EVALUATION OF CHLORHEXIDINE DIACETATE FOR PERMANENTLY DRYING OFF CHRONIC MASTITIC QUARTERS

Mammary quarters of 15 Jersey cows chronically infected with Nocardia spp., Pseudomonas aeruginosa, Escherichia coli, or Serratia spp. were infused with chlorhexidine diacetate (Nolvasan(R):Fort Dodge Laborator ies, Inc., Fort Dodge, Iowa) to permanently dry off the quarters. Quar ters became nonfunctional within 14 to 63 days without an appreciable increase in somatic cell counts of Nolvasan-infused or uninfused quart ers. Treated quarters remained nonfunctional after a non-lactating per iod. Histological analysis of Nolvasan-infused quarters demonstrated t hat secretory tissues had involuted to a nonsecretory state and appear ed similar to blind or nonfunctional quarters.