Bovine Acute Mastitis: Effects of Intravenous Sodium Salicylate on Endotoxin-Induced Intramammary Inflammation

Abstract

Effects of the nonsteroidal anti-inflammatory agent sodium salicylate on endotoxin-induced mastitis were evaluated in lactating cows. Escherichia coli endotoxin was administered to a mammary quarter 1h after initiation of a 12-h i.v. infusion of sodium salicylate. Milk SCC, BSA concentrations in milk, mammary inflammation, rectal temperature, appetite, milk production, and plasma and lymph PGF2α, were monitored. Gross mammary inflammation was not reduced by salicylate infusion, nor did sodium salicylate prevent increased milk SCC or BSA concentrations in milk, although treatment tended to decrease the magnitude of these responses. Sodium salicylate decreased subcutaneous abdominal vein PGF2α, metabolite, and PGF2α, metabolite tended to be reduced in lymph during the acute phase of inflammation. The increased rectal temperature after endotoxin infusion was reduced in cows treated with sodium salicylate. Appetite was reduced after endotoxin infusion in untreated cows and those treated with sodium salicylate. Milk production declined after endotoxin challenge in all cows. Although sodium salicylate did not substantially reduce mammary inflammation, it had an antipyretic effect and reduced PGF2α metabolite in mammary blood.