Exact Answer: 2-4 Weeks
Many dog owners are worried about how long their dogs will be in heat. It turns out dogs only go into heat once every six months, which means people get to enjoy their dog’s company for the other five.
Although It is not a question that most people think to ask, it is something that dog owners need to be aware of.
Dogs go into heat twice per year. The first of these heats happens between six months and one year old, while the second starts between eight months and two years old.

How Long Are Dogs In Heat?
Stages | Duration |
Estrous | 4 to 5 days |
Dog Pregnancy | 57-65 days |
That depends on a dog’s cycle. Female canines go in heat twice a year for two to three weeks each time.
If a dog owner had their female dog spayed before her first heat cycle, then she will never experience any more cycles again. However, if a dog goes into heat for the first time after getting spayed or neutered, she may still experience future heat as well.
A female would have her first heat when she is six months old after having all her puppy teeth. A female dog often goes into heat just before or just after the anniversary of the day when she was born–for example, if a dog was born July 1st, she might go into heat around June 20th and August 1st each year.
Dogs are in heat for different lengths depending on their age, but it lasts 7-10 days. Dogs come into “true estrus” twice in a cycle, with the second showing being significantly shorter than the first.

Each period can last anywhere from 4 to 14 days. However, in our pets’ modern world, where they are either spayed or neutered at an early age and never actually “in heat,” this can be difficult to identify because there is no true signal that the pet is approaching fertile time.
Therefore, it is better if one keeps a record of these days early on. Although the time between each cycle gets longer, the dog will be in heat throughout their lives.
Why Are Dogs In Heat For So Long?
Dogs are in heat for so long because they secrete hormones called prostaglandins to help female dogs try and get pregnant. This hormone release is what causes their reproductive cycle process to take time and helps them get pregnant.
Each of these hormones has a slightly different period of release. Still, one knows that an important hormone is oxytocin released at various times during the lifespan of an animal and helps trigger uterine contractions, also known as “winding down” for any given animal.
The first sign of estrus is swelling or enlargement of the vulva. The amount of discharge is different for each dog. In most cases, the pet owner comes to know that the dog is in heat when there is bloody vaginal discharge.
Dogs in heat will show these natural behaviors for about six to seven weeks. When her ovulation period ends, most females go back into the subfertile phase, which lasts three weeks.
If the female is bred again during this time, she will most likely return to heat very quickly after the end of the subfertile phase before lasting long enough to develop pregnancy. During this phase, the dog’s urine has pheromones and hormones, signalling the male dogs for reproduction.

Male dogs are wired to detect a female in heat even from a long distance. Also, doctors advise not to breed a young female dog during the first two cycles as they have not met their full maturity and must be put on hold for a while.
Conclusion
To reduce the risk of mammary cancer, many owners choose to spay their female dogs. This is also responsible for eliminating the possibility of unwanted litter. If there are any symptoms, make sure to contact a veterinarian as soon as possible, and one can discuss different options that are suitable for the dog.
During the early stages of the cycle, a female dog will not be as receptive as a male dog. The window for a dog to get pregnant is small and lasts between five days. Unlike humans, dogs will be in heat throughout their lives, and the cycles will get longer.
References
- https://avmajournals.avma.org/doi/abs/10.2460/javma.2001.219.770
- https://academic.oup.com/biomedgerontology/article/73/2/150/3788690?login=true

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