Vet. Res. 34 (2003) 689-716
DOI: 10.1051/vetres:2003030

Mastitis of dairy small ruminants

Dominique Bergonier^a, Renée de Crémoux^b, Rachel Rupp^c, Gilles Lagriffoul^d and Xavier Berthelot<sup>a

a</sup>  École Nationale Vétérinaire, UMR 1225 INRA-ENVT Host-Pathogens Interactions, 23 chemin des Capelles, 31076 Toulouse Cedex 3, France
^b  Institut de l'Élevage, Chambre d'Agriculture du Tarn, BP 89, 81003 Albi Cedex, France
^c  INRA-SAGA, BP 27, 31326 Castanet-Tolosan Cedex, France
^d  Comité National Brebis Laitières - Institut de l'Élevage, BP 27, 31326 Castanet-Tolosan Cedex, France

(Received 25 April 2003, accepted 23 June 2003)

Abstract
Staphylococci are the main aetiological agents of small ruminants intramammary infections (IMI), the more frequent isolates being S. aureus in clinical cases and coagulase negative species in subclinical IMI. The clinical IMI, whose annual incidence is usually lower than 5%, mainly occur at the beginning of machine milking and during the first third of lactation. These features constitute small ruminant peculiarities compared to dairy cattle. Small ruminant mastitis is generally a chronic and contagious infection: the primary sources are mammary and cutaneous carriages, and spreading mainly occurs during milking. Somatic cell counts (SCC) represent a valuable tool for prevalence assessment and screening, but predictive values are better in ewes than in goats. Prevention is most often based on milking machine management, sanitation and annual control, and milking technique optimisation. Elimination mainly relies on culling animals exhibiting clinical, chronic and recurrent IMI, and on drying-off intramammary antibiotherapy; this treatment allows a good efficacy and may be used selectively by targeting infected udders only. Heritability values for lactation mean SCC scores are between 0.11 and 0.15. Effective inclusion of ewe's mastitis resistance in the breeding goal has recently been implemented in France following experimental and large scale estimations of genetic parameters for SCC scores.

Key words: ewe / goat / mastitis / somatic cell count / epizootiology

Correspondence and reprints: Dominique Bergonier d.bergonier@envt.fr

© INRA, EDP Sciences 2003