Vet believes horses get fibromyalgia

Veterinarian believes some horses have syndrome similar to human connective-tissue disease

ONE IN EVERY 48 Americans suffers from fibromyalgia syndrome, a disease that causes muscle aches, painful tendons and ligaments, gastrointestinal discomfort, headaches, sleep disturbances, and fatigue. Those who have the disease describe its symptoms as similar to a chronic bout of severe influenza.

Despite the growing number of cases noted by physicians, fibromyalgia remains an enigma. Its cause is unknown; affected parts of the body appear normal upon diagnostic imaging and biopsy; no laboratory tests exist to detect the disease; and symptoms wax, wane, and sometimes disappear for periods of time, and might not be the same from one individual to the next. These mysteries, together with the fact that antidepressants and anti-anxiety drugs alleviate symptoms, have led some pathologists to dismiss the condition as a neurosis rather than a bona fide physical ailment. Yet, many open-minded physicians admit that, just because they cannot confirm fibromyalgia through present-day diagnostics, there is no reason to assume the condition does not exist.


One of those physicians--albeit, a veterinarian--is Brenda Bishop, V.M.D., who believes she has identified a form of the disease in horses in her practice, Sport Horse Associates in Carthage, North Carolina.

Fungal infection?
"It's interesting to me that fibromyalgia in horses presents many of the exact same symptoms described by human patients," Bishop said. Associated with those symptoms are bacterial, viral, and fungal infections that may be either the cause of the disease or the result of it. According to Bishop, no matter what came first, the disease or the infections, eliminating those infections produces results.

"In horses, according to my theory, an underlying chronic, systemic, low-grade fungal infection is usually present," Bishop said.

"Symptoms in horses are subtle in the early stages, extreme later on, easily recognizable, and in most cases easily treated with lasting, good results," she continued. "Interestingly, most of the symptoms take years to develop, so a thorough history of the horse is vital. It helps to work with a horse owner or trainer who has been involved with the horse for at least one year."

Bishop has developed a questionnaire to help owners identify horses that might be suffering from fibromyalgia. She pointed out that, while answering yes to one or two of the questions could indicate the horse has a different ailment, answers that reveal a cluster of symptoms would cause her to suspect fibromyalgia.
Some of the questions Bishop asks horsemen are:

• For horses kept in a herd, has the pecking order changed?
• Has your horse gone from being a herd boss to the bottom of the pecking order?
• Is your horse displaying chronic irritability?
• Is your horse severely depressed or listless?
• Does your horse show extreme anxiety and tension?
• In everyday situations, is your horse more nervous than normal?
• Does your horse have mood swings, going from nervous and high-strung to sleepy and depressed, or vice versa?
• Has your horse shown newly acquired problems walking on and off your horse trailer or on other sloping surfaces?
• Does your horse have problems standing quietly for the farrier or standing on three legs for more than 30 seconds?
• Does your horse exhibit excessive tail swishing when at work?;
• Is your horse kicking incessantly for no apparent reason?
• Does your horse pin its ears, bare its teeth, and threaten to bite other horses and people for no apparent reason?
• Is your horse a head-shaker or a cribber?
• Does your horse have persistent rain rot or mud fever?
• Does your horse often have diarrhea?

Bishop believes these symptoms are caused directly by deconditioning of the horse's muscles by the fungal attack or are the horse's psychological response to the illness. "To put it in plain English, I think they feel lousy," she said. "If you have ever known a person with fibromyalgia, they are just miserable, not just unhappy. They feel terrible."

A horse's body contains three types of muscle: striated or skeletal muscles, which attach to and move the skeleton; smooth muscles, which control the movement of lungs, intestines, and other organs; and heart muscles, which control cardiac function. In horses with suspected fibromyalgia, Bishop sees evidence of deconditioning of all three types of muscle. Skeletal muscle deconditioning would cause motor problems; smooth muscle deconditioning would cause intestinal and lung problems; and heart muscle deconditioning would contribute to fatigue.

Additionally, intestinal malfunction would rob the horse's body of nutrients, and diminished heart function would decrease the supply of oxygen to the whole body, causing a myriad of problems, including a proliferation of the fungal infection Bishop suspects is the root of fibromyalgia symptoms.

Research methods fail
If a systemic fungal infection exists in the horse's blood and tissues, one would expect that today's sophisticated pathology laboratories could pinpoint it, but Bishop maintains this is a formidable and usually unsuccessful task.

"Pathologists will tell you that, when they receive a sample for fungal culturing, it is difficult, time-consuming, and a challenge to grow any fungus out of it," she said. "It takes a minimum of three weeks and, at the end of three weeks, there is no way of knowing if what you grew was a primary pathogen or a secondary contaminant."

So, Bishop has based her diagnosis and treatment on what she calls the process of exclusion. Her best results have been achieved with a two-week regimen of a single, daily dose of a fungicidal drug top-dressed on the horse's feed.

Although Bishop acknowledged her research does not follow typical scientific protocol, she insisted that when accepted methodology fails, researchers must be innovative in their thinking.

"If you continue to think like you have always thought, you will continue to get the results you always got, and in this case that is nothing," she said. "If you don't think outside the box, you will never be able to move forward."