USE OF TICARCILLIN IN THE MANAGEMENT OF CANINE OTITIS-EXTERNA COMPLICATED BY PSEUDOMONAS-AERUGINOSA

Twelve dogs were referred with purulent and proliferative otitis exter na. Prior treatment included fluoroquinolones, glucocorticoids and pol yvalent ear drops over seven days to five months. In all cases the ver tical and horizontal ear canals were inflamed and thickened, with rupt ured tympanic membranes in four cases. No abnormalities were seen on r adiography of the osseous bullae. Numerous rod bacilli and degenerate neutrophils were seen on cytology. Pseudomonas aeruginosa resistant to fluoroquinolones and gentamicin was cultured in all cases. Treatment was initiated with 1 to 2 mg/kg prednisolone per os once daily, and a cleansing: and drying ear cleaner followed by topical administration o f injectable ticarcillin solution four times daily. Cases with rupture d tympanae also received 15 to 25 mg/kg ticarcillin three times daily intravenously until the membranes had healed. All cases were anaesthet ised for repeated saline ear flushes until no further discharge was ev ident and no rods were seen on cytology. Topical ticarcillin and the e ar cleaner were continued twice daily for 14 days after clinical resol ution. The duration of treatment ranged from 14 to 36 days. Treatment was withdrawn in one case which developed a drug reaction. All other c ases responded well with no adverse effects.