of Veterinary and Pharmaceutical Sciences in Brno,

Dysphagia is difficulty in eating or swallowing feed or water despite having good appetite. The cause of dysphagia in horses may be a painful pathological process in the mouth, obstruction in the oral cavity, pharynx or oesophagus or a neurological problem (Baum et al., 1988a,b). Clinical and neurological examination, endoscopy of the pharynx, oesopha-gus and guttural pouches as well as haematological and biochemical analysis are usually necessary to establish the cause of dysphagia. Selenium/vitamin E deficiency, the cause of the white muscle disease in foals (Lofstedt, 1997), was thought to be responsible for the masseter myode-generation and resulting dysphagia in adult horses in the papers published by Step et al. (1991) and Pearson et al. (2005). Three cases of dysphagia caused by myodegeneration of masticatory muscles that were diagnosed at the Equine Clinic, Universit