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Bruising (Hematoma) in cats

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/red, if spontaneous/multiple without trauma, mucous membrane bleeding, petechiae, pale mucous membranes, weakness or shortness of breath

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Definition

Bruising, also known as hematomas, are collections of blood that accumulate outside the blood vessels under the skin or in a cat’s tissues. They occur when blood leaks from injured blood vessels and can vary depending on their size and depth.

Can Occur with the Following Diseases:

Basics and possible causes

Bruising in cats often results from direct traumas, such as falls, collisions, or bites. When an injury occurs, blood vessels under the skin are damaged, causing blood to leak into the surrounding tissue. The skin may then show a reddish, bluish, or purplish discoloration, which turns yellow or green over time as the body breaks down the blood.

Another possible cause of hematomas is 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. disorders. These can be congenitalCongenital means "present from birth" and refers to characteristics or conditions that are already present at birth. This can include genetic disorders, developmental anomalies, or infections transmitted by the mother. or caused by various conditions such as liver problems or the use of certain medications. In such disorders, the blood cannot clot properly, leading to an increased tendency to bleed and bruising.

Infections or inflammatory conditions can also contribute to the formation of hematomas by weakening or damaging blood vessels. In rare cases, Tumors or other growths in a cat’s body can lead to bruising by putting pressure on blood vessels or by infiltratingInfiltration refers to the penetration or accumulation of cells or fluids in a tissue or area that is normally free of them. This can occur as part of inflammatory reactions, Tumors, or other pathological processes. them.

Typical accompanying symptoms

Swelling: Hematomas often cause Swelling in the affected area, which can be painful to the touch. These swellings can feel warm and impair the cat’s mobility, depending on their location.
Discoloration: The skin over a hematoma can go through a range of colors, starting with red or blue, then purple, and finally yellow or green as the healing process progresses.
Pain: Cats with hematomas may show symptoms of pain, such as hesitating to touch or move a certain area, or they may show signs of discomfort or irritability.
Lethargy: In some cases, especially if the bruising is caused by an underlying condition, cats may appear lethargic or be less active than usual.
Loss of appetite: Pain or discomfort can lead to a reduced appetite. This can be particularly true for hematomas in the mouth or facial area.

When to see a vet?

A visit to the vet is strongly advisable if the bruising is large, rapidly increasing in size, or the cat appears to be in severe Pain. Even if the cat shows other symptoms such as shortness of breath, weakness, pale gums, or unexplained Weight loss, a vet should be consulted immediately.

A vet visit is also necessary if a cat repeatedly gets bruising without an obvious traumaA trauma refers to a physical injury or damage caused by external force. Traumas can range from simple cuts to severe multiple injuries.. This could indicate an underlying health disorder that requires examination and treatment.

If a cat develops bruising after being given new medications or after surgery, the vet should be informed to rule out possible side effects or complications.

Symptom recognition for the pet owner and veterinary diagnostic procedure

For pet owners, recognizing hematomas can be difficult, especially in cats with thick or dark fur. Palpating the cat for unusual lumps or Swelling can help detect hematomas. If the cat shows signs of Pain or discomfort, this could also indicate a hematoma.

The vet will thoroughly examine the cat to determine the exact cause of the bruising. This may include a physical examination, blood tests to rule out coagulationCoagulation is the process of blood coagulation, in which liquid blood is transformed into a solid clot. This process is crucial for stopping Bleeding and promoting wound healing. disorders, and imaging techniques such as X-rays or 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. to assess deeper tissues.

In some cases, a biopsyA biopsy is a medical procedure in which a small amount of tissue is removed from the body to be examined under a microscope for signs of disease. Biopsies can help diagnose cancer and other conditions. or fine-needle aspirationFine-needle aspiration is a minimally invasive diagnostic technique that uses a thin needle to extract cells or fluid from a tumor, lesion, or organ. This sample is then examined microscopically to make a diagnosis. may be necessary to ensure that no Tumors or other serious diseases are present. The vet will also consider the cat’s 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. and ask questions about possible injuries, medications, and symptoms.

What the pet owner can do and professional therapy options

As a first measure, the pet owner can try to carefully cool the affected area to reduce Pain and Swelling. However, this should only be done if the cat allows it and does not react with 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. or fear.

It is important to keep the cat as calm as possible to prevent further injuries. Avoid moving or activating the cat too much until the vet has assessed the situation.

The pet owner should also ensure that the cat has access to water and food, but observe whether it shows signs of Pain or discomfort when eating or drinking. A soft, safe environment can help minimize 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. and the risk of further injuries.

