age that female dogs go into first heat
Dogs in heat need special care. Estrus or âheatâ is part of the reproductive cycle in female dogs. Dogs come into their first heat between about 6 and 24 months of age, with small breeds coming into heat sooner and large breeds later. Dogs typically have two heats per year, and each lasts about 18-24 days. The first signs of heat are typically a swollen vulva and a bloody vaginal discharge.