What causes bloat in rabbits?
Gastric Dilation (aka "bloat") is sometimes confused with Gastro-Intestinal Stasis (aka GI stasis, ileus) or simple/uncomplicated gas. These three conditions are related but they have separate causes, appearances, and treatments.
Signs that your rabbit isn't well include if the rabbit is not eating anything, or not seeming very happy and not moving around like usual.
See the related links and questions below for details.
Bloat is a very sudden, very severe gas attack where the rabbit's stomach becomes extremely distended and hard. The cause might be bacterial, or something toxic the rabbit ate, or a blockage in just the right spot in the digestive tract (like from eating something that can't be digested properly). Immediate veterinary intervention is required or else the rabbit will die a very painful death. The condition is so serious, and the treatments so agggressive, that a rabbit suffering from bloat does not have a good chance of recovery.
GI Stasis takes longer to develop and the attentive rabbit owner can notice the warning signs; with veterinary care, the chance of recovery is high. GI Stasis results from the rabbit stopping eating: the reason could be pain from an injury, gas, dental trouble, shock from a traumatic event, a hairball or blockage, another illness, etc. Treatment includes belly massage, hydration, force-feeding, pain medication, and gut motility drugs, at least; other treatments may also be required, depending on whatever it is that caused the GI Stasis in the first place. If GI Stasis isn't treated by a vet, it will likely lead to a very painful death for the rabbit.
Gas can develop from certain foods the rabbit eats. Rabbit owners should pay attention to their rabbit's habits, notice what foods give the rabbit gas, and strictly limit those foods in the diet or eliminate them entirely. Certain foods are more likely to cause gas than others, like cabbage and broccoli. Gas can be treated with belly massage, exercise, and simethicone. If untreated, gas might go away on its own, or it might lead to GI stasis.
One person wrote: One of my rabbits had bloat and he died. This does not always happen if you take it to the vets as soon as you realise something is wrong. If your rabbit gets bloat do not blame yourself as this is a common thing and it is usually related to them eating wood, plastic ect.