Like most mammals, unspayed female dogs experience an estrous cycle when they reach sexual maturity. A dog’s reproductive cycle, however, looks a lot different than that of a human female. So, do dogs have periods? What do pet parents need to know about dog periods?
Do dogs have periods?
Dogs, although they do ovulate, do not have menstrual periods like humans do. Female dogs have a reproductive or heat cycle, during which they become fertile and can become pregnant. Heat cycles are controlled by hormones, and marked by an increase in estrogen levels, then a sharp decrease in estrogen and finally, the releasing of eggs from their ovaries followed by an increase in progesterone.
During heat or estrus, a female dog may have a bloody discharge from her vulva—similar to a human period or menstruation, but not caused by the shedding of the uterine lining. Instead, the bleeding is caused by a combination of blood, mucus, and other fluids that are released from the dog’s cervix.
When do dogs go into heat?
The timing of a dog’s heat cycle can vary depending on the individual dog and her breed, but most dogs will reach sexual maturity and have their first heat cycle between six and twelve months of age.
Small breeds of dogs tend to have their first heat cycles earlier, around six months of age, while larger breeds may not have their first heat cycle until they are a year or even older. However, these are general guidelines and some individual dogs may have their first heat cycles at different ages.
The timing of heat cycles can also be affected by factors such as overall health, nutrition, and environment. According to VCA Hospitals, delayed heat may be caused by a number of reasons, like malnutrition, excessive physical activity, medicines that meddles with fertility, or a lack of exposure to other females experiencing heat. Additionally, hormonal imbalances and genetic problems may also cause abnormal estrous cycles.
How long do dog heat cycles last?
The length of a dog’s estrus cycle can vary depending on the individual dog and her breed, but it typically lasts between 2-4 weeks. It is divided into several stages:
- Proestrus: 3-17 days, average 7 days
- Estrus: 3-18 days, average 9 days
- Diestrus: 58-68 days, average 60 days
- Anestrus: 100-150 days
A dog is said to be in heat when they are in the proestrus and estrus stages of their reproductive cycle. In total, bleeding during a dog’s heat cycle (proestrus and estrus stages) typically lasts 1-3 weeks.
It’s important to note that not all dogs will have heat cycles that follow this exact timeline, and some may have cycles that are shorter or longer. Heat cycles can also be affected by health issues, so if you notice that your dog’s heat cycles are not following a normal pattern, it’s best to consult with a veterinarian to rule out any underlying health problems.