Bloat in Rabbits

Photo by Albo|Shutterstock.com

Simply put, bloat (or gastric dilation) occurs when there is a blockage somewhere in the small intestine, preventing stomach contents from moving through the digestive system. Since rabbits are unable to vomit or burp, the obstruction causes fluid and gas to accumulate with no place to go. This is different from GI Stasis! GI Stasis is a slowdown of the GI tract and may happen for a variety of different reasons. It is a symptom which can indicate that the rabbit is sick due to an infection, injury or health condition (such as overgrown teeth), stress or bad diet. There is no blockage in the GI tract.

Many different species can experience bloat (for example in dogs the stomach can twist, trapping the contents inside), but for rabbits, the cause is frequently an object trapped somewhere along the small intestinal tract. This object is often excess fur - especially during periods of heavy shedding, but it can be something foreign, such as carpet fibers, hard plastic, or certain foods like corn kernels. For those with chronic dental issues or long-haired breeds whose coats are not frequently brushed or shaved, the bunny may swallow a thick mat of fur that can cause problems.

Adhesions after human appendectomy.
Hic et nunc Public Domain via Wikimedia Commons

Certain diseases can also contribute to bloat. Adhesions, hernias, abscesses and neoplasms can externally compress parts of intestinal tract (Quesensberry, et al. 2021). 

Adhesions are bands of fibrous tissue that connect either two or more organs together or they may connect organs to the abdominal wall. These form as a response to tissue injury which may happen due to open abdominal surgery (such as a spay), or inflammation due to an infection somewhere in the abdominal cavity or the spread of cancer. If adhesions form around the bowel, the bands can twist, pull or clamp down on the intestine like a vise. Abscesses, inflammatory lesions, and tumors can cause an obstruction anywhere in the GI tract (Harcourt-Brown 2002). 

There is always fur in a rabbit's gut, which typically moves through the GI tract with no problems. The problem becomes when mats of fur get swallowed while the rabbit is grooming themselves. Long-haired rabbits are at higher risk and need frequent grooming.
Photo by Eric Isselee/Shutterstock

Veterinarians have a more precise way of diagnosing an obstruction. They are better at palpating the abdominal area than the average owner, and can estimate where the source of the obstruction lies. X-rays and ultrasound of the abdominal area may give details such as the precise location of the obstruction, the presence of gas, liquid, etc. However, if the patient is not stable enough for sedation, x-rays may not be done until later. 

Initial blood work will give the vet a great deal of information.

• What is the PCV/TS (Packed Cell Volume/Total Solids) values? Is the bunny anemic and/or dehydrated?
• What are the values of the liver enzymes? Extremely high liver levels coupled with anemia indicate liver lobe torsion, which is another life-threatening condition.
• BUN and creatinine levels, which reveal kidney function, will be high in cases of bloat.
• What is the Blood Glucose level? This is used as a prognostic indicator. If blood glucose levels are slightly elevated, this could mean that the bunny is just in GI stasis. Much higher levels confirms an obstruction and the seriousness of it. The higher the number the more aggressive the treatment will need to be. 

The photos on the left side (top and bottom) show the gas patterns and the size of the stomach at the beginning of treatment. On the right side (top and bottom) the images show what the stomach and intestines look after 4 hours of treatment.
Photos courtesy of Dr. Sari Kanfer Exotic Animal Veterinary Center.

Multiple x-rays will track the movement of the obstruction. The gas patterns should shift further down the intestines if medical treatment is working and the obstruction is making its way out. If movement is not seen, surgery may be advised as it suggests that the obstruction is either stuck or there may be some external factor such as a tumor, abscess or adhesion present.

During surgery, the vet may be able to move the obstruction manually or cut it out entirely. The decision will depend on the location of the obstruction and/or the condition of the intestine. If large portions of the small intestine show signs of necrosis, the prognosis of recovery is poor and the vet may recommend euthanasia. However surgery is not always necessary and carries significant risks. In fact, most cases of bloat are successfully treated with aggressive fluid treatment, pain management and stomach decompressions. 

Photo by Sasha_Wilks/Shutterstock

A proper diet of hay, veggies, plenty of fresh water and exercise will reduce the chance of illness in your bunnies, but will not eliminate it completely. Some rabbits may be genetically predisposed for GI issues, and some - at some point in their lives - will put something in their mouths that does not come out the other end. 

Since fur is a frequent culprit for bloat, making sure your bunny is regularly groomed is essential. A word of caution though, do not comb your bunny until he is bald, and his skin is irritated and bleeding. Stressing your bunny out can lead to GI stasis and damaging your bond with your pet. A better solution is to have shorter (10-15 minutes) - but more frequent (every 2-4 days) combing sessions during heavy shedding periods.

Some veterinarians may also recommend Laxatone hairball remedy during shedding periods to help excess fur pass more easily through the GI tract. This may be a good solution for those bunnies who readily and frequently bloat during heavy shedding cycles. 

As caretakers, we can reduce the risk by avoiding mixed-pelleted brands and treats that include seeds, corn kernels, peas, etc. Bunnies usually love to pull up carpet and chew up towels. Most of the time when they pull out the fibers, it is deposited into a pile. If they start eating large pieces of towel, carpet or excess amounts of cardboard, you need to remove the object or (in case of carpet) keep the bunny away from that area. 

Bunnies with chronic dental issues are particularly at risk. Provide a high fiber diet (if your bunny has few to no teeth, make sure to provide a high quality supplemental feed like Critical Care). For both dental and long-haired bunnies, please make sure they are regularly groomed (at least every 6-8 weeks, more frequently if it is shedding season).

It's important that we always keep an eye on our bunnies. Many health issues are time sensitive, and none more so than bloat. This illness is not something that can be solved at home. As soon as you suspect your bunny may be in distress, contact a vet as soon as possible.