What You Need To Know About Lymphoma In Dogs
The most common form of canine cancer, pet parents need to know about lymphoma in dogs, the treatment options available and the survival rate of this disease.
It’s one of the fast rising cancers in young people in North America today, but did you know that it actually leads the pack in the dog world when it comes to malignancies? It’s lymphoma and for humans and canines alike it requires early diagnosis and aggressive treatment to win the battle.
What Causes Lymphoma?
As with human cancers, there is no definitive answer. Researchers know it occurs more often in middle aged to older dogs and in breeds such as Boxers, Bull Mastiffs, Basset Hounds, Saint Bernard’s, Scottish Terriers, Airedales and Bull dogs. But research is also looking at environmental triggers. A recent study of diagnosed dogs showed increased cases where owners had sprayed herbicides on their lawns, lived in industrial areas or in households where chemicals like paints and solvents were used frequently. Weak immune systems seem to be another factor.
What is Lymphoma?
Lymphoma is the name applied to a group of blood cell tumors that develop from lymphatic cells. In dogs, there are five types, with multi-centric being the most common. This form of lymphoma affects the external lymph nodes and in most instances will invade the organs over time.
Alimentary lymphoma accounts for about 10 percent of canine lymphomas. It occurs in the gastrointestinal tract of dogs and can become fatal if the tumor is situated near the small or large intestine, restricting the bowel.
Symptoms and Diagnosis:
Multi-centric is characterized by painless swelling of the lymph nodes including the spleen and liver. While some pooches won’t show any signs of illness the symptoms can present dramatically and pet parents need to be on alert for weight loss, breathing difficulty, abnormal thirst, excessive urination, fever, anemia or even hemorrhaging or sepsis.
With alimentary lymphoma the actual diagnosis is more difficult, but symptoms that include vomiting, diarrhea, weight loss, excess passing of urine and lethargy should raise sufficient red flags to get your boy into the vet.
For most dogs suspected of having lymphoma a thorough physical exam should entail a complete blood count and urinalysis. The final diagnosis can be made through fine needle aspirates of affected lymph nodes or other tissues and use of ultra sound during this procedure can also help evaluate whether the liver, spleen, or abdominal lymph nodes are involved.
Treatment and Prognosis:
Treatment is determined by the stage of the disease and chemotherapy continues to be the treatment of choice for most patients.
For dogs with multi-centric lymphoma, surgery can be carried out if the disease is in its initial phase and careful mapping of the impacted organs supports this course of treatment. Radiation therapy given to patients either after the completion of chemotherapy or during ongoing sessions has also been found to be safe and effective.
For pooches with alimentary lymphoma, if local it can be treated effectively with surgical resection combined with chemotherapy. The involvement of local lymph nodes and liver is very common in this case.
While many dogs achieve complete remission with chemotherapy, the duration of the remission is temporary and typically lasts six to 20 months, depending on the type and stage of the illness. A second remission is more difficult to achieve and less than 50 percent of dogs undergoing chemo for a second time, will make it into another remission. The sad truth is that less than half the dogs treated for lymphoma will survive a year, and less than 20 percent will survive two.
One more reason to hug your dog today!
Mary Simpson is a writer and communications professional from Port Credit, Ontario. A soft touch for anything stray, she shares her century home with an eclectic collection of rescues that include orange tabby Chico, tuxedo Simon, and jet black Owen. She enjoys running, politics, exploring the wine regions of Niagara and is an avid supporter of the “shop local” movement.