Clostridium botulinum Dysautonomia: Grass Sickness
Domestic rabbits, wild rabbits, and hares may spontaneously develop sudden acute gastrointestinal hypomotility and dysphagia with mortality. At necropsy, the large intestine is impacted with variable small intestinal firmness. Mucoid enteropathy may also be present. Such cases warrant examination of pre- and postsympathetic and parasympathetic neurons of the myenteric and submucosal plexes, as well as somatic and autonomic lower motor neurons in the brain stem and spinal cord. Neurons reveal neuronolysis and neuronal central chromatolysis. Lesions are similar to those of equine dysau- tonomia, or “grass sickness” caused by Clostridium botulinum toxin. Botulinum toxin has been confirmed in the gastrointestinal content of 1 case in a wild rabbit.