How long is a puppy in heat?

As your female puppy grows, one significant milestone to prepare for is her first heat cycle. Understanding this natural process is crucial for her well-being and your peace of mind. 

What does it mean when a dog is in heat?

The term ‘in heat’ refers to the period when a female dog is fertile and receptive to mating. This phase, also known as being ‘in season,’ is a normal part of a dog's reproductive cycle. Recognising the signs and knowing how to care for your dog during this time ensures her comfort and prevents unwanted pregnancies.

When do dogs go into heat?

Female puppies typically experience their first heat when they’re between six and 24 months old. Smaller breeds may start as early as six months, while larger breeds might not have their first season until they're 12 to 24 months old. It's important to note that individual dogs may vary, so monitoring your puppy's development is key.

How long does a puppy's first heat last?

A dog's heat cycle generally lasts between two to four weeks. During this time, hormonal changes occur, and your dog becomes fertile. The visible signs, such as bleeding, usually persist for about seven to 10 days, but this can vary. Some dogs may have a heavier discharge, while others may keep themselves so clean that it's barely noticeable.

How often do dogs go into heat?

After the first season, most dogs go into heat approximately every six to seven months, or about twice a year. However, this can vary based on factors like breed, age, and the individual health of the dog. Larger breeds may have longer intervals between heats, sometimes up to 10 months, while smaller breeds might have more frequent cycles.

Phases of a dog's heat cycle

Understanding the stages of the heat cycle can help you recognise what your dog is experiencing:

1. Proestrus (preparation phase): This stage lasts about 9 days. The vulva swells, and a bloody discharge appears. Your dog may attract males but isn't receptive to mating yet.

2. Estrus (fertile phase): Also lasts around 9 days. Discharge may lighten in colour. This is when your dog is most fertile and receptive to males.

3. Diestrus (post-fertile phase): Lasts about 60 days. The body either returns to normal if the dog isn’t pregnant or continues to support a pregnancy. 

4. Anestrus (resting phase): Lasts about 4 months. No sexual activity occurs, and the body rests before the next cycle.

Suspect your dog is pregnant? For more info, read our guide ‘How to tell if your dog is pregnant.’

Symptoms of a dog in heat

There can be several signs that your puppy is in heat, including:

• Swollen vulva
• Bloody or straw-coloured discharge
• Increased urination
• Licking their genital area
• Behavioural changes E.g. They may be more affectionate or agitated
• Tail held to the side
• Attracting male dogs

How do I know when my dog's heat is over?

You’ll know your dog’s heat cycle is coming to an end when the swelling around her vulva goes down, any discharge stops, and she starts acting more like her usual self again. She’ll likely be less restless or clingy, and male dogs will start to lose interest in her too. It's a gradual shift, but these changes are signs things are settling back to normal. While it may be over, it's still best to wait a few extra days before resuming off-lead walks or interactions with male dogs just to ensure the cycle has fully ended.

What do I do when my dog is in heat?

When your dog is in heat, the main thing is to keep her safe, comfortable, and clean. Walks are still fine, but try to head out during quieter times and always keep her on a lead, as her scent will attract male dogs. You may also want to manage any discharge with doggy nappies or by keeping her in easy-to-clean spaces. She might be a bit more sensitive than usual, so offering extra cuddles and a calm, quiet environment can really help. Most importantly, be sure to keep her away from unneutered male dogs (even indoors) to prevent any accidental mating.

Can I walk my dog when it’s in heat?

Yes, you can walk your dog when she’s in heat, but you’ll need to take a few extra precautions. She’ll still need exercise and stimulation, but it’s best to keep walks shorter and on lead to avoid any unwanted attention from male dogs. Try to stick to quieter routes and times of day when other dogs are less likely to be around. Always keep a close eye on her as her scent can attract a lot of interest!

Can my dog get pregnant during her first heat?

Yes, your dog can get pregnant during her first heat. Although she’s still very young and not yet fully mature, her body is capable of ovulating and conceiving at this stage. Pregnancy during a first heat can be risky, as her body isn’t fully developed to support it properly, which can lead to health complications for both her and the puppies. If you’re not planning to breed, it’s best to keep her away from unneutered male dogs. You can also speak to your vet about spaying.

Does spaying a dog stop periods?

Spaying is a surgical procedure that removes a female dog’s ovaries and uterus, preventing future heat cycles (including bleeding) and pregnancies. Note that the bleeding, however, isn’t exactly the same as a human period. Some vets recommend spaying your dog after her first season, although the ideal timing can depend on your dog’s size, breed, and overall health, so it’s best to consult with your vet to find out the right time for your animal. 

Spaying not only eliminates the challenges of managing a dog in heat but also reduces the risk of certain health issues, such as uterine infections (pyometra) and mammary tumours. However, it’s a personal decision that should be made in consultation with your vet. For more info, read our guide ‘Should you neuter your dog.’

Speak to your vet for more advice

Overall, by recognising the signs your dog is in heat and knowing how to care for her you can ensure her comfort and health. If you’ve got any concerns or questions about your dog's reproductive health, chat to your vet for advice.

How long is a puppy in heat: FAQs