Equine Welfare: A Study of Dermatophilosis and the Management of Data Relevant to the Health and Wellbeing of Horses

Mollison, Pauline J (1990) Equine Welfare: A Study of Dermatophilosis and the Management of Data Relevant to the Health and Wellbeing of Horses. PhD thesis, University of Glasgow.

Abstract

This thesis considers aspects of equine welfare which have received little attention in the U.K. Skin disease, particularly bacterial skin disease, was highlighted as an area giving rise to concern with respect to equine welfare. Dermatophilosis was examined in detail as one of the commoner bacterial skin conditions responsible for animal suffering, and one for which management is often difficult. Essential fatty acids (EFAs) were evaluated as a dietary supplement in an alternative approach to the management of equine dermatophilosis. The pharmacokinetics of EFAs in the horse were investigated, with EFAs supplemented as evening primrose oil (EPO), containing linoleic acid (LA) and gamma-linolenic acid (GLA). A very slow conversion of LA to its active metabolites was found in the horse compared to other species. A daily dose regime of 20g of 80% EPO and 20% fish oil and vitamin E was adopted for the consequent treatment and prophylactic studies. In a placebo-controlled, double blind treatment study no significant effect was seen on severity or extent of distribution of lesions of dermatophilosis when horses received EFAs orally. When EFAs were supplemented over the traditional autumn high dermatophilosis risk period in a controlled prophylactic study, they did not prevent development of lesions or reduce incidence of infection. No significant improvement was afforded by EFAs on the condition of the coat, mane, tail or hooves, nor on general body condition. EFAs were not harmful and exerted no effect, adverse or beneficial, on haematological or biochemical parameters. The characteristics of D. congolensis were examined in relation to the site and severity of lesions of dermatophilosis, but no correlation was found. All isolates were different when examined by differential bacteriological growth characteristics and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Proteolytic enzyme production by D. congolensis was investigated with regard to the virulence of the organism, and several isolates demonstrated extracellular protease activity. The clinical and haematological consequences of bleeding horses at regular intervals were monitored in a group of animals maintained for commercial blood production. No adverse effect was recorded on clinical, protein or haematological profiles when 8 litres of blood were removed every three weeks. Thoroughbred animals supported regular bleeding better than non-Thoroughbred animals. A relational database system was created as a management tool for the manager of the horse herd. The information contained within the system, regarding horse details, bloodroom records and farm laboratory records, could be constantly updated. Rapid detection of poor performers or anaemic animals could permit prompt instigation of corrective action, avoiding undue animal distress. It is hoped that some of the work within this thesis has made a worthwhile contribution to the extension of knowledge concerning the welfare of horses in the U.K.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Veterinary science, Animal sciences
• Date of Award: 1990
• Depositing User: Enlighten Team
• Unique ID: glathesis:1990-78189
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 30 Jan 2020 15:37
• Last Modified: 30 Jan 2020 15:37
• URI: https://theses.gla.ac.uk/id/eprint/78189