Chronic pododermatitis and interdigital furunculosis in dogs

Chronic pododermatitis with interdigital furunculosis is a common and frustrating problem in dogs. It is characterised by the presence of recurrent interdigital furunculosis. It is a multifactorial condition with primary, predisposing and perpetuating causes that lead to the secondary infections. Almost any skin disease can trigger the initial inflammation, but atopic dermatitis, adverse food reactions and abnormal conformation are the most common. Predisposing factors such as short hairs, excess weight, and altered weight bearing may lead to the development of the interdigital furunculosis. Perpetuating changes prevent resolution; these include weight bearing on haired skin, conjoined pads, new pad formation, deep tissue pockets, ingrown hairs and sinus tracts. All of the contributing factors in each case must be identified and managed. Supportive care includes analgesia, weight loss, using boots, keeping the interdigital skin clean, and using lubricating creams. Secondary bacterial and/or Malassezia spp. infections should be managed with appropriate topical and/or systemic antimicrobials. Bacterial infections can be deep, mixed and/or antimicrobial resistant, and culture and antimicrobial susceptibility testing must be used to select effective drugs. Chronic inflammatory changes can be managed with topical or systemic glucocorticoids, topical 0.1% tacrolimus, ciclosporin or cytotoxic drugs. Chronic proliferative changes are poorly responsive to medical management alone, therefore surgical fusion or laser podoplasties should be considered. Long-term treatment of the primary, predisposing and perpetuating problems is required to maintain remission and prevent recurrence.