Topical salicylic acid treatment of digital dermatitis in dairy cows: Drug resides in milk and clinical efficacy

Abstract

Digital dermatitis (DD) causes skin lesions that commonly lead to lameness in cattle.  Tetracyclines have been a treatment of choice, but Salicylic acid (SA) is a non-antibiotic alternative that has comparable efficacy. There is no regulatory tolerance for SA in food animals in the United States, and no published data about milk residues after use to treat DD in cattle. The primary objective of our study was to describe drug residues in milk after topical treatment of DD lesions with SA. We also compared the efficacy of SA to tetracycline when treating DD, and tested the use of thermographic imaging as a method for staging the severity of DD lesions.