Cat Cancer

Diagnosis and Treatment of Cats With Cancer

Cat cancer is a devastating — and potentially fatal — disease that one in five felines will experience during their lifetime. If you are online searching for answers because you think your cat may have cancer, we strongly suggest seeking immediate care from a local veterinarian. This type of information is much too important to obtain from Dr. Google! However, here at GeniusVets, we understand that you might be trying to learn more about cancer and when to seek veterinary care for your feline friend. That’s why we decided to send some of the most frequently asked questions about cat cancer to veterinarians and compile their responses to provide you with helpful information you can trust.

Though we sourced the cat cancer information below from leading veterinarians, we encourage you to speak with your veterinarian — especially if you have any reason to suspect your cat may be sick. If you don’t have one, use the GeniusVets Directory to find a trusted vet near you.

What is cat cancer?

Cat cancer is similar to human cancer. It occurs when a cell in the body multiplies uncontrollably. As cancer cells proliferate, they spread to other parts of the body and cause a wide range of problems in your pet.

How will cancer affect my cat's health and quality of life?

How cancer affects your cat’s life depends on its type and location. Some forms are aggressive and cause a rapid onset of severe health problems. Others are much slower growing. Generally, cancer causes a decreased appetite, rapid weight loss, and poor grooming habits. Other symptoms may also be present depending on what type of cancer your cat has.

What are some of the most common types of cat cancer, and what would their symptoms be?

Lymphoma — particularly intestinal lymphoma — is one of the most common types of cat cancer.

Other common cancers in cats include:

  • Soft tissue sarcomas
  • Squamous cell carcinoma
  • Skin cancer
  • Bone cancer
  • Lung cancer
  • Mast cell cancer


Cats who have cancer often refuse to eat and experience rapid weight loss. They may also hide or become reclusive.

How will a veterinarian diagnose cancer in my cat?

Vets sometimes detect cancer while examining a cat. They may notice an unusual lump or bump or feel an enlarged spleen or tumor while palpating the abdomen. In most cases, though, they arrive at a cancer diagnosis after a cat owner brings their pet for a checkup due to concerning symptoms.

Symptoms you shouldn’t ignore in your cat include:

  • Weight loss
  • Decreased appetite
  • Hiding
  • Unusual lumps or bumps
  • Frequent vomiting
  • Blood in urine or stool
  • Difficulty urinating


Many pet owners mistakenly assume that cats often vomit so they think nothing of it, but vomiting, especially if it's happening frequently, is not normal cat behavior and should be assessed by your vet. 

If my cat does have cancer, what type of treatment options may my veterinarian recommend?

Treatment options vary depending on the type and severity of your cat’s cancer. The most common treatments include chemotherapy and surgery.

Why is early detection and diagnosis important for cats?

Early diagnosis is critical for cats. The earlier your veterinarian diagnoses cancer, the more likely they are to be able to treat it. Finding a small tumor is much better than finding a large one. In the early stages of cancer, cats don’t lose much of their body condition and remain in decent overall health. They tolerate chemotherapy and surgery much better during these stages than later when the cancer has had time to degrade their health.

With early treatment, vets can sometimes cure certain types of cancer in cats, so the earlier you act, the better. This is also one of the many reasons why veterinarians recommend annual exams.

Why is it so important to avoid self-diagnosing cancer in my cat?

Cats are stoic creatures by nature and often hide signs of illness — many times until it’s too late. And when they do show signs that something is wrong, many diseases share similar symptoms. While your cat’s problem may have a simple cause, there’s no way of knowing for sure without visiting a veterinarian. Even a highly skilled vet cannot look at a lump and determine whether it’s cancer. That certainly isn’t something you can do as a cat owner.

Diagnosing cancer in cats requires several tests, such as:


Without these tests and procedures, there’s no way of knowing whether your cat has cancer to begin an appropriate course of treatment.

If you would like to learn more about cat cancer, the Cornell Feline Health Center is an excellent and trustworthy source of information. We also recommend speaking with your veterinarian. If you don’t already have one, we are here to help you find a trusted local veterinarian.