Use of pirlimycin in a Streptococcus agalactiae eradication protocol

Abstract

Streptococcus agalactiae is a highly contagious obligate parasite of the bovine mammary gland. The epidemiology of the pathogen has been reviewed elsewhere.¹ S. agalactiae continues to be a prevalent pathogen in the dairy industry in Canada and across North America.¹ In Prince Edward Island (PEI), in 1994, 15% of herds were infected.² Prevalence rates in the late 1980s and early 1990s in other parts of Canada have ranged from 11 % to 43%.¹ In 1993 PEI dairy herds, infected with S. agalactiae, were 4 times more likely to get a milk quality penalty and 8 times more likely to lose Class 1 shipping status, due to repeat penalization, than culture negative herds.² At that time, imposition of a milk quality penalty, on Class 1 shippers, cost average sized producers approximately $1150/month and loss of Class 1 status cost, on average, $10,000.³