Bloat in Rabbits

by L. Seeman, MSN (January 2004)

One of the most disturbing conditions any bunny parent will face is GI Stasis. This condition usually develops gradually, is marked by a slowdown in GI motility, and now offers a good prognosis since a proven medical protocol has been established. The best advice I can give anyone is to follow Dana Kremple's guidance in her article, "GI Stasis: The Silent Killer."  This article provides crucial and lifesaving information for anyone helping their buns through this ordeal.

I contend there is an even greater threat, and one that is more difficult to recognize: Bloat. My husband and I faced this frightening ordeal with our 5-year old minilop Pokey in July 2002. One day he was fine and the next day he almost died. Since then, I have made it my focus to learn everything I can about this poorly recognized and usually fatal condition. I have seen more buns succumb to bloat in the past year, making me realize how important it is to educate as many people as possible. I have conducted a literature review, albeit limited, and spoken with many people in an effort to understand and try to make sense of this condition. The only mention of bloat in the literature is from the UK, most notably by veterinarians Paul Flecknell and Frances Harcourt-Brown. I have based this paper on this literature, but have also taken some liberties based on my personal experience, and my professional education and training. The rabbit's GI tract is subject to many threats by its very nature. It remains my belief that bloat is an entirely different phenomenon from GI Stasis, one that requires immediate veterinary intervention. Here's our story.

One day, our minilop, Pokey, was eating, drinking, eliminating and playing normally. The next morning we noticed he had not eaten his 11PM salad from the night before. He was hunched up in the back of his room and didn't want to come out and run which was very unusual for him. I immediately checked for bowel sounds (which were diminished), gave him some simethicone that he did not respond to, and called our vet. Our vet examined Pokey that same morning and confirmed my suspicions of GI Stasis. Pokey's temperature was 99.4F with an ear thermometer (this was a significant finding, but was not addressed at the time). His abdominal x-ray revealed an overly distended stomach with a huge, well-defined gas bubble inside the stomach. In comparison, this x-ray was a lot different looking from Pokey's previous x-ray during an episode of GI Stasis. I had never seen anything like this in rabbits despite looking at years of rabbit x-rays in my vet's office. And it developed overnight! Pokey was sent home to reduce the stress of being at the vet's. We gave him subcutaneous fluids, simethicone, and limited his food intake to just hay and water.

Pokey continued to lie around for a few more hours and then we heard his teeth chattering. It was such a loud noise, I didn't realize what it was at first. I grabbed him out of his room, took his rectal temp, which was 97.7F, placed him on a heating pad, and called our vet. Within minutes we were sure Pokey was going to die. His eyes were dull, he was having trouble regulating his temperature, his breathing was fast and labored, and the pain was overwhelming him. My husband and I rushed him to the vet, wrapped in towels. They were waiting for him and immediately gave him a shot of Torbutrol (butorphanol) for pain. His rectal temp had increased to 100F. That's when my vet told me if Pokey were a dog, she would think he had bloat. This condition is a medical emergency that many dogs and cows succumb to. The prognosis is poor in rabbits.

Fortunately, and rather miraculously, with continuous at home care aimed at relieving the symptoms, Pokey recovered. Other buns have not been so lucky. I believe this is because most vets in this country do not realize or understand that bloat exists in rabbits. Pokey's story is not unusual. Since his bloat episode, many people from across the country have contacted me with similar stories. After 2 foster rabbits developed bloat and died within hours of its onset in September 2003, I realized how imperative it is to get this information out.

GI Stasis VS Bloat:

Having cared for many rabbits through the years, I have witnessed GI Stasis and Bloat. There are subtle differences between the two conditions, but prompt recognition and treatment determine the outcome. Whereas GI Stasis has a prognosis of fair to good, the prognosis for bloat is poor to guarded.

