Lymphoma, Lymphosarcoma (cancer caused by blood cells, the lymphocytes) in cats

  • Occurrence: common
  • Location of illness: General/Whole body
Author: Dr. med. vet. Gisa Löwe | Last modified: 03.12.2025

Lymphoma, also known as lymphosarcoma, is a malignant cancer that originates from the lymphocytes, a type of white blood cell. These cells are an essential component of a cat’s immune system.

The most important facts at a glance

Lymphoma in cats are cancers caused by the uncontrolled proliferation of lymphocytes, specialized immune cells of the body. This disease can affect various areas of the body, including lymph nodes, the gastrointestinal tract, and the chest area. The exact causes of lymphoma are not yet fully understood, but genetic factors, environmental factors, and infections with viruses such as Feline Leukemia Virus (FeLV) and Feline Immunodeficiency Virus (FIV) play a role. Symptoms include enlarged lymph nodes, Respiratory distress, Weight loss, and Vomiting, while diagnosis is made through clinical examination, laboratory tests, and biopsy. Treatment depends on the form and stage of the lymphoma and often includes chemotherapy, sometimes combined with surgery or radiotherapy. The prognosis varies greatly, depending on the stage of the disease and the cat’s overall health. Preventive measures include avoiding FeLV and FIV infections, a balanced diet, and regular veterinary visits. Research focuses on genetic factors, new therapeutic approaches, and the role of viruses in the development of lymphoma. Advances in diagnostics and the development of new treatment methods could lead to better treatment outcomes in the future.

Causes

Lymphocytes are specialized cells formed in the lymph nodes, spleen, and other organs of the lymphatic system. They play a crucial role in fighting infections. In lymphoma, these cells multiply uncontrollably, which can lead to Tumors in various body areas.

The causes of lymphoma in cats are diverse and not yet fully understood. Genetic factors are believed to play a role, as do environmental factors and infections, particularly with the Feline Leukemia Virus (FeLV) and the Feline Immunodeficiency Virus (FIV). These viruses weaken the immune system and increase the risk of lymphoma development.

There are various forms of lymphoma in cats, classified by the primary affected area, such as mediastinal lymphoma (in the chest area), alimentary lymphoma (in the gastrointestinal tract), and multicentric lymphoma (in multiple lymph nodes). Each form can have different causes and risk factors.

Symptoms

Rare symptoms:

The symptoms of lymphomas in cats can vary greatly depending on the area affected. General signs may include weight loss, loss of appetite, lethargy, and fever. However, these symptoms are non-specific and can occur with many other conditions.

In alimentary lymphoma, which affects the gastrointestinal tract, vomiting, diarrhea, and abdominal pain can often be observed. Cats may also suffer from dehydration and poor body condition.

A mediastinal lymphoma can cause respiratory distress, cough, and an accumulation of fluid in the chest cavity, leading to shortness of breath. This form is often observed in younger cats, especially those infected with FeLV.

Multicentric lymphomas often affect multiple lymph nodes and can lead to swellings that are palpable. This form is less specific in its symptoms and can often only be detected in advanced stages.

Diagnosis

The diagnosis of lymphoma begins with a thorough clinical examination and a detailed medical history. The veterinarian will look for Swelling of the lymph nodes, Respiratory distress, and other non-specific symptoms.

Laboratory tests are essential and usually include blood tests to detect signs of anemia, changes in white blood cells, or other abnormalities. An X-ray or ultrasound examination can be used to identify Tumors or fluid accumulations.

The definitive diagnosis is often made by a biopsy, in which a tissue sample of the affected area is taken and examined microscopically. This method allows for determining the type of cells and assessing the degree of malignancy.

In some cases, immunohistochemistry or flow cytometry may be performed to characterize the type of lymphocytes and identify specific markers that can help distinguish between different types of lymphoma.

Therapy

The treatment of lymphoma in cats depends on the form and stage of the disease. Chemotherapy is the most commonly used method and can be used alone or in combination with other treatments. The goal is to control tumor growth and improve quality of life.

For alimentary lymphomas, surgical removal of the affected intestinal segment may be necessary, especially if the tumor causes obstructions. Chemotherapy is often used after surgery to destroy remaining cancer cells.

Radiation therapy can be used for localized lymphomas, especially if the tumor is located in an area where surgery is difficult. However, this method is less commonly applied in cats.

Palliative treatments aimed at alleviating symptoms can also be part of the management, especially in advanced cases. These include pain relievers and anti-inflammatory medications.

Prognosis and follow-up care

The prognosis for cats with lymphoma varies considerably and depends on several factors, including the stage of the cancer, the affected organs, and the cat’s general health. Early diagnosis and treatment can improve the prognosis.

Cats with alimentary lymphomas generally have a better prognosis, especially if the cancer is confined to the intestine and can be surgically removed. Mediastinal lymphomas often have a poorer prognosis, particularly when associated with FeLV.

The average survival time of cats that respond to treatment is between a few months and several years. Long-term remission is possible, but relapse is common.

