An evaluation of equine headshaking syndrome and its management

• Main Author: Taylor, K. D.
• Published: De Montfort University 2004
• Subjects: 636.1089683060724
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.406016

Headshaking is a general term for a syndrome of behaviours that are exhibited by some horses when they are exercised. These include sudden, intermittent shaking of the head, excessive snorting and attempts to rub the nose. Examination by the veterinary surgeon is often inconclusive (Lane and Mair 1987) although such horses may become unrideable and, if severely affected, destroyed. Advances in our understanding of the causes of the syndrome have been hampered by the absence of effective treatments and a preponderance of case reports over controlled, epidemiological studies. In this thesis, a range of epidemiological techniques were employed to answer questions relating to the presentation, aetiology and treatment of the syndrome. A case-control survey of 83 headshakers found no evidence to suggest that aspects of the management of the horse were significant, general risk factors. Inferences from the reports of 200 horse owners regarding the presentation of the syndrome, the intermittency of its appearance and association with trigger factors supported a proximate aetiology of nasal irritation. A field trial of a bitless bridle and a light-limiting facemask suggested that the presence of the bit or light alone are not significant triggers for British headshakers. This is in contrast to reports from the USA, which, in the absence of evidence of any difference in presentation of the syndrome, suggests that headshaking syndrome is the final common pathway for irritation caused by a number of different factors. An appropriate methodology for the assessmenot f the efficacy of alternative and complementary therapies for headshaking was described using the principles of clinical trials. The use of the horse-ownera s the assessoor f changei n the headshakings igns was supported by a demonstration of the consistency of their reports. Two doubleblinded, placebo-controlledc ross-overt rials, conducteda ccordingt o the methodology, reported no evidence of any specific effect of an herbal supplement or a magnatherapy headcollar. However, significant improvement was reported in the horses under both placebo and verum conditions. This supports the assertion that control for the nonspecific effects of treatment by placebo is essential if progress is to be made in understanding the aetiology and treatment of headshaking.