GI Stasis develops slowly, and it is usually several days before you suspect that something "isn't right" with your bunny. You may begin to notice that he eats his food more slowly, or may even leave his food and come back to it later. Food preferences may change and you may find him preferring hay to his usual meal of pellets and fresh veggies. By the time this happens, your bun is most likely on his way to developing stasis. In my experience the first real indicator that your bun "isn't right" is in his litter box. Subtle changes in fecal pellets, that is, a smaller size, a change in shape from perfectly round to oval, a change in consistency or quantity, often indicates a disruption in digestion. This is the reason it is so important to know what is "normal" for your bunny. It helps you identify the "abnormal" more quickly. While there are many reasons for GI Stasis to develop, you usually have time to get to the vet and initiate medical treatment of subcutaneous fluids, simethicone, analgesics for pain, and possible motility drugs if there is no indication of an obstruction.

Unlike GI Stasis, bloat happens suddenly and without warning. One minute your bun is eating, drinking, eliminating, and playing normally, the next minute he is depressed, moribund, and stops eating, drinking, and playing. Just like that. A bunny rapidly decompensates with bloat, and immediate veterinary intervention is crucial to his survival. A lower than normal body temperature (under 100F) usually occurs causing the bun to go into shock. Current literature from the UK reveals bloat is caused by a blockage or obstruction in the GI tract, that may be due to a foreign body (carpet) or tricobezoar (hairball). During postmortem exams on rabbits whose cause of death was GI Stasis or bloat, Dr. Paul Flecknell found an obstruction at the exit to the stomach (pylorus or duodenal flexure). The tissue at this site was often dead (necrotic). He also found instances in which the lining of the stomach had eroded with bleeding present. While not specifically documented, this creates the possibility that ulcers and/or scar tissue could be precursors to bloat. A study by Hinton (1980) showed 7% of all rabbits necropsied had gastric ulcers. Considering the nature of rabbits as prey animals, it makes sense that rabbits could and do develop stress ulcers. It is known that gastric ulceration in rabbits can develop form pain and fear due to catecholamine (epinephrine) release, and also with reduced gut motility such as repeated episodes of stasis. I realize this is mere speculation on my part, but believe this is possible and that more research is needed.

Diagnosis:
Upon physical exam, symptoms of bloat include dehydration, an "abnormal" feeling abdomen, that is, distended from an accumulation of gas (tympany), and a low body temperature. While blood work may be also be done, an abdominal x-ray is the most diagnostic tool. X-rays carry a significant risk in bloat because the rabbit is often on the verge of cardiovascular collapse due to the pressure the gas places on the chest cavity. Care must first be taken to stabilize the rabbit with fluids and pain meds. It is my experience that rabbits often become non-responsive due to the electrolyte imbalances, pain and shock associated with this condition. Harcourt-Brown states electrolyte imbalances may cause the rabbit to experience twitching, blindness and convulsions in the terminal stages of this condition.

The x-ray of a rabbit suffering from bloat reveals a hugely distended stomach located in the upper abdominal area, and may also reveal gas shadows in the small intestine closest to the obstruction. The enlarged stomach places pressure on the chest cavity and compromises lung and heart function. The compression of the chest cavity makes it difficult for the rabbit to breathe, and often leads to heart failure (cardiovascular collapse). However, heart failure is usually secondary to the gas buildup in the stomach and may be the reason bloat is often misdiagnosed.

Treatment:
Since Pokey's bloat episode, I have been fortunate enough to have my personal vet research and establish a medical protocol for bloat that increases the rabbit's chance of survival. While treatment is not always successful, it provides the rabbit with relief from the gastric distention, and pain medication to deal with the excruciating pain of bloat. This is a comfort to me and I am very grateful to her. None of the other vets in the Washington, DC-Metro area, including the many emergency vet hospitals that treat rabbits, provide this life saving treatment.

