Deep pyoderma in dogs can be difficult to treat. The most commonly isolated pathogen of dogs is Staphylococcus intermedius; however, coagulase-negative bacteria and Pseudomonas species infections can also be involved. Treatment of canine deep pyoderma requires identification of the underlying trigger and aggressive antimicrobial therapy. One of the complicating factors is the severe inflammation and fibrosis, which make it difficult to obtain appropriate concentrations at the sites of infection. In a large multicenter study, the treatment outcomes of amoxicillin/clavulanic acid (12.5 mg/kg PO Q 12 H) and pradofloxacin 3 mg/kg Q 24 H were compared in dogs with deep pyoderma confirmed by clinical examination and positive bacterial culture. Dogs were examined weekly for the first 3 weeks and then every 3 weeks until 2 weeks after clinical remission. In the pradofloxacin group (n = 56), 48 (86%) of dogs achieved clinical remission. Four dogs improved but were not cured, and 4 dogs did not respond to treatment. None of the successfully treated dogs relapsed. In the amoxicillin/clavulanic acid group (n = 51), 37 dogs (73%) achieved clinical remission. Three dogs showed clinical improvement, 5 dogs did not respond to treatment, and 6 dogs relapsed within 2 weeks of discontinuation of therapy. For both treatment groups, maximum treatment time was 9 weeks. Study funded by Bayer Animal Health, Leverkusen Germany

COMMENTARY: The most common underlying cause of deep pyoderma in dogs is demodicosis. Skin scrapings are always indicated in cases of deep pyoderma. This disorder may result from an untreated superficial infection that leads to folliculitis and furunculosis. Treatment of deep pyoderma requires clipping of the hair coat, appropriate topical antimicrobial shampoo therapy, and long-term antibiotic therapy. The author recommends culture and sensitivity in cases of deep pyoderma because, as shown in this study, treatment can extend as long as 9 weeks. Pradofloxacin is a new 8-cyano-fluoroquinolone with enhanced activity against gram-positive and anaerobic bacteria that also retains broad-spectrum activity against gram-negative bacteria. One of the advantages of fluoroquinolone antibiotics in deep pyoderma is the uptake and concentration in inflammatory cells. Pradofloxacin has been used to treat respiratory and urinary tract infections as well as skin infections. The drug is not yet available in the United States.

Pradofloxacin in the treatment of canine deep pyoderma: A multicentred, blinded, randomized parallel trial. Mueller RS, Stephan B.

VET DERMATOL

18:144-151, 2007.