Constipation in Cats – Causes, Symptoms and Treatment



Causes      Symptoms       Diagnosis      Treatment      Home treatment      Prevention


constipation in cats

What is constipation?

Constipation is the infrequent passage of hard and dry stools. There is no set number of bowel movements a cat must take in a day, but one to two is average. Constipation can affect cats of any age although it is seen more commonly in middle-aged to elderly cats.

Chronic constipation can lead to a condition known as megacolon, in which the colon becomes abnormally dilated and enlarged and loses its ability to contract. This may ultimately lead to obstipation, which is a complete blockage.


  • Dehydration: One of the most common causes of constipation in cats is due to dehydration. Water is reabsorbed from the colon and if the cat is dehydrated, the body will try to conserve water by removing additional water from the stool.
  • Reluctance to defecate: Dirty litter trays, not wanting to share a litter tray, incorrect placement of a litter tray or go outside (if it’s raining or cold).
  • Obstruction of the colon: Birth defects, hairballs, cancer, polyps or a foreign object.
  • Dietary: Diets which are low in fibre or eating food which contains hair and bones.
  • Drugs and medications: Antihistamines, diuretics, painkillers, and antibiotics can cause constipation in the cat.
  • Painful defecation: Causes include impacted anal glands or perianal bite abscess.
  • Neurological: Including damage to the nerves in the colon and anus, Manx syndrome, spinal cord injury, paralysis.
  • Hypothyroidism: A condition in which the thyroid gland doesn’t produce enough thyroid hormone which slows down metabolism. Hypothyroidism is rare in cats.
  • Pelvic injuries: Car accidents or trauma which lead to fractures narrowing the pelvic canal.
  • Metabolic/hormonal: Low potassium (hypokalemia), kidney failure, diseases of the thyroid and parathyroid glands.
  • Idiopathic. Sometimes it is not possible to find a cause of constipation.


As one would expect, the most obvious sign of constipation is straining in the litter tray. After a period of straining, the cat may pass small hard/dry feces and may cry in pain as he attempts to defecate.

As the condition progresses other symptoms may include:

Important: A urinary blockage produces similar symptoms to constipation such as frequent trips to the litter tray, genital licking, abdominal pain and crying. When a cat can no longer urinate, toxic waste products build up in the blood which are life-threatening.

A urinary blockage is a life-threatening medical emergency and requires immediate treatment.


Your veterinarian will perform a physical examination of your cat and obtain a medical history from you. The exam will reveal a hard and full colon.

Diagnostic tests:

Baseline tests: Routine serum biochemical profile, complete blood count, and urinalysis to check for underlying systemic disorders such as kidney disease or diabetes mellitus which could cause dehydration and electrolyte imbalances.

Imaging studies: X-ray of the abdomen and pelvis to assess the size of the colon and to determine the extent of impaction as well as to check for foreign objects.

Barium studies: Also called an esophagram, upper series or contrast study, a barium study is a diagnostic test to evaluate suspected gastrointestinal disease. Barium sulphate, a white radio-opaque metallic powder, is administered to the cat via syringe into the cheek pouch. Once swallowed, the barium coats the inside walls of the gastrointestinal tract which shows up the structures as bright white on xrays. The veterinarian can also monitor transit time of the barium during this procedure.

Colonscopy: If cancer is suspected, the veterinarian will recommend a colonoscopy. This procedure involves insertion of a flexible plastic tube with a light and camera (endoscope) into the colon to look for abnormalities.


Mild constipation:

Mild cases of constipation without accompanying symptoms such as vomiting or depression may be treated on an outpatient basis at home by giving your cat extra fibre, laxatives such as Metamucil (psyllium), stool softeners and increasing water consumption.

Severe constipation:

Treatment for severely constipated cats requires hospital treatment. Never administer an emema at home. This procedure is invasive and cats do not respond well. Many of the ingredients in human enemas are toxic to cats.

  • Enema or manual extraction of the feces.
  • Rehydration with intravenous fluids.

Treat the underlying cause:

  • Cancer: Surgical removal of tumours and/or chemotherapy/radiotherapy.
  • Blockage: Surgery to remove any blockages and/or increasing fibre, giving stool softeners to assist with defecation.
  • Drugs or medications: If possible, stopping any medications or adding extra fibre to the diet while the cat is on the drugs.
  • Anal glands/abscess: Treating abscess or impacted anal glands by emptying, applying antiseptic/antibiotics to the area and oral antibiotics.
  • Hypothyroidism:  Hormone replacement therapy (thyroxine).
  • Low potassium: Oral or intravenous potassium replacement and treat the underlying cause.
  • Kidney disease: Dietary management with a low protein diet, phosphorus binders, and supportive care.
  • Dietary: Switch to a high fibre diet and increase water consumption.

Home treatment: 

Adding bulk to the diet can assist in mild cases of constipation such as unprocessed wheat bran or Metamucil. Add approximately 1/2 to 1 teaspoon per day.

Pumpkin is also a good way to prevent constipation occurring as it is high in fibre and has a high water content, both of which help to keep bowel movements regular.  Add 1-2 teaspoons of canned or cooked pumpkin to your cat’s daily meal.

Laxatone is a petroleum gel which helps to lubricate the digestive tract.

Increase water consumption, which may include feeding more wet food, such as canned or raw meat as well as adding additional water bowls or investing in a cat water fountain.


Removing the cause if at all possible is the best course of action, which includes:

  • Speak to your veterinarian about hairball diets or add a small amount of lubricant to the food such as petroleum jelly or butter.
  • Brush the coat regularly to remove long hairs.
  • Regular treatment of parasites.
  • Add fibre such as pumpkin or flax seeds to the diet.
  • Provide access to clean, fresh drinking water at all times.
  • Increase water consumption by switching your cat to a wet diet and encouraging him to drink more.
  • Keep your cat’s weight down.
  • Ensure your cat gets plenty of exercise with interactive toys.
  • Make sure there are enough litter trays in the house. One per cat, plus one extra. Scoop solids twice a day and completely empty once a week.


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