When the diagnosis of bloat has been determined, the rabbit needs to be given warmed Lactated Ringers solution,preferably intravenously. Rabbits cannot absorb subcutaneous fluids when they are in shock. In addition, an external heat source to regulate body temperature, and analgesics for pain are also necessary. Once the bunny's condition is stabilized, a stomach tube is placed to decompress the stomach. My vet usually uses a red rubber catheter (Fr 15). A 20 cc syringe usually provides enough suction to withdraw the stomach contents manually. A rabbit's mouth and esophagus limits the size of the stomach tube that can be inserted, so that in many cases the small sized tube becomes clogged with food particles and fur. If this happens, the tube needs to be repositioned and gently irrigated until the stomach contents are withdrawn. A rabbit's stomach should never be decompressed with a needle puncture, or peritonitis and death can occur.

When the rabbit responds to treatment, he can be given simethicone and have gentle abdominal massage to break up the gas bubbles. As improvement continues he should be encouraged to engage in some mild exercise to reestablish normal GI movement, and provided with a wide variety of veggies to encourage eating. Interest in exercise and eating is a good prognostic sign. There is a possibility that gastric distention associated with bloat can recur. I know of one bun who re-bloated 2 more times during a two-day period and eventually succumbed to this condition. Usually if a rabbit bloats a second time within a two day period, my vet encourages euthanasia. Surgery to remove the obstruction should only be used as a last resort.

What To Look For:
This article was originally written in layman's terms so everyone would be able to understand the phenomenon of bloat. I now realize the importance of sharing this information with your vet and have included more comprehensive and technical information. However, if you are unable to get to a vet in time, or unable to find a vet willing to tube your bunny, the following is what I learned when Pokey went into bloat and the symptomatic treatment I provided.
1. Be alert to a very sudden change in eating habits. If your bun stops eating his usual meal of pellets and veggies without warning, give him simethicone and call your vet immediately.
2. Check your bun's temperature with a rectal thermometer. The ears regulate the the body temperature. If they start to feel cool to touch, chances are his body temperature is falling. A normal rabbit temp is 102-104F. Any temp under 100F is a medical emergency. This usually means the rabbit's system is shutting down and he is going into shock. Grab a heating pad (on low), and wrap it around your bun. When you transport him, wrap him in warm towels to maintain his body heat.
3. Get your bun to the vet immediately! Often the pain is so great, the bun gives up. A shot of pain medicine was crucial to Pokey's recovery.
4. Fluids are necessary to keep the bun hydrated and to help overcome shock. The quickest and least stressful way to accomplish this is with subcutaneous fluids. Your vet can show you how to do this at home. If your rabbit's condition is too far deteriorated, IV fluids are necessary because subcutaneous fluids cannot be absorbed. Simethicone is necessary to relieve gas buildup. Laxatone is often prescribed but its use is controversial. We gave Pokey a small amount of Laxatone after he was hydrated and it seemed to help. Additionally, Metaclopramide or Cisapride activates the GI system. DO NOT give this without your vet's knowledge because the stomach can rupture if an obstruction is present.
5. Keep your bun in a warm environment. We placed Pokey in a small room upstairs and closed the vent to the AC. The room temperature was 81F all night. I believe this helped him to stay warm.
6. Give your bun a small area to run. Pokey was allowed to roam around if he wanted to, which he did. Exercise encourages the GI System to move. In addition, a gentle stomach massage can help break up the gas as well.

The next morning (Day 2) Pokey's temperature was 102.4F and he started to eat hay and passed tiny, misshapened fecal pellets. As previously mentioned, I gave him a large dose of Laxatone, which helped him. By noon, he passed a few blobs of foul smelling goop and then passed gas the rest of the day. His bowel sounds became more active and the next day we started feeding him pellets that he ate directly from his food bowl. His diet was gradually advanced and by Day 4, Pokey was back to normal. In comparison, it took 2 weeks of constant home care and daily treatment before he recovered from GI Stasis last year.

Having been through these two medical situations with Pokey in the last 1-1/2 years, I firmly believe Bloat can be a primary disorder which can occur suddenly and without warning, as well as a complication of GI Stasis.

A special thank you to Wendy Behm, DVM at Blue Ridge Veterinary Associates in Purcellville, VA (540-338-7387) for reviewing this article.

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