include changes in the diet, especially for horses suffering from "Cushings disease", insulin resistance, or those on lush pasture. Anti-inflammatory drugs such as Banamine, Phenlybutazone, and DMSO are very important especially in the early stages when the acute inflammation is present.

The important thing to remember with laminitis is that proper treatment is enacted immediately and radiographs be repeated often for follow-up and review. Many horses have suffered extreme pain leading to euthanasia due to this debilitating condition, if proper shoeing and treatment occurs early on, perhaps your horse may not have to suffer a similar fate.

If you have a horse that has developed laminitis due to "Cushing's disease" or insulin resistance problem don't get caught up in the low-carb, low-starch feed graze that is happening. You must remember forage makes up the majority of the horse's diet so if you don't know the non-structural carbohydrate level in the hay you are feeding your horse it does not pay to waste your money on feeding a few pounds of a low-starch feed.

Please call your veterinarian or nutritionist to discuss the importance of the diet in these laminitic horses.