Skin problems are among the most common reasons dogs visit a veterinarian. The skin is the body’s largest organ and is exposed constantly to the environment — making it vulnerable to infections, parasites, allergies, and a wide range of inflammatory conditions. Many skin problems in dogs look similar on the surface but have very different causes and require very different treatments.
If your dog has been scratching, developing sores, losing hair, or showing any changes to their skin or coat, contact Walker Lake Veterinary Centre at (587) 786-6771 for an assessment.
Skin conditions in dogs are rarely straightforward. Many conditions share similar appearances, and treating the wrong diagnosis — particularly using the wrong medication — can make the condition significantly worse. Accurate diagnosis is essential before starting any treatment.
How the Dog’s Skin Works
The skin performs several essential functions — it acts as a physical barrier against pathogens and environmental irritants, regulates temperature, provides sensory information, and houses the immune cells that protect against infection.
When the skin barrier is disrupted — by allergies, parasites, infection, or trauma — these protective functions are compromised. Bacteria and yeast that live harmlessly on the normal skin surface take advantage of the disrupted barrier, causing secondary infections that compound the original problem.
This is why many skin conditions in dogs involve multiple simultaneous issues — a primary trigger combined with secondary bacterial and yeast infections — that all need to be addressed together for effective resolution.
Common Dog Skin Conditions
Hot Spots — Acute Moist Dermatitis
Hot spots are localised areas of acute, moist skin inflammation that develop rapidly — often appearing within hours. They are intensely itchy and painful, causing the dog to lick, chew, and scratch the area constantly, which perpetuates the inflammation and creates a cycle of worsening damage.
Hot spots appear as well-defined, red, moist, weeping patches of skin — often with matted hair over the surface. They can grow significantly within 24 hours if not treated.
Common triggers include:
- Allergies — environmental or food
- Insect bites — particularly flea bites in allergic dogs
- Moisture trapped under the coat — particularly in thick-coated or double-coated breeds
- Minor skin trauma — a scratch, wound, or area of irritation the dog focuses on
- Anal gland irritation — dogs with anal gland problems often develop hot spots on the hindquarters
Treatment involves clipping the hair from the affected area, thoroughly cleaning and drying the skin, topical antimicrobial treatment, and addressing the underlying trigger. Many cases also require oral antibiotics and anti-inflammatory medication.
Pyoderma — Bacterial Skin Infection
Pyoderma is a bacterial infection of the skin — the most common secondary skin infection in dogs. It occurs when the normal skin barrier is disrupted, allowing surface bacteria — most commonly Staphylococcus pseudintermedius — to invade the skin layers.
Surface Pyoderma
Affects only the very surface of the skin. Hot spots are a form of surface pyoderma.
Superficial Pyoderma
The most common type. Affects the superficial skin layers and hair follicles. Produces small pustules (pimples), crusted lesions, hair loss in small circular patches, and a characteristic moth-eaten appearance to the coat.
Deep Pyoderma
Less common and more serious. Infection extends deep into the skin and sometimes into surrounding tissue. Causes painful, swollen, draining lesions. Requires prolonged antibiotic treatment and often additional diagnostics to identify the underlying cause.
Pyoderma almost always has an underlying trigger — allergies are the most common. Treating the infection without addressing the underlying cause leads to recurrence.
Malassezia Dermatitis — Yeast Infection
Malassezia pachydermatis is a yeast organism that lives normally on dog skin. When the skin environment changes — due to allergies, hormonal disease, or moisture — Malassezia overgrows and causes infection.
Signs of Malassezia dermatitis include:
- Intense itching — often described as more severe than bacterial infections
- Greasy, waxy skin surface
- A characteristic musty, cheesy odour
- Brown or reddish discolouration of the skin and coat — particularly visible on white or light-coloured dogs
- Thickening and darkening of chronically affected skin
- Commonly affects the ears, paws, armpits, and groin
Yeast infections require specific antifungal treatment — either topical medicated shampoos and wipes, oral antifungal medication, or both depending on severity.
Mange — Sarcoptic and Demodectic
Mange refers to skin disease caused by microscopic mites living in or on the skin. There are two distinct types with different causes, presentations, and implications.
