Canine superficial pyoderma: epidermal collarettes and topical therapy
3-year-old French Bulldog with moderate pruritus and follicular papules, pustules and epidermal collarettes on the abdomen and inner thighs. Impression cytology of a pustule shows neutrophils with phagocytosed cocci. Skin scrapings are negative.
What is the most appropriate initial treatment according to current antimicrobial use guidelines?
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A. Oral cefalexin for 3 weeks as the sole treatment
It is a first-line systemic option, but guidelines prioritise topical therapy for localised or moderate superficial pyoderma; systemic antibiotics are reserved for extensive or non-responsive cases.
B. Oral enrofloxacin, because of its broad spectrum
Fluoroquinolones are critically important antimicrobials in human medicine and should not be used empirically: they are reserved for infections where culture and susceptibility testing justify them.
C. Chlorhexidine 2–4% shampoo two or three times a week, with 10 minutes' contact time, and look for the primary cause
Correct. Topical antiseptic therapy is effective against staphylococci (including methicillin-resistant ones), speeds healing and reduces systemic antibiotic use. Pyoderma is almost always secondary (allergy, ectoparasites, endocrinopathy): if the cause is not treated, it relapses.
D. Prednisolone at anti-inflammatory doses to control pruritus
Glucocorticoids do not treat the infection and may worsen it; they also mask the response to treatment. Control the infection first, then reassess any residual pruritus.
lightbulb Key takeaway
An epidermal collarette is the remnant of a ruptured pustule and is highly suggestive of superficial pyoderma due to Staphylococcus pseudintermedius. Always confirm it with cytology and treat first with topical antiseptics (chlorhexidine, benzoyl peroxide); recurrent pyoderma means looking for the underlying disease.
References: ISCAID: Guidelines for the diagnosis and antimicrobial therapy of canine superficial bacterial folliculitis (Hillier et al., 2014)
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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.