Discover the most common types of cancer found in dogs and cats — and how to tell when something might be wrong. Pets are susceptible to some of the same illnesses that humans are, including cancer, which affects an estimated 1 in 4 dogs and 1 in 5 cats during their lifetime. Some of the more common cancers found in dogs include mast cell tumors, melanoma, lymphoma, mammary gland tumors, osteosarcoma, and hemangiosarcoma. Common feline cancers include lymphoma, squamous cell carcinoma, mammary gland tumors, and fibrosarcoma (also called soft tissue sarcoma). Cancer in cats is less prevalent than in dogs, but it tends to be more aggressive. Thankfully, with early detection, many cancers are treatable. Signs and Symptoms Dogs and cats are great at hiding disease, which can make cancer difficult to spot. But keeping an eye on changes to your pet’s body and behavior will help you catch cancer early and greatly increase the odds of it being cured. Watch for the following signs: • lumps and bumps • abnormal odors • discharge and/or abnormal bleeding • wounds that don’t heal • weight loss and/or changes in appetite • respiratory issues, like coughing or difficulty breathing • unusual swelling • abnormal bathroom habits, like straining to urinate • lethargy • unexplained vomiting and/or diarrhea • limping or other signs of pain If you spot any of the signs above, take your pet to a veterinarian to be checked out. It could be a sign of cancer or another disease — or it might be nothing to worry about. In any case, consulting your vet about changes in your pet is key to keeping your furry friend healthy.