[header] How to diagnose lymphoma in boxers [title] Pay attention to swollen lymph nodes. [step] Swelling lymph nodes is one of the most recognizable symptoms for lymphoma. Swollen lymph nodes are most often noticed when the owner is petting the dog. 
The two most common places you may find them are under the jaw and behind the knee. [substeps] Lymph nodes that can be felt through the skin are paired, left and right.