Pregnancy diagnosis in cats and dogs is easily detected using ultrasonography. Although pregnancies may be detected as early as 22 days after ovulation the most reliable time is between 28 and 35 days. During this interval it possible to confirm pregnancy, estimate litter sizes and also detect pregnancy abnormalities such as resorptions, abnormal uterine thickening and placental problems. We can determine the expected due date of delivery by using a combination of gestational sac diameter, crown-rump length and head diameter.
Ultrasound is very useful for investigating delivery difficulties and assessing pup and kitten viability prior to Caeserean section.
Sedation is not required. Some shaving of belly hair may be needed to allow good contact with the ultrasound probe.