Symptoms of Canine Mammary Tumors: Recognizing the Sign

1. Onset Stage

Canine breast tumors are most commonly found in older female dogs, typically between the ages of 9 to 11. While they are less frequent in male dogs, they account for approximately 50% of all breast tumors in females. These tumors often develop in the fourth or fifth pair of mammary glands, which may be due to the higher concentration of mammary tissue in these areas. Female dogs without a breeding history or those experiencing pseudopregnancy have a significantly higher incidence rate compared to others. A survey in the United States revealed that breast tumors make up 13.4% of all canine tumors, with 41.7% occurring in unspayed females, and purebred dogs tend to have a higher incidence rate.

2. Hazards to Dogs

Canine breast tumors pose severe threats to the health of affected dogs. As the tumor tissue grows and expands, it can exert mechanical pressure on surrounding tissues, including blood vessels, nerves, ducts, and organs. This pressure can lead to nutritional disorders, degeneration, and even necrosis. The metabolic byproducts of malignant tumors can cause systemic toxicity, and the excessive growth of the tumor can rob the body of essential nutrients, resulting in extreme weakness, loss of appetite, weight loss, anemia, and a general cachectic state, severely impacting the dog's quality of life. Surgery is the widely accepted treatment for canine breast tumors, but other treatments such as radiation therapy, hormone therapy, and chemotherapy can also be employed.

3. Causes of Onset

The exact cause of canine breast cancer is not fully understood, but it is generally believed that a combination of genetic, hormonal, immunological, and environmental factors interact to contribute to the cancer's development and progression. Additionally, dogs that have had their ovaries and uterus removed after their first or second estrus have a 8% and 26% incidence rate of breast tumors, respectively. This suggests that early spaying can significantly reduce the risk of breast tumors in dogs. Dog owners should pay close attention to their pets, aiming for early detection, diagnosis, and treatment to ensure the best outcomes.