Types of Cancer

"Balancing the age and condition of the pet with the possibility of therapeutic success is never easy. But I say there's hope and reason to treat and manage even the more aggressive cancers that affect older pets. Early detection and urgent, specialized treatment are the best ways to manage neoplasia and prolong and improve a pet's quality of life." – Dr. Glenna Mauldin

Cancer, also known as neoplasia, is the uncontrolled, abnormal growth of cells or tissues in the body. The abnormal growth itself is called a neoplasm, tumour or cancer. A "mass" such as this can be benign or malignant. Benign cancers do not grow aggressively, do not invade the surrounding body tissues, and do not spread throughout the body. Malignant cancers tend to grow rapidly, invade the tissues around them, and spread, or metastasize to other parts of the body.

10 Common Signs of Neoplasia in Small Animals

Abnormal swellings that persist or continue to grow
Sores that do not heal
Weight loss
Loss of appetite
Bleeding or discharge from any body opening
Offensive odour/bad breath
Difficulty eating or swallowing
Hesitation to exercise or loss of stamina
Persistent lameness or stiffness
Difficulty breathing, urinating, or defecating

Where Cancer Occurs

Skin - Skin tumours are very common in older dogs, but much less common in cats. Most skin tumours in cats are malignant, but in dogs they are often benign. Malignant melanomas may affect the paw pads, nail beds, lips and eyes in the dog. They are not caused by ultraviolet light but by a combination of genes and environment.

Mammary Gland (Breast) - 50% of all breast tumours in dogs and greater than 85% of all breast tumours in cats are malignant. Spaying female pets before 12 months of age will greatly reduce the risk of mammary gland cancer.

Head & Neck - Neoplasia of the mouth is common in dogs and less common in cats. Signs to watch for are a mass or tumour on the gums, bleeding, bad breath, or difficulty eating. Since many swellings are malignant, early, aggressive surgical treatment is essential. Neoplasia may also develop inside the nose of both cats and dogs. Bleeding from the nose, breathing difficulty, sneezing or facial swelling are signs that may indicate neoplasia and require immediate attention.

Testicles - Testicular tumours are rare in cats and common in dogs, especially those with retained testicles (testicles that did not move to their normal positions during growth, and may be located in the abdomen or between the abdomen and scrotum).

Abdomen - Tumours inside the abdomen are common but it is difficult to make an early diagnosis. In addition of examination during routine office visits, weight loss or abdominal swelling need to be reported.

Bone - Bone tumours are most often seen in large breed dogs and dogs older than seven years, and rarely in cats. The leg bones, near joints, are the most common sites. Persistent pain, lameness, and swelling in the affected area are common signs of the disease.

Lymph Nodes - Lymphoma is a common form of neoplasia in dogs and cats. It is characterized by enlargement of one or many lymph nodes or other organs in the body. Cats diagnosed with contagious feline leukemia virus should be monitored for lymphoma. More about lymphoma