Salt poisoning in calves due to feeding of highly concentrated milk re
placers or incorrectly reconstituted oral rehydration solutions have b
een described. This paper reports the circumstances on the farms and t
he clinical findings in eight calves that were admitted to the clinic
for diagnostic reasons. In the majority of cases, mainly fever and res
piratory signs that were refractory to antibiotic treatment were menti
oned in the history. Upon admission to the clinic the calves exhibited
highly elevated respiratory rates and increased lung sounds (but no a
dventitious lung sounds), congested mucous membranes, ''injected'' scl
eral blood vessels, as well as abnormal posture and behavior. Marked c
entral nervous abnormalities were evident during the course of the dis
ease in two calves. In all eight cases, milk replacer concentrations w
ell above the recommended level were identified as the cause of the sa
lt poisoning. However, the essential element common to all cases was t
he fact that the animals did not have free access to water. The safest
way to lower sodium blood levels in calves that still drink seems to
be the feeding of whole milk or of milk replacers in normal concentrat
ion, in amounts that meet fluid requirements. Water should not be offe
red until blood sodium levels have returned to normal (135-150 mmol/l)
.