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Skin Lesions in Dogs

Author: Dr. med. vet. Gisa Löwe | Last modified: 17.02.2026

When to visit the vet?

Non-urgent see a veterinarian within 2–3 days

If the condition worsens / symptoms persist, consult a veterinarian.

Unsure about what’s wrong with your pet? Feel free to use our Symptom Checker for more clarity

Definition of

Skin lesions in dogs are visible or palpable changes in the skin that can take various forms, such as redness, swelling, ulcers, or crusts.

Can Occur with the Following Diseases:

Grundlagen und mögliche Ursachen

The skin is the dog’s largest organ and serves as a protective barrier against external influences. It consists of several layers, each fulfilling specific functions. If this barrier is broken or damaged, skin lesions can occur.

There are numerous causes of skin lesions in dogs, ranging from harmless to severe conditions. One of the most common causes is an allergic reaction, whether to environmental allergens like pollen or to food components. Allergies often lead to severe itching, which causes the dog to scratch and thus injure the skin.

Parasites such as fleas, ticks, or mites are also common triggers of skin problems. These parasites can not only cause direct damage to the skin but also transmit diseases that provoke further skin reactions.

Infections caused by bacteriaBacteria are microscopic, single-celled organisms that exist in almost every environment on Earth. Some types of bacteria are beneficial or even essential to life, while others can cause disease., fungi, or viruses can lead to skin lesions. Bacterial infections, such as pyoderma, are often secondary infections that develop when the skin is damaged by scratching or other injuries. Fungal infections, like the well-known ringworm, can also cause skin lesions, which often appear as circular, hairless patches.

Autoimmune diseasesAutoimmune diseases are conditions in which the immune system mistakenly attacks the body's own cells or tissues as if they were foreign substances. Examples in dogs and cats include autoimmune hemolytic anemia and systemic lupus erythematosus., where the dog’s immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body. mistakenly attacks its own tissue, can also cause skin lesions. Such diseases are often difficult to diagnose and require special tests.

Additionally, hormonal disorders, such as Cushing’s syndromeA syndrome is a group of symptoms that occur together and indicate a specific disease or condition. A syndrome can be caused by various factors and is often complex in its diagnosis and treatment. or hypothyroidism, can impair skin health and lead to lesions. These conditions disrupt the balance of hormones in the body, which can negatively affect the skin and coat.

Typische Begleitsymptome

Itching: Many skin lesions are accompanied by significant itching, which causes the dog to scratch, bite, or lick intensely.
Redness and swelling: Affected skin areas may appear red and swollen, indicating an inflammatory reaction.
Crusts and scales: The formation of crusts on the skin surface or the flaking of scales is often observed.
Hair loss: Localized or widespread hair loss can occur in conjunction with skin lesions, especially with fungal infections or parasiteA parasite is an organism that lives on or in another living being (the host) and feeds at its expense. Parasites can cause a variety of diseases in animals and humans. infestations.
Ulcers or open wounds: In more severe cases, open wounds or ulcers can form, which are susceptible to secondary infections.
Behavioral changes: Due to discomfort or pain, the dog may show signs of behavioral changes, such as lethargy or aggression.

Wann zum Tierarzt?

Eskalation: ORANGE for extensive, deep, or very painful lesions, weeping/pus, /bleeding, fever/apathy, rapid spread, or mucous membrane involvement; RED for signs of shock.

A visit to the veterinarian is urgently required if skin lesions are accompanied by other serious symptoms, such as fever, loss of appetite, or apathyApathy refers to a state of indifference and reduced interest or lack of emotional involvement in activities or events that would normally arouse interest.. These can indicate a systemic illness that requires immediate treatment.

If skin lesions do not heal within one to two weeks despite home care, or even worsen, a veterinarian should also be consulted. An accurate diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. is important to identify and correctly treat the underlying cause.

