Cancer in Cats and Dogs: Causes, Signs & Treatment

If a veterinary surgeon mentions cancer concerning your cat or dog, it can be one of the most difficult conversations you may face. Cancer is one of the leading causes of death in pets, second only to accidents. Understanding this complex disease can empower you to spot early signs and seek timely help.

What Is Cancer in Cats and Dogs?

Cancer, or neoplasia, arises when body cells begin to divide uncontrollably, disrupting normal tissue function. These abnormal cells can form masses called tumours. Some tumours remain confined, while others invade surrounding tissues or spread through the bloodstream to distant parts of the body, a process called metastasis.

Benign vs Malignant Tumours

Benign tumours grow slowly and usually stay in one place, often making them easier to remove surgically. However, they can still cause problems by pressing on nearby organs or vessels.

Malignant tumours are aggressive, fast-growing, and invade nearby tissues. They commonly spread rapidly through the body, making complete surgical removal challenging. The prognosis depends on tumour type, location, and how early it is detected.

Common Types of Cancer in Pets and Risk Factors

Both cats and dogs can develop over 100 types of cancer, some similar to those affecting humans. Older pets are more vulnerable, with about a quarter of dogs and one in five cats developing cancer during their lifetime.

• In dogs, lymphoma is the most frequent cancer, often affecting breeds such as Boxer puppies, Golden Retrievers, and German Shepherds.
• Bone cancers like osteosarcoma are more common in giant breeds including Great Danes and Wolfhounds.
• In cats, lymphoma is also the most common form, sometimes linked to the Feline Leukemia Virus (FeLV), while Siamese cats show a higher risk for certain tumours.
• Hormonal influence plays a role; for example, mammary tumours occur frequently in unspayed female dogs.
• Environmental exposures such as pesticides or frequent x-rays can increase cancer risk.

Recognising Symptoms of Cancer in Pets

Cancer signs can be subtle and overlap with other health issues, making regular veterinary checks essential. Signs to watch for include:

• Persistent or growing swellings or lumps.
• Sores that won’t heal.
• Unexplained weight loss or changes in appetite.
• Bleeding or unusual discharge.
• Difficulty eating, swallowing, breathing, or moving.
• Persistent lameness or stiffness.
• Offensive odour from wounds or swellings.

How Is Cancer Diagnosed?

Your vet will perform thorough physical examinations, palpating lumps and noting any abnormalities. Diagnostic tools commonly used include:

• Blood tests to identify abnormalities or tissue damage.
• Fine needle aspiration or biopsy to collect tissue samples for microscopic analysis.
• X-rays and ultrasounds to detect spread inside the body.
• Endoscopy allows direct viewing of internal organ tumours and biopsy collection in delicate areas.

Treatment and Management Options

Thanks to advances in veterinary oncology, many pets with cancer have options beyond euthanasia:

• Surgical removal can be curative if the tumour is localised and completely excised.
• Chemotherapy uses anti-cancer drugs, typically administered intravenously or orally, to manage cancers that have spread.
• Radiotherapy uses high-energy rays to target cancer cells while sparing normal tissues, available at specialist veterinary centres.

Early diagnosis improves outcomes. Many pets enter remission or maintain quality of life with appropriate treatment and supportive care.

Promoting Responsible Pet Care

Being aware of breed-specific risks, regular health screenings, and prompt veterinary consultation are vital aspects of responsible pet ownership. Always seek veterinary advice if you notice any worrying signs. Early intervention can make a life-changing difference.