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Bruising (Hematoma) under the Skin 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

ORANGE for multiple, spontaneously occurring bruises, petechiae, Bleeding gums, or apathy; RED for Pallor, collapse, shortness of breath, or increased abdominal circumference (internal Bleeding possible).

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Definition

Bruises or hematomas in dogs are accumulations of blood under the skin caused by bleeding into the surrounding tissue. These blood accumulations can be caused by injuries or other medical conditions.

Can Occur with the Following Diseases:

Basics and possible causes

A hematoma occurs when blood vessels under the skin are damaged, causing blood to leak into the surrounding tissue. This can be caused by physical traumas such as bumps, falls, or fights. In some cases, bruising can also occur without an obvious injury, which may indicate underlying health problems.

Another possible cause of hematomas in dogs is clotting disorders. If the blood does not clot properly, bleeding can occur even with minor injuries. Such clotting disorders can be due to geneticsGenetics is the science of genes, heredity, and the variation of organisms. It studies how genetic information is passed from generation to generation and how it influences the development, appearance, and behavior of living things. or triggered by diseases such as von Willebrand disease or liver disease.

The appearance of hematomas can also be linked to certain medications that affect blood coagulationBlood coagulation is a process that helps stop Bleeding when a blood vessel is damaged. Platelets and certain proteins in the plasma form a blood clot that seals the wound., such as some anti-inflammatory drugsAnti-inflammatory drugs are medications that reduce inflammation. They can be divided into nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids and are used in dogs and cats to reduce Inflammatory conditions and Pain. or anticoagulantsAnticoagulants are medications that slow down or inhibit blood coagulation. They are used to prevent the formation of blood clots and are used in dogs and cats with certain heart conditions or coagulation disorders.. An overdose or the wrong choice of medication can increase the risk of bruising.

Typical accompanying symptoms

Swelling: Hematomas often lead to visible Swelling under the skin. This Swelling can be soft or firm and varies in size.
Discoloration: The skin over a hematoma may have a blue, red, or purple color that may fade over time.
Pain: The area around the hematoma may be painful or sensitive to the touch, which the dog may show by pulling back or growling.
Limited mobility: In the case of larger hematomas, especially in the legs or joints, the dog may have difficulty moving.
Discomfort or Lethargy: In the case of large or frequent hematomas, the dog may show general discomfort or lethargy.

When to see a vet?

A visit to the vet is absolutely necessary if the dog develops bruises repeatedly or without a recognizable cause. This can indicate a serious underlying condition that needs to be investigated. Even if the hematoma is very large or the dog is in severe Pain, a professional should be consulted.

If the hematoma does not heal within a few days or if the symptoms worsen, a visit to the vet is advisable. Bruises that occur near vital organs are particularly concerning and require immediate attention.

Symptom recognition for the pet owner and veterinary diagnostic procedure

Pet owners should regularly check their dog’s body for unusual Swelling or discoloration. Small bruises can often be overlooked, so it is important to be alert to signs of Pain or Behavioral changes.

The vet will first perform a thorough physical examination of the dog to assess the size and location of the hematoma. Blood tests can help identify underlying clotting disorders or other diseases. In some cases, an 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. examination 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 to determine the extent of the Bleeding and possible internal injuries.

What the pet owner can do and professional therapy options

At home, the pet owner can cool the affected area to reduce Swelling and relieve Pain. However, care should be taken to ensure that the animal does not get too cold. An ice pack wrapped in a towel can be helpful.

It is important to keep the dog calm to avoid further injury or Bleeding. Avoid involving the dog in active play or strenuous activities until the vet gives the green light.

If the dog is taking medication that affects blood coagulationBlood coagulation is a process that helps stop Bleeding when a blood vessel is damaged. Platelets and certain proteins in the plasma form a blood clot that seals the wound., the pet owner should consult the vet before changing or stopping the medication. It is important that all medication adjustments are made under veterinary supervision to minimize the risk of side effects or complications.

