A Study in Treating a Canine’s Bacterial Infection with Potential Antibiotic Resistance.

Astro, a female 6.5-year-old Border Collie, came to us with a red, swollen, circular lesion on her muzzle that had been present and progressing for about a month. It was a bit tender, but Astro was not very itchy and did not have any other lesions or skin problems. She had been treated unsuccessfully with an oral antibiotic for 2 weeks.

We ruled out contagious causes such as mites and ringworm. Based upon cytology, we suspected it was bacterial infection that either had not been treated long enough or was resistant to the first antibiotic. We advised the client to use an antiseptic cleanser, changed the patient’s oral antibiotic, and added a topical antibiotic. The response was slow, but there was minor improvement at recheck after 2 weeks on the antibiotic. Slow improvement continued, and the lesion finally cleared after a 6-week course of antibiotic. Astro’s fur has regrown, and the lesion has not recurred in the last 6 months.

Overall, the swelling in Astro’s lesion was representative of a deep skin infection. These infections require longer courses of antibiotic than the more common superficial skin infections. Luckily, Astro’s infection responded to a longer course with a different antibiotic. The addition of topical therapy is also critical in patients with skin infections. Many of our patients have multi-drug resistance, and infections can be very difficult or sometimes impossible to treat with the antibiotics that are available to us. Resistant bacterial infections are becoming increasingly more common and aggressive, reminding us how important proper use by veterinarians and clients alike is in battling this ever increasing, world-wide problem.