Cancer is a serious illness in dogs as well as humans. Approximately 1 in 4  dogs will develop cancer at some time in their lives. This figure rises to 1 in 2 for dogs over 10 years old. It’s the leading cause of death in adult dogs. 

Cancer is an illness that touches many of our lives. Half of us will develop cancer during our lifetime. Around 1000 new cases are diagnosed every day in human medicine. And every day a dog owner will also face the anguish of a cancer diagnosis for their beloved companion. Just as for humans, outlook depends on the type of cancer, how early it is identified and on individual response to treatment. Always talk to a vet if you are worried your dog may have cancer.

 

Overview

Cancer in Dogs: what is it?

Cancer happens when cells somewhere in the body start to multiply uncontrollably. This means the cancer cells make more and more copies of themselves

• As the cells multiply, they may grow into lumps or tumours.
• Cancer cells may also replace the healthy working cells in an organ like the liver or the bone marrow.
• Cancer may start in one organ or part of the body but spread to other areas or organs over time. This spread is called metastasis and it makes the cancer much harder to control.
• Just like humans, pets can have different types of cancer. This includes cancers of the blood cells, skin, stomach, bones, mammary glands and brain.
• Lymphoma is one of the most common cancers in pets, accounting for around 20% of cancer diagnoses in dogs and 30% for cats. Pets are 2-3 times more likely to get lymphoma than humans.

 

Symptoms

What are the warning signs of cancer in dogs?

Finding cancer early is the best way to get the best possible outcome for your pet. You’ll know your dog better than anyone! Always be on the lookout for any changes in them or in their habits. Especially as they enter their senior years. Warning signs include:

• Lumps or bumps under the skin
• Changes in tummy shape
• Unexplained weight loss
• Changes in appetite
• Vomiting and diarrhoea, especially if it goes on longer or keeps coming back
• Unexplained coughing 
• Not wanting to play or exercise
• Severe lameness or pain
• Changes in behaviour: becoming more grumpy or withdrawn
• Seizures

Many of these symptoms can be caused by other illnesses, so try not to worry if you find a lump or if your dog is vomiting.  Call a vet or visit your local practice for advice.

 

Risk

Which dogs are most likely to get cancer?

Dogs of any age, size or breed can get cancer. But there are some higher risk factors as well. These include:

• Age: undoubtedly the biggest risk factor for cancer
• Breed: different breeds may have a higher risk for certain types of cancer. Higher-risk dog breeds include Boxers, Beagles, Golden Retrievers, Labradors, Rottweilers, Flat-coated retrievers, German shepherds, and Great Danes. On the other hand, breeds slightly less likely to get cancer include Chihuahuas, French Bulldogs, Shih Tzus, Dachshunds, and Pomeranians.
• Obesity: Cancer is one of the many health problems associated with obesity.
• Sex: Female dogs develop mammary tumours, which are among the most common forms of cancer in pets. Unneutered females have the greatest risk for mammary tumours.
• Environmental factors: Prolonged exposure to strong sunlight Ultraviolet (UV) radiation, passive smoking due to living with owners who smoke indoors, air and water pollution, strong agricultural chemicals and pesticides.
• Infectious illnesses: Infectious diseases rarely cause cancer directly. Canine transmissible venereal tumour is a rare infectious cause of cancer in dogs. It’s spread between dogs during mating.

Are my family or other pets at risk?

Cancer won’t spread directly to other pets or humans in the house.

Dogs who share the same health and environmental challenges, including obesity or passive smoking, will also be at risk of developing cancer.

 

Diagnosis

How do vets diagnose cancer in dogs?

Your vet will examine your pet and find out from you as much as they can about any changes you’ve noticed. Then they may carry out additional tests:

• Blood tests
• Urine tests
• Imaging, like x-rays, CT scan, ultrasound or MRI to look inside the body
• Biopsy: to check if a lump contains tumour cells. The lab can also tell what type of tumour it is
• Staging: information from the test results may be used to assess how severe the cancer is.

Staging describes the growth of a cancer and indicates how far it has spread.

• Stage 1: The cancer is small and hasn’t spread to other parts of the body.
• Stage 2: The cancer has grown a bit bigger, but still hasn’t spread.
• Stage 3: The cancer is larger. It may have spread into the tissues around it and the nearest lymph nodes.
• Stage 4: The cancer has spread to other parts of the body, such as the liver, lungs or bones.

