The abdomen is located between the chest and the pelvis and it houses a number of important organs including the liver, spleen, kidneys, stomach, intestines, pancreas and bladder.
Also known as 'abdominal distension', there are a number of causes of a swollen belly (abdomen) in cats, the swelling may be due to fluid, a tumour, gas, obstruction, worms etc. Depending on the severity of the swelling, breathing may become difficult and you may find your cat becomes lethargic.
What causes a swollen abdomen in cats?
- Ascites - Fluid accumulation in the abdomen, there are a number of possible causes including liver disease, ruptured bladder, right sided heart failure and peritonitis.
- Cushing's Syndrome - A metabolic disorder due to the overproduction of the hormone cortisol. It is caused by the over administration of cortisone (known as "veterinary induced"), adrenal or pituitary tumours.
- FIP - A fatal viral infection caused by certain strains of the coronavirus.
- Dietary intolerance - Can cause a build up of gasses in the stomach. Giving your cat milk is one common cause of bloat.
- Cancer - There are many cancers which can occur in the abdomen resulting in swelling.
- Gastrointestinal obstruction - Due to ingestion of foreign object, hairballs, tumours etc.
- Pregnancy - Your cat's belly will be noticeably larger around the fifth week of pregnancy. Some cats will experience morning sickness in the early weeks and may lose their appetite.
- Organ enlargement - Due to tumours or fluid build up.
- Pyometra - Infection of the uterus.
- Worms - Roundworms, in particular, can cause abdominal distension, particularly kittens.
- Weight gain - There are medical causes of weight gain, however, the most common reason is overfeeding and/or inactivity.
What other symptoms may be present?
This depends on the cause of the swelling, but common symptoms may include:
- Difficulty breathing, vomiting, abdominal pain with ascites.
- Vomiting and diarrhea with abdominal obstruction.
- Flatulence and diarrhea are common symptoms of dietary intolerance/bloat.
- Cancer symptoms may vary depending on the organ(s) affected but may include weight loss or gain, change in bowel habits, difficulty breathing, loss of appetite, lethargy.
- Cushing's syndrome symptoms are typically thin skin, hair loss, muscle wasting, increased thirst and appetite.
- Pregnancy begins to show around the fifth week, however, you may notice a "pinking up" of the nipples prior to this.
- Pyometra comes in two forms, open or closed. With open pyometra, a foul smelling discharge will drain from the vagina.
- Worms, particularly in kittens can be serious as they can cause bleeding (hookworms) or compete with the cat for food (roundworms). Common symptoms are weight loss, despite having a pot-bellied appearance, and you may notice worms in your cat's feces.
How is the cause of abdominal swelling diagnosed?
Your veterinarian will perform a complete physical examination of your cat and obtain a medical history from you. He will want to know when you first noticed symptoms. He will need to perform some diagnostic tests, some of which may include:
Complete blood count, urinalysis, and biochemical profile to evaluate organ functions.
X-ray and/or ultrasound to look for cancers and evaluate the organs for enlargement.
Specific tests for Cushing's syndrome include ACTH stimulation test, low-dose dexamethasone suppression test (also known as ACTH suppression test), urine Cortisol:Creatinine Ratio (UC:Cr): This tests levels of cortisol in the urine and is measured against levels of creatinine. If the level is normal, hyperadrenocorticism can be ruled out.
ECG - To evaluate the heart function for abnormalities.
How is abdominal swelling treated?
Treatment is based on addressing the underlying cause of the swollen belly, with exception to the pregnancy of course. Pregnancy lasts around 65 days.
- Gradual withdrawal of medication or surgery to remove the adrenal glands or tumour if your cat is found to have Cushing's syndrome.
- A female cat with pyometra should be spayed and given a course of antibiotics.
- Worming medications to treat hookworm or roundworm.
- If dietary intolerance is believed to be the cause, eliminate the suspect food from your cat's diet.
- Ascites is treated by addressing the underlying cause but may include removal of fluid build-up in the abdomen (abdominocentesis) and/or diuretics to encourage the production of urine which can help to flush excess fluids from the body.
- FIP is almost always fatal, prednisone may be prescribed along with supportive care.
- Hairballs may be treated with a prescription diet or adding oil-based products (such as butter) to the diet to help the hairball pass. Other intestinal blockages may have to be surgically removed.
- Placing your cat on a veterinary supervised diet and increasing exercise to help reduce weight in the obese cat.