Find out about cancer in dogs, including symptoms, diagnosis, as well as treatment and management options. Learn more about common canine cancers such as bone cancer (osteosarcoma), lymphoma, mast cell tumours, and melanoma.
Does My Dog Have Cancer?
Discovering a lump or noticing unusual symptoms in your dog is worrying for any pet owner. It is best to make an appointment with your vet to get it checked out as soon as possible.
While many lumps or growths are not malignant or cancerous, there are several cancers that are frequently encountered the veterinary oncology field.
It can be helpful to know how to recognise the common symptoms of these cancers in dogs and understand what treatments are available, to ensure your dog’s well-being.
While a cancer diagnosis may feel daunting, keep in mind that many dogs live happy and fulfilling lives with the appropriate care.
What is Cancer in Dogs?
Cancer refers to the uncontrolled growth of abnormal cells within the body. These cancerous cells can invade and damage surrounding tissues and organs.
They sometimes also spread to other parts of the body through the bloodstream or lymphatic system — a process called metastasis. This makes early detection and treatment all the more important.
Essentially, cancer disrupts the body’s normal cellular processes, leading to a variety of health problems and can be fatal for dogs. Some canine cancers progress slowly, while others are aggressive and metastasise rapidly.
In Singapore, some of the canine cancers that vet clinics and animal hospitals more frequently encounter include mast cell tumours, lymphoma (affects the lymphatic system), osteosarcoma or bone cancer, melanoma (pigment cell cancer), and hemangiosarcoma (blood vessel cancer).
Read on to learn more about five commonly seen canine cancers, how you can recognise their typical symptoms, how vets diagnose cancer in dogs, and the treatment strategies to consider.
If you are concerned and think your pet might have cancer, always seek a definitive diagnosis and customised treatment plan from your veterinarian. Early detection and professional care can significantly improve an animal’s quality of life.
For questions or bookings, please WhatsApp our friendly Paws N’ Claws team at 8891 4417 (Upper Thomson) or 8809 0787 (Yishun).
Common Canine Cancers
Dogs can develop many of the same types of cancers as humans and also display similar symptoms. Veterinarians in Singapore see a wide variety of canine cancers — often affecting the animal’s lymph nodes, skin, bones, blood vessels, oral cavity (mouth), nasal cavity, and more.
Here’s an overview of five types that are prevalent in dogs, in no particular order:
1. Mast Cell Tumour
Origin: Mast cells are immune system cells that live in the bone marrow and in body tissues. Highly common in dogs, mast cell tumours (MCTs) mostly occur in the skin or just underneath the skin, although they sometimes also affect other areas of the body such as the spleen, liver, gastrointestinal tract, and bone marrow.
MCTs are among the most common malignant skin tumour in dogs, making up a significant portion of skin cancer cases.
Symptoms: When they occur on the skin, mast cell tumours often appear as raised skin lumps or masses that can vary in size and colour. They can resemble pimples, cysts, or lipomas — a non-cancerous (benign) fatty lump. Other possible signs include swelling, ulceration, itching, or redness.
Risk factors: Mast cell tumours can occur in any dog, though certain breeds — including Boxers, Labrador Retrievers, Golden Retrievers, Staffordshire Bull Terriers, and Pugs — seem to be more prone to developing them.
Age is another factor, with most mast cell tumours occurring in in middle-aged to older dogs. They usually present when the dog is around 7 to 9 years old.
2. Osteosarcoma: Bone Cancer
Origin: Osteosarcoma in dogs originates from the bone cells, primarily affecting the long or larger bones such as the legs or pelvis. It is a painful cancer and highly aggressive, which means it has a strong tendency to metastasize (spread) rapidly to other parts of the body, typically the lungs.
Symptoms:
- Lameness or difficulty walking that does not go away
- Swelling at the site of the cancer
- Palpable mass (can be felt)
- Sudden bone fracture
- Pain, especially when the limbs are touched or when walking
Risk factors: Certain large and giant dog breeds, such as Rottweilers and Great Danes, could have an increased genetic risk for developing osteosarcoma.
3. Lymphoma, aka lymphosarcoma
Origin: A malignant disease of the lymphatic system — the network of tissues, vessels, and organs that help the body fight infection, lymphoma is considered a blood cancer, as it starts in white blood cells (lymphocytes). Dogs with the condition tend to have swollen or enlarged lymph nodes. Because the symptoms can be vague and mimic other conditions, a proper diagnosis by a veterinarian is key.
Symptoms:
- Swollen lymph nodes — often around the neck, underarms, or groin area — which are usually firm and not painful
- Lethargy, decreased appetite, and weight loss
Risk factors: Genetic predisposition is a factor, with studies flagging breeds such as Boxers, Golden Retrievers, and Cocker Spaniels as being more susceptible to lymphoma.
The condition also predominantly affects middle-aged to older dogs, with the incidence rate increasing with age.
That said, do note that it is possible for lymphoma to affect any dog of any breed and at any age.
4. Melanoma: Pigment Cell Cancer
Origin: Arising from pigment-carrying cells, melanoma tumours often appear as dark lumps (although they can also lack pigment) on the dog’s skin, in or around the mouth, nail beds, and eyes. Malignant oral melanoma is particularly aggressive, demanding immediate veterinary attention.
Symptoms: Melanoma tumours are usually dark, irregular lumps and often ulcerated. Depending on the site and severity of the tumour, malignant melanoma in dogs will have a range of symptoms.
