Going into heat in dogs: how long it lasts and what you need to know

A female dog’s heat cycle, also called oestrus, is a normal part of reproductive life. The timing and visible signs vary with breed, age, and the individual dog. A cycle often lasts around two to four weeks overall, but fertile timing cannot be determined reliably from calendar days alone.

Common signs include swelling of the vulva, bloody or lighter discharge, more frequent urination, and changes in behaviour. Some dogs become more affectionate or restless, while others show few obvious changes.

During heat, keep your dog securely on a lead outdoors and prevent unsupervised contact with intact males. Dog parks, daycare, and off-lead areas may be unsuitable during this period. Keep bedding clean and provide a calm place to rest.

Contact your veterinarian if the cycle seems unusually prolonged, your dog appears unwell, discharge has a strong or unusual smell, or you have concerns about pregnancy or reproductive health. Discuss spaying and the appropriate timing with your veterinary team.