Owner-reported health and disease in U.S. senior horses

Background: Information on health care and health status of U.S. senior horses (≥15 years of age) is currently sparse. Objectives: (A) Provide an overview of owner-reported (1) medical conditions, (2) management/treatment practices for equine metabolic syndrome and pituitary pars intermedia dysfunction (PPID), (3) frequencies of routine health care practices and (4) supplement and pharmaceutical use in U.S. senior horses (≥15 years of age). (B) Evaluate potential risk factors for certain medical conditions and for low routine health care. Study design: Online survey. Methods: Descriptive and inferential analysis (binomial logistic regression and ANOVA) of 2717 questionnaires from owners of U.S. senior horses. Results: The most common owner-reported veterinary-diagnosed medical conditions were osteoarthritis (30%), dental disorders (15%), lameness (14%), PPID (12%) and ocular disorders (6%). Advancing age was found to be a risk factor for PPID (odds ratio [OR] [95% confidence interval, CI] = 1.14 [1.10–1.18]), dental (OR [95% CI] = 1.18 [1.15–1.22]) and ocular (OR [95% CI] = 1.05 [1.01–1.10]) disorders. Only 36% of horses were free of owner-reported veterinary-diagnosed medical conditions at the time of the survey. During the year prior to the survey, most routine healthcare practices (i.e., veterinary health care, dental care and anthelmintic treatment) were typically undertaken one to two times per year, while farrier visits occurred mostly every 5–6 weeks. Retired senior horses had a higher risk of no health care visits (OR [95% CI] = 2.1 [1.38–3.06]), no dental care (OR [95% CI] = 2.0 [1.31–3.00]) and low farrier attendance (i.e., ≤4 times/year) (OR [95% CI] = 2.4 [1.57–3.63]) compared with senior horses used for pleasure riding. The most frequently administered drug was firocoxib (18%) and joint supplements were the most provided supplements (41%). Main limitations: Potential recall, response and sampling bias. Risk factor analyses do not establish causal relationships. Conclusions: Medical conditions are highly prevalent in U.S. senior horses. Retired senior horses have an increased risk of low routine health care.