Cancer is a disease where abnormal cells divide without control and can invade nearby tissues and spread to other parts of the body. As with humans, any cells in your pet's body can be affected, including cells in their skin, bone, muscle, liver, lung, spleen, intestinal tract, and nervous system. Your pet’s body becomes more vulnerable to cellular changes as they get older, which can challenge immunity and lead to cancer, but advancements in pet nutrition, vaccinations, routine veterinarian checkups, and parasite prevention can help our furry family members live longer.
What Are the Most Common Types of Cancer in Cats and Dogs?
Lymphoma
Lymphoma is the most common cancer in dogs and cats, making up 20% of all canine cancer cases and 30% of all tumors in cats. It starts in the lymphatic system — a network of tissues and glands that support your pet’s immune system.
Osteosarcoma
Osteosarcoma is the most common bone cancer in dogs. Unfortunately, it’s an aggressive cancer. Osteosarcoma commonly affects the limbs of large or giant breed dogs, but can also occur in other parts like the skull, ribs, vertebrae, or pelvis. In both cats and dogs, osteosarcoma can show up as these symptoms:
- A swollen mass on the skull, jaw, or ribs
- Seizures
- Wobbly or weak legs
- Breathing difficulties
- Loss of/decreased appetite
- GI issues
- Fatigue
- Weight loss
Mast Cell Tumors
Mast cells are a type of white blood cell. When cancerous, these cells can form hard-to-find tumors underneath the skin. Note: it’s impossible to diagnose a mast cell tumor without looking at cells under a microscope.
If you find a bump on your pet’s skin, don’t panic and assume it’s a mast cell tumor — about 90% of mast cell tumors on the skin are benign. But if you do find a new growth, it’s important to get your veterinarian’s opinion, especially if your pet also has any of these symptoms:
- Nodules on the head, neck, or ears
- Itching at the site of nodules
- Weight loss
- Vomiting
- Fatigue
- Black stools
These tumors may grow and shrink within a relatively short time, so it’s not safe to assume a shrinking mass is fixing itself and you don’t need to go to the veterinarian.
Mammary Cancer
Mammary cancer (or breast cancer) affects the mammary glands, but that doesn’t mean it’s exclusive to female cats and dogs. While most cases of mammary cancer affect female pets, males can still develop breast cancer. The risks are higher for a female cat or dog that isn’t spayed, so if you don’t plan on breeding your pet, getting her spayed can reduce her risk of getting breast cancer.
Mammary cancer almost always appears as a lump on the chest area, much like humans. Breast cancer affects cats more — it’s the third most common type of cancer for felines. Unfortunately, about 90% of feline mammary tumors are malignant. Thankfully, removing the tumor surgically is proven to be very successful and is the most common form of treatment.
10 Possible Signs of Cancer in Dogs and Cats
Looking for early warning signs is a great way to help prevent or treat pet cancer because it helps you to catch it as soon as possible. Thanks to all of the advancements in treatments and care, pet cancer is more treatable than ever.
What Are the Early Warning Signs of Pet Cancer?
Pet cancer is understandably a major concern for Pet Parents. The earlier the cancer is detected, the more effectively it can be treated, so look for these signs and symptoms in your dog or cat.
1. Growing or Changing Lumps
Pet Parents should check for lumps initially on their pet and, over time, note if any change in size, shape, or consistency. A lump that grows rapidly or changes in texture or shape should be evaluated. Biopsies, abdominal ultrasounds, x-rays, and screening tests can help the veterinarian and oncologist determine whether the lump is cancerous or benign.
2. Swollen Lymph Nodes
Lymph nodes are located throughout your pet’s body, but the ones behind the jaw or knees are the easiest to check. Enlarged lymph nodes may indicate a common form of cancer known as lymphoma. A biopsy or cytology of any enlarged nodes can help determine the diagnosis.
3. Abdominal Distension
If your pet’s belly or stomach area enlarges quickly, it could indicate a mass, tumor, or internal abdominal bleeding. Abdominal radiographs or ultrasounds can help determine the cause.
4. Chronic Weight Loss
If your dog or cat loses weight without a change in diet, schedule an appointment with your veterinarian. Weight loss is not a diagnostic sign of cancer, but it can indicate something is wrong.
5. Chronic Vomiting or Diarrhea
If your pet has severe or persistent vomiting or diarrhea, see your veterinarian as soon as possible. Gastrointestinal tract tumors can cause chronic vomiting and/or diarrhea, so radiographs, ultrasound examinations, and an endoscopy are all useful tools to rule out cancer.
6. Unexplained Bleeding
Bleeding from the mouth, gums, or any of your pet’s orifices that wasn’t caused by an injury should be checked. Bleeding disorders can occur in dogs and cats, but if a pet has unexplained bleeding, your veterinarian should do a thorough examination.
7. Cough
Your veterinarian might perform a chest radiograph to determine the cause of the cough.
8. Lameness
Unexplained lameness is a common sign of bone cancer, especially in large or giant breed dogs. Radiographs of the affected area can help detect this type of cancer.
9. Straining to Urinate
Straining to urinate and blood in the urine usually indicate common urinary tract infections or inflammatory disease. If these symptoms aren’t quickly controlled with antibiotics or reoccur frequently, bladder cancer may be a possibility. Veterinarians can evaluate your pet’s bladder to establish a diagnosis.
10. Oral Odor
If your dog or cat seems to be chewing differently, or changes preference from hard food to soft, it could be an oral tumor. Another sign is foul breath. Your veterinarian can do a thorough oral examination with radiographs.
What Can I Do to Help My Pet?
Feeding nutritionally balanced dog or cat food, and keeping pets as active and fit as possible is crucial, whether your pet has cancer or not. If your pet is diagnosed with cancer, you don’t have to think of it as the end of the line. With today’s advanced treatments and continued research, dog and cat cancer patients now have increased longevity and better quality of life.
To learn more about pet cancer treatments, or get resources and questions to ask your veterinarian, check out the American Animal Hospital Association’s guidelines for Pet Parents. There’s also valuable insight at the Animal Cancer Foundation.
Help Us Fight Pet Cancer
See how Blue Buffalo™ and its partners are funding pet cancer research to help treat and hopefully cure pet cancer.
