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Your Guide to Cancer in Cats

Cancer in cats often goes undetected until more advanced stages. Yet spotting and treating cancer early gives your kitty their best shot at a good outcome. Today's post explains some common symptoms of cancer in cats and treatments. 

Understanding Cat Cancer

Cats are stoic creatures with a natural instinct to hide any signs of illness or pain as a defense mechanism against predators. Sadly, their remarkable ability to hide signs of illness means that cancer is often advanced by the time pet parents begin noticing symptoms of the disease.

Knowing some of the most common signs of cancers in cats can help pet parents detect the earliest signs of the disease and seek veterinary care right away. As with many conditions in both cats and people, early detection and treatment typically lead to much better outcomes.

Signs of Cancer in Cats

Different forms of cancer will lead to different symptoms so it can be challenging to generalize about the most common signs of cancer in cats. That said, pet parents should always keep an eye out for the following cancer symptoms in cats:

  • Lumps that change in appearance, sores, shabby or rough fur
  • Lack of energy
  • Change of personality
  • Stiffness
  • Rapid weight change (gain or loss)
  • Loss of appetite
  • Bouts of vomiting
  • Difficulty eating
  • Change in litter box use, struggling to pass urine or feces, diarrhea 
  • Breathing difficulties
  • Bad breath 

If your cat is displaying any of the symptoms above, contact your primary care vet or veterinary oncologist right away to have your feline friend examined. 

If your vet suspects that your cat has cancer they will focus on diagnosis, pain management, treatment and possibly palliative treatment to maintain your cat's quality of life for as long as possible.

Causes of Cancer in Cats

So what causes cancer in cats? As with cancer in people, there is no signal cause of cancer in cats. Some factors that can increase the chances of your kitty developing cancer include:

  • Exposure to smoke
  • Exposure to asbestos
  • Exposure to toxins
  • Excessive sun exposure
  • Lack of exercise
  • Living outdoors
  • Feline leukemia disease (FeLV)
  • Feline immunodeficiency virus (FIV)
  • Being spayed after age 12 months
  • Poor nutrition

Common Types Of Cancer In Cats


As one of the most commonly diagnosed feline cancers, lymphoma has the ability to affect the lymphocytes (a kind of blood cell) and lymphoid tissues situated in many places throughout the body (e.g. lymph nodes, liver, bone marrow). It can be caused by other conditions such as feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV). Lymphoma can affect cats of anty age, breed, or sex, with the gastrointestinal tract being the most commonly affected area of the body. 

Treatment options include chemotherapy, which most cats can tolerate with minimal side effects. In about 70% of feline patients, chemotherapy resulted in less presence of cancer (remission). 

Squamous Cell Carcinoma (SSC)

Squamous cell carcinoma (SCC) is found in the cells of the oral cavity and is the most frequently seen kind of oral tumor in cats. The signs of SSC in felines usually show as dental problems (drooling, oral odor, dental bleeding, difficulty eating) that are examined by a veterinary professional who can identify SSC via biopsy.

Although surgery is recommended to address SSC in cats, unfortunately, cats' mouths are quite small in relation to the size of the tumor by the time it is usually diagnosed. If surgical intervention is deemed appropriate, sections of the upper or lower jaw will likely be removed to reduce the likelihood of the cancer invading other, deeper structures of the mouth.

Radiation and chemotherapy treatments are other options – but sadly, the majority of cats with SSC cannot be cured. If this is the case, the focus of your pet's compassionate veterinary team will be in keeping your feline friend as comfortable and pain-free as long as possible.


Fibrosarcoma is a cancer that affects the soft tissues of the body and although slow to spread, is aggressive in the areas in which it takes hold. This cancer usually shows physical symptoms in the form of skin lumps or masses that doesn't seem to cause the cat pain. In more advanced cases, cats will show signs of dehydration, lethargy, and poor appetite. 

Surgery is the usual initial treatment for fibrosarcoma, but it is likely that the tumor will return even with particularly aggressive removal of the growth. Because of this, radiation or chemotherapy is often recommended concurrently. With successful treatment, cats with this condition can live without the disease for 1 – 2 years.

Mammary Tumors

It may surprise you to know that mammary (breast) cancer is also a common cancer in cats, with up to 90% of mammary tumors being malignant (having the potential to spread to other body parts). More advanced cases can see the tumors spread to lymph nodes and lungs, which is why early detection is key. 

Surgically removing the mammary tumor, especially if the growth is small, is the most effective treatment. If the cat's condition has progressed (i.e. tumors are large, or lymph nodes are affected) then post-surgery chemotherapy might be advised by your veterinarian or veterinary oncologist. 

Early Detection Is The Best Prevention

Take preventive steps such as having your female cat spayed to reduce the chance of mammary cancer, getting your kitty vaccinated against feline leukemia, and ensuring they attend their routine veterinary checks to keep an eye on their overall health. Since there are several cancers for which the causes are unknown, early detection is your best tool. You and your expert veterinary team are the first line of defense in your feline friend's fight against cancer! 

Veterinary Oncology in Ambler 

At Spring House Animal Hospital we believe that caring for a cat with cancer should be a team effort. Our goal is to provide pet owners with the most accurate diagnoses and staging information possible, along with appropriate treatment recommendations for their pets.

Learn More About Our Veterinary Oncology Services

Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.

If your cat is showing signs of cancer, seek veterinary care right away. Contact Spring House Animal Hospital today to book an urgent examination for your kitty.

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