Pododermatitis and interdigital furunculosis in dogs
3-year-old Shar Pei with swelling, interdigital nodules that drain, alopecia and pain on all four feet for months. It has partly improved with several antibiotic courses but relapses when they are stopped.
Which test should you perform first?
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A. Radiographs of the feet to rule out osteomyelitis
Bone involvement is uncommon in pododermatitis. Radiographs may help in selected cases (foreign body, a single foot), but they are not the first step when all four feet are affected.
B. Deep skin scrapings (squeezing the skin) or trichogram, plus cytology of the exudate
Correct. Demodicosis is a common cause of pododermatitis and recurrent furunculosis, especially in breeds such as the Shar Pei. The feet are hard to scrape: trichograms or expressing the exudate help. Cytology confirms the infection and guides culture.
C. An 8-week elimination diet
Food allergy and atopy are common causes of pododermatitis, but an elimination diet comes after ruling out ectoparasites and controlling infection.
D. Biopsy to rule out neoplasia
Neoplasia is unlikely with symmetrical lesions on all four feet. Biopsy is reserved for refractory cases or after ruling out more common, easily diagnosed causes.
lightbulb Key takeaway
With pododermatitis, consider Demodex, allergies (atopic, food), conformational or orthopaedic causes (especially in Bulldogs) and foreign bodies if a single foot is affected. Interdigital 'cysts' are usually sterile furunculosis due to hair and keratin in the dermis, with secondary infection.
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Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.