Combination treatment of a pseudomonad abscess in a western black-tailed rattlesnake Crotalus molossus molossus

A three-year-old male western black-tailed rattlesnake (Crotalus molossus molossus), which was refusing food and losing weight was presented with a swelling on the right side of the head below the eye. An abscess was suspected and treatment with subcutaneous enrofloxacin was started immediately. After identification of the causative agents as Pseudomonas aeruginosa and Stenotrophomonas maltophilia, and following susceptibility testing, enrofloxacin treatment was replaced with marbofloxacin, intralesional gentamicin/betamethasone treatment and gentamicin administered subcutaneously at an increased terrarium temperature of 35 °C. Seven days later, the formed pus plug was debrided and a combined marbofloxacin/gentamicin/betamethasone treatment was continued for an additional seven days. The swelling disappeared. Marbofloxacin was continued for ten more days, after which time microbiology tests were negative for S. maltophilia and P. aeruginosa. The animal began to eat and gain body weight. To our knowledge, this is the first report of an abscess treatment in a rattlesnake and the first to demonstrate the effective treatment of a S. maltophilia-induced infection with a combination of marbofloxacin and gentamicin.