What to do when your female dog reaches sexual maturity and comes into heat

When your dog reaches sexual maturity, a range of things happen - both physically and mentally. It's different for females and males, but both go through big changes. A female dog's sexual maturity shows itself through her coming into heat.

Sexually mature female dogs

Depending on the breed and the individual, a female dog reaches sexual maturity somewhere between about 7 and 24 months of age - that's when she'll have her first heat. Smaller breeds often have their first heat earlier than larger breeds. Most female dogs come into heat twice a year, roughly five to seven months apart. The heat cycle consists of four phases - pre-heat (proestrus), peak heat (oestrus), post-heat (dioestrus), and rest (anoestrus). What we commonly call "the heat" covers the pre-heat and peak heat phases, and usually lasts around three weeks. During the heat, your female dog is fertile, which means she can get pregnant.

It's common for a female dog's mood and behaviour to change before, during, and after her heat. She might seem low or a bit down, and not feel like playing as usual. Some female dogs lose their appetite and eat less than usual, while others are the opposite, with an increased appetite and eating more than usual. Your female dog may also become easily irritated during her heat, which is entirely normal.

False pregnancy

After a heat cycle, your female dog's maternal instincts may be triggered, and she can have a false pregnancy. This is when her body thinks she's had puppies, and she may start acting a bit unusually at home. That can show up as her "looking after" small toys as if they were her puppies, guarding them, and so on. She might also start nesting a lot on the sofa or in bed to prepare for whelping. If your female dog is heavily affected by false pregnancy, it can be worth asking your vet for advice and help.

Heat pants

To stop your female dog from staining the floor and furniture during her heat, she can wear heat pants, which are available from most pet shops. Heat pants come in different sizes, so choose one that fits your particular dog.