9. Contagious Mastitis
Dr. Keller obtains milk samples from all cows with a SCC linear score of over 5 and sends them to the state veterinary diagnostic lab for culture.
The following week, Dr. Keller reports the culture results to Oliver McCormick
Dr. Keller continues, “You have several different kinds of bacteria that are responsible for your subclinical mastitis problem. About 55% of the cows with high SCC linear scores are infected with Staphylococcus aureus and 30% have Streptococcus agalactiae.”
“Staphylococcus aureus and Streptococcus agalactiae infections are considered to be ’contagious udder pathogens’. Infection with these pathogens is usually strongly associated with milking technique, and they are spread from cow to cow. Even ifyou cure a cow, she will likely be immediately re-infected from one of her herd mates.