Skin Infections in Dogs (Bacterial & Yeast)

What Causes Skin Infections in Dogs?

Common underlying causes of skin infections include allergic skin disease, parasites, hormonal conditions and other disorders that affect the skin barrier. Skin infections typically occur when the skin barrier becomes disrupted, allowing bacteria and yeast that are normally present on the skin to overgrow and cause disease. In many dogs, this occurs secondary to an underlying condition, most commonly allergic skin disease.

Skin infections are best understood by considering the underlying causes and contributing factors:

While infection is often the most visible issue, it is usually not the primary cause. Without identifying and addressing the underlying driver, infections are likely to recur or persist.

Signs of Skin Infections in Dogs

Signs may vary depending on the type, severity and depth of infection, and may affect localised areas or be more widespread. In many dogs, signs are recurrent or ongoing, particularly where an underlying condition is present.

• Red, inflamed or irritated skin
• Pustules, papules or small raised lesions
• Crusting, scaling or flaking skin
• Hair loss or patchy coat changes
• Greasy skin or changes in coat texture
• Odour associated with infection
• Licking, scratching or chewing
• Darkening or thickening of the skin in chronic cases
• Moist, painful areas consistent with hot spots

The distribution and recurrence of lesions often provide important clues to the underlying cause.

Why Skin Infections Become Recurrent or Chronic

Skin infections often recur because treatment focuses on the infection itself rather than the underlying condition. While infections may improve with routine or first-line treatments, they frequently return if the primary driver is not addressed.

This can lead to a self-perpetuating cycle:

• An underlying cause (such as allergy) disrupts the skin barrier
• The skin becomes inflamed and more susceptible to infection
• Bacteria and yeast overgrow
• Infection develops, causing further inflammation and irritation
• Scratching, licking or chewing further damages the skin
• The skin barrier becomes increasingly compromised

Each stage reinforces the next, leading to recurrent flare-ups and, in some dogs, progression to chronic or more severe disease.

How We Diagnose Skin Infections in Dogs

Skin infections can resemble many other dermatological conditions and are often secondary to an underlying disease, so a systematic approach is required to confirm the infection and identify contributing factors. Where referral is recommended, your dog’s assessment begins with a dermatology consultation, where our clinician reviews their history and previous treatments, and performs a thorough examination to assess the severity, distribution and progression of disease.

From here, our clinicians tailor a targeted diagnostic approach to your dog’s individual presentation.

A tailored diagnostic approach may include:

• Cytology and Fine-Needle Aspirates – used to identify bacteria, yeast and inflammatory cells, helping guide targeted treatment decisions.
• Elimination Diet Trials – used in selected cases where a cutaneous adverse food reaction is suspected.
• Airborne Environmental Allergy Testing – used in selected cases where environmental allergy is suspected as an underlying cause of recurrent skin disease and infection, helping guide allergen-specific immunotherapy (ASIT).
• Biopsy and Dermatopathology – recommended in selected cases where skin disease or infection is severe, chronic or not responding as expected.
• Skin scrapings and parasite testing – where parasitic causes are suspected
• Assessment of flea exposure and response to effective flea control – particularly where flea allergy dermatitis is suspected
• Hormone disorder testing – used in selected cases where endocrine disease is suspected

Each step helps build a complete clinical picture, ensuring that treatment is based on an accurate diagnosis rather than repeated short-term management.

How Skin Infections in Dogs Are Managed

Management depends on the type and severity of infection, the presence of an underlying condition, and your dog’s individual needs. Effective treatment requires not only resolving the infection, but also addressing the factors driving recurrence.

Depending on the diagnosis, treatment may include:

• Targeted antimicrobial therapy for bacterial or yeast infection
• Topical therapies such as medicated shampoos, wipes or sprays
• Treatment of underlying allergy or skin disease
• Parasite control, where relevant
• Dietary management where a food-related trigger is identified
• Medications to reduce inflammation and itching (pruritus)
• Long-term strategies to support skin barrier function and reduce recurrence

For dogs with recurrent skin infections, long-term management is often required. The goal is not simply to treat individual episodes, but to achieve more stable disease control, reduce flare-ups, and improve comfort and quality of life.

Related Conditions

Dog Allergies

Ear Disease in Dogs

Nail, Paw and Pad Conditions (Pododermatitis)

Parasites in Dogs

Explore other common conditions in dogs here →