Prevention

The prevention of lymphoma in cats is a challenge, as the exact causes are often unknown. Nevertheless, there are some measures that may reduce the risk. One of the most important measures is avoiding infections with the Feline Leukemia Virus (FeLV) and the Feline Immunodeficiency Virus (FIV), as these viral infections can increase the risk of lymphoma development. Regular tests and vaccinations against FeLV can help minimize the risk.

A healthy and balanced diet can also contribute to the cat’s overall health and potentially strengthen the immune system. Ensure your cat receives high-quality food and avoid Overweight, as Obesity can increase the risk of various diseases.

Regular veterinary visits are crucial to monitor your cat’s health and detect early signs of disease. Early detection and treatment of health problems can reduce the risk of developing more serious conditions.

Finally, it is advisable to minimize stress for your cat, as stress can weaken the immune system. A calm and safe home, along with sufficient play and activity opportunities, can help promote your cat’s well-being.

Outlook on current research

Research into lymphoma in cats currently focuses on various aspects, including the genetic and environmental factors that contribute to the development of this disease. Scientists are investigating the specific genetic mutations that can lead to an increased risk of lymphoma in cats. A better understanding of these genetic factors could lead to more targeted diagnosis and treatment strategies in the future.

Another important area of research is the development of new therapeutic approaches. Work is currently underway to improve chemotherapy protocols to minimize side effects and maximize effectiveness. Furthermore, there are promising studies on immunotherapies designed to stimulate the cat’s immune system to specifically fight cancer cells. These approaches could lead to gentler and more effective treatment in the long term.

The role of viruses, particularly the Feline Leukemia Virus (FeLV) and the Feline Immunodeficiency Virus (FIV), is also being intensively researched. It is known that these viruses can increase the risk of lymphoma development, and researchers are working to better understand the mechanisms by which these viruses contribute to cancer development. In the long term, vaccination strategies against these viruses could help reduce the risk of lymphoma.

In addition, there are studies on environmental triggers that may contribute to the development of lymphoma in cats. These include factors such as passive smoking, certain pesticides, and other environmental toxins. These studies aim to develop preventive measures that can reduce the risk of the disease.

In clinical research, new diagnostic tests are being developed to detect lymphomas earlier and more accurately. The use of biomarkers that can be detected in the cat’s blood or tissue is being intensively researched. These tests could help to detect the disease in a stage where it is still more treatable in the future.

Frequently asked questions (FAQs)

  1. What is lymphoma in cats? Lymphoma is a type of cancer that affects the lymphatic system, which is part of a cat’s immune system. It is one of the most common cancers in cats and can occur in various forms, depending on which lymphocytes or areas of the body are affected.

  2. What are the symptoms of lymphoma in cats? The symptoms can vary depending on the affected area of the body. Common signs include loss of appetite, weight loss, lethargy, vomiting, diarrhea, respiratory distress, or swollen lymph nodes. A veterinarian should be consulted if lymphoma is suspected.

  3. How is lymphoma diagnosed in cats? Diagnosis is made through a combination of clinical examination, blood tests, X-ray or ultrasound examinations, and a biopsy of the affected lymph nodes or organs. An accurate diagnosis is crucial for choosing the right treatment.

  4. What treatment options are available for cats with lymphoma? The main treatment usually consists of chemotherapy, which aims to destroy cancer cells or slow their growth. In some cases, radiation therapy or surgical removal may also be necessary. The treatment is tailored individually to the cat.

  5. Can lymphomas be cured in cats? The chances of a cure depend on the type and stage of the lymphoma. Some cats can go into remission with treatment, meaning that the disease is no longer detectable. However, a complete cure is rare, and the disease may recur.

  6. How long can cats with lymphoma live? Life expectancy varies greatly and depends on the aggressiveness of the lymphoma, the cat’s general health, and the effectiveness of the treatment. Some cats can live for several months to years, especially if they respond well to treatment.

  7. Are there risk factors for developing lymphoma in cats? Yes, risk factors include infection with the Feline Leukemia Virus (FeLV) or the Feline Immunodeficiency Virus (FIV), passive smoking, and possibly certain environmental toxins. Genetic factors could also play a role.

  8. Can I take preventive measures against lymphoma in my cat? Some risk factors can potentially be reduced through vaccinations against FeLV and FIV, as well as by avoiding passive smoking and environmental toxins. A healthy diet and regular veterinary check-ups can also help maintain your cat’s health.

  9. How is the quality of life of a cat with lymphoma ensured during treatment? Quality of life is ensured through close veterinary care, which aims to minimize treatment side effects and alleviate disease symptoms. A balanced diet and plenty of rest are also important.

  10. Can alternative therapies help in the treatment of lymphoma in cats? While some alternative therapies, such as acupuncture or herbal supplements, can be used as an adjunct to conventional treatment, they should never serve as a substitute for veterinarian-recommended treatment. It is important to always discuss such options with a veterinarian.

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