Canine cancer

Few things strike as much fear into our hearts as discovering a strange lump. Most of us will be keen to get anything abnormal we find on ourselves checked out urgently by our GP; but what about our poorly pets, who rely solely on us to decide whether to visit the vet or not?

What is cancer?

Cancer means an abnormal growth of cells and, unfortunately, it's a common disease of all dogs. It may be benign (slow-growing, removable) or malignant (aggressive, spreading throughout body) with roughly one in four dogs eventually succumbing to the disease. For dogs over 10 years of age, approximately 50% of deaths are cancer-related; and like us, there are many different types of cancers resulting in a huge variation in clinical signs observed.

What causes cancer?

Causes of cancer are largely unknown making prevention extremely difficult, but being aware of possible signs of disease in your dog greatly helps early detection and finding the appropriate care for recovery.

Is a lump always cancer?

Common lumps on dogs vary greatly in size, shape, severity, and whether they're visible to the naked eye or hidden inside your dog. Some conditions resemble lumps but are in fact ticks; their lump-like, pea-sized body requiring very careful removal - as a non-cancerous lump known as a 'tick bite granuloma' may form afterwards requiring surgical intervention.

As with older people, elderly pets are more likely to grow warts and other small growths of the skin or associated structures. These occasionally appear unsightly but are usually non-serious, rarely causing problems or spreading. However, do get your vet to examine your pet to check, and monitor them closely.

Lipomas (fatty lumps) tend to be more frequent in overweight dogs, usually presenting as soft, smooth, non-painful lumps under the skin above the ribcage of more mature dogs. These rarely require removal; in fact many non-serious growths are usually 'cosmetic', with surgery indicated only if they cause discomfort, suddenly grow rapidly, interfere with bodily functions (e.g. obstruct passageways), ulcerate, repeatedly get infected or act as a persistent focus for your dog to lick and chew.

What should I watch out for?

Cancer may affect any part of your dog's body, often involving whole body systems too, (such as skin, lymph nodes, gastrointestinal tract, blood, and bone).  Be aware that signs of cancer aren't always obvious in the form of new lumps or growths, or changes in size, shape, or consistency of existing lumps. So always get your dog checked by your vet even if you notice any vague signs too. For example, vomiting, diarrhoea, weight loss, increased water intake and urination, lethargy, and lack of appetite are all clinical signs common with many diseases, but may be your first warning sign of cancer, especially when they prove unresponsive to treatment.

Other presenting signs include difficulty urinating, and bloody urine (common with urinary tract infections), which may also indicate the disease. Prostate cancer will be suspected in any male dog straining to defecate, and passing thin, ribbon-like stools. Any limp or change in gait must also be investigated especially in more at risk bone cancer breeds, like Flat-Coated Retrievers. Foul breath and excessive drooling - even teeth that have 'moved' - can indicate oral growths that are often some of the more challenging types of cancer to treat.

How will my vet investigate/ treat my dog?

More serious lumps, such as mammary cancers, mast cell tumours and melanomas, usually require speedy treatment, with surgical removal, X-rays and laboratory tests to confirm identity and prognosis. Often lumps will be sampled (what's known as a 'biopsy') to help direct vets to appropriate therapy.

If your vet suspects your dog may be seriously ill, they'll most likely recommend a series of diagnostic tests and suggest treatment options relying on their investigation, animal's health and even the budget of the owner. Cancer can prove expensive if all treatment options are explored. These can be anything from surgery to chemotherapy, radiation therapy, changing diet or chronic pain relief.

Ethical considerations

The incidence of certain reproductive cancers (such as mammary, prostate, testicular, uterine and ovarian) is greatly reduced by neutering as this removes any influence caused by sex hormones. Bear in mind cancer therapy can be controversial, as it's our choice (not the dog's) so a realistic outlook is essential when considering your options.

The growing importance of ethical considerations and palliative care these days must also be recognised, with exciting developments and treatment possibilities being explored every day. So whenever your pet just isn't feeling 'themselves' make an appointment with your vet, as with cancer - just like many other causes of illness - early diagnosis and treatment is key to a more favourable outcome, often preventing serious, painful or even life-threatening growths from developing further. The golden rule for any lump is what all good train station platform announcers advise: 'If you suspect it - report it!'

This article was written by Marc Abraham and was originally published in the Crufts Magazine -

Marc Abraham is a vet based in Brighton.  He regularly appears on UK television.  For more information about Marc please visit

Who can I contact for further advice?

The Kennel Club is not a veterinary organisation and is unable to provide general or case specific veterinary advice.  If you have any questions regarding any of the issues discussed in this article then please contact your local veterinary practice for further information.

How you can help with canine cancer research

If your dog has been diagnosed with cancer, then you may be able to help further research into scientists understanding of this complicated disease. 

  • The Kennel Club Cancer Centre at the Animal Health Trust has a list of current breed specific research projects where you, or your vet, may be able to send samples of your dog's blood, cancer biopsies or a DNA from cheek swabs.

What is the Kennel Club Cancer Centre at the Animal Health Trust?

This new research and treatment centre was launched in 2013 and provides Cancer treatment to dogs, horses and cats, as well as pioneering new research to aid earlier diagnosis, treatment, and the prevention of some forms of the disease.  The Centre contributes to the AHT's well-established cancer research programme and brings together the expertise of the AHT's clinical oncology team, its molecular scientists and geneticists to investigate different cancers and different aspects of cancers in animals.

The Kennel Club Charitable Trust provided the AHT with an interest-free loan of £1.5 million to help with the construction of the building and the overall development of the new Cancer Centre.  The loan is the latest in a series of link-ups between the Kennel Club and the Animal Health Trust. The Kennel Club Charitable Trust has also provided a £1.2 million grant to the AHT to fund the Kennel Club Genetics Centre at the AHT, which is investigating the genetic cause of several other inherited diseases in dogs and developing DNA tests to check for these. There will be considerable synergy with this work and research into cancer.

The Kennel Club Cancer centre is able to offer each and every patient the treatment for its specific cancer and is able to combine surgery with chemotherapy and / or radiotherapy on one-site, which is less stressful for the animals being treated.  In addition, by treating these animals at the AHT, additional information can be collected to contribute to on-going cancer research.

Cancer remains one of the biggest threats to the wellbeing of dogs, but we hope that through the new Kennel Club Cancer Centre at the AHT, we will be able to take major strides towards improving the health and welfare of not just dogs but other animals too.


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