Megacolon in cats

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Feline Megacolon is a serious condition that can affect cats. As the name sounds, the disease causes a very large colon. While cats with this condition can not usually be cured without surgery, there are several things that can be done.

Diagnosis of Megacolon in Cats
feline megacolon

Most of the time a vet will diagnose megacolon by taking an xray. A radiograph of a cat with megacolon will show a very dilated colon filled with firm stool. The colon in this diagram to the right shows a colon that is at least twice the size of that of a normal cat.

Cats with megacolon will generally have extreme constipation. However, sometimes, when there is rock hard stool in the colon some liquid can get by and it can look like the cat has diarrhea.

Unfortunately it is difficult to tell sometimes whether a cat has megacolon or if the cat simply has constipation issues. The difference between the two is that when a cat has megacolon the colon will no longer function properly ever again. If there is simply constipation then once the cause of the constipation is resolved the cat should be able to defecate normally again.

Causes of Megacolon in cats

Cats with megacolon have lost their ability to move stool through the large intestine. Megacolon is usually the result of a colon that has been stretched too much for too long. There are several possible causes of megacolon:

  • Constipation that has been untreated for too long
  • An obstruction in the intestines which causes stool to pile up in front of it
  • Hirschsprung's disease which is a genetic condition in which the nerves supplying the colon stop working
  • "Idiopathic" which means that we simply don't know the cause
Treatment of Megacolon and constipation in cats

There are a number of things that your vet may do to help a cat with megacolon:

  • IV fluid therapy. This is important because most cats with megacolon will be dehydrated. The fluids help to rehydrate the cat and also to add fluid to the rock hard stool in the colon.
  • Warm water enemas.
  • Lubrication of the rectum with ky jelly or other lubricant.
  • Potentially a general anesthetic can be administered and the vet will manually palpate the colon and try to break up the stool. This can be helpful, but if a colon is very damaged it can potentially rupture with this type of palpation.

cat straining to poop

Once some of the stool is removed then there are a number of things that your vet may recommend to help to move your cat's bowels:

Do not try any of these methods for your cat without the advice of you veterinarian!

  • Oral administration of lactulose which helps to soften stools.
  • Occasional microlax enemas.
  • Cisapride or metaclopramide tablets which help to move the intestines.
  • Miralax granules added to the food.
  • A change in diets. Some cats with megacolon do well with the addition of fiber (bran, pumpkin, metamucil) while other cats do better with a prescription low residue diet.
Surgery for cats with megacolon

If a cat truly has megacolon (which means that the colon is not able to function at all) the only option may be to have surgery done. The surgery is called a subtotal colectomy. When a subtotal colectomy is done, the majority of the colon is removed. Most cats do very well after this surgery, however, there are a few important factors to know about this surgery:

  • It can be very expensive. The surgery is difficult and usually the cat requires a long hospital stay. It can cost between $1500.00 and $3000.00.
  • It can be a risky surgery. Some cats do not survive the surgery.
  • Most cats will have slightly soft stools after the surgery. However, there are some cats that end up with chronic diarrhea after having a subtotal colectomy.

Generally, however, cats who have a subtotal colectomy do extremely well. If your cat is having chronic problems with constipation then this is definitely a good option to consider.

What if I can't afford surgery and my cat still can't poop?

Unfortunately there are some cats who just do not respond to the medical treatments for megacolon. If surgery is not an option and medical therapy is not working, unfortunately a good number of cats with megacolon need to be euthanized.

If you think your cat may have megacolon and you would like to talk to a vet about the situation, you can ask Dr. Marie an online vet question.

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Dr. Marie was quick to respond and thorough in suggesting treatment for my cat. I am so thankful- I have been so worried about my cat. Now I have additional options to discuss with my vet.

The service was incredibly fast and the vet's suggestions were right on target. This was incredibly helpful given that none of the vets in my area, mine now included, will take off hours calls now.

Dr. MarieDr. Marie is a veterinarian who practices in a busy animal hospital in Ottawa, Ontario. She created Ask A Vet Question as a resource for good, accurate veterinary advice online. Dr. Marie treats dogs, cats, hamsters, guinea pigs, and rats. She has been a vet since 1999.

Is an online vet visit just as good as a trip to your veterinarian? No! But, many times, asking an online veterinarian a question can help save you money. While Dr. Marie can't officially diagnose your pet or prescribe medications, she can often advise you on whether a vet visit is necessary. You can also ask Dr. Marie for a second opinion on your pet's condition.