Pyoderma (Bacterial Skin Infection) in Dogs: Symptoms, Causes & Treatment

What Is Pyoderma?

Pyoderma means "pus in the skin." In dogs, it refers to bacterial skin infections, most commonly caused by Staphylococcus pseudintermedius—a bacterium that normally lives on canine skin but can overgrow when the skin barrier is compromised.

Pyoderma is one of the most common reasons dogs see a veterinarian. It can affect the surface of the skin (superficial pyoderma) or extend into hair follicles and deeper layers (deep pyoderma). Superficial pyoderma is more common and generally easier to treat; deep pyoderma can be more challenging and may require longer therapy.

Understanding the underlying cause is essential. Pyoderma often occurs secondary to allergies, parasites, hormonal disorders, or other conditions that damage the skin's defenses.

Symptoms of Pyoderma in Dogs

Early Signs

• Pustules—small pus-filled bumps, often around hair follicles
• Papules—red, raised bumps
• Itching (pruritus)—ranging from mild to intense
• Patchy hair loss with reddened skin underneath
• Oily or flaky skin

Progressive Symptoms

• Crusts and scales forming over affected areas
• Epidermal collarettes—circular areas of scaling with a raised edge (classic for superficial pyoderma)
• Spreading lesions to multiple body areas
• Hot spots (acute moist dermatitis)—wet, raw, painful patches
• Foul odor from infected skin

Emergency Signs

• Deep pyoderma—painful, swollen, draining wounds; fever; lethargy
• Cellulitis—widespread red, hot, swollen skin
• Signs of systemic infection—loss of appetite, fever, depression

What Causes Pyoderma in Dogs?

Pyoderma occurs when bacteria that normally inhabit the skin multiply excessively. Staphylococcus pseudintermedius is the usual culprit. Underlying factors that predispose dogs include:

• Allergies—atopic dermatitis, food allergies, flea allergy dermatitis (most common underlying cause)
• Parasites—demodectic mange, sarcoptic mange, flea infestation
• Endocrine disorders—hypothyroidism, Cushing's disease
• Skin folds—breeds with excessive folds (e.g., Bulldogs, Shar-Peis) trap moisture
• Trauma—wounds, excessive scratching
• Immunosuppression—from medications or disease
• Poor grooming—matted hair, moisture retention

Breeds Most at Risk

• Bulldogs (English and French)
• Golden Retrievers
• German Shepherds
• Labrador Retrievers
• Shar-Peis
• Cocker Spaniels
• West Highland White Terriers

How Pyoderma Is Diagnosed

Your veterinarian will perform:

• Physical examination—evaluating the distribution and appearance of lesions
• Cytology—microscopic examination of skin impressions or pustule contents to identify bacteria and inflammatory cells
• Skin scrapings—to rule out parasitic mange
• Culture and susceptibility—for recurrent or deep pyoderma to identify the bacteria and guide antibiotic choice
• Tests for underlying causes—allergy testing, thyroid panels, or other workups if indicated

Treatment Options for Pyoderma

Medical Management

• Antibiotics—typically 3–4 weeks for superficial pyoderma; 6–8+ weeks for deep pyoderma. Common choices include cephalexin, amoxicillin-clavulanate, or others based on culture.
• Topical therapy—medicated shampoos (chlorhexidine, benzoyl peroxide) 2–3 times weekly during treatment
• Anti-itch medication—if pruritus is significant
• Treatment of underlying cause—essential to prevent recurrence (e.g., flea control, allergy management)

Surgical Options

Surgery is rarely needed. In severe deep pyoderma with abscesses or fistulas, surgical drainage or debridement may be required.

Alternative/Supportive Therapies

• Omega-3 fatty acids—skin support
• Probiotics—some evidence supports skin health
• Regular bathing with appropriate shampoos during and after treatment

At-Home Care

• Complete the full course of antibiotics—stopping early leads to recurrence and resistance
• Bathe as directed with medicated shampoo
• Address underlying allergies or parasites with your vet
• Keep skin folds clean and dry if applicable

Prognosis & Life Expectancy

Superficial pyoderma typically resolves with appropriate treatment. Deep pyoderma may take longer but usually responds when the underlying cause is addressed. Pyoderma itself does not shorten life expectancy. Recurrence is common if predisposing factors (e.g., allergies) are not managed.

Prevention

• Manage underlying conditions—allergies, parasites, endocrine disease
• Maintain good skin hygiene—regular grooming, cleaning skin folds
• Use flea prevention year-round
• Avoid over-bathing with harsh products that strip natural oils
• Work with your vet on a long-term skin-care plan for prone dogs

Cost of Treatment

• Initial visit and cytology: $75–$200
• Antibiotics (3–4 weeks): $30–$100
• Medicated shampoo: $15–$40
• Culture and susceptibility (if needed): $75–$150
• Workup for underlying cause: $150–$500+ depending on tests

Frequently Asked Questions