Lymphoma-Like Lung Disease in Dogs (Pulmonary Lymphomatoid Granulomatosis)

  • Occurrence: very rare
  • Location of disease: Chest, General/Whole body
Author: Dr. med. vet. Gisa Löwe | Last modified: 15.10.2026
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When to visit the vet?

Non-urgent see a veterinarian within 2–3 days

?

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

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Definition

Pulmonary lymphomatoid granulomatosis is a rare, progressive disease in dogs characterized by the appearance of cancerous lymphatic cells in the lungs. These cells form nodules or granulomas that can impair normal lung function.

The most important facts at a glance

Pulmonary lymphomatoid granulomatosis in dogs is a condition involving the uncontrolled proliferation of lymphocytes, a type of white blood cell. These cells accumulate in the lungs and form granulomas. The exact causes are unclear, but it is suspected that a dysregulation of the immune system in combination with genetic factors plays a role. Viruses or other pathogens may also be involved, although no specific agents have been identified. Certain dog breeds may be genetically more susceptible.

Typical symptoms include cough, respiratory distress, lethargy, and nasal discharge. Diagnosis is made through clinical examinations, X-ray images, and often a lung biopsy to confirm the presence of cancerous cells. Treatment often involves immunosuppressive drugs and occasionally chemotherapy to slow the disease. Supportive measures such as oxygen administration and antibiotics may also be required.

The prognosis is guarded to poor, as the disease is progressive and can impair quality of life despite treatment. Early diagnosis and treatment can provide the best results, but the long-term prognosis is often poor. Since the causes are not fully understood, there are no specific preventive measures. However, regular veterinary check-ups and a healthy lifestyle can help promote the dog’s overall health and resilience.

Causes

Pulmonary lymphomatoid granulomatosis is a form of lymphoproliferative disease involving the uncontrolled proliferation of lymphocytes. Lymphocytes are a type of white blood cell that play an important role in the immune system. In this disease, it is believed that lymphocytes grow and accumulate uncontrollably, leading to the formation of granulomas.

The exact causes of the disease are not yet fully understood. However, it is thought that a dysregulation of the immune system in combination with genetic factors plays a role. Some researchers also suggest that viruses or other infectious agents could play a role in triggering this disease, although no specific pathogens have been identified so far.

Another possible factor could be a genetic predisposition in certain dog breeds. Some breeds seem to be more frequently affected, suggesting that certain genetic markers or mutations could increase susceptibility.

Symptoms

Rare symptoms:

Symptoms of pulmonary lymphomatoid granulomatosis in dogs can vary but are often associated with breathing problems. The most common symptoms include cough, respiratory distress, and a general decrease in activity due to limited lung function.

Some dogs may also show signs of systemic illness, such as fever, weight loss, and loss of appetite. Since the disease affects the lungs, abnormal-sounding breath sounds or an altered respiratory rate may also be observed.

In advanced stages of the disease, there can be a significant impairment of quality of life as the lungs are no longer able to sufficiently supply the body with oxygen. This can lead to a bluish coloration of the mucous membranes and extreme weakness.

Therapy

Treatment for pulmonary lymphomatoid granulomatosis focuses on controlling symptoms and slowing the progression of the disease. In many cases, immunosuppressive drugs are used to reduce the activity of the immune system and slow the growth of lymphatic cells.

Chemotherapy approaches may also be considered, especially if the disease is aggressive or does not respond to conventional treatments. The choice of medication and the duration of treatment depend on the severity of the disease and the dog’s response to therapy.

In addition to medication, supportive therapy may be required to improve the dog’s quality of life. This may include oxygen therapy, the administration of antibiotics to prevent secondary infections, and nutritional support.

Prognosis and follow-up care

The prognosis for dogs with pulmonary lymphomatoid granulomatosis is generally guarded to poor. The disease is progressive and can lead to a significant impairment of quality of life despite treatment.

Survival time can vary depending on how early the disease is diagnosed and how well the dog responds to treatment. Some dogs may respond well to therapy and remain stable for a period of time, while in others, the disease may progress rapidly.

In many cases, however, the long-term prognosis is poor, and treatment aims primarily at relieving symptoms and improving quality of life rather than achieving a cure.

Prevention

Since the exact causes of pulmonary lymphomatoid granulomatosis are not fully understood, there are no specific preventive measures to avoid the disease. However, early detection and diagnosis are crucial to achieving the best possible treatment outcomes.

Regular veterinary examinations and attentive observation of symptoms can help detect the disease at an early stage and start treatment in a timely manner. Dog owners should seek a veterinarian immediately if there are signs of respiratory distress or other unusual symptoms.

A healthy lifestyle, including a balanced diet and appropriate exercise, can contribute to the dog’s overall health and resilience, even if it may not directly prevent the development of the disease.

Outlook on current research

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Pulmonary lymphomatoid granulomatosis in dogs is a very rare lymphoproliferative lung disease. This very rarity also shapes the research outlook: unlike more common tumors or inflammatory lung diseases, there are so far only a few case reports and small case series, so many statements regarding cause, biological behavior, and optimal therapy are still uncertain. Typically, the disease can clinically and radiographically mimic other diffuse or nodular lung diseases, and the final diagnosis must usually be made histopathologically. (pubmed.ncbi.nlm.nih.gov, pubmed.ncbi.nlm.nih.gov)

The most important research focus currently is better differentiation from lymphomas, inflammatory granuloma diseases, and other interstitial lung diseases. For this, immunohistochemistry, clonality analyses, and more precise morphological classification are gaining importance. The goal is to clarify whether it is always the same biological entity in dogs or rather a spectrum of related lymphoproliferative processes. (pubmed.ncbi.nlm.nih.gov, pubmed.ncbi.nlm.nih.gov)

A second focus is therapy and prognosis research. Due to the small number of cases, it is currently unclear which patients benefit more from chemotherapy, glucocorticoids, or combined approaches. The outlook is therefore cautious: progress will likely be achieved first through multicenter case collections, standardized diagnostics, and molecular characterization, rather than through individual spectacular therapeutic innovations. (pubmed.ncbi.nlm.nih.gov)

Overall, research here is still in its infancy, but that is precisely why every cleanly documented case is scientifically particularly valuable.

