iStock. Courtesy of the Humane Society of the United States (HSUS) 

Rabbits have very complicated digestive tracts. This allows them to utilize a high-fiber diet that humans cannot. They have a very large cecum, which is a pouch at the opening to the intestine and which is filled with millions of bacteria to aid in the digestive process.

The cecum is the dark horizontal cylindrical object toward the bottom of this radiograph. The white circular area to the far left is the stomach. Photo courtesy of LBAH.

This may be unpleasant to read, but rabbits even eat their feces at night in order to help keep this population of bacteria happy. It’s when we feed diets that have too many calories and not enough fiber that the problem called gastrointestinal (GI) stasis starts.

High fiber in the form of timothy hay gives rabbits enough bulk to stimulate the intestines and stomach to push the food along. The hay also supplies the bacteria. Any hair or fiber that normally builds up in the stomach from grooming will be pushed along and not cause a blockage.

When this problem was first recognized decades ago, it was thought that the hair and fiber coalesced into a ball in the stomach was the primary problem. The hair-and-fiber ball would be surgically removed until it was realized that the problem resulted from not enough fiber in the diet and not blockage from the ball. This lack of fiber in the diet caused the intestines to stop pushing food along (peristalsis), leading to stasis. Thus, the disease is called GI stasis.

Rabbits that do not eat and do not produce droppings need to be seen immediately if their lives are to be saved. A knowledgeable vet will give them pain medication, fluids, assistance with feeding, antibiotics, and medication to promote movement of the intestines. Most rabbits recover, but if they’re brought in after being ill for several days, they may not respond to treatment and may pass away.

There are several important things you can do aside from feeding timothy hay to prevent this. Minimize stress resulting from overcrowding and overheating. Rabbits can tolerate excess cold but are sensitive to heat. On warm days, keep housing cool with air conditioning or a fan. Keep the environment clean, and provide fresh water at all times.

The most important thing you can do is to observe your rabbit closely and bring it in at the first sign of any problem. We have a very detailed web page dedicated to GI stasis.