Sarcoptic Mange (Scabies)
Caused by Sarcoptes scabiei — a highly contagious mite that burrows into the skin. Sarcoptic mange causes intense, relentless itching out of proportion to the visible skin changes, which initially appear as small red papules and crusting at the ear margins, elbows, and ventral abdomen. It spreads readily between dogs and can transiently affect humans.
Any intensely itchy dog — particularly one that has been in contact with foxes or other dogs — should be tested for sarcoptic mange.
Demodectic Mange (Demodicosis)
Caused by Demodex canis — a mite that lives in hair follicles and is present in small numbers on virtually all dogs. It only causes problems when the immune system fails to keep the mite population in check.
Localised demodicosis — patchy hair loss without significant itching, typically around the face and forelegs — is common in puppies and often resolves without treatment as the immune system matures.
Generalised demodicosis — widespread hair loss, skin thickening, secondary infections, and significant systemic illness — is more serious and requires treatment. It can indicate an underlying immunosuppressive condition in adult dogs.
Ringworm — Dermatophytosis
Despite its name, ringworm is not caused by a worm — it is a fungal infection of the skin, hair, and nails. It causes circular patches of hair loss, scaling, and crusting, classically in a ring pattern — though this presentation is not always present in dogs.
Ringworm is contagious to other animals and to humans, making prompt diagnosis and treatment important in households with multiple pets or young children.
Folliculitis and Furunculosis
Folliculitis is inflammation and infection of the hair follicles — it typically appears as pustules, papules, and crusting along the back and flanks, and is often a manifestation of superficial pyoderma. Furunculosis occurs when infected follicles rupture, spreading infection deeper into the skin. It is painful and requires systemic antibiotic treatment.
Interdigital furunculosis — painful, swollen, draining lesions between the toes — is a particularly stubborn form that is frequently associated with allergies.
Seborrhea
Seborrhea refers to abnormal production of sebum — the skin’s natural oil. It may manifest as dry, flaky skin (seborrhea sicca) or greasy, waxy skin with an unpleasant odour (seborrhea oleosa), or a combination of both.
Primary seborrhea is a genetic condition seen in certain breeds — Cocker Spaniels, Basset Hounds, West Highland White Terriers, and German Shepherds. More commonly, seborrhea is secondary to another condition — allergies, hormonal disease, nutritional deficiencies, or parasites.
Alopecia — Hair Loss
Hair loss in dogs has many potential causes including:
- Allergies — causing secondary infections and self-trauma that damage hair follicles
- Hormonal conditions — hypothyroidism causes symmetrical hair loss, dull coat, and weight gain; Cushing’s disease causes hair loss, pot-bellied appearance, and skin thinning
- Seasonal flank alopecia — a benign cyclical pattern of hair loss in certain breeds linked to changes in day length
- Post-clipping alopecia — hair that fails to regrow after clipping, more common in some northern breeds
- Colour dilution alopecia — affects blue and fawn coloured dogs with a dilute coat gene
- Pattern baldness — common in certain breeds including Dachshunds and Chihuahuas
Skin Tumours
Skin tumours are common in dogs — particularly in older animals. Most are benign but some are malignant. Any new lump, bump, or skin growth should be assessed by a veterinarian. A fine needle aspirate — a quick, minimally invasive procedure — can often characterise a lump without requiring full surgical removal.
Common benign skin tumours include lipomas (fatty lumps), sebaceous cysts, histiocytomas (common in young dogs), and papillomas (warts). Malignant tumours include mast cell tumours — which can appear benign — and melanomas.
⚠️ Never assume a skin lump is harmless without veterinary assessment. Mast cell tumours in particular are highly variable in appearance and can look identical to benign lumps. The only way to assess a lump is through cytology or biopsy.
Diagnosing Skin Conditions
Skin Cytology
The first and most important diagnostic tool for most skin conditions. A sample of cells or discharge from the affected skin is collected on a slide and examined under a microscope. Skin cytology identifies bacteria, yeast, inflammatory cells, and sometimes cancer cells — providing rapid, in-house results that directly guide treatment.
Skin Scraping
A firm scraping of the skin surface is examined microscopically for mites — essential for diagnosing sarcoptic and demodectic mange.
Wood’s Lamp and Fungal Culture
A Wood’s lamp — an ultraviolet light — causes some strains of ringworm to fluoresce, providing a rapid screening test. Fungal culture provides definitive confirmation of ringworm and identifies the specific species.