Avoid using medication without veterinary advice, as many human painkillers can be toxicToxic means "poisonous" and refers to substances that can have harmful effects on the body, including damage to organs, cells, or disruption of metabolic processes. to cats. The vet will prescribe the appropriate medications and treatments to relieve Pain and promote healing.

Outlook on current research

Research into bruising (hematoma) in cats is a growing area of veterinary science. Bruising occurs when blood vessels under the skin are damaged, leading to an accumulation of blood in the tissue. Current studies focus on understanding the mechanisms that influence the formation of hematomas in cats. Researchers are particularly examining the role of coagulationCoagulation is the process of blood coagulation, in which liquid blood is transformed into a solid clot. This process is crucial for stopping Bleeding and promoting wound healing. disorders and the effect of trauma on blood vessels. These investigations aim to develop 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. tools and more effective 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. protocols.

A central research area is the genetic 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. of some cat breeds to 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. disorders, which can increase susceptibility to hematomas. Studies are attempting to identify the genetic markers associated with an increased tendency to bleed. This could lead to breeding measures in the future that reduce the risk of such problems. In addition, research is being conducted on how environmental factors, such as 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., can influence the frequency and severity of hematomas.

Another exciting research area deals with the development of new diagnostic methods. The use of imaging techniques, 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. and MRI, is being investigated to better determine the exact location and size of hematomas. Furthermore, work is underway to develop blood tests that can identify specific biomarkers for bruising in cats. These tests could enable early detection of bruising, even before visible symptoms appear.

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. strategies for hematomas are also the subject of intensive research. The use of 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. is being explored to accelerate the healing of hematomas. Additionally, alternative therapies such as the application of cold compresses or special ointments are being investigated to alleviate symptoms and promote the absorptionAbsorption refers to the uptake of substances by living cells or tissues. In the context of veterinary medicine, it often refers to the absorption of nutrients, drugs, or toxins from the digestive tract into the bloodstream. of the bruising. The combination of traditional and alternative 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. methods could enable optimized care for cat symptoms in the future.

While research into hematomas in cats is still in its early stages, current studies promise to significantly expand the understanding of bruising in cats. This could lead to significant advances in 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 treatment, ultimately improving the quality of life for affected animals.

Frequently asked questions

1. What are the most common signs of a bruise in cats?

The most common signs of bruising in cats are skin discoloration, Swelling, and Sensitivity to touch. In some cases, the cat may also show signs of Pain or lick or scratch the affected area.

2. Can bruises in cats heal on their own?

Yes, smaller bruising can often heal on their own as the body gradually breaks down the blood in the tissue. However, it is important to observe the cat and consult a vet for larger or painful bruising.

3. What should I do if I discover a bruise on my cat?

If you discover bruising on your cat, you should observe the area closely. If the bruising gets larger, the cat is in Pain, or shows other symptoms, you should seek veterinary attention. A thorough examination is important to rule out serious health problems.

4. Are there home remedies to support the healing process of bruises in cats?

Some home remedies, such as cold compresses, can help reduce Swelling and support the healing process. However, it is important to use these remedies with caution and observe the cat closely. If in doubt, a vet should always be consulted.

5. Can bruises in cats be a sign of a more serious problem?

Yes, bruising can indicate more serious health problems such as coagulation disorders or injuries. If your cat frequently develops bruising or shows other symptoms, a vet should be consulted to clarify the cause.

6. How long does it usually take for a bruise to heal in a cat?

The healing time for bruising in a cat depends on its size and severity. Smaller bruising can heal within one to two weeks, while larger or deeper hematomas may take longer. Close observation is important to monitor the healing process.

7. How does a hematoma differ from a simple scratch in cats?

A hematoma is an accumulation of blood under the skin that leads to discoloration and Swelling, whereas a scratch is an open wound on the skin surface. Hematomas are generally painful and can lie deeper in the tissue than scratches.

8. Can a poor diet increase the tendency to bruise in cats?

Yes, inadequate nutrition can affect blood vessel health and lead to coagulation disorders, which can increase the tendency to bleed. A balanced diet is important to promote your cat's general health and well-being.

9. Should I always check my cat for bruising after a trauma?

Yes, after a trauma, it is advisable to check your cat for bruising or other injuries. Hematomas can be a sign of internal injuries that may require veterinary treatment.

10. Can vaccinations cause bruising in cats?

In rare cases, vaccinations can lead to small bruising at the injection site. These are usually harmless and disappear on their own. However, if you notice unusual Swelling or other reactions, you should inform your vet.