Neuroma formation following partial beak amputation (beak trimming) in the chicken.

Branches of the trigeminal nerve, which innervates the beak in the chicken, were damaged after partial beak amputation (beak trimming) and degeneration in the nerve extended from 2 to 3 mm proximal to the cut stumps. Within 10 days the damaged nerves showed regeneration and axon sprouts had been formed. This neural regeneration was rapid so that by 20 to 30 days bundles of regenerating fibres were present and neuromas formed adjacent to the scar tissue of the stump of the beak. These neuromas became more extensive over the 70 day observation period.