Frequently Asked Questions (FAQs)

1. What is pulmonary lymphomatoid granulomatosis?
Pulmonary lymphomatoid granulomatosis (PLG) is a rare, cancerous disease in which atypical lymphatic cells and granulomas appear in the lungs. It is now considered a lymphoproliferative disease and is seen as an intermediate position between inflammatory granulomatosis and lymphoma.
2. Which dogs are affected?
The disease occurs in dogs of all ages, more frequently in middle-aged animals. There is no clear breed predisposition, though a slight increase is found in medium and large breeds. A connection with chronic inflammatory conditions or certain infections is being discussed.
3. What Symptoms occur?
Typical signs are chronic cough, respiratory distress, exercise intolerance, weight loss, loss of appetite, and fever. Symptoms usually develop over weeks. In advanced cases, extrathoracic manifestations involving the kidneys, skin, or central nervous system are also possible.
4. How is the diagnosis made?
X-ray and CT usually show nodular, sometimes confluent lung changes, often with lymph node enlargement. Definitive diagnosis requires a biopsy, usually taken transthoracically, bronchoscopically, or surgically. Histological and immunohistochemistry examination (predominantly T-cell-rich infiltrates) is crucial.
5. How is the disease treated?
The therapy of choice is chemotherapy, often using protocols also used for lymphoma (for example, CHOP). Corticosteroids supplement the treatment. For solitary lesions, surgical removal may be considered, but the disease is usually multifocal.
6. Is PLG a true lymphoma?
PLG is now classified as an angioimmunoproliferative process with a lymphomatoid character. It shows features reminiscent of both granulomas and lymphomas. Treatment is based on lymphoma protocols and provides the best response rates under them.
7. What prognosis can be expected?
Untreated, the disease is rapidly progressive and fatal within a few months. With chemotherapy, many dogs achieve remission with median survival times of six to twelve months, some animals significantly longer.
8. Can PLG transform into a classic lymphoma?
A transition into a more aggressive T-cell lymphoma has been described. For this reason, structured follow-up with imaging and clinical assessment is important to detect changes early and adjust therapy.
9. What side effects does chemotherapy have?
Modern veterinary chemotherapy protocols are significantly gentler than human chemotherapy. Possible side effects include mild gastrointestinal complaints, temporary leukopenia, and rarely infections. Quality of life remains good for most dogs during therapy.
10. How does PLG differ from bacterial pneumonia?
Bacterial pneumonias respond to antibiotics and usually show diffuse inflammatory changes. PLG shows nodular structures, does not respond to antibiotics, and progresses without specific therapy. Histology is ultimately decisive for the correct diagnosis.

Literature

  • Lucke, V. M., Kelly, D. F., Harrington, G. A., Gibbs, C., & Gaskell, C. J. (1979). A lymphomatoid granulomatosis of the lungs in young dogs. Veterinary Pathology, 16(4), 405–412. https://doi.org/10.1177/030098587901600402
  • Postorino, N. C., Wheeler, S. L., Park, R. D., Powers, B. E., & Withrow, S. J. (1989). A syndrome resembling lymphomatoid granulomatosis in the dog. Journal of Veterinary Internal Medicine, 3(1), 15–19. https://doi.org/10.1111/j.1939-1676.1989.tb00323.x
  • Berry, C. R., Moore, P. F., Thomas, W. P., Sisson, D., & Koblik, P. D. (1990). Pulmonary lymphomatoid granulomatosis in seven dogs (1976–1987). Journal of Veterinary Internal Medicine, 4(3), 157–166. https://doi.org/10.1111/j.1939-1676.1990.tb00890.x
  • Leblanc, B., Masson, M. T., Andreu, M., Bonnet, M. C., & Paulus, G. (1990). Lymphomatoid granulomatosis in a beagle dog. Veterinary Pathology, 27(4), 287–289. https://doi.org/10.1177/030098589002700412
  • Fitzgerald, S. D., Wolf, D. C., & Carlton, W. W. (1991). Eight cases of canine lymphomatoid granulomatosis. Veterinary Pathology, 28(3), 241–245. https://doi.org/10.1177/030098589102800308
  • Smith, K. C., Day, M. J., Shaw, S. C., Littlewood, J. D., & Jeffery, N. D. (1996). Canine lymphomatoid granulomatosis: An immunophenotypic analysis of three cases. Journal of Comparative Pathology, 115(2), 129–138. https://doi.org/10.1016/S0021-9975(96)80035-1
  • Park, H.-M., Hwang, D.-N., Kang, B.-T., Jung, D.-I., Song, G.-S., Lee, S.-J., Yhee, J.-Y., Yu, C.-H., Doster, A. R., & Sur, J.-H. (2007). Pulmonary lymphomatoid granulomatosis in a dog: Evidence of immunophenotypic diversity and relationship to human pulmonary lymphomatoid granulomatosis and pulmonary Hodgkin’s disease. Veterinary Pathology, 44(6), 921–923. https://doi.org/10.1354/vp.44-6-921