Megacolon of Dogs


Megacolon - subtotal colectomy surgery

Q: I know you don't answer questions from anyone who isn't a subscriber, however. Maybe you could suggest where I might find info on a procedure for megacolon called "subtotal colectomy". I'm interested in knowing what kind of life my 5 yr old male cat will live, (my life too) after the procedure. This web site is the only one where I could find anything about megacolon, however no one who has had the procedure done on their cat has posted any feedback concerning post surgery "life"

A: O-

We have two patients who have undergone subtotal colostomy surgery. Both appear to be doing fine, as far as I can tell. One of the owners did say that her cat has more bowel movements than she had in the past (three or four a day instead of one or two) but that is the only change noticed. Overall cats are reported to do well following subtotal colectomy but I only have personal experience with this small number of patients. We have had very good luck avoiding the necessity for surgery using lactulose to aid in keeping stools soft along with a fiber source such as metamucil or canned pumpkin added to the diet.

Mike Richards, DVM


Q: Dear Dr. Mike, My brother has a springer spaniel that has been diagnosed with megacolon. He has taken the dog to many vets and even to Michigan State University for treatment. The best treatment he has been able to come up with is a daily enema. Why is this ailment so different in dogs than in cats? And, as always we are looking for any new cures or ideas on cures that we can get. Any information that you have on this ailment would certainly be helpful as well as any suggestions for cure. Thank you in advance for your time and consideration. Matthew

A: Matthew- Megacolon is very different in dog than it is in cats. I am not able to explain the differences because I don't really understand why the problem occurs in cats or in dogs unless there is an obvious cause like an obstruction, tumor, etc. Someone probably can explain this but if so, I haven't found a really clear explanation in any texts I have!

Anyway, the major difference in treatment is the general success of surgery for this condition in cats and the lack of success for surgical correction in dogs.

Cisapride (Propulsid Rx) has been recommended for this condition but I have seen articles saying it should not be used or is ineffective, too. Personally, I'd be hard pressed not to try it if I was treating a dog with this condition because there are few alternatives. There may be benefits from using ranitidine (Zantac Rx) or nizatidine (Axid Rx) may help with this by increasing intestinal mobility, according to information posted on the Veterinary Information Network. These were the only two medications of this type mentioned (famotidine, Pepcid Rx, and cimetidine, Tagamet Rx are other medications in this this group of "H2" blockers but the post suggested that the Zantac and Axid may be the only ones with this effect.

I know this isn't much help. You have worked hard to get good advice and I wish there was more to give.

Mike Richards, DVM


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...