Gastrointestinal dilation or bloat in rabbits is a dreaded, life-threatening emergency condition that occurs when a rabbit’s gut, especially the stomach and intestines get filled with gas and fluids causing a distention.
The distention is often caused by a sudden obstruction mostly at about 5-8 centimeters from the stomach or on the ileoceco-colonic junction, where the small intestines meet the cecum. 
Causes and how does it occur?
The delicate hindgut digestive system of rabbits and their inability to vomit (burp or eructate or let anything out from the stomach to the mouth due to a tight sphincter or valve proximal) predispose them to bloat.
Besides the lots of saliva produced in the mouth to moisten food being eaten and help in digestion, the stomach also produces a lot of fluids for the same reasons. Due to an obstruction, the fluid may be unable to leave the stomach and it gradually fills it up. Afterward, there is a bacterial overgrowth in the stomach, mainly the gas-producing bacteria which will produce gas.
This accumulation of fluids, including saliva, those produced by the stomach, and the gases produced by bacteria will with time make the stomach dilated (balloon-like full) - bloat.
The obstructions in the intestines are often caused by ingested things, including fur that forms a hairball (long-hair breeds such as the angora rabbits are vulnerable to hairballs) or other materials including carpet, rubber, plastics, cloth fibers and so on, coupled with low fiber diets. Also, obstructions can be due to tumors and abscesses. 
Other possible causes include low fiber diets, excessive drinking, pyloric blockage, gastric ulcers, exercising immediately after eating and excessive eating. 
This distressful and painful condition should not be confused with GI stasis or ileus which occurs due to the slow down or cessation of gut motility or movement.
Finally, since the stomach wall of rabbits is not as elastic as in many other animals  the dilation stretches stomach walls and prevents blood flow and this makes it to slowly die off. Also, the dilation can affect blood flow to other vital organs including their kidney and heart.
Bloat in rabbits symptoms
Bloating happens all over a sudden and your rabbit may die within a short time. To know if your rabbit is bloated, you need to look at the various symptoms which include the following:
- Sudden loss of appetite and refusal to eat (anorexia)
- Distention and severe abdominal pain characterized by teeth grinding, reluctance to move or a hunched posture.
- Breathing difficulties and a rapid heartbeat.
- Depression and stress
- Reduced or lack of fecal matter
- Your pet may lie down in a stretched posture with little response to any stimuli
- Hypovolemic shock and heart failure
If there is no treatment, your pet may succumb to death after a period of between 4 to 24 hours. Owners who do not regularly check their bunnies you will suddenly find the affected one dead without any signs of illnesses.
Diagnosis is through physical examination, abdomen palpation as well as looking at some of the clinical symptoms that your rabbit has.
Radiographs such as X-rays may be taken to help determine bloating severity. Additionally, blood work to determine the blood sugar level can also essential in the diagnosis of this condition.
Treating bloat in rabbits
Bloat in rabbits needs an emergency response. The rabbit needs to be hospitalized and aggressively treated. The main objective of the treatment is to stabilize the affected animal physiologically before surgical and other treatment options are considered. Treatment options will include:
- Massage in the direction of the anus to help dislodge the blockage if it is not so severe
- IV fluid therapy to help correct electrolyte balance and dehydration
- Gas decompression to help relieve pain, which will include fluid aspiration using orogastric intubation to help relieve pressure on the cardiopulmonary system and the gut.
- Surgical intervention to remove the obstruction after stabilization
- Antibiotic therapy at around the time of surgery
- Analgesics to help relieve pain such as buprenorphine hydromorphone, oxymorphone, or butorphanol before and after surgery
- Dimethicone to help break the gas
- Appetite stimulants
- Gastrointestinal motility stimulant agents
- The syringe or tube feeding using Oxbow Critical Care for Herbivores, or EmerAid Herbivore
After treatment, the patient may be hospitalized and monitored for several days until he or she recovers completely. The vet will also monitor the urine production for the first three days as kidney failure is common after surgery.
Some of the possible complications of gastric dilation include gastric rupture, kidney failure, and GI stasis if the rabbit does not eat. Finally, the prognosis is poor to guarded.
How to prevent bloat in rabbits
As we have seen, bloating in the rabbit can cause sudden death. Therefore, you need to ensure you have adopted some preventive measures to reduce the chances of it happening. Some of the preventive measures include:
- Provide your rabbits with the recommended diet, which must be high in fiber and low in carbs and sugars. Increase grassy hay and reduce pellets. Go for brands such as Kaytee Timothy Hay or Oxbow Timothy Hay.
- secondly, foods such as dandelion, celery, dill will help increase appetite  which will reduce possibilities of other conditions such as GI stasis.
- Regularly groom your pet by brushing it to remove loose fur that would otherwise be ingested as it tries to self-groom.
- Consider getting rid of other ingestible materials in areas that your pet can access.