Mammary Cancer in Cats and Dogs

Understanding Mammary Cancer in Cats and Dogs: Signs, Risks, and Treatment Options

Mammary cancer, also known as mammary gland tumours, is a significant health concern for female cats and dogs, especially those that haven’t been spayed. This type of cancer affects the mammary glands, which are similar to breast tissue in humans. Tumours can range from benign (non-cancerous) to malignant (cancerous). Early detection and proper treatment are essential in improving the prognosis for pets diagnosed with mammary cancer.

What is Mammary Cancer?

Mammary cancer develops when abnormal cells grow uncontrollably in the mammary glands. Both cats and dogs have multiple mammary glands (dogs typically have five pairs, and cats have four pairs), meaning tumours can develop in multiple locations. The disease is more common in females, but male pets are not immune.

Mammary tumours can be benign or malignant. In dogs, about 50% are benign, while the other 50% are malignant. Unfortunately, the situation is more severe in cats, with about 85-90% being malignant.

According to the Veterinary Society of Surgical Oncology, mammary tumours in female dogs account for 42% of all diagnosed tumours and have a lifetime risk of 23-34%. This highlights the significant impact of this type of cancer in dogs and emphasises the need for preventive measures like spaying and early detection.

Causes and Risk Factors

There are a variety of factors that contribute to the development of mammary cancer in pets, but some key risks include:

1. Hormonal Influence: Mammary cancer is highly influenced by hormones, particularly estrogen. Historically, veterinarians recommended spaying female pets after their first heat cycle to manage their reproductive health. However, new research has led to a shift in thinking. It is now widely believed that spaying your pet before her first heat cycle offers the greatest protection against developing mammary cancer. Spaying a dog before her first cycle can reduce the risk of mammary cancer to nearly zero, and for cats, spaying before six months of age also significantly decreases the risk.
2. Age: The risk of developing mammary cancer increases as pets get older. Mammary cancer is more commonly seen in middle-aged to older dogs and cats.
3. Breed Predisposition: Certain breeds are more predisposed to developing mammary cancer. In dogs, breeds such as Poodles, Spaniels, Dachshunds, and Terriers are at higher risk. For cats, Siamese and Domestic Shorthairs seem to be more susceptible.
4. Obesity: Overweight pets, especially during their younger years, are at an increased risk of developing mammary cancer.

Symptoms to Watch For

Early detection of mammary cancer is critical, and pet owners should be aware of the signs and symptoms. These may include:

• Lumps or Masses: The most common sign is the appearance of one or more lumps or masses in the mammary gland area, which can be small and firm or large and irregular.
• Swelling: Any unusual swelling around the mammary glands should be checked.
• Ulceration: Malignant tumours may cause the skin over the affected area to ulcerate or break open.
• Pain or Discomfort: Pets may show signs of pain when touched in the mammary area or lick the affected area excessively.
• Lethargy: In advanced stages, pets may become more lethargic or show decreased appetite.

If you notice any of these signs in your pet, it’s essential to consult a veterinarian as soon as possible for a thorough evaluation.

Diagnosis

Veterinarians diagnose mammary cancer through a combination of physical examinations, diagnostic imaging (such as X-rays or ultrasounds), and biopsy procedures. A biopsy, where a tumour sample is taken and examined under a microscope, is the only definitive way to determine whether the tumour is benign or malignant.

Treatment Options

The course of treatment depends on various factors, including the size, location, and stage of the tumour and whether it has spread to other parts of the body (metastasis).

1. Surgical Removal: Surgery is the most common treatment for pet mammary cancer. If the tumour is caught early, the entire tumour can be removed, sometimes alongside the affected mammary glands and lymph nodes. In more advanced cases, more aggressive surgery may be required.
2. Chemotherapy: For malignant tumours or cases where the cancer has spread, chemotherapy may be recommended to slow the growth and spread of the cancer cells.
3. Radiation Therapy: This is less commonly used for mammary cancer but may be an option in specific cases.
4. Hormonal Therapy: Because many mammary tumours are hormone-dependent, some treatment protocols involve using hormonal therapy to manage the disease.

Prognosis

The prognosis for pets with mammary cancer varies based on several factors, such as the size of the tumour, whether it is benign or malignant, and whether it has spread. Benign tumours generally have a good prognosis, especially when removed early. Malignant tumours can be more aggressive and carry a higher risk of spreading to the lungs, liver, and other organs.

Due to the high malignancy rate in cats, the prognosis is more guarded, and early detection combined with aggressive treatment is vital. The outcome is more favourable in dogs if the tumour is caught early and hasn’t metastasized.

Prevention

The most effective way to prevent pet mammary cancer is to spay them early, particularly before their first heat cycle. As veterinary recommendations evolve, spaying before the first cycle is now considered the best practice for minimizing the risk of mammary cancer. Maintaining a healthy weight and providing regular veterinary check-ups can also reduce the risk of developing this type of cancer.

Which Petcover Policy is Best for Mammary Cancer?

If you’re looking for pet insurance for mammary cancer, selecting a more comprehensive policy for illness and chronic conditions is crucial. At Petcover, the Mid-Range and Superior plans are the best options.

• Superior Plan: This top tier offers plans with the most extensive coverage and the highest limits. Given the potential costs of surgery, chemotherapy, and follow-up treatments for mammary cancer, the Superior Plans provide peace of mind by helping cover these expenses.
• Mid-Range Plan: The Mid-Range plans still provide extensive coverage for illnesses, including cancer, though they may have slightly lower claim limits than the Superior Plans. It’s a solid option for pets diagnosed with conditions like mammary cancer that require ongoing treatment.

It’s always best to review the policy details or contact us to ensure the plan you select offers the right coverage for your pet’s needs.

Conclusion

Mammary cancer is a serious health issue in both cats and dogs, but early detection and prompt treatment can significantly improve the outcome. Regularly checking your pet for any lumps or abnormalities and seeking veterinary care are essential in safeguarding their health. By being proactive about their care, including timely spaying and maintaining a healthy lifestyle, you can help reduce the risk of mammary cancer and ensure a longer, happier life for your furry companion.

If you’re considering pet insurance to cover mammary cancer or other illnesses, choosing one of Petcover’s Mid-Range or Superior Plans helps ensure your pet will have the protection it needs in case of a diagnosis. For more information on these policies, visit Petcover New Zealand and explore the available coverage options.