Grading: for some types of cancer, the vet laboratory will grade the tumour cells. This means assessing how much they differ from normal healthy cells. It can help with understanding how the cancer is likely to progress.

 

Vet treatment

How can vets treat dogs with cancer?

Finding out your dog has cancer can be devastating. But there are ever more options and successes  It’s important to talk through everything with your vet and your family before deciding on treatment.

Depending on the type of cancer, treatment may mean stopping it in its tracks for a time (remission) or helping your dog to feel well for as long as possible. Treatment options are similar to humans’ and include:

• Chemotherapy
• Radiation treatment
• Surgery: possibly followed by chemotherapy or radiation
• Cryotherapy
• Immunotherapy with special cancer vaccines.

Your vet or cancer specialist may suggest one or more of these treatment options for your dog’s cancer.

Treating cancer will be costly, both financially and in terms of commitment. Before starting treatment, it’s essential to think carefully about what’s involved for your dog and your family. Considerations include:

• How much treatment will cost (realistically)
• Repeated visits to the clinic for ongoing treatment and monitoring
• Potentially uncertain outcomes – how well your dog responds and for how long
• Side effects of treatment
• Other illnesses, especially in older dogs

There are many safe and well-tolerated treatments for cancer in dogs. Some of which can offer months or even years of symptom control and quality of life. But starting treatment has to be the right choice for your pet and for you.

• Will your dog be stressed by trips to the vet?
• Do they have other illnesses?
• Can treatment improve or maintain your dog’s quality of life and help them to continue a life they can enjoy with you
• Will you be able to give medicine to your pet without distressing them or yourself?

Palliative care

For some dogs and some cancers, the right treatment will be palliative care. This means controlling symptoms to make them feel better for as long as possible. This can include:

• Anti-sickness medicines
• Pain relief
• Special diets to ensure they get the nutrition their body needs
• Seizure control medicine
• Acupuncture

 

Home treatment

How to care for a dog with cancer at home

There are no home cures for cancer. But there are cancer treatments which work best when cancer is recognised and treated promptly by a vet. Home care is an essential part of your dog’s recovery and wellbeing both during and after treatment.

• Give your dog all medicine as prescribed by your vet at the correct time and dose.
• Some cancer medicines can be harmful to humans and other pets. Handle these with care. Wear gloves and wash your hands thoroughly after handling these medicines.
• Feed your dog a high-quality diet to aid their recovery. Your vet may advise a special prescription diet such as Hills Prescription Diet On-Care or a/d for convalescence.
• Let your dog rest and sleep as much as they need to.
• Give your dog a comfortable safe and secure place to sleep, away from noise or boisterous housemates.

Prevention

Can we prevent cancer in dogs

We rarely know what causes cancer in dogs. So it’s impossible to prevent it completely. But there are key lifestyle and diet factors that can help to reduce your dog’s risk of getting some types of cancer.

• Feed your dog a healthy high quality diet, suitable for the age and lifestyle
• Keep your dog slim, with a healthy body condition score
• Make sure your dog gets plenty of exercise.
• Don’t keep sparsely-haired dogs out in the sun for prolonged periods, and consider using sunblock on exposed skin
• Don’t smoke indoors or in cars with your dog there.
• Keep up to date with regular preventive treatments, and an annual health check at the vets

 

When to worry

When to worry about your dog with cancer

If your dog has become poorly very quickly,  if they haven’t improved with treatment or if treatment is no longer helping them, then sadly the time may have come to consider euthanasia. You and your vet can help your beloved friend to have a peaceful and dignified escape with an overdose of anaesthetic. With this heartbreaking act of kindness, we can prevent them from suffering.

Our quality of life guide can help you understand if your dog is coping with the changes. Always talk things through with your vet if your pet or you are struggling. And together we can make sure we offer the best treatment options at the right time for your pet.

Assess quality of life

Losing a beloved friend is heartbreaking. But help and support are available to help you during this difficult time. The Blue Cross Pet Bereavement Helpline, Joii bereavement advisors and Samaritans are there for you.

Cancer is a distressing illness. But early identification and talking openly with your vet and specialists means we can all ensure the best outcomes for your pet