Canine Lymphoma

What is it?

Lymphoma is a common type of cancer in dogs. It results from the unregulated growth of malignant lymphocytes that often affects lymph nodes, bone marrow, liver, and spleen, but can also be seen in the eyes, skin, and gastrointestinal tract. There are several classification systems for lymphoma based on whether or not it is high or low grade (relates to the aggressiveness), where it is located in the body, and what type of cells are involved (T-lymphocytes vs. B-lymphocytes). Dogs can present with enlarged lymph nodes and no clinical signs of illness. Some dogs may be depressed, lethargic, vomiting, losing weight, losing fur/hair, febrile, and/or have decreased appetite. Lymphoma is diagnosed with diagnostic lab work and an aspirate of the lymph nodes. Some dogs with lymphoma will have an increased blood calcium.

How is it treated?

Chemotherapy is the treatment of choice for most pets with lymphoma. There are a wide range of chemotherapeutic drugs that can be used in combination to treat this disease. Giving prednisone, a steroid, alone can improve the quality, and sometimes quantity, of life. While there is no cure for lymphoma, chemotherapy often results in remission (no outward signs of cancer). The first remission can last 6 to 8 months or more depending on the chemotherapy protocol used. A second remission is generally a little more difficult to achieve and lasts a shorter time.

What is the prognosis for lymphoma?

Again, there is no cure for lymphoma, but with a good therapeutic protocol, average survival time can be 9 to 12 months or longer. Prognosis is better if an animal presents with only enlarged lymph nodes and with B-cell lymphoma rather than T-cell lymphoma. A dog appropriately treated for lymphoma can live a relatively comfortable, productive life for many months. The following symptoms of disease may occur quickly in your dog with or without treatment. A personalized treatment plan is important to slow the progression of lymphoma. Talk to your veterinarian regarding the best treatment protocol for your dog.

What symptoms can present as the disease progresses?

Early stages:

  • enlarged lymph nodes (may be seen in one or all regions- under jaw, in the chest region, armpits, behind the knees, groin)
  • weight loss
  • inappetance, anorexia
  • vomiting
  • diarrhea or black, tarry stool
  • fever
  • conjunctivitis – eye infections
  • lethargy, depression
  • reclusive behavior
  • loss of fur or hair
  • increased water consumption
  • increased urination

Late stages:

  • persistent early stages
  • severe weight loss
  • difficulty breathing, coughing
  • seizures, paralysis
  • difficulty swallowing
  • anorexia
  • congestive heart failure
  • unable to rise
  • bruised, ulcerated skin

Crisis – Immediate veterinary assistance needed regardless of the disease

  • Difficulty breathing
  • Prolonged seizures
  • Uncontrollable vomiting/diarrhea
  • Sudden collapse
  • Profuse bleeding – internal or external
  • Crying/whining from pain*

*It should be noted that most animals will instinctually hide their pain. Vocalization of any sort that is out of the ordinary for your pet may indicate that their pain and anxiety has become too much for them to bear. If your pet vocalizes due to pain or anxiety, please consult with your tending veterinarian immediately.

Common Signs of Pain

  • Panting
  • Lameness
  • Difficulty sleeping
  • Pacing
  • Abnormal posture
  • Body tensing
  • Poor grooming habits
  • Tucked tail
  • Dilated Pupils
  • Licking sore spot
  • Muscle atrophy
  • Decreased appetite
  • Vocalizing/yowling
  • Reclusive Behavior
  • Aggressive Behavior
  • Avoiding stairs/jumping
  • Depressed
  • Unable to stand

Download Canine Lymphoma brochure