The genetic risk factors in one of the most common cancers in dogs – mast cell tumours – have been identified.
Also, check out our list of the best pet insurance for dogs.
Researchers at the Animal Health Trust, in association with the Broad Institute in the UK, Utrecht University and Upsala University, studied over 800 DNA samples from Labradors and Golden Retrievers.
The research showed that 70% of Labradors and Golden Retrievers carry this genetic marker. It’s been long known that these two popular breeds are the most susceptible to developing the disease. Now that we know what genes cause it, there is hope that scientists will be able to create preventative and diagnostic tests.
What are mast cell tumours?
Mast cell tumours (MCTs) are one of the most common skin cancers in dogs. They occur in mast cells, normally involved in immune response, mutate and start proliferating uncontrollably.
Mast cell tumours appear on the skin, and very rarely in internal organs but can spread to them, and are usually noticed during physical examination. They vary in size and appearance. They can look like a lesion, hairless, or simply feel like a lump or a soft movable mass just underneath the skin. Most frequently they are around 3cm large but can grow up to around 20cm to 30cm.
Mast cells are involved in immune response and contain a substance called histamine, which is released when the immune system detects an allergen that it needs to attack. This can lead to uncontrollable allergic reactions when the cells begin malfunctioning due to cancer.
The prognosis and treatment depend on the grade of MCT. Some of the lower grades are removed surgically. A higher grade, meaning a more malignant type of MCT, may require a combination of surgical intervention, chemotherapy and other forms of treatment.
How likely is a dog to get mast cell skin cancer?
The Animal Health Trust’s team compared DNA from healthy dogs to DNA from dogs with mast cell tumours. The results showed that a dog that has two copies of the risk factor DNA is 3 to 4 times more likely to develop the disease.
Some breeds are more susceptible to it than others. For example, 7 in 10 Labradors and Golden Retrievers are likely to suffer mast cell skin cancer in their lifetime. Other breeds thought to be prone to developing the disease are Schnauzers, Boston Terriers, Pugs, Terriers, English Bulldogs, Cocker Spaniels, Staffies, Beagles, Rhodesian Ridgebacks, Weimaraners, Shar Peis and Boxers.
It is estimated that over 12,000 dogs were affected by mast cell tumours last year.
How common is cancer in dogs?
One in four dogs will develop cancer throughout its lifetime, according to the Animal Health Trust. Furthermore, 50% of dogs over the age of 10 are likely to get cancer, according to WebMD.
Common types of cancers found in dogs are: skin cancer, osteosarcoma, breast cancer, cancer of the blood vessels and lymphoma.
All breeds can be affected by cancer, but some breeds are more susceptible to particular types of cancer.
If you are considering buying a certain breed or wonder about the types of cancer your dog is susceptible to, consult with a veterinary professional to learn more.
Symptoms of cancer in dogs?
Cancer symptoms depend on the type of cancer, but common signs of cancer are swelling or a lump, wounds or sores that don’t heal, bleeding from a body orifice. Other signs can be difficulty breathing, going to the toilet or swallowing; lameness, loss of appetite.
You can feel your pet's body for lumps if you're worried, but bear in mind that not all lumps mean tumour or cancer.
Always take your dog to a vet if you suspect something’s wrong.
What causes cancer in animals and can it be prevented?
The causes of cancer can be genetic, environmental or viral.
Not much is known about the exact causes of cancer, but it is known that environmental carcinogens like pesticides, UV light, asbestos, radioactive materials, environmental cigarette smoke can increase the risks.
It is hypothesised that some low quality pet foods can also contribute to the development of cancer. Certain artificial preservatives and ingredients usually used in kibbles are believed to cause cancer.
In addition, we know that genetic predisposition plays a role, too, as it does with MCTs.
Hormones can also have an impact. Although the evidence is inconclusive, many veterinary professionals believe that chipping a female dog before her first heat reduces her risks of developing breast cancer.
The older a dog is, the more likely it is to develop cancer. As dogs live longer today, more of them get cancer, which is why more cases are recorded.
There is no sure way to prevent cancer from occurring right now, but research like that of the Animal Health Trust can lead to effective methods of prevention and diagnostics.
Is there a lot of research into cancer in dogs and how can you get involved?
The Animal Health Trust is one of very few charities in the world, and the only one in the UK, that has a program dedicated to beating cancer in dogs.
Their research into mast cell tumours was made possible by individual pet owners, the Kennel Club Charitable Trust and private charity Zoe’s Journey.
Zoe’s Journey was set up by the owner of a Golden Retriever called Zoe who had cancer. The charity’s purpose is to raise money for Animal Health Trust’s cancer research program.
Check out the Zoe’s Journey website and learn more about how you can get involved.
You can also donate on Animal Health Trust’s website
We believe that cancer research is the only way to decrease the number of dogs whose lives are lost to cancer, and are therefore ourselves in the process of donating £2,500 to Zoe’s Journey.
If your dog has been diagnosed with cancer, you can further help canine cancer research by arranging to send samples of DNA cheek swabs, biopsies or blood to one of the research groups registered with the Kennel Club. The charity has set up a bio-acquisition research collaboration to help veterinary scientists carry out cancer research.
This is how Dr Mike Starkey, research lead and Head of Molecular Oncology at Animal Health Trust, and his team got some of the DNA samples for their mast cell tumours study.
“Ultimately our aim is to prevent dogs from losing their lives to cancer and reduce the number of dogs that develop cancer,” says Dr Mike Starkey