OBJECTIVES

Bacterial pyoderma is the most frequent skin disease in dogs; Staphylococcus intermedius is the most common cause. Traditionally, bacterial infections have been treated with amoxicillin-clavulanate, cephalexin, enrofloxacin and orbifloxacin, among others. These drugs have shown to be efficient when used in high doses for a long time. Azithromycin, a macrolide large spectrum antibiotic, has been proved to be efficient against Gram positive, Gram negative, anaerobic and intracellular microorganisms as well as some protozoa. The purpose of this study was to evaluate the efficiency of azithromycin in the treatment of deep and superficial bacterial pyodermas in dogs, as well as the occurrence of adverse side effects.

MATERIALS

Twenty-six dogs (14 females, 12 males) brought to the Veterinary Dermatological Clinic of the Federal Rural University of Rio de Janeiro were used. Ages ranged from 6 months to 14 years. Eight animals had superficial and 18 had deep pyodermas. Fifteen of the dogs had some underlying skin disease (demodicosis, hypothyroidism, allergic dermatitis and immuno-mediated skin disorder). Bacterial infection was diagnosed by cytologic examination of material collected from pustules or microabscesses.. The dogs were treated orally with azithromycin (10 mg/kg) every 24 hours, for five to ten days, according to the deepness of the lesion. Only one dog, weighting 60 kg, received the azithromycin (5 mg/kg) every 12 hours. After this period the animals returned for a new dermatological evaluation.

RESULTS

Of the 26 animals treated with azithromycin, 23 (88.5%) recovered of superficial infections within five to seven days and of deep ones within seven to ten days. In two dogs (7.7%) the lesions diminished, but when the treatment was stopped other pustules appeared. Only one animal (3.8%) showed no clinic improvement. Minimal side effects were observed in six animals (23.8%); intense salivation and lack of appetite on the first day of drug administration was observed in three dogs (11.6%), but there was no need of treatment. The other three (11.6%) animals developed vomiting; one of them (3,8%) four hours after the administration of azithromycin, but recovered on the next day. Another dog vomited during the last two days of therapy. Only one dog needed antiemetic therapy (metoclopramide).

CONCLUSION

Azithromycin was efficient in the treatment of canine pyoderma; 88.5% of the treated animals recovered, even when low doses for relative short periods were used. Although some of the patients presented side effects (23.8%) such as vomiting, salivation and slight lack of appetite, it should be pointed out that only one animal needed antiemetic drug to continue the treatment. Only one dog did not present clinical improvement of the lesions; it is quite possible that this was due to bacterial resistance to azithromycin.