Biopsy
For unusual, persistent, or treatment-resistant skin conditions, a skin biopsy provides a tissue sample for detailed histological examination. This is the most definitive diagnostic tool for many skin conditions including autoimmune diseases and neoplasia.
Allergy Testing
As discussed in the allergies article, identifying specific allergens guides long-term management for dogs with allergy-associated skin disease.
Hormonal Testing
Blood tests assessing thyroid function, cortisol levels, and sex hormones are indicated when a hormonal cause of skin disease is suspected.
Treating Dog Skin Conditions
Topical Treatments
Medicated shampoos, conditioners, sprays, and wipes are the foundation of many skin condition treatments. They deliver antimicrobial, antifungal, or anti-inflammatory agents directly to the skin surface with minimal systemic effects.
Effective use of medicated shampoos requires sufficient contact time — typically 10 minutes — before rinsing. Many owners rinse too quickly, significantly reducing efficacy.
Systemic Antibiotics
Bacterial skin infections typically require 3 to 8 weeks of antibiotic treatment depending on depth of infection. Short courses are a common cause of treatment failure and recurrence. Culture and sensitivity testing guides antibiotic choice for recurrent or resistant infections.
Antifungal Medications
Malassezia and ringworm infections are treated with appropriate antifungal medications — either topical, systemic, or both depending on the extent of infection.
Antiparasitic Treatment
Mange mites are treated with antiparasitic medications — modern isoxazoline products (the same class used for flea and tick prevention) are highly effective against both Sarcoptes and Demodex. All in-contact animals must be treated for sarcoptic mange.
Addressing the Underlying Cause
Any secondary skin infection — bacterial or yeast — requires treatment of both the infection and its underlying trigger. Without identifying and managing the primary cause — most commonly allergies or hormonal disease — infections will recur.
If your dog has skin problems that keep coming back, book an appointment at Walker Lake Veterinary Centre. Call (587) 786-6771 or book online. Located at 5109 22 Avenue SW, Southwest Edmonton.
Book an Appointment at Walker Lake Veterinary Centre
Walker Lake Veterinary Centre provides skin examination, cytology, skin scraping, and comprehensive dermatology assessment for dogs and cats across Walker Lake, Summerside, Ellerslie, Heritage Valley, and Southwest Edmonton.
Call us at (587) 786-6771 or book online. We are located at 5109 22 Avenue SW, Edmonton.
Clinic hours:
- Monday, Tuesday & Thursday: 9:00 AM – 7:00 PM
- Wednesday & Friday: 9:00 AM – 6:00 PM
- Saturday: 9:00 AM – 3:00 PM
- Sunday: Closed
Frequently Asked Questions
Why does my dog keep getting skin infections?
Recurrent skin infections almost always have an underlying cause — most commonly allergies, hormonal disease, or an anatomical predisposition. Treating only the infection without identifying the root cause leads to a cycle of resolution and recurrence. A thorough dermatology workup is warranted for any dog with more than two episodes of skin infection per year.
Can I use human skin cream on my dog?
Most human skin products are not appropriate for dogs. Many contain ingredients — including some steroids, antifungals, and preservatives — that can be harmful if ingested through grooming, or that are simply not effective for canine skin conditions. Always use veterinary-recommended products.
Is my dog’s skin condition contagious to my family?
Some conditions are contagious — sarcoptic mange and ringworm can both affect humans, causing itchy skin lesions. If your dog is diagnosed with either of these conditions, discuss appropriate precautions with your veterinarian and consider consulting your doctor if any family members develop skin irritation.
My dog has a lump under the skin — what should I do?
Any new skin lump or growth should be assessed by a veterinarian. A fine needle aspirate provides rapid information about the nature of the lump with minimal discomfort. Do not monitor lumps indefinitely without assessment — some malignant tumours grow slowly and appear benign.
How long does it take to treat a skin infection in dogs?
Surface and superficial bacterial infections typically require 3 to 4 weeks of treatment. Deep bacterial infections may require 6 to 8 weeks or longer. Yeast infections typically respond within 2 to 4 weeks of appropriate antifungal treatment. Complete resolution of the underlying cause — particularly allergies — may take considerably longer and require ongoing management.
