How Long Are Dogs in Heat?

If you have an unspayed female dog, our team at Englishtown Vet MD can help you better understand her heat cycle, so you can keep her healthy, safe, and comfortable. Let’s take a look at the full picture—timing, care, and how to prevent unplanned dog pregnancy.

When Will an Unspayed Female First Go Into Heat?

Most dogs experience their first heat cycle between 6 to 12 months of age. Smaller breeds tend to go into heat earlier, while larger breeds may not have their first cycle until they’re closer to 18 to 24 months old.

If you’ve recently welcomed a young, unspayed female into your home, it’s important to prepare for her first cycle. Signs may include swelling of the vulva, light bleeding or discharge, increased urination, and changes in behavior like restlessness or clinginess.

Understanding Your Dog’s Heat Cycle

A typical dog’s heat cycle lasts about 2 to 3 weeks. Most female dogs go into heat about twice a year, but cycles can vary widely, especially in the early years.

There are four stages of a dog’s heat cycle:

1. Proestrus (7-10 days) – Initial stage with vulva swelling and bloody discharge. Males may be interested, but your dog won’t yet be receptive.
2. Estrus (5-10 days) – This is when your dog is fertile and will be receptive to mating. Discharge may become lighter in color.
3. Diestrus (about 60 days) – Fertility ends, and the body returns to normal, whether or not the dog becomes pregnant.
4. Anestrus (several months) – The resting phase before the next cycle begins.

Do Dogs Naturally Stop Going Into Heat?

Unlike humans, dogs do not go through menopause. An unspayed female will continue to experience heat cycles throughout her life, though the frequency and intensity may change with age. This makes ongoing management—and eventual spaying—important for long-term health.

Caring for a Dog in Heat

Caring for a dog in heat involves both physical and emotional support:

• Provide comfort: She may be more anxious or tired than usual. Keep her calm with extra snuggles and a quiet environment.
• Use female dog diapers or washable pads: These can help manage discharge and keep your home clean.
• Avoid outdoor walks where unneutered males might be nearby: Her scent can attract attention from far away.
• Keep her secure: An unspayed female can become unexpectedly resourceful about escaping to find a mate.

How to Prevent Unplanned Dog Pregnancy

The only guaranteed way to prevent unplanned dog pregnancy is by spaying your dog. Spaying not only stops the heat cycle, but also significantly reduces the risk of mammary tumors, uterine infections, and other health concerns.

Spaying Pets Promotes Long-Term Health

If you’re unsure whether spaying is right for your dog—or when to schedule the procedure—our team is happy to discuss the benefits of spaying your pet, as well as the best time to spay your pet based on age, breed, and health. Contact us today for a consultation.