A severe outbreak of bovine mastitis assoicated with Mycoplasma bovigenitalium and Acholeplasma laidlawii.

An outbreak of clinical mastitis is described in which 75 cows of a herd of 200 Friesian cows were affected in one or more quarters over a period of three months. Sixty animals failed to return to normal despite various intramammary and systemic antibiotic treatments. Heifers, dry cows and lactating animals were affected. The milk of 15 out of 53 animals tested yielded mixed cultures of Mycoplasma bovigenitalium and Acholeplasma laidlawii. Thirteen of 34 sera showed evidence of antibodies to A laidlawii.