I own a Boxer. Initially he started eating less, then he started becoming very lazy and would stare at me a lot like he understood he wasn’t going to live much longer. He used to breath very uneasily and he became very weak. By the time we found out he had cancer he had lost a lot of weight. He almost completely stopped eating and barking. All he would really do is stare lovingly at all of our family members and then one morning I found him sleeping and he never woke up.
We had a French Poodle that developed melanoma cancer. The first symptom I noticed was that he was sleeping a lot. The second thing was that he stopped getting excited by things like a knock at the door. We took him to the vet and that is when we found out he had cancer.
My parents have had several dogs, all of them either Dachshunds or Labradors. One of the Dachshunds developed a tumor on his back, which ended up being a benign Lipoma when he was taken to the veterinarian to see about it. He began whining and sleeping more than usual before being taken to the veterinarian. Even though it was benign he passed soon away, he was about 11 years old.
also see Treating Dogs' Thyroid Cancer With Radioiodine
also see The Surgical Treatment of Canine Adenocarcinoma
also see Cutaneous Lymphoma in Dogs Explained
also see Identifiable Dog Lymphoma Symptoms
also see Symptoms of Canine Prostate Cancer
also see 5 Subtle Canine Cancer Symptoms Worth a Trip to the Vet
also see Canine Cancer Treatment Options: A Brief Overview
also see Plasmacytoma and Myelomas in Dogs