Reza Behmanesh - Department of Veterinary Radiology, Faculty of Specialized Veterinary Sciences, Islamic Azad University, Science And Research Branch, Tehran, Iran.
Mohammad Nasrollahzadeh-Masouleh - Department of Veterinary Radiology, Faculty of Specialized Veterinary Sciences, Islamic Azad University, Science And Research Branch, Tehran, Iran.
Ehsan Khaksar - Department of Small Animal Internal Medicine, Faculty of Specialized Veterinary Sciences, Islamic Azad University, Science And Research Branch, Tehran, Iran.
Saeed Bokaie - Department of Food Hygiene, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.

Domestic rabbits (Oryctolagus cuniculus) are an excellent model for cardiovascular research because the size of these animals is more suitable for study and experimentation than smaller animals. One of the most important diagnostic imaging methods is echocardiography, which is used today to evaluate the anatomical and functional cardiovascular system and is one of the most accurate and sensitive non-invasive methods for examining heart disease. Ventricular function indices can be assessed with cardiac imaging techniques. One of these important cardiac parameters is the ejection fraction (EF), which has a valuable place along with other involved parameters. EF is a measure of the percentage of blood that comes out of the heart with each contraction. For this study, ۱۰۰ adult and young standard domestic rabbits, six months to one year old and in both sexes (۵۰ female and ۵۰ male rabbits) without anesthesia and sedation were used. In this study, the mean EF in domestic rabbits studied in males was ۵۸.۷۵۳ ± ۶.۸۸۹ and females ۶۱.۳۹۷ ± ۶.۵۳۰, which are comparable to the items mentioned in the valid books and the average size of EF measured in this study, there is no significant difference between this research and other research. There was no significant difference in the percentage of EF between most weight groups, but there was a significant difference (p < ۰.۰۵) in weight groups (۲۱۶۱–۲۳۲۰ g and ۲۴۸۱–۲۶۴۰ g). Echocardiographic EF reference values for domestic rabbits (Oryctolagus cuniculus) non-anesthetized with are presented providing reference values for future studies.

echocardiography, Ejection fraction, Rabbit, Heart