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How Long Does A Dog Period Last?

How Long Does A Dog Period Last

Once a female dog reaches about 4 months old, that’s usually when they start experiencing heat that will happen every 6 months. This usually indicates that your dog is ready to breed and mate. During the heat or estrus season, you may want to look out for hormonal changes, signs and changes in behaviour.

The earliest signs that your dog is in heat are through the body changes and behaviour. Differences that you can observe include their vulva swelling, growing big, and reddening that bleeds or contains blood-tinted discharges. Aside from that, you will notice a change in their behaviour such as frequent peeing, heightened alertness and nervousness. When in contact with other dogs, your dog will most likely be extra friendly towards them, present themselves to them by raising their rump and moving their tail aside, or have a tendency to mount or hump them.

During dog period season, it’s important to be alert to your dog’s needs, so be sure to take care of them properly during the heat cycle. Generally, bigger dogs bleed more than smaller dogs do. They might get their blood or discharge everywhere, so be patient in cleaning those. It’s important to note that bitches are not in pain during dog heats, but are more uncomfortable and sensitive.

If you are a new owner of a bitch or anticipating the arrival of your dog’s heat, here are the basic information about dog period below. 

When Does A Female Dog Heat Start?

Depending on the size of the breed, dog period can start for as early as 4 months (for smaller breeds) to 6 months old. However, some bigger breeds start later at 18-24 months. It is advised to not start breeding until their first and second cycle passes since their eggs are not mature enough. Make sure your dog is fully mature before pairing them up to mate. If you are unsure if your dog is ready for breeding, you may consult with your veterinarian to see if they are safe to breed. Waiting for the dog to more mature after 2 cycles will lead to a healthy pregnancy. 

How Long is Each Cycle? 

A dog’s heat period will typically last between 2-4 weeks. The length of the dog period varies depending on the breed, size, and age of the dog. You will notice the heat period ending once their vulva returns to its normal size without the bleeding or discharge. They are still fertile until the end of their period, so chances of them being pregnant are high until the end of their cycle.  

Do note that the frequency may change per cycle, but the consistency of their heats must be consistent. If the dog period is inconsistent, you may visit your veterinarian to check their irregular cycles. 

The average cycle of a dog period starts every 6 months. Smaller breeds may go into more heat periods 3-4 times a year. Some bigger dog breeds only go into heat every 12-18 months. Make sure you are tracking the cycle of your dogs, so you’ll know when to expect them, and you’ll be ready each time. The older your dogs get, the lesser the frequency of their period. Dogs will go into heat their whole life, and may still get pregnant even if they get into heats less.

How to Prevent Your Dog From Going Into Heat?

If you want to prevent your dog from going into heat, the only option is through spaying them. It is highly recommended to spay your dogs if you have no plans to breed them and to avoid unwanted pregnancies from happening. Aside from that, spaying will help reduce risks for mammary cancer and uterine infections. 

You may schedule the spaying of your dog with your veterinarian, and be sure to do it when your dog is not in heat to avoid complications.

The Estrus Cycle in 4 Stages

When a dog period occurs, they go through 4 stages. Knowing what happens in those stages and when they’ll happen will help you prepare for behavioural changes and problems that may arise during this time. The four phases are as follows:

  1. Proesterus

This is when the heat starts that lasts up to 7-10 days. This is also when the physical changes start to manifest, such as the swelling of the vulva and bleeding happens. They will also start attracting other dogs. You will notice your dog become more clingy, seeking comfort during this time.   

  1. Estrus

This is the mating period of the cycle that lasts up to 3 to 21 days. Bleeding will reduce or stop, but discharge is still present. You will also notice your dog peeing more, marking spots around the house. If in the same proximity as a male dog, they will start presenting themselves to them indicating that they are ready to mate.

  1. Diestrus

This stage of the cycle happens after the heat that lasts up to 10-140 days. Their body will prepare themselves for pregnancy or return to rest. Physical changes will return to normal and the discharge will stop.

  1. Anestrus

This is the uterine repair stage of the dog’s body, where they are on downtime that lasts up to 90-150 days before the next heat cycle occurs again.


Once your dog reaches 4-6 months of age, that is when they may start their heat cycle that lasts up to 4 weeks. Each cycle’s length varies depending on the breed, age, and size of the breed. It is important to be on the lookout for signs and behaviour changes, so you are prepared to take care of your dog during this sensitive time. Being more patient and more adaptive to their needs will greatly help your dog. 

A dog period goes through 4 stages and knowing what happens for each stage will help you prepare for each heat cycle. On the other hand, if you want to prevent a dog heat from happening, the only option would be is to spay your dog. 

Taking care of your dog during their heat cycle is a big responsibility, so be sure to take care of them properly!

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