Ad Ellis

A retinoscopic survey of 333 horses and ponies in the UK

INTRODUCTION Ophthalmic examination in the horse is generally limited to crude assessment of vision and screening for ocular lesions. The refractive state of equine eyes and the potential impact on vision and performance requires further investigation. OBJECTIVE To assess the refractive state of a large, mixed-breed sample of horses and ponies in the United Kingdom (UK). PROCEDURE The refractive state of both eyes of 333 horses and ponies was determined by streak retinoscopy, and the effect of age, height, gender, breed and management regime on the refractive state assessed. RESULTS Emmetropia was found in 557 of 666 (83.63%) of eyes; 228/333 (68.5%) of the horses/ponies were emmetropic in both eyes. Refractive errors of greater than 1.50 D (in either direction) were found in 2.7% of the eyes tested. Ametropic eyes included hyperopia (54%) and myopia (46%). Anisometropia was found in 30.3% of horses and ponies. Breed of horse/pony was the only factor that affected refractive state (in the left eye only, P < 0.05) with Thoroughbred crosses having a tendency toward myopia and Warmbloods/Shires toward hyperopia. DISCUSSION AND CONCLUSION The retinoscopic survey found emmetropia to be the predominant refractive state of the equine eye with no evidence of an overall trend toward myopia or hyperopia. However, individual and breed-related differences were found. Such factors should be considered in the selection of horses for sport and leisure, and when evaluating their performance potential. More comprehensive visual testing would be valuable in identifying underlying causes of behavioral problems.

The influence of boot design on exercise associated surface temperature of tendons in horses

Sport horses frequently injure tendons of the lower limb. Tendon boots are commonly applied for structural support and trauma prevention during competitions. However these boots may increase heat stress in the area. Two separate studies were carried out with the aim to improve understanding of the effect of boots on heat around the tendon area. Study 1 measured heat emitted from two types of boots (traditional and perforated, cross-over design) covering the superficial digital flexor tendon in 4 horses during a set ridden and lunged exercise test. Study 2, a field test, measured the effect of boot style (traditional, perforated and open fronted) on skin surface temperature in 130 horses, after completing a cross country event test (either a BE 100 three day event or a CIC* - two day short format event). An infrared thermometer was used to measure temperatures during both studies. Boots designed with perforations demonstrated greater heat emissions than traditional (non-perforated) boots (+3.5 ° C, P<0.01)...