Cancer in Cats and Dogs – The Unfortunate Reality

Did you know, according to The Veterinary Cancer Society, cancer is the primary cause of death in 47% of dogs and 32% of cats. Though cats get fewer cancers than dogs do, this equates to an estimated 6 million dogs and cats being diagnosed with cancer every year. This is a harsh reality for many dog and cat owners, but it is one that you should be aware of so you can notice the signs and understand what treatment options are in store for the future.  

Common Cancers for Dogs

Cancer in dogs can take several forms, affecting their bones, body tissues, and blood. Though there are many kinds that your dog could develop, here are the most common types to keep in mind.

  • Lymphoma:  This cancer accounts for about 20% of all canine cancers. It can affect any breed at any age, and shows up as swollen lymph nodes under their jaws, in the front of their shoulders, and behind their knees. If your pup responds well to chemo treatment, they should be able to get back to good health in about 12-18 months. 
  • Mast Cell Tumors: Seen frequently in Boxers and Bulldogs, these tumors form on the skin, varying from acute to aggressive. They tend to spread to other parts of the body, and these cells are usually easy to identify with a fine needle aspirate. With this, your dog might be vomiting often, have diarrhea, and have a loss of appetite. For this one, surgery is required to remove the entire tumor.
  • Osteosarcoma: Known as the most common bone cancer in canines, it generally shows up more in larger breeds, such as Great Danes and Irish wolfhounds. This cancer attacks their bones and limbs, progresses rapidly, and can spread to their lungs and other bones. In the beginning, you may notice pained limbs and swelling, and in most cases, amputation is the course of treatment. Though it would be nice to say most live after treatment, less than 10% of dogs who undergo it live longer than three years afterward. 
  • Melanoma: As the leading oral cancer seen in dogs, keep an eye out for this one if your breed has a darker tongue and gums.These tumors develop quickly and can show up anywhere on the body. Unfortunately, if you see it in your dog’s mouth, it means it has already spread throughout the rest of their body, making it incurable. Surgery is complicated, the metastasize cells do not respond to radiation, and chemo does not have any effect on this type of cancer. 

Common Cancers for Cats

If you are a cat person, then this section would be yours to pay close attention to. As noted above, cats have fewer cancers that they can develop, but not zero. In fact, almost one out of every three cats will be diagnosed with cancer at some point in their lives. For cats, regardless of the type of cancer they have, pain management and palliative treatments are always key options to help prolong their quality of life and allow them to live as long as possible. 

  • Lymphoma: Just like dogs, Lymphoma is the most common cancer diagnosed in cats. It can, again, be found in many places on their bodies, such as their spleens, livers, and bone marrow. For cats, the feline leukemia virus has been linked to causing this cancer to develop, and cats with feline immunodeficiency virus are at a higher risk. As for signs, if your cat is experiencing stomach issues, tiredness, and vomiting, this could be the culprit. Overall, 70% of cats who get diagnosed quickly will go into remission.  
  • Squamous Cell Carcinoma: Also known as SCC, this cancer forms in the cells that are lining the oral cavity in your cat’s mouth. It is the most common oral tumor in cats, and it makes your cat drool a lot, have a foul odor, have trouble eating, and experience frequent mouth bleeds. To know for sure if your cat has this, a biopsy is performed, and surgery is typically the first line of defense. However, if the tumor is large and your cat’s mouth is too small, curative surgery is only possible in about 10% of cases. Because of this, radiation and chemo are the next best alternative options. But please be aware that even with these efforts, very few cats who have SCC are cured.
  • Fibrosarcoma: Turning towards the softer tissue, Fibrosarcoma is a slow-spreading cancer, but it is locally aggressive. As an owner, you may notice your cat’s skin containing a mass that does not appear to be causing them any pain. However, if left untreated or it advances, your cat may become lethargic, dehydrated, or become anorexic. Even though surgery is the first suggestion, tumors often return later on, so radiation and chemo are usually recommended adjunctive treatments. With the combination of both treatments, your cat may live without any cancer for another 1-2 years.
  • Mammary Tumors: Believe it or not, this breast cancer is something ubiquitous in cats. Nearly 90% of felines mammary tumors are malignant, meaning they will not spread to other parts of their body. If it does, it is likely to go to the lungs or lymph nodes. If the tumor is small, surgery is the first recommendation, as it is the most effective way to cure this type of cancer. If larger or if there is evidence that it spread, post-surgical treatment such as chemo may be in the treatment plan. 


Though you can easily reduce the risk of cancer in your cat or dog with natural herbal detox remedies because they significantly boost their immune systems, cancer is something not 100% avoidable. Cancer is that awful struggle both beloved pets and humans are subjected to, and it can be tough to come face to face with it. But the best thing you can do on your end is to know the symptoms, become educated on the different types of pet cancers, and know your treatment options so you can best prepare. In the end, give your pet the best fighting chance, love, and quality of life they deserve, and understand that no matter what happens, you will persevere through it.