At the first sign of a secondary infectionA secondary infection occurs when an already weakened individual suffers an additional infection, often because the immune system is impaired by the primary infection., such as pus or strongly foul-smelling skin, an immediate veterinary visit is necessary to initiate appropriate treatment with antibiotics or other medications.

Symptomerkennung für den Tierhalter und tierärztliches diagnostisches Vorgehen

It is important for pet owners to regularly check their dog’s skin for changes. The coat should be examined for bald spots, crusts, or redness. Changes in the dog’s behavior, such as frequent scratching or licking, should also be observed.

The veterinarian will take a thorough medical historyThe medical history is the systematic collection of a patient's medical history through questioning. It includes information about previous illnesses, treatments, allergies, and lifestyle habits. to identify possible triggers or pre-existing conditions. A physical examination of the skin is crucial to determine the type of lesions. The veterinarian can perform various diagnostic tests, such as skin swabs, biopsies, or blood tests, to identify infections, parasites, or allergic reactions.

Skin tests, such as an allergy testAn allergy test is a method for the diagnosis of allergic reactions. The body is exposed to various allergens to identify which substances trigger an allergic reaction. or a fungal culture, can be performed to identify specific causes. In cases of suspected systemic illness, further diagnostic procedures, such as ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. or X-rayX-ray is an imaging technique that uses X-rays to create images of the inside of the body. It is often used to diagnose bone fractures, lung diseases, and other conditions., may be necessary.

Was kann der Tierhalter tun und professionelle Therapieoptionen

The pet owner can help alleviate symptoms by cleaning the affected skin areas with a mild, dog-friendly shampoo. This can help remove excess flakes or crusts and soothe the skin. However, it is important not to use aggressive or human-specific products, as these can irritate the dog’s skin.

Preventing excessive scratching is crucial to avoid further damage. Special Elizabethan collars or protective clothing can be used for this purpose. The pet owner should also ensure that the dog does not have access to potential allergens, whether in the environment or in food.

A balanced diet can contribute to skin health. Omega-3 fatty acids, found in fish oil, can have anti-inflammatory effects and strengthen the skin barrier. However, pet owners should consult their veterinarian before administering supplements.

Regular check-ups with the veterinarian are important to monitor the healing process and adjust treatment if necessary. The pet owner should follow the veterinarian’s instructions precisely to ensure effective treatment.

Ausblick auf aktuelle Forschung

Current research on skin lesions in dogs increasingly focuses on identifying specific biomarkers that can help determine the cause of the lesions. Advances in molecular diagnostics have made it possible to identify specific proteins and genetic markers associated with inflammatory skin diseases. In the future, this could significantly improve diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. and therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. by enabling veterinarians to develop more targeted treatments.

Another significant area of research is the role of the skin microbiome in the development and healing of skin lesions. Studies show that the balance of microorganisms on the skin surface plays an important role in skin health. Disruptions in this microbiome can lead to skin lesions or delay their healing. Future therapeutic approaches could therefore include probiotic treatments aimed at restoring the natural balance of the skin flora.

In immunology, intensive research is being conducted on how the immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body. of dogs reacts to skin lesions. There is evidence that inflammatory processes are not only the cause of lesions but also influence their healing. New therapeutic approaches aim to modulate inflammatory reactions to accelerate healing and prevent recurrence.

Another research area investigates the influence of environmental factors on the development of skin lesions in dogs. Factors such as air pollution, nutrition, and stressStress refers to the state of an organism reacting to external stimuli or demands. In veterinary medicine, stress can have physical or psychological effects on animals, impacting their health and well-being. are subjects of current studies, as they may play a role in exacerbating skin problems. This research could lead to the development of preventive measures to reduce the occurrence of skin lesions.

Furthermore, there are advances in the development of new topicalTopical refers to the direct application of medications or treatments to the skin or mucous membranes for a local effect, without being absorbed into the body. treatments that work in innovative ways. For example, nanotechnology-based creams are being researched that can deliver medication more efficiently and targeted to affected skin areas. Such advanced treatments could reduce the side effects of conventional therapies and accelerate healing processes.

