Early Signs of Lymphoma in Dogs: What Pet Owners Should Know
Lymphoma is a common form of cancer in dogs, affecting the lymphatic system—a critical part of the immune system that includes lymph nodes, the spleen, and bone marrow. Recognizing the first signs of lymphoma in your dog can make a crucial difference when it comes to early diagnosis and effective treatment.
Understanding Lymphoma in Dogs
Lymphoma arises from lymphocytes, a type of white blood cell that plays a central role in the body’s defenses against illness. Since lymphatic tissue exists in many areas throughout the body, lymphoma can manifest in various forms and locations.
Although it can affect any dog, middle-aged and older dogs are more frequently diagnosed. Some breeds, such as Golden Retrievers, Boxers, and German Shepherds, may be genetically predisposed.
Common Early Signs of Lymphoma
The early symptoms of lymphoma depend on the type and location of the disease. However, enlarged lymph nodes are the most common and often the first visible indication.
- Multicentric lymphoma: The most common type, accounting for up to 85% of cases, begins with swollen, firm, non-painful lymph nodes beneath the skin—in areas like the jaw, shoulders, armpits, and knees.
- Alimentary lymphoma: This form affects the gastrointestinal tract and is often first noticed through symptoms like vomiting, diarrhea, weight loss, abdominal discomfort, and lethargy.
- Mediastinal lymphoma: Involves lymph tissue in the chest, leading to breathing difficulties, coughing, or swelling of the face and forelimbs. Thirst and urination may also increase.
- Extranodal lymphoma: Begins in unusual sites such as the skin or eyes. Cutaneous forms can cause red, flaky skin, thickened patches, ulcers, or mouth lesions.
How to Recognize Lymph Node Swelling
Swollen lymph nodes may appear as hard, round, and painless lumps under your dog’s skin. Locations to check include:
- Under the jaw (submandibular)
- In front of the shoulders (prescapular)
- Behind the knees (popliteal)
- The armpits and groin area
In some dogs, there may be no other immediate symptoms. This is known as Substage A—dogs appear well apart from lymph node enlargement. In Substage B, additional clinical signs may be present.
Progressive Symptoms to Watch For
- Lethargy
- Loss of appetite
- Weight loss
- Increased thirst or urination
- Vomiting and diarrhea
- Weakness
- Difficulty breathing or coughing (in cases involving the chest)
- Skin lesions or hair loss (cutaneous lymphoma)
Diagnosis and Staging
Upon noticing early signs, it's vital to consult your veterinarian promptly. Diagnosis often includes:
- Fine needle aspiration (FNA): A quick test to examine cells from an enlarged lymph node.
- Biopsy: Provides more comprehensive tissue analysis if needed.
- Blood work and imaging: Helps evaluate systemic spread and organ involvement using X-rays or ultrasound.
- Molecular tests: Designed to classify the lymphoma as B-cell or T-cell for prognosis and treatment guidance.
Why Early Detection Matters
Starting treatment early can improve the dog’s response and increase the likelihood of remission. Chemotherapy is the mainstay of treatment, with response rates as high as 90% for multicentric lymphoma. Dogs often tolerate chemotherapy well, with minimal side effects.
Conclusion
Early detection of lymphoma in dogs begins with careful observation. If you notice unusual swelling in your dog’s neck, shoulders, or legs—or gastrointestinal issues without a clear cause—consult your veterinarian as soon as possible. Timely diagnosis enables quicker treatment, improves prognosis, and extends quality of life for your canine companion.