For oral melanoma, common signs include bad breath, difficulty eating or swallowing, excessive drooling, swelling or pain in the mouth, bleeding from the mouth, tooth loss, weight loss.
Skin melanoma in dogs may present as dark skin patches, and bleeding or ulcerated masses. If it is on the nail bed, signs include limping, licking toes, and discoloured or loss nails.
Risk factors: Vets often see malignant melanoma in middle-aged to older dogs. While there is a view that dogs with darker coats may be at a higher risk, do note that this has not been strongly supported by data.
5. Hemangiosarcoma: Blood Vessel Cancer
Origin: Hemangiosarcoma (HSA) originates from the cells that line blood vessels and can lead to internal bleeding. It can affect various organs, including the spleen, liver, heart, and skin. This highly malignant cancer tends to rapidly spread to other parts of the body. The prognosis is unfortunately often poor due to HSA’s aggressive nature.
As there is a risk of sudden and life-threatening complications, prompt veterinary care is essential.
Symptoms: Depending on where the tumour is located, dogs with hemangiosarcoma may show no clinical signs or only mild, non-specific signs of illness such as lethargy, exercise intolerance, and reduced appetite.
For HSA at the skin, it typically appears as a red or purple mass under the skin, with possible bruising or bleeding from the tumour.
For HSA at the spleen or heart, the dog is at risk of the tumour rupturing and bleeding. This will cause severe emergent signs such as:
- Sudden collapse or severe weakness
- Pale gums
- Rapid or difficulty breathing
- Distended (swollen) abdomen due to internal bleeding
- Sudden death
For emergencies, please call us right away, at 8891 4417 for the Upper Thomson vet clinic, or 8809 0787 for our Yishun clinic.
If we are not responding quickly enough or it is past our operating hours, please reach out to other emergency vet clinics or animal hospitals near you ASAP.
Learn more about our veterinary emergency services at Paws N’ Claws.
Diagnosing Tumours in Dogs
Tumours are broadly categorised as either benign or malignant. Accurate diagnosis is fundamental to effective dog cancer treatment. Visiting your veterinarian will help determine how dangerous and aggressive a tumour is.
Vets are not able to diagnose if a tumour is malignant just by looking at or feeling it. They will need to conduct tests and sampling before they can provide a definitive diagnosis.
Vet clinics use a combination of diagnostic techniques to identify and characterise canine cancers, including:
- Physical examination: To identify and assess any visible abnormalities such as lumps.
- Fine needle aspirate (FNA): A quick, minimally invasive procedure to extract cells for examination.
- Biopsy: Provides detailed tissue analysis, if the FNA was inconclusive or if the veterinarian needs additional information.
- Imaging tests: X-rays, ultrasound, or MRI may be used to assess the spread or extent of the tumour.
Cancer Treatment and Management
Surgery, chemotherapy, radiation therapy, and immunotherapy are among the standard cancer treatments that veterinarians will typically administer. For dogs who are undergoing cancer treatment, supportive care should also be considered.
How is Cancer in Dogs Treated?
Cancer treatment for dogs is tailored to the specific type and stage of tumour. Your veterinarian will recommend the treatment depending on factors such as: (i) how advanced or large the tumour is, (ii) whether the cancer typically spreads to other organs, (iii) the severity of the symptoms, (iv) the likely outcomes for your dogs, and (v) how aggressive you would like the cancer treatment to be.
Treatment options include:
- Surgery: Remove localised tumours.
- Chemotherapy: More effective treatment for systemic cancers like lymphoma.
- Radiation therapy: Targeted treatment to shrink specific tumours, often in combination with surgery.
- Immunotherapy: Boosting the dog’s immune response to fight cancer cells.
The good news is that cancer treatment for dogs is usually well-tolerated and has few side effects.
How Can I Manage My Dog’s Comfort?
Some cancers are highly treatable. For example, some forms of lymphoma or mast cell tumours can respond very well to treatment, leading to long-term remission. Surgery can also be curative when the cancer is localised and completely removed.
However, for many canine cancers, the goal of treatment is to manage the disease, slow its progression, and maintain the dog’s quality of life for as long as possible.
Alongside treatment, management strategies could include:
- Pain relief: Managing pain and discomfort, such as with medications.
- Regular monitoring: Detecting recurrence or spread of cancer.
- Nutritional support: Providing a balanced diet to support your dog’s recovery.
- Lifestyle adjustments: Modifying your home and your pet’s environment for comfort, such as limiting physical activity, ensuring easy access to his favourite resting spots at home, providing access to warmth, and more.
Many dogs with cancer can live long and happy lives with appropriate veterinary care. Do have open and honest conversations with your veterinarian about your dog’s prognosis and treatment options, and ask questions when in doubt.
Fear-Free Veterinary Care
At Paws N’ Claws Veterinary Surgery in Singapore, our team is equipped with the necessary knowledge and resources to handle a wide range of cancers and related conditions. We are Fear-Free aligned, prioritising your pet’s physical and emotional well-being. From advanced diagnostic tools to tailored treatment plans, we are here to help your pet recover and feel better.
If your pet requires specialised care beyond our scope, we are more than happy to recommend or refer you to qualified oncology specialists or hospitals, to ensure that your dog receives the most appropriate treatment. Your pet’s health is our top priority.
Our friendly and knowledgeable team at both our vet clinics in Yishun and Upper Thomson will gladly address any questions you may have.
Have a question? WhatsApp us at 8891 4417 (Upper Thomson) or 8809 0787 (Yishun).
Alternatively, please fill in the form below to send us a query.