Outlook on current research

Research into bruises (hematomas) under the skin in dogs focuses on various aspects to develop a better understanding and more effective treatment approaches. One focus is on investigating the microscopic and macroscopic processes that lead to the formation of hematomas. Scientists are trying to understand the exact mechanisms of blood coagulationBlood coagulation is a process that helps stop Bleeding when a blood vessel is damaged. Platelets and certain proteins in the plasma form a blood clot that seals the wound. and vascular injuries in dogs and how these processes are influenced by genetic, environmental, or health factors.

Another area of research is the development of new diagnostic tools to determine the cause of bruising in dogs more quickly and accurately. Modern imaging techniques such as high-resolution 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. and MRI scans are being studied to optimize them for identifying and assessing hematomas in dogs. These technologies could make it possible to detect subtle changes in the tissue that are not visible to the naked eye, thus promoting a more precise 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..

Additionally, the role of geneticsGenetics is the science of genes, heredity, and the variation of organisms. It studies how genetic information is passed from generation to generation and how it influences the development, appearance, and behavior of living things. in the predispositionA predisposition is an innate inclination or susceptibility of an organism to certain diseases or conditions. In dogs and cats, there may be a genetic predisposition to certain conditions such as hip dysplasia or certain heart diseases. for hematomas is being investigated. Researchers analyze genetic patterns and markers in different dog breeds to find out if certain breeds or genetic variants have a higher risk of bruising. These studies could lead to targeted breeding strategies to reduce the risk of hematomas in future generations.

The development of new therapeutic approaches is also a focus of research. Scientists are working on formulating medications that specifically target the mechanisms that cause bruising. This could include the development of 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. applications or systemic drugs that speed up healing or prevent the formation of hematomas. Similarly, the role that dietary adjustments and supplements can play in promoting vascular health and reducing the risk of hematomas is being investigated.

Overall, the research aims to deepen the understanding of how hematomas develop in dogs and to develop innovative methods for preventionPrevention includes measures taken to prevent diseases or injuries. In veterinary medicine, this includes vaccinations, parasite control, and health monitoring., 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.. In the future, this could lead to an improved quality of life for dogs prone to bruising and provide veterinarians with more effective tools to manage these symptoms.

Frequently asked questions

1. What are Bruising (hematoma) in dogs?

Bruises in dogs, also known as hematomas, are accumulations of blood under the skin that can be caused by an injury, a blow, or spontaneous Bleeding. They are often visible as skin discolorations and can vary in size.

2. What do bruises look like in dogs?

Bruises in dogs often appear as dark or reddish spots under the skin. The color can change over time to blue, green, or yellow as the body breaks down the accumulated blood.

3. What causes bruising in dogs?

Bruises can be caused by physical traumas such as bumps or injuries, but also by medical conditions such as blood clotting disorders or certain medications that impair blood coagulation.

4. Are hematomas painful in dogs?

Yes, bruises can be painful for dogs, especially if they press on nerves or sensitive tissue. The dog may be sensitive to touch and show signs of discomfort.

5. How long does it take for a bruise to heal in a dog?

The healing of a bruise in a dog can take a few days to several weeks, depending on the size of the bruise and the dog's general health. Smaller bruises usually heal faster than larger ones.

6. When should I take my dog to the vet for a bruise?

You should see a vet if the bruise is large, does not get better within a few days, or if your dog shows other symptoms such as lethargy, loss of appetite, or Bleeding in other areas. These could indicate a more serious underlying condition.

7. Is there anything I can do to help heal my dog's bruising?

Yes, you can support healing by cooling the affected area to reduce Swelling and ensuring that your dog does not overexert themselves. Also, make sure your dog receives a balanced diet to promote tissue repair.

8. Are certain breeds more prone to bruising?

Some dog breeds may be more prone to bruising due to genetic predispositions or specific health problems. For example, breeds with known blood clotting disorders like the Doberman Pinscher are more likely to be affected.

9. What is the difference between a bruise and a hematoma in a dog?

The term “bruise” is often used synonymously with “hematoma”, but a hematoma can also be a larger collection of blood in a tissue or cavity, while a bruise typically describes smaller, superficial collections of blood.

10. Can bruising in dogs be a sign of a serious health problem?

Yes, bruises can indicate more serious health problems, especially if they occur for no apparent reason. Conditions that affect blood coagulation, such as von Willebrand disease or liver problems, can lead to spontaneous Bleeding.