The neonatal period is a challenging phase for calves, and during this phase constant adaptations are required. The aim of the present study was to evaluate the invasive hemodynamics with the Swan-Ganz catheter in neonate calves to understand adaptive changes during the first 30 days of life. A prospective and observational study was conducted with 10 Holstein calves. Assessments of the right atrial pressure (RAP), right ventricular pressure (RVP), pulmonary artery pressure (PAP), pulmonary capillary pressure (PW), cardiac output (CO), heart rate (HR), pulmonary vascular resistance (PVR), and blood gas levels were performed. The analyses of PAP, PVR, PW, HR, sO2, and arterial blood gases differed (p < 0.05) between the evaluated periods. Our results indicated transient pulmonary artery hypertension during the process of extrauterine adaptation during the first 30 days of life. This hypertension must be considered as physiological and consequent to the neonatal adaptation process.
