Background and aim: 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 and are economical and cost-effective in research. One of the most important diagnostic imaging techniques is echocardiography, which is used today to perform anatomical and functional evaluation of the cardiovascular system and is one of the most accurate and sensitive non-invasive methods for examining heart diseases. Ventricular function indices could be assessed by cardiac imaging techniques. One of these important cardiac parameters is the ejection fraction, which has a valuable position along with other involved parameters. Ejection fraction is a measure of blood percentage that comes out of the heart with each contraction.
Materials and Methods: For this study, 100 six-month to one-year adult, standard and young Oryctolagus Cuniculus (in Iran) and in healthy   appearance of both sexes (50 female rabbits and 50 male rabbits) were studied without anesthesia and sedation.
Results: In this study, the mean ejection fraction in the studied Oryctolagus cuniculus was 58.753±6.889 in male animals and 61.397±6.530 in females which indicates that the ejection fraction in the assessed male population was significantly higher than the female population.
Conclusion: The measured ejection fraction values were comparable to those mentioned in the authoritative books and there is no significant difference in the average size of ejection fraction measured in this study with the previous research.

Background and aim: Horses of native breed are considered as the national capital in every country, and their preservation and propagation is of great value and importance. One of the most valuable native horse breeds in Iran is the Turkmen horse. The purpose of this research was to obtain the normal echocardiographic size of a healthy Turkmen horse and compare the size of the parameters between female and male and immature and adults.
Materials and Methods: Fifty healthy Turkmen horses, which were kept in horse riding clubs in Tehran and the suburbs of Tehran, were randomly selected. Then, after preparation, by using Mindary M7 echocardiography device and with phased water from the standard right parasternal approach, short axis views were taken at the papillary muscle stage and aortic root and long axis at the chamber 4.
Results: The mean and standard deviation of each parameter were calculated. The findings showed that the factors of left ventricular internal volume at the end of diastole, left ventricular internal volume at the end of systole, ejection fraction and the percentage of left ventricular muscle shortening are significantly higher in female horses than in male horses. Also, the factors of left atrial diameter, aortic root diameter, right atrium diameter, interventricular wall thickness in diastole and systole, left ventricular free diameter at the end of diastole and systole, factors of the internal volume of the left ventricle at the end of diastole and cardiac output in adult horses are more than immature.
Conclusion: The measurements specified in this research can be considered as a criterion for echocardiography of Turkmen horses. It is absolutely necessary to check the components of each horse with its gender and maturity status.