With Recent Advances in Veterinary Oncology, Is Animal Cancer Now Treatable? 

Understanding Cancer in Pets 

Cancer is, at its simplest, a disease of uncontrolled cell growth. Normally, the body’s cells divide and grow in a highly regulated way. Cancer occurs when this control mechanism breaks down, and abnormal cells multiply without restraint. These rogue cells can form a tumour (a lump or mass) or spread through the bloodstream or lymphatic system to other areas of the body. This is a process known as metastasis. 

Not all tumours are malignant (cancerous). Some are benign, meaning they don’t spread or invade nearby tissues, although they can still cause problems depending on their size or location. Malignant tumours, on the other hand, can grow aggressively and spread to other organs, which is what makes them potentially life-threatening. 

Certain types of cancer are seen more frequently in pets. In dogs, common cancers include: 

• Lymphoma: affecting the lymphatic system 

• Mast cell tumours: this is usually a type of skin cancer 

• Osteosarcoma: bone cancer, especially common in large breeds 

• Haemangiosarcoma: a cancer of blood vessel cell 

• Mammary (breast) tumours: particularly common in unspayed females 

In cats, we often see: 

• Lymphoma: particularly linked to feline leukaemia virus (FeLV) or affecting the gut 

• Squamous cell carcinoma: affecting the skin, mouth, or nose 

• Mammary carcinoma: again, more common in unspayed females 

• Soft tissue sarcomas: these arise from connective tissue 

Age is one of the biggest risk factors. Cancer is much more common in older pets. Other factors, such as breed, genetics, hormonal status, and environmental factors (such as second-hand smoke or sun exposure), can all play a part. 

The most powerful tool we have against cancer is early detection. Subtle signs such as unexplained weight loss, a lump that’s growing, changes in appetite or behaviour, or wounds that don’t heal should never be ignored. The earlier a diagnosis is made, the more options we have for successful treatment. 

How Cancer Is Diagnosed 

When a vet suspects cancer, the goal is to confirm exactly what type of cancer is present, where it is in the body, and how advanced it is. This process is called diagnostic staging. Ways to gain more information about the type of cancer present include: 

Fine Needle Aspirate and Biopsy 

A fine needle aspirate (FNA) is often the first step. A small needle is used to collect cells from a lump or organ, which are then examined under a microscope by a pathologist. It’s quick, minimally invasive, and often performed under light sedation or even without anaesthesia. 

If the FNA doesn’t provide a clear answer, a biopsy may be needed. This involves taking a small piece of tissue to examine the architecture of the cells, giving a more definitive diagnosis. 

Diagnostic Imaging 

To see whether cancer has spread or to assess internal organs, vets may use X-rays, ultrasound, CT, or MRI scans. These technologies have become increasingly sophisticated, allowing for detailed visualisation and precise surgical planning. 

Grading and Staging 

These two terms can often confuse owners; grading and staging are separate things we use to assess the cancer.  

• Grading describes how aggressive the tumour looks under the microscope. 

• Staging indicates how far the cancer has spread in the body. 

Both are crucial for deciding on the most appropriate treatment plan. 

Vets in general practice frequently work closely with specialist oncologists, pathologists, and surgeons to create a tailored approach for each patient. This collaborative model is one of the reasons modern cancer care in pets has become so successful. 

Advances in Cancer Treatment 

Not long ago, options for pets with cancer were limited. But veterinary oncology has evolved dramatically, often mirroring breakthroughs in human medicine. Let’s explore the main types of treatment available today and how they’ve improved. 

Surgery 

For many cancers, surgery remains the most effective and immediate treatment. The aim is to remove all cancerous tissue along with a margin of healthy tissue to reduce the risk of recurrence. 

Advances in anaesthetic safety, pain management, and surgical technique mean that even complex tumour removals are safer and more comfortable than ever. Specialist soft tissue and orthopaedic surgeons can now perform intricate procedures, including limb-sparing surgery in bone cancer or reconstructive techniques after tumour excision. A lot of these things would have been unthinkable a generation ago. 

In some cases, surgery alone can be curative, especially for small, well-defined tumours caught early. 

Chemotherapy 

Mention the word chemotherapy and most people picture the gruelling side effects often seen in human cancer patients. Fortunately, veterinary chemotherapy is very different. 

In pets, the goal is to maintain quality of life rather than pursue aggressive, high-dose protocols. Doses can be adjusted so that side effects are mild or minimal. Most pets continue to eat, play, and enjoy walks throughout their treatment. 

Chemotherapy can be given as injections or tablets, depending on the cancer type. It may be used alone or after surgery to mop up microscopic cancer cells that could otherwise cause recurrence. 

Lymphoma, for example, often responds extremely well to chemotherapy, and many dogs can achieve long periods of remission. Owners are often pleasantly surprised at how well their pets tolerate it. Side effects can include temporary tummy upset, mild lethargy, or lowered white blood cell counts, but serious reactions are rare and carefully monitored by the veterinary team. 

