Vet-Savvy Information on Megacolon in Cats

I Love Veterinary blog is reader-supported, and we may earn a commission from products purchased through links on this page, at no additional cost to you. Learn more About Us and our Product Review Process >

Can megacolon in cats be defined as an enlarged or large colon? It is fun to play with words and compare their meanings or sounds to other words to remember them. Possibly Megamind had a big head because he had a big brain. So, a megacolon means a large colon, right? 

Therefore, what is megacolon in cats? Continue reading to find out if the wordplay will work this time.

Cat lying on the floor

What is Megacolon in Cats?

The colon is part of the large intestines that stores feces and absorbs water back into the body. Within its muscle wall, this colon contains nerves from the Central Nervous System, specifically from the spinal cord. For feces expulsion, these nerves stimulate the colon’s contraction.

Megacolon is a medical condition where the colon does not contract normally due to defective nerves, causing the colon muscles to stretch out and enlarge, about 3 to 4 times larger in diameter. This enlargement prevents the normal passage of feces into the rectum, leading to severe constipation, known as obstipation. 

Thus, a megacolon is the enlargement of the colon beyond normal, leading to constipation.

What are the Symptoms Thereof?

The symptoms of megacolon in cats include painful constipation with few bowel movements. Stools may be smaller in quantity, appear hard, and not pass frequently. There would be loss of appetite, weight loss, anemia, vomiting, dehydration, straining to defecate, and lethargy. Some impacted cats will have a painful, hard structure in the abdomen when touched.

What Causes Megacolon in Cats?

Several factors can lead to a megacolon, but the most common one is prolonged or repeated constipation. 

Causes of constipation could be an obstruction in the colon by foreign objects, anal region paralysis, dehydration, a colon or pelvic canal tumor, prolonged gastrointestinal diseases, sac abscesses, or even strictures. A dirty litter box can also trigger constipation as the cat would not be comfortable passing out feces regularly, eventually leading to a megacolon.

By not passing out feces on time, the colon continues to absorb water from the feces, leaving them hard and dry, leading to great difficulty during defecating. As more feces pile up, they become drier and harder and eventually stretch the walls of the colon, leaving them non–functional.   

A nerve defect can also cause a megacolon due to an injury to the spinal cord. Idiopathic megacolon can sometimes occur. This means there are no known reasons why it occurs. It’s spontaneous.

The Available Treatment Options for Feline Megacolon

Feline megacolon can be treated by veterinarians medically and surgically. 

Treatment for megacolon in cats medically does not appear to address the underlying issue but rather assists the cat in passing feces regularly and easily to avoid the accumulation of toxins. Some drugs used in this treatment include high-fiber or low-residue diets (prescription diets), stool softeners, enemas, colon wall stimulants, and laxatives. 

For dehydrated and lethargic cats, your veterinarian would administer fluids to restore their hydration status, an anti-emetic to the vomiting cat to stop the vomiting; and iron supplements to the anemic cat.

Your cat may also be anesthetized, given laxatives or enemas, and the impacted feces manually pulled out. 

Medical treatment is usually temporary, as it does not correct the underlying problem. Therefore, the rectification of the issue causing the megacolon is important. 

Surgery seems to be the solution to solving the problem, once and for all, usually for idiopathic causes. A veterinarian will perform a subtotal colectomy to remove the part of the colon with the problem, leaving the anal sphincter intact. 

The side effects of this surgery include soft stools occurring after the surgery, which get better after a few months, but the stools rarely go back to normal. 

Home remedies for megacolon in cats include: 

  • Providing lots of fresh water at different parts of the house to encourage your cat to drink more water.
  • Adding pumpkin or wet cat food, wheat bran, and probiotics to the diet.
  • Having enough litter boxes at home to encourage frequent defecation.
Cat on the bed

Do Kittens Get Megacolon?

Megacolon is common in middle-aged and older cats. However, kitten megacolon sometimes occurs. It can occur in cats as young as 3 or 4 or younger. 

However, a megacolon can be congenital or acquired. We discussed the acquired megacolon in the causes section, which is very common. 

Kittens usually suffer from congenital megacolon. Congenital megacolon occurs during development when the neural crest, which contains nerves, ceases before reaching the anus, leading to the kitten having a dilated colon with functional obstruction because no nerves are present to stimulate contraction. If this happens, the kitten will be born with a megacolon, which will start showing a few days after birth. 

Megacolon in kittens could also be a thyroid gland malfunction, manifesting shortly after birth or a little later, but it is reversible after giving daily thyroid supplements.

How Vets Diagnose Megacolon in Cats?

Veterinarians diagnose primarily based on the presenting clinical signs. This is known as the patient’s history. This history could include symptoms you’ve noticed in your cat over time.

To determine what is causing these symptoms, the veterinarian will perform a physical examination. On examination, the palpated colon feels hard due to impaction. A veterinarian performs a rectal exam to rule out any tumors or obstructions in the pelvic canal.

The veterinarian will also take an x-ray to determine the size of the colon and the spine if nerve damage is suspected, as well as other information, such as ruling out abdominal tumors. The veterinarian in charge or on duty would perform blood and urine tests, a colonoscopy, and an ultrasound. 

Can a Cat Function Without Its Colon?

The colon plays a vital role in the body by absorbing water back into the body and storing feces. Life without a colon is possible, but that would mean no place to store enough feces so that bowel movements would be more frequent than in cats with an intact colon. 

Also, since the colon won’t absorb water, the feces would be waterier than those of intact cats. Cats who have undergone megacolon correction surgery should drink more water to compensate for water loss from their feces.

Can Feline Megacolon be Cured?

Megacolons are chronic conditions, and thus their curability differs depending on their severity and cause. The longer it has been there, the more severe the treatment is. The good news is there is a treatment for megacolon in cats. 

The Prognosis

Megacolon in cats’ prognosis varies depending on the cause and severity of the condition. 

If the colon can restore its muscle usage and constipation ceases, the prognosis is good, and the cat might have a chance of survival and a normal life. Nevertheless, recurrence is common, and cat owners should watch their cats to ensure they pass stools regularly. This can be done with the help of medications and diets prescribed by your veterinarian. 

After surgery, there is a guarded prognosis, and it takes longer to recover. The cats do very well if there are no complications during the surgery. 

End-Stage Feline Megacolon

End-stage megacolon in cats occurs when the colon gets dilated, usually from unknown colon dysfunction. In these cases, muscles do not move as quickly or efficiently to expel feces, resulting in hypomotility (slow movement of the muscle wall) and the widening of the colon.

White cat with blue eyes

Wrapping Things Up

Megacolon is a severe disease, especially in kittens, and needs immediate attention. As soon as symptoms start, visit your nearest veterinarian to help resolve the issue. 

Megacolon is not a death sentence; with the proper intervention, you can enjoy a longer and happier life with your cat.