Discipline: Veterinary Medicine
The study aimed to describe the ultrasonographic features and measurements of the heart of the Philippine brown deer, Rusa marianna (Desmarest, 1822) through transcutaneous ultrasonography of eight animals, four males (two adult and two juvenile) and four females (two adult and two juvenile), using an ultrasound machine with a 5.0 MHz micro-convex scanner. Variations on the ultrasound features and measurements between sex and age were also determined. B-mode ultrasonography revealed the lumen of the chambers of the heart as anechoic with hyperechoic pericardium. The ventricular walls, interventricular septum, mitral valve and aortic valve were seen as hypoechoic structures. M-mode ultrasonography revealed the right ventricular wall, interventricular septum and left ventricular wall as low, medium and high amplitude waves, respectively. Mitral valve was seen as a two peaked wave. The adult animals had higher left ventricular diameter and lower heart rate (P<0.05) than the juveniles. Fractional shortening and cardiac dimensions were not significantly different between sexes and age groups. The results of the present study may be used as baseline data and reference for the diagnosis of diseases and disorders of the heart in Philippine brown deer.