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In this report is presented the case of extended estrous accompanied by early embryonic development in bitch. The animal is 3 year’s old Jack Russell terrier, with history of two successful pregnancies. On the day 8 and 9 after the beginning of a normal estrous, the bitch mate with a 7 years old male dog of the same breed. In the following two weeks after the copulation the clinical signs of estrous continued. The whole blood test was in norm and the echographic examination does not reveal any pathological changes of the uterus. Only the vaginal smear gives some consideration for local infection so treatment of the genital organs was prescribed. After treatment the clinical signs disappeared. Thirty five days after breeding, another ultra-sound was performed and pregnancy with 5 fetuses was found. On the 64th day after copulation, five puppies were born alive. This report shows that even if bitch expressed clinical signs of extended estrous, a possibility of early pregnancy must be taken in consideration, especially when there is information for successful mating with male.