There are some symptoms in canines that have cancer that might be more pronounced than others, such as the canine that has cancer in their lympnodes, this can mean swelling at each of the nipples, the glands in their neck, and backs of the legs. While with some of the other types of cancer it may not be more than noticing the pet is not acting the same as usual, or is getting thinner without the diet being changed.

Some types of cancer may not have immediate symptoms, until later in the illness, while other types can have symptoms similar to human symptoms, like nausea, diarrhea and weight loss that can be symptoms of abdominal tumors. This can also include swelling or an enlarged abdomen.

Mammary cancer occurs in unsprayed female dogs and will appear as welling of the breast tissue, and this is one of the most common forms of cancer in female dogs. Bone cancer, which often affects large dogs and canines that have suffered an injury, can cause the canine to be lame and cause severe pain.

There are other symptoms that can appear in the pet such as a coughing, blood in the urine or stool, difficulty breathing, bad breath or strong body odor, lumps or discoloration of the skin.