title: A field investigation of subclinical mastitis in sheep in southern England.
abstract: The prevalence, aetiology and epidemiological features of subclinical mastitis were investigated in 358 lowland ewes in seven flocks in southern England. Milk samples (2092) were collected at 3-weekly intervals; those which were both bacteriologically and Whiteside test positive were deemed to have originated from glands with subclinical mastitis. The period prevalence of subclinical mastitis was 11.7% and the prevalence remained relatively constant over the course of lactation (5.5-7.0%). The predominant bacterial isolates from 48 glands with subclinical mastitis were streptococci (42%), coagulase-negative staphylococci (33%), Pasteurella haemolytica (17%) and Staphylococcus aureus (8%). Coagulase-negative staphylococci were the predominant isolates (53%) from samples which did not show a positive Whiteside test result. The prevalence of subclinical mastitis increased with age of ewe but was not influenced by the presence of teat lesions. There was a significant association between the development of clinical mastitis (26 glands) and antecedent subclinical mastitis caused by the same organism (10 glands).
authors.affiliation: Department of Animal Health, Royal Veterinary College, Potters Bar, England.
authors.forename: G H
authors.initials: GH
authors.lastname: Watkins
authors.forename: A R
authors.initials: AR
authors.lastname: Burriel
authors.forename: J E
authors.initials: JE
authors.lastname: Jones
mesh_terms: D000818:Animals; D004739:England / Q000453:epidemiology; D005260:Female; D008413:Mastitis / Q000453:epidemiology / Q000662:veterinary*; D008892:Milk / Q000382:microbiology; D015995:Prevalence; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology*