Dr. James Orsini, Associate Professor of Surgery
George D. Widener Hospital for Large Animals, New Bolton Center
Q1. What is the standard treatment for laminitis?
Q2. How can a shoe help in the prevention or treatment of laminitis?
Q3. What is the difference between acute and chronic laminitis?
Q4. What are the causes of laminitis?
Q5. What is the success rate for laminitis treatments?
Q6. What is laminitis?
Q7. What are the symptoms of laminitis?
A1. The treatments can be quite varied depending on the underlying cause. Generally clinicians treat the primary disease that led to laminitis, which in many cases will minimize progression of the disease. For example, if the primary cause is diarrhea the diarrhea is treated and 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. With laminitis, treat the pain, support the foot and reduce the inflammation using anti-inflammatory drugs. In many cases, cold therapy (also called cryotherapy) or ice therapy has been effective. The study for new and better treatments is ongoing.
A2. The shoe distributes the weight of the limb over a larger surface area and moves the breakover point further back on the foot, thus reducing the stress on the lamellar tissue along the front of the foot while consistently supporting the sole of the foot. With the advent of glue-on-shoes, we have a uniform adherence of the shoe to the hoof wall, and therefore can reduce stress concentration on any one part of the hoof wall.
A3. In acute laminitis, no radiographic evidence shows 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.
A4. Laminitis has many causes, including:
- Severe colic, a disease/condition of the intestines, is one of the more common causes for laminitis. Research supports a belief that ‘laminitis trigger factors’ shower the lamellar tissue, causing an 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;
- Prolonged and excessive weight bearing by one or more limbs;
- Retained placenta;
- 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; and
- Carbohydrate overload; if a horse eats too much grain or grass, resulting digestion problems can lead to restricted circulation that ultimately results in laminitis.
The bottom line is 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 all and pedal bone can cause rapid failure of this magnificent structure.
A5. The success rate varies widely and depends on many factors, such as rapidity of onset and degree of separation of the hoof wall and pedal bone, weight of the horse (many ponies can have repeat episodes of laminitis and live a good quality of life just because they are lighter weight), control and treatment of the underlying cause for the laminitis in the first place and overall general health of the individual horse. The good news is that our success rate in treating laminitis continues to improve every year because veterinarians, farriers, horse owners, trainers and other health care providers better understand the disease and how to treat it.
A6. Laminitis is a painful inflammation 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. The front hooves are most commonly affected, although the hind feet are sometimes affected.
A7. Symptoms of laminitis include:
- Increased temperature of the wall, sole, and/or coronary band of the foot;
- A pounding pulse in the digital palmar artery (The pulse is very faint or undetectable in a cold horse, readily evident after hard exercise.);
- Walking very tenderly, as if walking on egg shells;
- The horse standing in a "founder stance" (the horse will attempt to decrease the load on the affected feet. If it has laminitis in the front hooves, it will bring its hind legs underneath its body and put its forelegs out in front.)