A 17-month-old Holstein Friesian heifer was presented after one day with dysphagia, slight paralysis of the tongue and swelling of the eyelids. Clinical examination of the animal revealed an extended posture of the head and neck, severely increased salivation, reduced lingual tone and mandibular paralysis with complete absence of the swallowing reflex. The right eye showed a drooping eyelid, mucopurulent discharge, exposure keratitis, corneal opacity and miosis. On the left side, a moderate exophthalmos and slight mucous discharge from the nostril were observed. Neurological examination revealed the absence of multiple cranial nerve reflexes suggesting a pituitary syndrome. On X-rays, a soft-tissue opacity with sharp margins and a diameter of approximately 5 cm was seen. It was located ventral to the ethmoid bone with possible intraneurocranial origin. Rhinoscopically, a mass located distal to the ethmoid bone with an uneven, slightly reddish surface partly covered by purulent exudate was visualised. Post-mortem examination of the euthanized animal confirmed neoplasia, which ranged from the fossa hypophysialis of the corpus ossis basisphenoidalis to the ethmoid bone. Histopathologic findings matched a small, round, blue cell tumour.
Keywords: Mandibular paralysis; bovine; cranial nerve lesions; tumour.