This study has identified many prevalent clinical signs of disease in geriatric horses. Description of the most prevalent health problems and further identification of risk factors for these conditions will aid in targeted improvements in veterinary care, owner education and welfare.

The low prevalence and relatively poor agreement of owner-reported disease compared to that detected on veterinary examination suggests inaccurate or under-recognition, or inaccurate reporting of health problems by owners of geriatric horses, which could lead to a delay in presentation for veterinary treatment. Increased veterinary involvement and improved owner education in the care of geriatric horses should facilitate earlier identification of disease, particularly that which is not readily detectable by owners, and aid management of health and welfare problems.

No abstract

Ophthalmic lesions were detected in 67 of 83 horses and ponies aged 15 years or more. Degeneration of the vitreous, followed by senile retinopathy, were the most common lesions and both of them became more common with advancing age, although few of the owners reported disturbances of vision in their animals.

Summary Reasons for performing study: The mechanisms underlying the increased risk of laminitis in horses with equine Cushing's disease (ECD) are poorly understood. Hypothesis: That abnormalities in glucose homeostasis, similar to those which cause microvascular dysfunction in human diabetics, contribute to development of laminitis in horses with ECD. Methods: Thirty‐one aged horses were divided into 3 groups based on clinical signs and dexamethasone suppression testing (DST). Group 1 (n = 12) had clinical ECD as evidenced by hirsutism. Group 2 (n = 10) had a positive DST but no hirsutism. Group 3 (n = 9) were controls without ECD, with a negative DST and no clinical evidence of ECD. Biochemical indices of glucose metabolism, vascular function and oxidative stress were determined in single morning blood samples. Results: Group 1 had abnormalities in glucose homeostasis, including increased levels of glucose and insulin, compared to Groups 2 and 3. Groups 1 and 2 had significantly lower plasma thiol (PSH) levels and nonsignificantly lower albumin‐corrected PSH levels than Group 3, consistent with oxidative stress. Conclusions and potential relevance: The observed abnormalities in glucose metabolism and oxidative stress could potentially contribute to development of laminitis in horses with ECD, by similar mechanisms to those that cause microvascular dysfunction in human diabetics. The absence of inter‐group differences in the biochemical indices of vascular function precludes their use as preclinical diagnostic indicators of vascular dysfunction. The study also highlighted limitations in the premortem diagnosis of ECD.