Pyoderma: When Topicals Are Enough (And When They’re Not)

Current guidelines put topical therapy first for superficial bacterial skin infections

The cytology shows cocci. The dog is scratching. You reach for the antibiotic prescription pad.

But should you?

“Last time you gave him antibiotics and it worked.” It’s a common client objection when you recommend a different approach. But current guidelines have shifted, and there’s good reason for it.

Topical therapy is the treatment of choice for superficial bacterial folliculitis.

Not adjunctive. First-line.

First, Define What You’re Treating

Pyoderma is a bacterial infection of the skin. There’s no such thing as Malassezia pyoderma. The term “bacterial pyoderma” is redundant. Pyoderma is bacterial by definition.

The depth matters for treatment:

Surface pyoderma sits on the stratum corneum. Think facial folds, skin fold dermatitis, areas where excessive skin contact creates a moist environment for bacterial overgrowth.

Superficial pyoderma involves the epidermis and hair follicles. This is your classic bacterial folliculitis.

Deep pyoderma extends into the dermis and beyond. These cases present differently and require different treatment.

The Guidelines Have Shifted

Current antimicrobial stewardship guidelines recommend topical therapy as first-line treatment for surface and superficial pyoderma. This represents a shift from older recommendations that defaulted to systemic antibiotics.

The reasoning? Topical antimicrobials deliver high concentrations directly to the infection site, reduce systemic antibiotic exposure, and help address the growing concern of antimicrobial resistance in veterinary dermatology.

Superficial pyoderma can resolve with topicals alone. It may require aggressive topical therapy, but resolution is achievable without systemic antibiotics.

What Topical Therapy Looks Like

For surface pyoderma, treatment focuses on the affected areas: cleaning, drying, and applying topical antimicrobials to skin folds and affected regions.

For superficial pyoderma, the approach is more intensive:

• Antimicrobial shampoos (chlorhexidine-based products are commonly used)
• Leave-on products like mousses, sprays, or wipes
• Frequency matters: Often requires bathing or application every 2 to 3 days initially

The key is contact time. A quick rinse won’t cut it. The antimicrobial needs adequate contact with the skin to be effective.

When to Escalate to Systemic

Topical therapy doesn’t work for every case. Consider systemic antibiotics when:

• The infection is deep (extending into the dermis)
• The affected area is too large for practical topical treatment
• The patient won’t tolerate frequent bathing or topical application
• Topical therapy has failed after adequate trial

When topicals have failed, the next step is systemic therapy, ideally guided by culture and susceptibility.

Duration of Treatment Has Changed Too

The old recommendation: treat for 21 days, or one week past clinical resolution.

The current guideline: treat for two weeks, then recheck while still on therapy.

The point is to reassess while treatment is ongoing rather than treating blindly for a set duration. If the recheck can’t happen at exactly two weeks, treatment continues until the patient can be evaluated.

When to Culture

The guidelines identify specific scenarios where culture and susceptibility testing is warranted:

• History of recurrent pyoderma
• Failure to respond to empirical therapy
• Presence of rod-shaped bacteria on cytology (suggesting gram-negative infection)
• Cases where you suspect resistant organisms

If a treated infection recurs, the concern is whether a more resistant organism is involved.

The Bigger Picture: Pyoderma Is Secondary

Pyoderma is almost always a secondary problem.

The underlying causes include:

• Allergies (the most common)
• Parasites (Sarcoptes, Demodex)
• Endocrine disease (hypothyroidism, Cushing’s)
• Autoimmune conditions
• Conformational issues (skin folds)

Addressing the underlying cause addresses the pyoderma. Treating the infection without addressing the cause is a recipe for recurrence.

Practical Takeaways

1. Start with cytology. Confirm bacterial infection before treating.
2. Consider topicals first for surface and superficial pyoderma.
3. Adequate contact time is essential for topical efficacy.
4. Recheck at two weeks while still on treatment.
5. Culture selectively: recurrent cases, treatment failures, rods on cytology.
6. Find the underlying cause. Recurrent pyoderma means something else is going on.
7. Consider adjunctive support. Omega fatty acids and regular medicated bathing can reduce reliance on systemic antibiotics.

The goal isn’t just clearing this infection. It’s understanding why it happened in the first place.

This post is based on a VetOnIt CE webinar by Dr. Jason Pieper, DACVD. For RACE-approved dermatology CE, visit our on-demand library.

References

¹ Pieper J. Canine Dermatology: Pyoderma and Otitis. VetOnIt CE Webinar, 2025.