The clinical, blood biochemical and autopsy findings on a cow affected by a 'non-alert downer cow syndrome' are described in detail and compared with brief clinical and biochemical details from six similar cases attended elsewhere. The significance of the biochemical observations is discussed in relation to the observations from many other clinical milk fever cases in a dairy practice in Victoria. This syndrome developed in 1.9 per cent of 584 cases of milk fever. The essential findings in the syndrome were that all cows had an initial clinical episode suggestive of milk fever but showed an unsatisfactory clinical response to calcium borogluconate therapy. After a day or two all cows became laterally recumbent, some exhibited expiratory moaning and all developed mucoid faeces which, in many cases contained spots of blood. All cases had significantly lower erythrocyte and plasma potassium concentrations than those in milk fever cases which responded to treatment.