Gastrointestinal (GI) disease is the most common and most serious health concern in domestic rabbits. The rabbit digestive system is highly specialised and sensitive — small deviations from appropriate diet or husbandry can trigger life-threatening GI stasis or other disorders. Understanding rabbit GI physiology is foundational to good welfare provision.
Rabbit GI Physiology
Rabbits are obligate hindgut fermenters. Their digestive system evolved to process large volumes of fibrous vegetation. The caecum — a large fermentation chamber — hosts a complex microbial community that digests fibre and produces caecotropes (soft night faeces) rich in vitamins and nutrients that rabbits reingest directly from the anus. This process (caecotrophy) is essential for nutritional health and must not be disrupted.
GI Stasis
GI stasis (ileus) occurs when gut motility slows or stops. It is frequently life-threatening and can kill within 24–48 hours. Causes include:
- Inadequate hay intake leading to insufficient gut fill and fibre fermentation
- Pain from any source causing gut motility reduction
- Stress (predator exposure, sudden environmental changes)
- Dental disease causing reduced eating
- Dehydration
Signs include reduced or absent faecal output, hunched posture, tooth grinding (bruxism), abdominal distension, and inappetence. Immediate veterinary attention is required.
Diet and GI Health
Hay must comprise 80% or more of the diet — equivalent in volume to the rabbit's body size daily. Hay provides the indigestible fibre that maintains gut motility and wears teeth appropriately. Commercial pellets should be limited (1–2 tablespoons per kg body weight per day). Fresh leafy greens (not iceberg lettuce) can be offered. Sugary treats, bread, and fruit should be avoided or strictly limited as they disrupt caecal microbiota.
Dental Disease and GI Connection
Rabbit teeth grow continuously throughout life. Dental malocclusion (overgrown incisors, molar spurs) causes pain that reduces eating, leading to GI stasis. Regular veterinary dental checks (annually at minimum, more frequently in lop breeds) are essential. Diets high in hay naturally wear teeth appropriately and reduce dental disease incidence.
Other GI Conditions
Caecal dysbiosis: Overgrowth of Clostridium or E. coli causes diarrhoea (true diarrhoea, not soft caecotropes) and can be fatal in young rabbits. Associated with high sugar/starch diets.
Intestinal obstruction: Fur balls (trichobezoars) can occasionally cause obstruction; regular grooming and sufficient hay reduce risk.
Bloat: Gas accumulation in stomach or caecum is an emergency requiring immediate veterinary treatment.
Husbandry Welfare Implications
GI welfare in rabbits is inseparable from overall husbandry quality. Unlimited hay access, appropriate companionship (reducing stress), adequate space for exercise (promoting gut motility), and regular veterinary dental assessment are the pillars of GI health maintenance. Rabbits showing any sign of reduced food intake or faecal output should receive veterinary assessment within hours.