Oxytocin and Other Alternatives to Antibiotic Therapy of Clinical Mastitis

Abstract

Mastitis is the most common cause of antibiotic use in adult dairy cows. Antibiotic treatment of clinical mastitis incurs the cost of the drugs used, the discarded milk, and the loss of the option to cull the cow until after the withdrawal time has elapsed if treatment fails. Oxytocin (OT) has been proposed by practitioners as an alternative to antibiotic therapy of mild clinical mastitis. Efficacy of OT has not been established against untreated controls. Safety of OT is reviewed; OT at doses used for milk ejection appears safe, but at higher doses it may affect the estrous cycle and may cause abortion in heatstressed cattle. Efficacy of intramammary antibiotics in clinical mastitis caused by environmental pathogens is not well established in controlled research. A recent study by the author comparing OT to intramammary cephapirin or amoxicillin used according to the label in mild clinical environmental mastitis showed no overall difference in bacterial or clinical cure rates. Antibiotics did have higher clinical cure rate than OT in infections due to pathogens other than coliforms and streptococci. Protocols for treatment of clinical mastitis on dairy farms should be developed cooperatively by producers and veterinarians based on knowledge of the pathogens involved on each farm. Treating every mastitic quarter with intramammary antibiotics in a herd with mostly environmental mastitis is not economically justifiable. Records of mastitis treatment should be kept so that chronic cows can be identified. On farms with mostly environmental mastitis, antibiotics should be used selectively. Antibiotic therapy of quarters from which no pathogen can be isolated and coliform quarters is difficult to justify. For certain infections combinations of intramammary and systemic antibiotic therapy may be necessary. Use of OT to increase milk ejection, increased frequency of milkout, and anti-inflammatory therapy may be important elements of mastitis treatment protocols. Chronic cows in environmental mastitis herds are unlikely to respond to treatments that have already failed, and should be culled, dried, or segregated.