Vet’s 2025 Guide to Canine Skin Infections 🩺 Bacterial, Fungal, Parasitic & Ulcerative Cases

By Dr. Duncan Houston BVSc

💡 What Are Skin Infections in Dogs?

Skin infections result from overgrowth or invasion by bacteria (e.g., Staph), yeast (Malassezia), fungi (ringworm), or parasites (mites like Demodex or Sarcoptes). They may be primary (directly from pathogens) or secondary (due to allergies, trauma, endocrine issues).

🚩 Common Types & Signs

• Pyoderma (bacterial): red bumps, pustules, crusts, often itchy and sweet‑smelling.
• Yeast dermatitis: greasy coat, musty odor, brown discoloration, thickened skin in ears, folds, groin.
• Fungal (ringworm): round areas of hair loss, scaling, flakes; may fluoresce with UV lamp.
• Parasites:
  • Demodectic mange: patchy hair loss, scaling, pustules—usually non‑itchy unless secondary infection.
  • Sarcoptic mange: intensely itchy papules, contagion risk.
• Ulcers: deep, open wounds that bleed or ooze; often secondary to pressure, trauma, infection.
• Pododermatitis: inflamed, often infected paws—redness, swelling, licking.

🧪 How These Are Diagnosed

1. History & exam: onset, location, itchiness, breed predisposition.
2. Skin cytology: impression or aspiration to see bacteria, yeast under a microscope.
3. Skin scraping: test for mites in demodex or sarcoptic cases.
4. Tape prep: for yeast or fungal spores.
5. Fungal culture/UV lamp: confirm dermatophytes.
6. Biopsy: for chronic ulcers or atypical cases.

🛠 Treatment Guidelines

🔹 Bacterial Infections (Pyoderma)

• 🧼 Topical shampoos (antibacterial like chlorhexidine), sprays, ointments.
• 💊 Oral antibiotics (cephalosporins, clavamox) for moderate/severe cases.
• 📆 Typically 3–6 weeks; re‑evaluate at 2 weeks.

🔹 Yeast Dermatitis

• 🧴 Medicated shampoos or wipes (miconazole, ketoconazole).
• 💊 Oral antifungals (itraconazole) if extensive or chronic.
• 🌡 Identify and manage triggers like allergies or moisture.

🔹 Fungal Infections (Ringworm)

• 🌿 Topical antifungals plus oral meds (terbinafine, itraconazole).
• 🏠 Environmental cleanup to remove spores (vacuum, disinfect).
• 📆 Continue until culture negative, often ~4–6 weeks.

🔹 Demodex & Sarcoptic Mange

• 🪳 Demodex: topical/systemic miticides (isoxazolines, amitraz) + manage secondary pyoderma.
• 😷 Sarcoptic: treat all dogs in contact with miticide therapy, itch relief, insecticidal shampoos.

🔹 Ulcers & Pododermatitis

• 🩹 Clean wounds, topical/systemic antibiotics, bandage protection.
• 🦶 For paw dermatitis, address underlying causes—remove allergy triggers, trim fur, clean.

📈 Prevention Tips

• 🚿 Regular grooming and cleaning—especially folds, paws, ears.
• 🏠 Keep skin dry and reduce humidity.
• 🩻 Treat underlying allergies, endocrine issues.
• 🧹 Environmental cleaning for fungal/parasitic cases.
• 🐕 Flea and tick prevention to avoid bite‑related infections.

🏡 Ask A Vet App Home‑Support Tools 📲🐾

• 📆 Medication & bathing reminders.
• 📊 Logs of symptoms: scratching, odor, crusting.
• 📸 Upload lesion photos for remote vet review.
• 🔔 Alerts for persistent or worsening symptoms.
• 📚 Guides: cleaning, de‑sporing environments, wound care.

🔑 Key Takeaways 🧠✅

• 🧫 Infections include bacterial, yeast, fungal, and parasitic—secondary infections are common.
• 🔬 Diagnosis relies on cytology, scraping, culture, and sometimes biopsy.
• 💊 Treatments range from topical cleansers to oral medications.
• 🛁 Regular cleaning, grooming, and underlying-condition management prevent recurrences.
• 📱 Ask A Vet app supports at-home care with tracking, reminders, and vet guidance.

🩺 Final Thoughts ❤️

In 2025, managing canine skin infections requires both clinic-based diagnostics and home-based care. With a correct diagnosis, tailored therapy, and strong owner compliance—supported by tools like Ask A Vet—most dogs fully recover and enjoy healthy skin again. Vigilance and early intervention are your best tools. 🐕✨

Visit AskAVet.com and download the Ask A Vet app to schedule treatments, upload photos, set alerts, and connect with veterinary experts anytime. 📲🐶