A small episode of single quarter coliform infections in lactating dairy cows kept at pasture.
For a period of 150 days, an Escherichia coli infection in a single quarter of the udder of 13 cows occurred on average every 9 days, in a herd of 120 cows kept at pasture under temperate environmental conditions. Most cases were clinically mild, affecting cows in lactations 1 to 10 and at all stages of lactation; none were evident at calving. Samples of secretion from infected quarters sometimes had few demonstrable organisms. Eleven different serotypes in 8 (0) groups were recovered; one isolate was multiply resistant to antibiotics and one infection persisted for 120 days. A precise explanation for this episodic exacerbation of the new infection rate was not established, but probable contributing factors were recognised.
D000821:Animal Feed; D000818:Animals; D001315:Australia; D002417:Cattle; D004196:Disease Outbreaks / Q000662:veterinary*; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000662:veterinary*; D005260:Female; D007774:Lactation; D008414:Mastitis, Bovine / Q000453:epidemiology*; D011247:Pregnancy; D012621:Seasons