Bronson, J., DVM: Laminitis

By Dr. Joanna Bronson | http://bronsonvetservices.com/ Laminitis, commonly known as founder, continues to affect an estimated 7-14% of the world’s equine population. This condition is not only very painful, but can become life-threatening.

Records dating back to the 12th century B.C. hint at the effects of this condition when the Hittites warned about using extra care when feeding and watering their horses after exercise to avoid “barley surfeit” (surfeit meaning excess).

There are 3 basic types of Laminitis, but all have similar symptoms and outcomes.

Endocrine-associated Laminitis is the most common form and appears in horses who have an insulin imbalance. These horses are susceptible to Laminitis due to one of 3 pre-existing conditions. EMS (Equine Metabolic Syndrome), PPID Pituitary Pars Intermediate Dysfunction, and Cushing’s Disease. These conditions can be springboards for an attack of founder from an intake of excessive starch and sugar or lush pasture.

Laminitis is not genetically passed from generation-to-generation, however, a secondary predisposition such as Cushing’s or EMS can be inherited. These diseases can predispose a horse to be more susceptible to developing Laminitis with the right triggers.

When a horse is ill, Laminitis may be triggered by toxins in his bloodstream. This condition is called Sepsis-Related Laminitis. Horses suffering from diarrhea, colic, a retained placenta, or metritis (a uterine infection), a high fever or respiratory bugs are all targets for this form.

Any time a horse is injured and cannot bear weight on a limb, he is at risk for Supporting-Limb Laminitis, as the non-weight bearing leg puts excess pressure on the good leg. Even when the injured limb heals, damage may already have affected the weight-bearing leg.

A foundered horse will be very reluctant to move. He may shift his weight frequently. Foundered horses cannot stand square and may seek relief by leaning back on their hind legs, although back legs may also be sore.

A foundered horse may also exhibit a glazed, painful facial expression. He will experience increased heart and respiratory rates and might develop a sweat. His arterial pulse near the hooves will be elevated and will feel as though it is bounding. Affected horses will have warm-to-hot hooves. Modern diagnoses and treatment options are progressive, but a cure for Laminitis is still unknown. Once a horse has developed Laminitis, he is more likely to suffer from flare-ups as he ages. Unfortunately, all equine species are susceptible to developing this devastating disease.

Other contributing factors that may result in Laminitis may come from one or more of the following situations: Exposure to black walnut shavings used for bedding Excess glucocorticoids (corticosteroid-steroid administration)

Any Metabolic syndrome/inactivity (associated with obesity)

Ingestion of ergot alkaloids (endophyte-infested grass or hay)

Unaccustomed strenuous exercise

Excessive concussion with a hard surface “road founder”

Stress: high-stress occupation or environment, long transportation, hospitalization Poor hoof conformation or improper trimming or shoeing

History of Laminitis (previous damage) Chronic Laminitis means a horse has lost some of the correct alignment between the hoof capsule and the coffin bone, a movement known as rotation.

Besides a complete physical, radiographs are essential to determine the degree of damage from coffin bone rotation. A normal coffin bone has no rotation. When founder occurs, the coffin bone begins to rotate downward inside the hoof capsule. The degree of rotation can be determined through x-rays. There are treatment options that can provide relief for both acute and chronic conditions. Careful feeding, exercise, and monitoring can help horses continue to live and work for many years. However, the need for care is ongoing. An affected horse must be on a regular hoof trimming schedule and may have to wear shoes to provide hoof protection and prevent lameness. The key to control is in the hands of the owner.

Feeding a horse affected with chronic laminitis poses a challenge. Since grass is high in sugar, keeping him on a dry lot (no grass) is usually suggested. Use of a grazing muzzle can provide some supervised turnout on sparse grass. Grass hay and no grain are also recommended. Feeding a ration-balancer or multi-vitamin/mineral supplement provide the balance of necessary nutrients.

Foundered horses may also need a thyroid supplement, which can be determined through a blood test, to check for the insulin form of Laminitis.

Due to the seriousness of this disease, all lameness issues should be examined as soon as possible, since catching a problem early on with aggressive treatment is always best, especially with the risk of Laminitis.

Dr. Joanna Bronson graduated from Michigan State University College of Veterinary Medicine in 2000 at the top of her class. Following graduation, she worked as an intern at a large equine referral practice in Cleveland, Ohio specializing in lameness, surgery, and racetrack medicine. In 2005, she opened Bronson Veterinary Services in Coldwater, Michigan, a full-service equine, small animal hospital and surgical center.

Saddle Up! Magazine

https://www.facebook.com/SaddleUpMagazine