Special Breed Risk: Siamese Cats & Megacolon

Siamese cats are at greater risk for Megacolon than other cats.

Constipation is a condition where an animal either does not defecate, or does so very infrequently; this causes retention of feces in the colon or rectum. There are many different conditions which can cause constipation. Constipation can lead to a disease known as megacolon. Fecal materials begin building up in the animal and the body cannot find a way to get rid of them. Over 12 percent of the cases of megacolon are present in Siamese cats which puts them at a greater risk than average for this disease.

If left untreated, constipation can cause serious problems because the fecal mass continues to impact the gastrointestinal tract. The fecal material keeps getting dryer and dryer until it becomes extremely difficult to evacuate. Obstipation occurs when the cat cannot defecate because the colon has become very impacted. This could lead to megacolon where the colon gets dilated preventing its normal movements to clear the colon because it gets somewhat paralyzed.

If the cat has not been able to evacuate feces for a long enough period of time, the cat may start getting weak, start losing weight, get anorexia, have abdominal pain and vomiting. If your cat is exhibiting these symptoms it is extremely important not to try to treat this yourself but bring the cat to a veterinarian. The earlier the cat is evaluated and treated the better it is.

Lactulose is available at PetMeds®

The most common prescription medications used to treat Siamese cats that develop megacolon include a drug called Lactulose. Lactulose is a synthetic disaccharide (a type of sugar), which is broken down in the colon by the bacteria present there into lactic, acetic, and formic acid. This increases the osmotic pressure and acidifies the fecal matter causing the stool to soften by increasing the water content. Lactulose generally comes as a 16 ounce bottle of syrup or solution 10gm per tablespoon (15ml) It is given by an oral syringe and because it is so sweet mixing it with regular food might not go over well and is really not advisable.

Depending on the severity of the constipation, a veterinarian may also recommend a pro-kinetic agent to help move fecal material along the GI tract. Choice medicines in this category include cisapride and metoclopramide. Cisapride works by promoting gastric emptying and increasing peristalsis in the tract. Metoclopramide increases strength of the gastric contractions.

Unfortunately there is no permanent cure for megacolon in Siamese cats. It is unknown why Siamese cats seem to have one of the highest prevalence of the disease compared to the other species. Pet owners and veterinarians can work together to help control the symptoms of the disease to the best of their ability and allow the cat to live as much of a normal happy life as possible. Additionally if you have any questions about the medications used to treat megacolon, constipation, or any other condition that your pet is suffering from a 1800PetMeds pharmacist is also available and would be happy to help answer your questions.

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  1. Hi Eddie,

    That sounds like a very effective and safe medication. I’m very glad to hear about it.

    I’ve had a few cats with bowel issues in the past and I felt very sorry for them. Having bowel issues affects the whole system and not in a good way.

    A backed up sewer system is big time bad news.

    What I’ve found is switching to wet food only and making sure the drinking dish is washed with soap and water every day makes a big difference in bowel health.

    Kibble is incredibly dry and it can suck a lot of moisture out of the gut.

    The clean water dish encourages the cats to drink more.

    The whole idea is to get more water in the gut via wet food and the drinking dish.

    So, if a cat already has bowel blockage or dry stools, combine both the medication you’ve recommended with more wet food and clean drinking dishes.

    The existing stool has to be softened and released.

    I would say that after the medication is helping, the increased water intake might be referred to as a permanent solution.

    It worked well for my cats that had dry stools and partial blockage.

    That medication sounds like a life saver. Thanx for writing about it.

    =^..^= Hairless Cat Girl =^..^=

  2. I feed my cat, who probably has some siamese in her, Royal Canin Fiber Response dry and I think this helps – it has lots of fiber which moves things along. I agree with at least rubbing the H20 dish out with your fingers each time you fill it to keep it more pleasant. 🙂

  3. Dr. Michael Dym, VMD veterinarianOctober 28, 2013 at 12:17 am

    I prefer all wet foods for cats prone to constipation, as the extra moisture is more important in constipation and hydration of cats. Also helpful to use natural sources of fiber added to meals such as psyllium husks from health food store and/or wheat bran added to meals.

  4. Adding a little organic cold milled Golden Flax to the wet food could help too. It’s a good source of fiber and has a natural slippery quality to it (though it is dry in the bag) when added to food. I add it to soup and stew, yogurt and pasta sauce, etc.

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