Same as humans, dogs experience estrus, or heat. The difference is women go through heat every month, while dogs go through it every six months.
From about six months old, until their last dying breath, female dogs will experience estrus roughly every six months. During this period, she is receptive to mating.
Hormonal changes cause differences in your dog, signaling she is in heat. How long does the process last? How long are dogs in heat? We have answers to all of your questions.
When does heat start?
Dogs go into heat as young as four months in smaller breeds. However, on average, the heat starts when your dog is up to six months old.
Some giant breeds might not go into heat until they 18 months old. It is advisable not to mate your female dog in the first and second cycle. She has not reached full maturity, and her eggs are not yet mature.
If you intend on breeding your dog, consult with your vet to check when your dog is mature enough.
How long the cycle lasts?
In people, the heat cycle lasts for about one week. In dogs, the heat lasts between 2 and 4 weeks. Early in the cycle, a female dog will not be receptive to male dogs. Some dogs, however, are receptive to male through the entire cycle.
You will notice the heat has ended when your dog’s vulva has returned to normal size and there is no more vaginal discharge. There is a relatively small window when your dog is most fertile. Usually, it starts on the 9th or 10th day and lasts for about five days.
However, female dogs can become pregnant until the end of the cycle. Here are all of the stages of the heat cycle:
- Proestrus, the first week of the cycle is when you notice vaginal discharge. Males are attracted to female dogs, but females are often unwilling to mate during this period. Lasts between 4 and 20 days
- Estrus is the period when your female dog is willing to mate. Symptoms include swollen vulva and yellowish vaginal discharge. Mating occurs during this phase that lasts between 5 and 13 days
- If the mating is successful, your dog enters the metestrus phase, which is the period after mating. It can last between 60 and 90 days. If pregnant, pregnancy can last between 60 and 64 days
How to recognize dog in heat?
The most easily recognizable sign is vaginal bleeding. Same as people, female dogs have vaginal discharge when they are in heat. Unlike women, vaginal discharge may not become apparent after a few days have passed. In humans, the first two days are when the vaginal discharge is the strongest.
That is not the case in dogs. Vulvar swelling should be taken as the first sign of heat. Another common symptom is your female dog paying increased attention, such as licking, to her rear end.
Female dogs in heat are attractive to male dogs from the first day of their period. However, they will not be receptive until 7 or 10 days later. Female dogs are more receptive to mating when the vaginal discharge becomes less bloodstained.
Some female dogs experience heavy vaginal bleeding. If that happens, it might be best to consult your veterinarian.
During the period, you can also notice your female dog urinating more frequently. Her urine contains both pheromones and hormones that signal interested males that she will be receptive.
How often do female dogs come into heat?
Now that we answered how long are dogs in heat, let’s talk about frequency. Usually, dogs go into heat two times per year. Or in other words, every six months.
However, it can vary from one dog to another. There is a great deal of variability in the time between cycles when cycling first begins. That is normal. Most female dogs take 18 to 24 months to develop a regular cycle.
Small breeds tend to cycle more regularly than larger breeds. In some females, three to four heat cycles per year can be normal. Large breeds, on the other hand, have a heat cycle once every 12 to 18 months. In giant breeds, 12 months cycle is common.
Is period a lifetime thing?
Once estrus begins, it will take some time for the cycle to become regular. As mentioned, most female dogs regulate their period after 24 months.
It is a good idea to keep a record during the early days. And yes, it is a lifetime thing. Unlike people, dogs do not experience menopause. They will go into heat regularly until their last day.
When is the best time to mate your dog?
This question is hard to answer. Simply put, not all dogs are the same. Most dogs ovulate and are receptive to mating in their 9th, 10th, or 11th day of oestrus.
At that time, the discharge is less bloody and the female is actively looking for a male. However, ovulation can happen earlier or later during the heat cycle.
Male dogs, on the other hand, are receptive every day of the year. They do not have “heat cycle”.
Are there any tests you can do?
Yes, there are two tests veterinarians use to determine when to mate your dog. Both can be performed at any veterinary practice.
A vaginal smear test is a simple microscopic examination of vaginal cells. It will detect changes in cell appearance and numbers. Reliable, this test has been used for many years to determine when is the best time to mate your female dog.
The test is non-invasive and does not cause any discomfort in dogs. You have to perform the test serially, over several days to determine changes in the cells that predict ovulation.
A serum progesterone test measures the progesterone levels in the blood. Due to its accuracy, this test has become quite popular. Most pets require several tests to predict ovulation.
What can you do to ensure successful mating?
You might be surprised, but male dogs are more stress-sensitive when it comes to mating. While male dogs can mate any day of the year, and do not have a heat cycle, they are more stress sensitive. Successful mating is more common when the male dog is in his environment.
Therefore, in most cases, female dogs are taken to the male dog’s home for successful mating. Female dogs can get pregnant during their first cycle. However, that is not recommended, since the dog is not fully mature yet.
Spraying and neutering
Dogs that are meant to be house pets, spraying and neutering are often recommended. Spraying is best done before the first heat, eliminating the risk of accidental pregnancy and reproductive diseases later on.
Make sure to consult with your veterinarian before neutering your dog. Ask any questions you may have. Dogs can be sprayed while in heat, but there is an additional risk due to the engorged vessels and tissue of the reproductive tract. That means a higher chance of bleeding during surgery. Some veterinarians charge a higher price for neutering dog in heat.