Like humans, dogs and cats can face the challenge of cancer, and early detection is key to giving your pet the best chance at recovery.
Dr Rod Straw is the clinical director and head of oncology at Brisbane Veterinary Specialist Centre (BVSC). He was the first veterinary oncology specialist in Australia. It’s a growing specialty and he says it is now being embraced by the wider profession.
“Cancer is the leading cause of death in pet dogs, and the second most common in cats, next to renal disease,” he explains.
“However, while a cancer diagnosis is such a horrible thing to happen, it is not something you should bury your head in the sand about. If you do get a diagnosis, all’s not lost. I’m very confident that in Australia we have a very good network of getting the best treatment to patients.”
Signs of cancer in cats and dogs
Pets can’t tell us how they feel, so keep an eye on your dog or cat for any of these signs:
- Unusual lumps or bumps that grow or change
- Unexplained weight loss or loss of appetite
- Persistent vomiting, diarrhoea or blood in stool/vomit
- Difficulty breathing or changes in respiration
- Lameness or trouble walking
- Sores or wounds that don’t heal
- Bleeding or discharge from any orifice
- Sudden changes in behaviour or energy levels
Regular veterinary check-ups can educate owners on what causes cancer in dogs and cats – and help to detect cancers earlier, when they are most likely to be treated quickly and effectively.
Firstly, says Dr Straw, when looking for the first signs of cancer in dogs, keep an eye out for any unusual lumps or bumps under the skin. “Any lump or bump needs to be evaluated,” he says. “Don’t just assume it’s benign.
“Other signs of potential cancer include going off food, unexpected weight loss, discharge from any orifice, lameness, changes in respiration such as breathlessness, changes in bowel habits, such as any blood or dark faeces, or blood in vomiting.”
First port of call should be your general practice vet, who can advise on further steps.
Common causes of cancer in dogs and cats
- Genetics: certain breeds are more prone to specific cancers
- Age: older pet are at higher risk
- Environmental Toxins: exposure to chemicals like pesticides or smoke.
- UV Radiation: excessive sun exposure can cause skin cancer, especially in light-coated dogs and cats
- Hormones: hormonal changes can influence cancers like mammary tumours
- Obesity: increases risk for some cancers due to inflammation.
- Chronic Inflammation: long-term irritation can lead to cancer development.
- Infections: some viral or bacterial infections may increase cancer risk, such as feline leukemia virus (FeLV).
Common cancers in dogs or cats
The most common high-grade malignancy that affects dogs is lymphoma. Dr Straw says lymphoma cancer in dogs responds well to anti-cancer drugs, but it often needs to be seen by a specialist as well as a vet.
Lymphoma (also called lymphosarcoma or malignant lymphoma) is a cancer of the white blood cells, similar to Non-Hodgkin lymphoma in humans. Typically it presents as swellings in the lymph nodes, but can appear anywhere throughout the body.
Dr Straw says the most common signs of cancers that vets see are the lumps or bumps found in dogs or cats, although he stresses these are not always malignant.
“Some of them are benign, but then again, some benign tumours can be problematic and can affect quality of life. Anything like that needs to be addressed.”
Treatment options
“The mainstay of most solid-cancer management is a good-quality surgical approach,” says Dr Straw. “Surgery is still the mainstay of how we treat most solid cancers (not the leukaemias, lymphomas).
“For leukaemia and lymphoma, we have all the chemotherapy options that are available to humans and we’re also getting into some of the more novel and sophisticated immunotherapies.”
Cutting-edge treatments
Radiation is another cancer treatment and BVSC is now offering the game-changing TrueBeam technology, which is improving outcomes for pets with cancer.
“We started doing radiation therapy back in 2007 and it was the first place in Australia where you could get radiation for animals,” says Dr Straw.
“Now there are several locations – two in Sydney and one here in Brisbane – that are dedicated to treating animals with cancer. In our Brisbane facility, we’ve just augmented it with one of the top-of-the-range radiation therapy units that can deliver the modern type of radiation, which almost eliminates the side effects that we see with radiation.
“We have the opportunity to do targeted radiation that’s sub-millimetre accurate and we can pick out little, tiny brain tumours in small patients that we treat, and we can be very effective in treating areas that previously we couldn’t radiate.”
Cancer prevention
You can reduce the risk of cancer in pets through regular check-ups, a balanced diet and exercise, but there are targeted prevention tips for certain types of tumours.
Dogs and cats without pigment in their coat (or with areas that have no pigment) are particularly susceptible to sun-related cancers, so Dr Straw recommends avoiding sunlight whenever possible for those pets, whether it is a Dalmatian that likes sunning itself or cats with no pigment around their noses that like to sit in the window and sunbake.
Other prevention tips relate to hormone-associated cancers such as breast cancers, prostate cancers or testicular cancer.
“You can avoid getting testicular cancer if you castrate male dogs,” says Dr Straw. “There’s a bit of controversy around spaying, but from a cancer standpoint, if female dogs are spayed before their first heat, it’s almost completely protective for breast cancer. In cats, it’s not quite as protective, but it is still a benefit to spay.”
ONE Pet Cancer Care
Dr Straw and colleague Dr David Lurie have recently developed a concept of cancer treatment, called ONE Cancer Care for Pets.
“It’s all about surrounding the patient and delivering comprehensive cancer care,” explains Dr Straw. “There are many elements involved in cancer treatment, such as chemotherapy, immunotherapy, radiation therapy and surgery – each of those don’t work independently; it’s an integration.
“There are also neurologists, clinical pathologists, histopathologist and imaging specialists. The general practitioner plays a major role in all of this. The idea is that it’s a network. And that’s what ONE stands for: the Oncology Network of Excellence.
“We want to get everybody involved to produce the best outcome for the patient and to allow good oncology care to be available to as many pets as possible.”