Metritis in dairy herds: an epidemiological approach with special reference to ovarian cyclicity

A four year retrospective study of metritis cases was performed in two dairy herds of 95 to 140 cows (herd A) and 60 cows (herd B). Systematic clinical examination and plasma progesterone analysis for ovarian status assessment were performed at 30 days after parturition. Calving conditions had been recorded earlier. These two herds were characterized by a high incidence of metritis (20 to 40% of the calving cows according to year or herd). Higher incidences were found (1) in Spring and (2) in females with difficult calvings. The major findings were that: (1) there was a 50% risk (approximately) that non-cycling females, at 30-37 days post-partum would be suffering from metritis, as opposed to a 34% risk in cycling animals (P less than 0.05); (2) there was no individual susceptibility to this infection. It has been suggested that for better monitoring and more effective treatment, this cyclicity factor should be given careful consideration.