Megacolon in Cats, Causes, Diagnosis,Treatment, Prevention

Megacolon in Cats
Megacolon in Cats

Megacolon in cats literally means enlarged colon. It happens when the large intestine is filled with fecal matter which causes it to enlarge beyond its normal diameter. Here is more:

Megacolon in Cats

Cats tend not to chew their food but rather swallow in chunks. Sometimes they chew on other foreign things such as strings, paper, hair that cause intestinal blockage.

Megacolon in Cats
Megacolon in Cats

The digestive process in cats takes about 8 -20 hours and before being eliminated.  This may also depend on the type of food: raw, dry and canned.

Given that a lot of cats don’t often drink a lot of fluids especially those that consume dry foods with no fiber, they may pass harder stools or experience constipation.  A cat can hold in feces for several days, however constipation in cat’s results from less water retention in stool and it is often overlooked and untreated for a long period. This is especially in cats that pass stool outside the home.

The connection from the small intestines to the anus is made possible by the existence of the colon which has contracting muscles.

The colon contracting muscles is responsible for:

  • Absorbing water and salts from the remnants and releasing it back to the body
  • Reservation of  waste before releasing it, which is done by the rectum
  • Transporting feces to rectum for elimination
  • Manufacturing of useful vitamins using bacteria available in the digestive tract

When does Megacolon Occur?

The accumulation of compact fecal depostis in the colon that are unable to push through to the rectum. Depending on the dehydration level of the cat, it may experience constipation.

Consistent constipation that is immune to medication may lead to obstipation where there is a loss of rectal function.

Obstipation may be too severe that it causes the colon to enlarged and stretched. The stretching may even be up to three to four times the normal size.

With an enlarged colon, the colon muscles are not able to contract thus don’t release the waste blocking the waste and gas passage; this may be deadly fatal.


Megacolon is contacted either through acquired or congenital causes:

Acquired causes

  • Severe untreated constipation
  • Severe dehydration
  • Idiopathic megacolon “a major unknown cause that accounts for sixty-two percent according to research
  • Low potassium levels
  • Poor diet
  • Inactivity
  • Lodged foreign matter in the large intestine such as hairballs, bones.
  • Voluntary retention of defecation by the cat especially if there lacks a litter box or it is too dirty
  • Side effects of drugs such as Barium, Antacids, Sucralfate
  • Pelvic canal tumors

Congenital Causes

  • Injury or lack of Auerbach’s complexes- nerves located in the muscle layer to allow for This accounts for at least six percent
  • Hirschsprung’s disease which affects the colon supplying nerves
  • Deformities to the spinal cord especially in Manx cats that account for at least five percent of the major causes of Megacolon
  • Narrow or fractured pelvic area
  • Colon inflammation after a surgery
  • Anal stricture or anal sac abscess
  • Neurological disorder resulting to problems with posture for bowel movements
  • Colon cancer

Symptoms of Megacolon in Cats

  • Lack of or infrequent defecation
  • Pain when passing stool also is known as dyschezia
  • Small, bloody, mucus-filled stool
  • Appetite loss
  • Abdominal pain and discomfort
  • Hard and very dry feces
  • Straining when passing stool also is known as tenesmus
  • Interrupted or prolonged moments when passing stool
  • Vomiting and possible diarrhea
  • An unkempt hair coat
  • Solid colon diagnosed through palpation
  • Weight loss
  • Ovariohysterectomy   that at times results in uterine horn fragments left in ovaries especially in female cats

Which are Cats Most Susceptible to Megacolon?

