REGULAR FEATURE EQUINE WELLNESS by Sara Perkins, DVM Equine Cushing’s Disease L Common Senior Horse Disease Can Cause Numerous Health Problems ong summer days turn into crisp fall and decaying teeth. These subtle signs occur years old have been diagnosed. days and before we know it, winter has due to suppression of the immune system. Diagnosis is made based upon on clinical arrived. When we think of old man Exercise intolerance, excessive urina-symptoms and bloodwork. Often blood is winter in horse form, we think of an old tion, excessive drinking, weight loss, infer-pulled to check the horse for elevated ACTH horse who has a long, shaggy hair coat and tility, mental impairment, and excessive levels. This is considered a screening test, a swayed back, fat deposits in odd meaning a horse who has elevated places, and is an easy keeper. As a levels of ACTH has the disease, but child, I was taught these were signs a horse who has normal levels of of a well-loved older horse, but ACTH may still have Cushing’s. Ad-something deeper is going on. These ditional tests including the TRH clinical symptoms could be signs of (thyrotropin releasing hormone) equine Cushing’s Syndrome, also stimulation test or dexamethasone known as PPID (Pars Pituitary In-suppression test are often per-termedia Dysfunction). formed for a final diagnosis. Equine Cushing’s disease occurs Research has demonstrated a when the portion of the brain that close link between equine metabolic regulates hormones — the pituitary syndrome and Cushing’s. Both con-gland — has become enlarged and ditions are linked to insulin resis-therefore the hormone cascade tance and laminitis. A horse that is becomes altered. Dopamine, a hor-overweight can be predisposed to Diagnosis for equine Cushing’s is made based mone that regulates other hor-insulin resistance leading to lami-mones, is often inhibited or is not upon on clinical symptoms and bloodwork. nitis (founder). Horses that are be-accurately recognized by the body. Often, blood is pulled to check the horse for ing tested for Cushing’s should have Without dopamine regulation, a elevated ACTH levels. their insulin and glucose levels test-hormone called ACTH (adrenocor-ed as well. Horses that suffer from ticotropic hormone) is produced in Cushing’s and equine metabolic excess. Excess ACTH results in the syndrome need to be managed with body’s natural stress hormone, cor-medication, diet, and exercise. tisol, to become activated at elevated Unfortunately, there is no cure levels due to the excessive amounts for equine Cushing’s, but a daily tab-of ACTH. Excessive stress hormone let called Pergolide can be adminis-(cortisol) suppresses the immune tered for treatment. Pergolide is a system and predisposes these older dopamine agonist helping regulate horses to infections. the excessive levels of ACTH. Studies The classic picture of a horse have demonstrated that the admin-suffering from Cushing’s includes a istration of compounded Pergolide long, curly hair coat (hirsutism), fat is not as effective in managing the deposits in odd places, a cresty neck, disease as administering labeled potbellied appearance, and delayed Pergolide. Additional treatments in-shedding. Subtle signs can include suffering sweating can all be additional signs of the clude cyproheptadine. from repeat hoof abscesses, skin infections, disease. Traditionally, older horses suffer Equine Cushing’s cannot be prevented eye ulcers, laminitis, slow healing wounds, from Cushing’s but horses as young as ten but precautions can be taken to lower the severity of the disease. These precautions include weight management, continued ex-Dr. Sara Perkins , DVM, graduated from the College of Veterinary ercise of older horses, and testing for the Medicine at WSU in 2000. In 2001, Dr. Perkins became an intern at disease at the first appearance of subtle Rood and Riddle in Lexington, KY, gaining experience in equine surgery, signs. Weight management cannot be em-medicine, anesthesia, lameness, and neonatal care. In 2002 she went to the University of California at Davis Veterinary Medical Teaching phasized enough; feeding your horse only Hospital and worked with the equine internal medicine group as a what he needs, placing a grazing muzzle resident. In 2005 she started Equine Medical Services, based out of Rainier, during peak growing seasons, and limiting Washington. Her main focuses include sports medicine, reproduction, the number of sugary treats such as carrots and nutrition. She owns a farm where she breeds Lusitanos. She rides dressage and cutting and apples is so important. Let’s help our old horses. She partnered with Equinavet in 2017. Learn more at www.equinemedservices.com . horses live well! NWHS 10 December 2020 The Northwest Horse Source PHOTO ©STANDRET -STOCK.ADOBE.COM PHOTO ©VPROTASTCHIK -STOCK.ADOBE.COM www.nwhorsesource.com
The Northwest Horse Source NWHS 1220: Page 10
