Uroperitoneum in neonatal foals has been described several times and t
he clinical signs have been well documented The condition presents a c
hallenging diagnosis because the early signs are often minimal. The fa
ilure to recognise it results in a delay in the surgical treatment and
may be the most critical determinant of case fatality. In this case,
rupture of the neonatal bladder was diagnosed in 4 day old male foal.
Marked hyponatrsemia, hypochloraemia and hyperkalaemia developed and t
hese electrolyte abnormalities were considered to be of potential diag
nostic value. The BUN concentration was normal and of no use in diagno
sis. The clinical signs of this case together with the metabolic distu
rbances of diagnostic value are described and compared with the findin
gs in previous cases.