Please choose the correct ending to complete the given sentence: Pets and Animals: [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.

Ending1: If you see swelling or the dog is having a hard time restraining himself from going home, it may be a sign of lymphoma. [substeps] Swelling can be caused by fluid trapped under a valve or pituitary edema, which is also known as mucus inside the intestinal artery. Ending2: [substeps] Swollen lymph nodes are usually small (about 4-6 millimeters) in diameter, about 1/8th of an inch in diameter. They are located on the feet, abdomen, and genital area. Ending3: 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. Ending4: Coagulation of an inflamed lymph node, often due to bacteria or viruses, can produce swollen lymph nodes. [substeps] Intravenous fluid is also commonly seen in swollen lymph nodes.

Answer format: ending1/ending2/ending3/ending4