Dandy-Walker-Like Syndrome in a Quarter Horse Colt

A 6-hour-old Quarter Horse colt was examined because of an inability to rise. An uneventful parturition after a normal gestational length from a multiparous mare was reported by the owner. The colt was administered dexamethasone (4 mg) and gentamicin (400 mg) IV and mare’s colostrum (900 mL) PO before referral. Upon examination, the colt (59 kg) was depressed and recumbent. The rectal temperature was 97.6uF, heart rate was 110 beats/min, and the respiratory rate was 40 breaths/min The colt had a prominent domed forehead, but no other significant abnormalities were detected on physical examination. Hematologic and biochemical abnormalities were limited to an increased hematocrit (53%; reference range, 37– 49%), hypoproteinemia (4.3 g/dL; reference range, 5.1– 7.6 g/dL), and an increased serum creatine kinase activity (1597 U/L; reference range, 65–380 U/L). Results of the arterial blood gas analysis were normal. Initial treatment included fluids (500 mL 0.45% NaCl IV q2h), mannitol (1 g/kg IV q12h), amikacin (25 mg/kg IV q24h), ceftiofur (10 mg/kg IV q12h), equine plasma (1000 mL IV once), and feeding via a nasoesophageal tube (500 mL mare’s milk q2h)