Determining the optimal time of mating in bitches has become a routine in veterinary practice. Endogenous LH has an important role in ovulation induction and the beginnings of fertile period in bitches but its dosing is difficult and veterinary clinics don’t apply it widely.The indirect methods of establishing fertile period are: examination of vaginal smear, determination of progesteron blood levels, vaginoscopy, or the simple examination of clinical changes of external genital segment and characteristics of vulvar discharge and receptivity. The purpose of this study is to determine the connection between estrus clinical signs and the examination methods most frequently used to assess the exact time of ovulation (vaginal smear, vaginoscopy, serum progesterone dosing ).