Ultrasounds are sound waves with a frequency of higher than the upper range of human hearing i.e., approximately 20,000 cycles per second (20 kilohertz). High frequency sound waves between 3.0 to 7.5 MHz (1 million cycles/sec is known as 1 megahertz) are commonly employed in diagnostic examination of dogs. The modern ultrasound units provide unparalleled contrast, temporal and colour resolution. It is equipped with a wide range of specialized transducers to allow imaging of patients of various sizes. The most common application of the technique is abdominal sonography, thoracic sonography and echocardiography. Small abnormalities deep within organs can be detected through 'ultrasound-guided' aspirate or biopsy. Abscess, cyst, neoplasm and alteration in vascular pattern of abdominal organs such as liver, gall bladder, spleen, intestine, stomach, uterus, kidney and urinary bladder can be well visualized with their parenchyma. Pregnancy, intestinal obstruction, hepatitis, uroliths, pyometra, ascites etc. can be diagnosed using this method. Software were developed to predict the gestational age through measurement of gestational sac diameter (GSD), body diameter (BD), head diameter (HD) and crown-rump length (CRL) of foetus.