Digestive masses in cats

A mass in the stomach or intestines of a cat is usually due to a tumour, and most of them are cancerous. The outcome varies a lot depending on where the tumour is, what type it is and whether it has spread. These tumours are more common in middle-aged and older cats.

Tumours of the stomach and intestines are uncommon in cats. Cancers of the stomach make up about 1% of all cancers in cats, and those of the intestines make up less than 10%. In most cases, a specific cause can’t be identified, but environment, food, genetics and other diseases may all play a role. The majority of intestinal tumours in cats develop in the small intestine. Early diagnosis and treatment improve the chance of a good outcome.

Overview

What are digestive masses in cats?

“Mass” in veterinary medicine is the term used for a lump or abnormal structure found in the body. Those affecting the stomach and intestines in cats are usually tumours. In rare cases, it may be something else, for example, an abscess, a foreign body or the gut sliding inside itself (intussusception). Some types of tumours are more common:

Lymphoma is the most common intestinal tumour type in cats and can happen anywhere along the digestive tract. This tumour can have two different appearances, as one solid mass or as abnormal cells spread throughout the intestinal wall. It can also have very different behaviours, with some progressing slowly and others very fast.
Adenocarcinoma is the second most common type. This type will often be very aggressive and spread quickly.

Symptoms

Symptoms of a digestive mass in cats

Symptoms will depend on location, size and what organs are affected. Commonly signs are:

Vomiting, sometimes with blood or a “ground coffee” appearance
Loss of appetite
Weight loss
Lack of energy or lethargy
Diarrhoea, sometimes with blood or black, tarry stools
Straining or urgency to poo
Tummy pain (causing things like abnormal stretching or standing with an arched back)
Excessive drooling
Pale gums and anaemia

Risk

Cats at higher risk of digestive masses

Like most types of cancer, digestive tumours are more common in older cats.
Siamese cats appear to develop digestive masses more often than other breeds.

Diagnosis

Diagnosis of digestive masses in cats

A mass may sometimes be noticed by a vet during a physical examination. It may also be found on imaging tests when trying to find out why a pet is unwell. Tests may then be recommended to gather more information:

An ultrasound scan can be useful for finding out more about the location, size and general structure of a mass. FNA samples can be taken for citology guided by an ultrasound scan.
Endoscopy can be useful if the mass is in the stomach or end portion of the large intestine, and also allows biopsy samples to be taken
X-rays may sometimes help, especially if the mass is suspected to be causing an obstruction
Blood tests are useful to know how a mass may be affecting other organs and overall health
CT or MRI scans can get more precise information about size and location of a mass and are the best way to look for the spread of disease

A definitive diagnosis of a mass allows for a more accurate prognosis and treatment plan. This requires a biopsy of the mass to be taken, usually through surgery. This is then examined and classified in a lab by a specialist.

Vet treatment

Vet treatment of digestive masses in cats

Treatment depends on the type of mass, location and stage of disease.

Surgery is the first treatment option, whenever possible. This may be recommended, even if the disease has already spread, in order to improve comfort and quality of life.
Chemotherapy is the treatment for diffuse lymphoma and can be used together with surgery for other cancerous masses.
Radiation therapy may also be an option in specific cases.

Other treatments may also be used to relieve symptoms of disease, such as pain relief and anti-vomiting medication.

Home treatment

Home treatment of digestive masses in cats

A balanced, easy-to-digest diet and small, frequent meals often help improve digestion in cats with masses.

Prevention

Can digestive masses be prevented in cats?

Digestive masses do not have a specific cause that can be prevented. As with most health problems, a balanced diet and healthy lifestyle will help prevent disease.

When to worry