Laminitis is a painful condition in horses with many causes, including excessive weight bearing in one limb, usually as a result of a problem in another limb, most commonly the opposite limb. This causes an inflammatory condition of the lamellar tissue, the strong connecting tissue that attaches or bonds the pedal bone and the inner hoof wall together. Laminitis is very serious and can be life threatening due to the chronic and unrelenting pain associated with the loss of support and tearing of the tissue in the hoof.

Some of the potential causes of founder include excessive consumption of grain or green grass, colic, diarrhea, or any severe systemic disease. Severe colic is a disease/condition of the intestines, in most cases, and is one of the more commonly listed causes for laminitis. Research supports a belief that ‘laminitis trigger factors’ showed the lamellar tissue causing a inflammatory/enzymatic condition and failure of the bond between the hoof wall and pedal bone. Endocrine diseases such as Cushing’s Disease and Equine Metabolic Syndrome have been shown to be risk factors for the development of laminitis. Prolonged and excessive weight bearing by one or more limbs is yet another risk factor for the development of laminitis.

Retained placenta is another disease condition that has been identified as a risk factor for laminitis. Systemic diseases such as pneumonia and diarrhea result in a showering of the body with bacteria and can lead to a toxin release termed endotoxemia and end with laminitis. Repeat trauma/injury to the horse’s feet when running on a hard surface with poorly protected feet can end in laminitis. The bottom line is that the equine digit is capable of sustaining tremendous loading and weight bearing even at speeds of up to 40 miles per hour, but under certain conditions, weakening of the bond between the hoof wall and pedal bone can cause rapid failure of this magnificent structure. Also, the duration of lameness is a risk factor for the opposite supporting limb. Additionally, there are other risk factors such as prolonged work on hard surfaces without adequate foot protection, often called road founder, prolonged weight-bearing on a single limb because of a problem in the contralateral limb, Equine Cushings Syndrome and injection of steroids. However, sometimes the cause is impossible to determine and even though your vet may have an idea, there is no method of being for sure in some cases. Probably more money has been spent studying founder than any other equine disease, and yet the mechanism of how the disease occurs is still not completely understood. Consequently, this makes founder very difficult to treat when the reason it occurs is unknown.

By the time the horse is showing symptoms of laminitis, structural and vascular damage has already occurred in the foot and the disease has a head start on any treatment. Also, the damage may be so severe that the treatment may fail regardless of which treatment is chosen. The pathophysiology of laminitis that occurs following systemic disease has been the subject of many studies, but is still not clearly defined. Theories over the last twenty years include diminished blood supply to the foot, endotoxemia and inflammation, abnormalities of coagulation and absorption of toxins. Currently, the balance of the evidence points towards a generalised inflammatory response to which the lamellae within the foot are particularly susceptible. It has not been determined whether this is related to the weight-bearing function of the foot or some other factor.

TREATMENT If the primary cause is diarrhea, treat the diarrhea; if it is due to excessive weight bearing on one limb, the goal is to improve the weight distribution as soon as possible in the other leg. Specifically with laminitis you treat the pain, support the foot, reduce the inflammation using anti-inflammatory drugs; in many cases, cold therapy, also called cryotherapy or ice therapy, has been effective.

In acute laminitis, there is no radiographic evidence of separation of the hoof wall and pedal bone. In chronic laminitis, radiographs or x-rays reveal a change in the position of the pedal bone and hoof wall which equals separation or loss of the bond between the hoof wall and pedal bone.

DRUGS These drugs are primarily aimed at providing relief from the pain, controlling inflammation, improving blood supply and also preventing coagulation in the vessels within the digit. Phenylbutazone is used to control the pain and limit inflammation, acepromazine to improve the blood supply and DMSO also to limit inflammation. Of these, phenylbutazone is the only one that clinically demonstrates an obvious and immediate effect, but even the use of phenylbutazone is controversial in some quarters because the pain relief it provides encourages a horse to stand and/or move around. A sensible compromise is to use enough phenylbutazone to limit discomfort, but not to promote excessive use of the limbs. Other clinicians use oral isoxsuprine and topical nitroglycerine to increase digital blood flow, systemic aspirin and heparin to reduce coagulation within the digital vasculature, and pentoxiphylline for its anti-endotoxic and rheologic effects. Additionally, flunixin (Banamine) or ketoprofen are used instead of or in conjunction with phenylbutazone.

SHOEING The shoe distributes the weight of the limb over a larger surface area, supports the sole of the foot and provides a mechanism for treating the diseased foot with the addition of a special plate on the bottom of the shoe we term a ‘hospital plate.’ With the advent of ‘glue-on-shoes’ we have a uniform adherence of the shoe to the hoof wall and thus reduce stress concentration on any one area of the hoof wall.

The Role of Nutritional Therapy in the Treatment of Equine Cushing’s Syndrome and Laminitis

Equine Cushing’s syndrome, a relatively common and complex condition, is difficult to treat with conventional medicine. Cushing’s syndrome involves a hyperplasia or adenoma of the anterior pituitary gland. Biochemical alterations include increased endogenous cortisol, insulin resistance, elevated adrenocorticotrophic hormone, and decreased thyroid hormone levels. Symptoms include hirsutism (excessive and increased hair growth) with no loss of the winter coat in summer, refractory laminitis, weight problems (over or underweight), polyuria/ polydipsia (Pu/Pd), frequent infections, lowered immunity to intestinal parasites, decreased intestinal wall integrity, and infertility. Laminitis (an inflammation of the laminae of the foot) is a common and often fatal complication of Cushing’s syndrome that tends to be refractory (a period of time during which an organ or cell is incapable of repeating a particular action) to conventional treatment. One of the most common therapies is phenylbutazone, a non-steroidal anti-inflammatory drug (NSAID) known to cause significant changes in the permeability of the intestinal wall. Recent research has shown an intestinal bacterial exotoxin to be one of the triggering factors in laminitis. By removing phenylbutazone and healing the intestinal wall, laminitis becomes more responsive to treatment.Good hoof-care combined with nutritional management and the application of other modalities, including acupuncture, Chinese and Western herbs and natural alternatives, can complete the healing process. The successful treatment of equine Cushing’s syndrome is one of the best examples of treating a disease using the holistic approach. While each case requires different combinations of modalities, the outcome is usually positive with individually selected treatments. Natural therapies that help keep the gut healthy and enhance the immune system are the best options to explore as preventative measures against some of these problems.