If, after the successful completion of the physical sex act (called the ‘tie‘ in dogs), the bitch fails to conceive, you may be faced with an infertility problem – in either the male or the female, or both. This is especially likely to be true, if the same dogs were brought together at the correct time and mated more than once during the ‘standing‘ heat period (7th, 9th and 11th day after the first droplets of blood were seen at the commencement of the heat period. Infertility would become even more the suspicion, if the same two dogs are brought together at another (the next) occasion when she comes in heat,