Dog Heat Cycle: Vet-Verified Signs, Frequency & Facts

Understanding your dog’s heat cycle (or estrus cycle) is paramount if you have an unspayed female at home. Without learning how it works, it is impossible to know what is normal and what isn’t, and how to look after your dog while she is in heat. A good knowledge of your dog’s heat cycle is also important for avoiding unwanted pregnancies and predicting your dog’s behavior. Additionally, if you’re trying to breed your female dog, it’s essential to learn how the canine cycle works to be able to have a successful pregnancy and litter.

This article will help you understand everything you need to know about dog heat cycles, and how to care for your female dog.

When Does a Female's Heat Cycle Start?

Different breeds may come into heat (also called into season) at different times. Some breeds mature faster than others and will have their first heat cycle earlier. Smaller breeds typically begin their cycle at a slightly younger age than larger dogs since larger dogs have to take more time to grow. Usually, dogs will become sexually mature and start their heat cycles around 6 months of age.

However, this doesn’t mean that they should start breeding at this time. Dogs are not full-grown at this point. Getting pregnant at such an early age can be detrimental for their health and the pups.

How Often Do Dogs Go in Heat?

Most dogs will go into heat twice a year, every 6 to 7 months. This can vary slightly depending on the breed, with the Basenji or Tibetan Mastiff being reported as typically having only one cycle per year.

Once heat cycles start happening, especially after the second one, they tend to be quite regular. There is no exact time when dogs have their cycles, unlike wolves that have a breeding season from late January through March in the Northern Hemisphere.

What Are the Signs of Heat?

Determining whether or not your canine is in heat requires you to observe her body and behavior. The heat or estrus cycle has four stages. During the first one, called proestrus, you may notice swelling around the genitals and your dog attracting males, but not being interested in them yet. This stage lasts around 7–10 days. Another obvious sign you can notice during this time is an unusual vaginal discharge. This discharge is often bloody and will become lighter in color as your dog enters the second stage, the estrus, or what is usually referred to as being in heat. This is the time when your dog is fertile and will accept mating and it lasts about 9–10 days but it can go up to 3 weeks.

Some dogs may not have much discharge at all, or they may lick it constantly making it almost unnoticeable. It mostly depends on the dog.

Your dog may also urinate more frequently, as they are attempting to spread their scent around. The urine contains pheromones, which will let males know that the females are fertile. At this point, males can smell the female from a great distance away. Dogs in heat may also urinate inside the house. This is normal and instinctual, not necessarily a sign of poor training. Usually, the behavior will stop after the dog enters the next stage of the heat cycle. .

If you need guidance on keeping your dog healthy and comfortable during heat, we suggest you speak to a vet.

How Long Does the Dog Stay in Heat?

The entire heat cycle lasts approximately 6 months, but the time where your dog will show signs of being in heat and can get pregnant lasts for 1.5 to 3 weeks. This will vary from individual to individual. If mating occurs, your dog will get pregnant and have a litter of pups around 63 days later.

When Can the Female Become Pregnant?

Female dogs ovulate during estrus, whenever their discharge becomes thin and she accepts males. This is the best time for the female to mate, as it has the highest chance of success. However, sperm can survive in the female’s uterus for up to a week. This means that they may become pregnant after the estrus finishes.

Should a Female Have a Heat Cycle or Litter of Puppies Before Being Spayed?

No. There is no evidence that letting your dog have a litter of puppies before they are spayed will provide any benefits to her. For this reason, we do not recommend letting the female have a litter unless you are a dog breeder. There is a lot more that goes into breeding than simply putting two dogs together.

The exact time to spay your dog depends on her lifestyle and her breed, so it’s best to follow your vet’s guidance on this topic. There is new information nowadays and the general recommendation of spaying dogs before the first heat is not suitable for all.This is because spaying the dog affects their hormone levels, which can have an effect on their development. However, you should be very careful for your dog not to become pregnant while you wait for the right time for her surgery. Getting pregnant can also be worse for their health, especially if they are too young.

See also:

• Dog Mating: Everything You Need to Know!

• Do Dogs Have Periods? Vet-Reviewed Facts & FAQ

Final Thoughts

Understanding your dog’s physical and behavioral changes though her heat cycle, is important to know what is normal and what isn’t so you know when your vet’s input is necessary. If you’re not planning to breed your dog, you should speak to your vet about the best time to have her spayed to prevent unwanted pregnancies and serious health issues in the future.

Featured Image Credit: Sigma_S, Shutterstock