Ultrasonographic measurement of the adrenal gland in neonatal foals: reliability of the technique and assessment of variation in healthy foals during the first five days of life

Background Adrenalglandultrasonographicmeasurementsareusefulinclinicalevaluationofpatientswith adrenal dysfunction in several species. In human healthy neonates, the ultrasonographic size of the adrenal glands decreases during the first days of life. Ultrasonography of adrenal glands was demonstrated to be feasible in neonatal foals. The aims of this study were to describe a technique for ultrasonographic measurement of adrenal gland size to test its reliability in neonatal foals, and to assess any variation of ultrasonographic measurements during the first five days of life in healthy foals. Methods First,measurementsoftheadrenalglandswereretrospectivelyobtainedbythreeobserversin26adrenalgland images of 13 healthy and sick neonatal foals. The interobserver and intraobserver agreement were tested. Later, adrenal gland ultrasonographic images and measurements were acquired by one operator in 11 healthy neonatal foals at one, three and five days of life and differences among the measurements obtained at the different time points were assessed. Results Interobserveragreementrangedfromfairtoexcellent(0.48–0.92),exceptforcortexwidth(<0.4); intraobserver agreement ranged from good to excellent (0.52–0.98). No significant differences were found among the measurements obtained at one, three and five days of life. Conclusion Adrenalglandsultrasonographicmeasurementscanbeobtainedconsistentlyinequineneonates,and in contrast to people they do not vary during the first five days of life in healthy foals.