Lameness, weight loss, colic, and equine Cushing's syndrome are the four top reasons for euthanizing an older horse, said Catherine McGowan, BVSc, PhD, RCVS, European specialist in equine internal medicine, who presented research by Thomas McGowan, BSc, DVM, PhD, at the American College of Veterinary Internal Medicine Forum, held June 3-6 in Montréal, Quebec.

To date there have been no studies specifically relating to mortality and survival of aged horses.

McGowan and colleagues surveyed owners of horses age 15 years or greater in Queensland, Australia, and then contacted the respondents two to four years later. The survey gathered information from owners regarding age, breed, management, and health of the horses the respondents owned or obtained. Detailed veterinary medical exams were performed on 66% of the horses.

They then gathered follow-up information from 171 owners regarding 513 horses. Of the 513 horses, 44.9% were aged 10-14 years, and 31.5% were 15-19 years old.

The survey reported 91 deaths. Of these, 11% of the deaths reflected horses found dead with the remaining 89% euthanized. Age was an important risk factor with the risk of mortality increasing by 14% per year of age over 15. Other risk factors included owner dietary management, historical long hair coat or delayed shedding or laboratory diagnosed equine Cushing's syndrome, signs of dental disease (difficulty eating), colic, lameness (laminitis and grade 4/5 lameness), low body condition score (2.5 to 5 or less), and elevated fibrinogen.

According to McGowan, the most important risk factors included preventable or manageable conditions including weight loss, dental disease, and equine Cushing's syndrome.

General health screening, in particular, attention to management, diet, dental prophylaxis, and endocrine function, is important for aged horses.

About the Author

Jennifer Whittle, Web Producer

Jennifer Whittle, Web Producer, is a lifelong horse owner who competes with her Appaloosas in Western performance events. She is a University of Kentucky graduate and holds a bachelor’s degree in Community Communications and Leadership Development, and master's degree in Career, Technical, and Leadership Education. She currently lives on a small farm in Lawrenceburg, Kentucky.

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