Radiotherapy 

Radiotherapy uses targeted beams of radiation to destroy cancer cells while sparing as much healthy tissue as possible. It’s particularly useful for tumours in places where surgery isn’t practical, such as inside the nose, mouth, or brain. 

Modern equipment, such as linear accelerators, allows for pinpoint accuracy. Treatments are carefully planned using advanced imaging, ensuring the correct dose is delivered exactly where it’s needed. 

Cancers that respond well to radiotherapy include nasal tumours, brain tumours, oral cancers, and soft tissue sarcomas. 

Side effects are usually localised to the treatment area and are often temporary, such as mild skin irritation or hair loss. Pets tolerate radiotherapy far better than most people expect. 

Targeted Therapy and Immunotherapy 

One of the most exciting developments in veterinary oncology is the rise of targeted therapy and immunotherapy. These treatments are designed to attack cancer cells specifically, leaving normal cells largely untouched. 

The best-known examples in dogs are toceranib phosphate, and its close relative, masitinib. These are tablets that target specific receptors involved in tumour growth and blood supply. They are particularly useful for mast cell tumours but have shown benefits in several other cancers too. 

Meanwhile, immunotherapy works by harnessing the pet’s own immune system to recognise and destroy cancer cells. This area is rapidly advancing, with cancer vaccines and monoclonal antibody treatments under investigation for various tumour types. 

Although these newer options can be expensive, they represent the future of veterinary cancer care. It means more precise, personalised, and less invasive. 

Palliative Care and Pain Management 

Not all cancers are curable, but every pet deserves comfort and dignity. Palliative care focuses on controlling pain, maintaining appetite, and maximising quality of life. 

Modern pain relief options, including non-steroidal anti-inflammatory drugs (NSAIDs), nerve-targeted medications, and even low-dose chemotherapy or radiation for pain control, can all make a profound difference. 

Often, cancer can be managed like a chronic disease, with regular monitoring and adjustments to treatment over time. Many owners find that, with good support, their pet continues to enjoy many happy months (and sometimes years) beyond the initial diagnosis. 

Treatment Expectations: When Is Cancer Curable or Controlled? 

Cancer outcomes in pets vary enormously. Some tumours are easily removed and never return; others are more aggressive or widespread. A cure means all cancer cells have been eradicated, and the pet remains cancer-free for life. Remission means the cancer is no longer detectable but could return later. 

Examples of curable cancers include: 

• Low-grade mast cell tumours completely removed surgically 

• Small benign mammary tumours (especially if the pet is spayed) 

• Certain benign skin masses such as histiocytomas, although these can be self-resolving rather than cured. 

• Localised thyroid tumours or anal sac adenocarcinomas treated early 

Other cancers, such as lymphoma, can often be placed into long-term remission, allowing pets to live full, active lives for many months or even years after diagnosis. 

The key factors influencing outcome include: 

• Type of cancer: Some are inherently more aggressive 

• Stage: how far it has spread 

• Grade: how abnormal and fast-growing the cells are 

• Location: accessibility for surgery and impact on vital organs 

• Overall health: if your pet has any concurrent health issues, and how well they are able to tolerate treatment. 

It’s vital to remember that veterinary oncology is always about the individual patient. The treatment plan is tailored to the pet’s needs, family circumstances, and the goal of maintaining a good quality of life throughout. 

Supporting Pets (and Owners) Through Cancer 

A cancer diagnosis affects the whole family. It’s completely normal to feel overwhelmed or frightened at first. Your veterinary team will guide you through each step, and they will explain options, costs, likely outcomes, and what daily care involves. Open communication is crucial. Ask as many questions as you need; no query is too small. Often, it is a good idea to go back and talk to your vet after you have received the diagnosis so that you have time to process the news and ask questions based on your individual concerns.  

Practical ways to support your pet include: 

• Nutrition: Offer a balanced, high-quality diet; some pets benefit from small, frequent meals. 

• Comfort: Provide a warm, quiet space and gentle exercise tailored to their energy levels. 

• Monitoring: Keep a diary of appetite, weight, and activity to share with your vet. 

• Medication adherence: Follow all instructions carefully for chemotherapy or pain relief. 

• Complementary approaches such as acupuncture or specific nutritional supplements may be suggested in some cases, but always discuss these with your vet first to ensure they are safe and evidence-based. 

Above all, let it be a comfort to you that pets very much live in the moment. They don’t dwell on their diagnosis; they focus on the love and comfort they feel each day. 

Emerging technologies include: 

• Liquid biopsies: blood tests that detect tumour DNA, offering early and minimally invasive diagnosis. 

• Genetic testing: allowing vets to tailor treatment based on the cancer’s molecular profile. 

• Personalised medicine: matching therapy to the specific genetic mutations in a tumour. 

• Immunotherapies: such as cancer vaccines that train the immune system to prevent recurrence. 

• The concept of One Medicine: a collaboration between human and veterinary oncology. This means discoveries in one field often benefit the other. It’s an exciting time, full of hope for both pets and people.