If you are planning on breeding your dog, it’s important that you’re familiar with a normal heat cycle. That way you know what to expect, and when to expect it.

A bitch will first come on heat around 6 months of age. Larger breeds are often slower to mature, so may be closer to a year old before their first cycle. It’s a good idea not to breed a dog on that first cycle, but to wait until she is more physically mature.

The average heat period in a bitch lasts around 3 weeks. The most obvious initial sign of heat is a bloody discharge from her vagina, and the vagina itself will become red and swollen. This bleeding lasts around 2 weeks. Male dogs will be attracted to her as soon as she goes into heat, but she is not fertile at this point, and is not likely to welcome any attention from the stud dog.

The ideal time for mating is around 11-13 days after the onset of bleeding. By this time, the bleeding may well have stopped, but that’s fine, she’ll still accept a mate.

Female dogs go into heat twice a year. Don’t breed your bitch on two heat periods in a row; her body needs time to recover from the hard work of raising a litter. One interesting characteristic of the dog reproductive cycle is that after their heat period is over, they have the same hormonal changes whether they are pregnant or not. This means that phantom pregnancies, where a non-pregnant dog “mothers” a stuffed toy or another pet and even produces milk, is a very normal phenomenon.

In Summary – Unless you are planning on breeding your bitch, her heat periods will be a nuisance for you. You’ll need to clean up drops of blood if she comes indoors, and you’ll have amorous male dogs loitering around your fence line. If you don’t want puppies, It’s a good idea to spay her before her first heat period, which will not only avoid the inconvenience, but will protect her from developing breast cancer later in life.