The Cellular and Immune Response in Milk and Regional Lymph During Experimental Mastitis

Abstract

Experiments have been carried out to study antibody and cellular responses in mammary lymph and milk from ewes with experimental mastitis. Virulent staphylococci were infused into one mammary gland from which lymph was collected for varying periods by cannulation of the efferent mammary lymphatic duct. Anti-α-haemolysin titres rose to relatively high levels in the plasma and lymph, and in the secretion from the infected gland in ewes with acute mastitis, but not in ewes with subacute mastitis. The contribution of the supramammary lymph node to the lymph titre, appeared to be slight. In 2 animals, there was a suggestion of local antibody production by the infected gland. The cellular response in the lymph was characterised by the appearance of polymorphs in large numbers during the first 24. hr. after infection of the gland. In all animals, mature plasma cells in lymph reached a maximum at 5 days, while the maximum antibody titre in lymph occurred 2 days later. In sub-acute mastitis, as signs of inflammation diminished, cellular changes in the milk, similar to those seen during involution of the mammary gland, were observed.