The presence of fur within the stomach is a relatively common finding, and is present through natural grooming. The fur becomes a problem when gut motility is reduced, which leads to gradual dehydration of the ingesta and a fur mass that can no longer be passed. The hairball is merely seen to be a secondary phenomenon, and the rabbit is depressed, anorectic, and shows obvious signs of discomfort. Foreign bodies Foreign bodies such as ingesta mixed with hair, carpet threads, pieces of plastic and rubber, clay based litters have the potential to occlude the gastrointestinal lumen and restrict normal movement of the gut contents.
Common sites are the junction of the pylorus and duodenum and the ileocaecocolonic junction.
Obstruction is often confused with ileus, but whereas ileus is characterised by a gradual onset of signs, obstruction is characterised by the rapid change from a happy healthy animal on one day to a severely depressed anorectic, producing no faeces the next. The animal often presents in shock, with moderate to severe hydration and so fluid therapy is required immediately. Contrast radiography can confirm obstruction and differentiate the masses. This can be differentiated from the gastric stasis patients where there is a distinct halo of air surrounding the food bolus, and much less fluid. An dysbiosis within the caecum, dehydration of the caecal contents, or reduced caecal motility may result in material remaining within the caecum and not being discharged into the colon as per normal.