Ancillary Therapy For Bovine Respiratory Disease

Abstract

Through ancillary therapy we attempt to improve response to antimicrobial drugs. Ameliorating the harmful effects of inflammation, blocking the activity of histamine, and improving immune function serve to alter the pathophysiology of the infectious process. We tend to assume that this alteration is consistently beneficial. But other possible effects include drug interactions and direct toxicity. This paper reviews the pharmacodynamics and pharmacokinetics of selected antiinflammatory, antihistamine, and immunomodulating drugs used in the therapy of bovine respiratory disease. Antiinflammatory drugs used in the therapy of bovine respiratory disease include glucocorticosteroids and non-steroidal antiinflammatory drugs (NSAIDs) such as aspirin, flunixin meglumine, and phenylbutazone. The glucocorticosteroids are potent antiinflammatories but also have deleterious effects on immune function with continued therapy. The NSAIDs have varying pharmacokinetics and also may produce toxicity through their potent prostaglandin-synthesis inhibition. An antihistamine labeled for use in cattle is available, but efficacy data has apparently not been published. Laboratory data supporting the use of vitamin C as an immunomodulator has been published, but clinical trial data is lacking. The literature concerning the immunomodulatory effects of levamisole indicates that results are variable at best.