Obstipation and Megacolon in Dogs

This condition can cause a blockage of feces and it is most common in middle aged cats and dogs with geriatric issues. Medically, this disease is touted as a hard extrication of feces from the animal’s colon or large intestine. If you find that your dog is having a hard time passing stool or shows signs of lethargy, it is possible that your pet is experiencing obstipation and megacolon. The veterinarian will be able to detect this condition and confirm it for you. Unfortunately for your pet, once obstipation is diagnosed, then you have to deal with megacolon, which is the subsequent result of having obstipation. In this case, take your pet to the veterinary specialist immediately as it can get worse.

Megacolon and obstipation refers to dogs that have waste in the colon, and are experiencing difficulty passing the stool, resulting in an abnormal colon distension that is usually associated with severe constipation.

The first warning sign that your pet is having problems starts with the normal constipation. If you have identified that it is no longer routine, especially if you monitor your pet’s normal elimination cycle, you should consider going to a veterinary specialist. In the meantime, some of the signs to notice are:

• Straining to pass feces
• Passing less stool than is normal
• Loss of weight
• Producing harder or drier feces
• Vomiting
• Lack of appetite
• Indoor defecation instead of outside
• Liquid stool in small amounts
• Bloody stool
• Stool with mucus
• Dehydration

All breeds can be affected by this condition. The type of diet that you feed your pet could be an instigator.

Megacolon, in some cases, can occur after a large amount of stool leaves the colon distended and the nerves are permanently damaged in the large intestine. An example of how this may occur is trauma to the dog’s pelvis. This would result in obstruction of the normal passage of the stool. However, any condition that results in the purposeful obstruction of feces will definitely cause megacolon. Other causes may be:

• Tumor
• Medication that causes constipation
• Painful elimination of stool
• Obstruction in the intestine such as a hair mass
• Spinal issues (some breeds may be predisposed)

Diagnosis of this condition is usually commenced by observation. The pet owner must take notice of the dog’s defecation habits. One of the above symptoms should lead you to seek veterinary assistance. Once your pet is in the care of the veterinarian, a physical examination will be done. The examination will include palpating the abdomen to see how firm it is. An x-ray will also be done for further evaluation and to assess the severity of the obstipation. The veterinarian will need your dog’s medical history to see if this has ever happened in the past, or whether any associated condition could cause the problem. The veterinarian could also use the medical history to detect any underlying issues. Some tests that could be used in the diagnostic process could include:

• Neurological exam  
• Blood count
• Colonoscopy
• Urinalysis
• Biopsy
• CT scan
• Biochemical profile
• Barium study

Treatment of this condition could involve surgery, especially in severe instances. Subtotal colectomy is one of the best approaches to this chronic disorder. However, some veterinarians will use other measures before considering surgery. These would include:

• Diet with high fiber
• Frequent intravenous hydration
• Enemas
• Removing feces on a frequent schedule
• Psyllium
• Laxatives
• Cisapride, which is a medication designed to put the colon back in good working condition
• Lactulose is a sugar syrup that softens the stool

With the treatment of any underlying disorders that may cause obstipation leading to megacolon, the prognosis can be positive. However, constipation that continues to remain a problem despite dietary changes and medication may lead to permanent stretching of the colon. Surgery to correct the megacolon may mean permanent loose stools or even diarrhea; however, with veterinary advice the condition can be a manageable change in your pet’s life.