Transorbital echoencephalography in cattle.

The purpose of this study was establishment of the criteria of transorbital echoencephalography in cattle and experimental applications to bovine practice. Quantitative investigations using magnetic resonance (MR) imaging revealed that this examination could be applied to cattle under 3 months of age. The method of transducer positioning was established in Japanese Black (J.B.) and filial (F1) cattle (turning caudally at an angle of about 16 degrees and dorsally at an angle of about 23 degrees) or in Holstein cattle (turning caudally at an angle of about 20 degrees and dorsally at an angle of about 21 degrees). Examinations in clinical calves revealed that the cerebral parenchyma and the lateral ventricle could be detected antemortem or postmortem. In this study, the diagnoses of hydrocephalus or hydranencephaly was possible using antemortem transorbital echoencephalography. Transorbital echoencephalography was especially useful as the imaging method for bovine hydranencephaly.