Common symptoms of oral cancer in dogs include excessive drooling, bad breath and difficulty eating. Bleeding from the mouth, weight loss and loose teeth are other common symptoms.
Oral squamous cell carcinoma and oral melanoma are the two most common mouth cancers in dogs. Both metastasize quickly and can cause death. The symptoms are similar for both, as well as other malignant oral cancers. Dogs can also get benign tumors, which are usually surgically removed to prevent dental problems.
The symptoms of most oral tumors resemble those of noncancerous dental problems. Many owners notice a change in their dogs' eating habits, especially a reluctance to chew harder substances and a preference for softer food rather than dry kibble. In advanced cases, dogs may lose teeth. Sometimes swelling is visible in the face or around the eyes, and lymph nodes can become swollen as well. The swelling can become severe enough to cause an eye to bulge out. There is also occasionally increased nasal discharge that may be bloody. Coughing and difficulty swallowing can also occur in some cases. A close examination may reveal a visible growth or mass in the mouth, but since many dogs resist examination, this can be difficult to see at times.
Dogs exhibiting these symptoms should be seen by a veterinarian as soon as possible as an early diagnosis is key to successful treatment.