Which of the following is a differential diagnosis for a dog presenting with a superficial skin patch and cytology showing cocci with PMNs?

• A. Surface pyoderma
• B. Flea allergy dermatitis
• C. Dermatophyte infection
• D. Demodicosis

Answer: (A)

A surface pattern of cocci with neutrophils on cytology points to a superficial bacterial pyoderma. In dogs, this typically reflects a shallow infection of the epidermis, often caused by Staphylococcus species, producing crusts and purulent exudate on a superficial patch.

Dermatophyte infection would show fungal elements such as hyphae on cytology or microscopy, not cocci. Demodicosis centers on Demodex mites seen in cytology rather than bacteria. Flea allergy dermatitis is an allergic condition; while secondary bacterial infection can occur, the hallmark cytology is not cocci with PMNs and does not define it.