Cats of all gender, race, and age are prone to megacolon. However, the most susceptible cats are:

  • Short hair domestic cats
  • Long haired domestic cats
  • Middle-aged cats aged between 5-8 years
  • Male cats are at a higher risk with studies showing at least 70%
  • Obese cats
  • Siamese cats
  • Manx cats with spinal deformities
  • Cats with chronic constipation

How to Diagnose Megacolon in Cats

  • Blood work on general health
  • X –rays on abdomen and pelvis
  • Abdomen Radiography to best analyze the influencing factors and the impact on the colon
  • Chemistry panel or use of the biochemical
  • Thyroid test
  • Colonoscopy /endoscopy
  • Urinalysis
  • Biopsy
  • Ultrasound
  • Historical and physical examinations
  • Rectal penetration
  • Rectal palpation that identifies problems with pelvis and anus
  • Neurological and barium testing


The main aim in treating megacolon is having the large intestine cleaned out. Then find the underlying cause so as to prevent it accordingly. Note that treatment for megacolon largely depends on three factors:

  • How long the problem has existed
  • The severity of the problem
  • The underlying cause

Treatment for mild forms of megacolon

Mild forms may not require any kind of intervention at all. On the other hand, some mild to moderate cases require some form of treatment. Note that the most successful treatment involve a combination of several treatment options.

  • Increase the fiber intake in their diets using pumpkin, psyllium, wheat, rice bran
  • Use of fiber formula such as Royal Canin Gastro Fiber Response
  • Use of vitamins and minerals that are not contained in plain water
  • To best avoid cases of swallowing hairball that may cause blockage, Defurr-Um tasty treats can be ingested daily to inhibit fur ball ingestion. It contains chicken flavor and malt syrup.
  • Use of laxatives that will increase fat absorption while inhibiting water absorption (emollient laxatives, for example, dioctyl calcium and sodium sulfosuccinate.
  • Use of White Petrolatum and Mineral Oil that acts as lubricant laxatives and lactulose
  • Fluid therapy to hydrate and add fluid to stool
  • Stool softeners such as lactulose
  • Use of natural products such as Apricot Seed and Linum
  • Meat diets for severe megacolon disorder as cats are “obligated carnivores “intensely drawn to moist foods that are highly packed with amino acids
  • Ingestion of Similase a digestive enzyme supporter
  • Adoption of a highly digestible, low deposit diet where almost all is used up in the cat’s body and fewer remnants excreted.
  • Rectum lubrication using KY jelly or other forms of lubrication
  • Use of medication such as cisapride, Nizatidine, Miralax that contain prokinetic agents for colon muscle stimulation.

Major forms of treatment

  • Approved Enema using warm water and a catheter/ feeding tube
  • Manual extraction of fecal matter
  • Subtotal colectomy a surgical procedure that removes part of the affected colon to create a narrowed pelvis that will allow for passage of soft feces.
  • Total Colectomy where there is the removal of the whole colon to eliminate all chances of infection.
  • Widening of the pelvic area in cases where there is an abnormal narrow pelvis.

Cost of Treatment

  • The treatment for megacolon is an expensive process that costs $ 500-$6000 depending on the type of treatment chosen.
  • Basic treatment using aesthetics, enema, hospital admission and IV fluids may cost about $500
  • Medication such as cisapride may cost $1.50-$ 2 per capsule, and depending on dosage this may translate to $950-$1000 per year. This is without considering the diet expenses.
  • Surgery: Colectomy charges may cost between $1500- $1800 and this is considered as the best treatment though it might have some complications.


  • Moisture-rich diets such as leafy vegetables, beet pulp, rice, wheat bran and cat grass
  • Proper hydration. The whole idea is to keep the cat well hydrated therefore you can frequently add water to the cat food.
  • Use of digestive enzymes and probiotic that will improve the fermentation process.
  • Regular exercise to improve and retain the ideal body weight
  • Brush off your cat’s loose hair to prevent the formation of hairballs that may be swallowed during grooming.
  • Early correction of abnormal pelvic fractures within six months
  • Proper cleaning of cat litter box
  • Frequent combing of long-haired cats to eliminate excess hair, debris nad loose fur. This allows faster movement along the GI tract so as to prevent hairballs.
  • Regular use of laxatives that also act as hairball medication.

After Effects

After treatment, the cat may experience diarrhea, leakage of stool but it will get better with time though not perfect.

Cat euthanasia is an option for cats that do not respond to treatment.

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