Displacement of the abomasum in the cow. Incidence, etiological factors and results of treatment.

Fiftynine cases of abomasal displacement were registered during a 10 year period in a veterinary district in Norway with a dairy cow population of approx. 2500. Of these, 88% were left displacements and 12% right displacements. Ten per cent recovered spontaneously without subsequent relapse. Corrective surgery was performed on the remainder, and 92% of these recovered completely. Surgery was, in most cases, performed on the same day as the diagnosis of abomasal displacement was made. The displacements occurred at all times of the year: 86% of cases involved cows in third or subsequent lactation 95% were diagnosed within the period 4--64 days after calving, and 70% of the cows had been treated for other illness with disturbance of digestion during the week immediately prior to the demonstration of the displacement. In a further 25%, ketosis was diagnosed at the same time as the displacement. Etiology and pathogenesis are discussed.