Use this URL to cite or link to this record in EThOS:
Title: The welfare of sheep with sheep scab (Psoroptes ovis infestation)
Author: Corke, M. J.
Awarding Body: University of Cambridge
Current Institution: University of Cambridge
Date of Award: 2001
Availability of Full Text:
Full text unavailable from EThOS.
Please contact the current institution’s library for further details.
The effects of sheep scab, (Psoroptes ovis infestation) on the welfare of sheep were studied. Flocks of sheep naturally infested with sheep scab and flocks of uninfested sheep, were studied before and after treatment with acaricides. A group of sheep, experimentally infested with Psoroptes ovis mites, were studied throughout the infestation. Behaviour was studied using focal and scan sampling techniques. Sheep scab resulted in increases in rubbing, scratching and biting. Rubbing and scratching in infested sheep were sometimes accompanied by non-functional mouthing, considered to be a stereotypy. Times spent grazing, cudding and idling were not affected by sheep scab, but the bout lengths of grazing and idling were reduced. The experimental group showed an increasing neutrophilia through the infestation, with erratic increases in eosinophil count and fibrinogen, while haemoglobin concentration and haematocrit decreased. Naturally infested flocks showed lymphopenia after treatment. Serum globulin concentrations increased through the infestation, with a concurrent decline in serum albumin. The serum globulin started to decline within one month after treatment. Some lactate dehydrogenase isoenyzme fractions increased during the infestation. Prolactin decreased and β- endorphin increased throughout the experimental infestation, although seasonal factors may have influenced these results. There was no change in pressure nociceptor threshold due to sheep scab. A questionnaire survey of sheep farmers suggested that sheep scab in Britain had increased in incidence and distribution over the last decade. The welfare of sheep infected with sheep scab and the control of sheep scab are discussed in the context of the experimental findings.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available