Häufig gestellte Fragen

What are the most common causes of skin lesions in dogs? Skin lesions in dogs can be caused by a variety of factors, including allergies, infections (bacterial, viralViral refers to viruses and their effects on the organism. Viral infections in dogs and cats can range from harmless colds to severe, life-threatening diseases., or fungal), parasiticParasitic refers to diseases or conditions caused by parasites. Parasitic infections can affect the digestive tract, skin, and other organ systems. infestations (such as fleas or mites), and autoimmune diseasesAutoimmune diseases are conditions in which the immune system mistakenly attacks the body's own cells or tissues as if they were foreign substances. Examples in dogs and cats include autoimmune hemolytic anemia and systemic lupus erythematosus.. Physical causes such as injuries or irritations from environmental factors also play a role.
Can skin lesions in dogs heal on their own? Some skin lesions can heal on their own, especially if caused by minor injuries or irritations. However, it is important to identify the cause of the lesions, as untreated infections or allergies can lead to more serious health problems.
How can I recognize skin lesions in my dog? Skin lesions can manifest as redness, swelling, crusts, ulcers, or hair loss. Dogs often show additional scratching, biting, or licking of the affected areas, which can indicate itching or pain.
Are skin lesions in dogs contagiousContagious means infectious. Diseases that can easily be transmitted from one animal to another or from animals to humans are referred to as contagious.? Some skin lesions, particularly those caused by fungal infections or certain bacterial infections, can be contagiousContagious means infectious. Diseases that can easily be transmitted from one animal to another or from animals to humans are referred to as contagious. and spread to other animals or humans. It is important to get a veterinary diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. to assess the risk of contagion.
What treatment options are available for skin lesions in dogs? The treatment of skin lesions depends on the underlying cause. Options may include topicalTopical refers to the direct application of medications or treatments to the skin or mucous membranes for a local effect, without being absorbed into the body. ointments, oralOral means "through the mouth" and refers to the intake of food, medication, or other substances through the mouth. In veterinary medicine, many treatments are administered orally. medications, special shampoos, or diets. In some cases, changes in the dog’s environment or lifestyle are also necessary to support healing.
Can my dog’s diet affect skin lesions? Yes, diet can have a significant impact on a dog’s skin health. A balanced diet rich in essential fatty acids, vitamins, and minerals can help strengthen the skin barrier and reduce inflammatory conditions.
Should I clean the affected skin area of my dog? It is often helpful to gently clean the affected skin area to remove dirt and bacteriaBacteria are microscopic, single-celled organisms that exist in almost every environment on Earth. Some types of bacteria are beneficial or even essential to life, while others can cause disease.. However, only use cleaning agents recommended by your veterinarian to avoid further irritation.
When should I see a veterinarian? You should consult a veterinarian if your dog’s skin lesions do not heal within a few days, worsen, or if your dog shows signs of pain, severe itching, or general malaise. A quick diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. can prevent more serious health problems.
Can skin lesions indicate serious health problems? Yes, in some cases, skin lesions can be signs of serious health problems such as autoimmune diseasesAutoimmune diseases are conditions in which the immune system mistakenly attacks the body's own cells or tissues as if they were foreign substances. Examples in dogs and cats include autoimmune hemolytic anemia and systemic lupus erythematosus. or systemic infections. A thorough examination by a veterinarian is crucial to make the correct diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients..
How can I prevent Skin lesions in my dog? Preventive measures include regular grooming, avoiding allergens, a balanced diet, and protectionProtection refers to safeguarding against diseases or harm. In veterinary medicine, this can include protecting animals through vaccinations, the use of parasite control products, or providing a safe environment. against parasites. Regular veterinary examinations can also help to identify and treat potential problems early on.