If mating occurs during this period, the eggs can then be fertilized and an embryo can be produced. [substeps] Female dogs, will generally go into heat during puberty, at around 6 to 24 months of age depending on breed.
[header] How to tell if your dog is in heat [title] Understand the basic reproductive cycle of your dog. [step] When wondering if your dog is in heat, it first helps to understand her normal hormonal cycle. When a female dog reaches maturity, and is physically ready to reproduce, her estrogen levels increase, initiating the release of eggs from her ovaries.