The Heat Cycle
The estrus cycle, also known as the heat cycle is the period when the female dog eliminates eggs and is ready to reproduce. Typically, females are in heat 2 times per year. The estrus cycle has 4 stages:
- Proestrus (lasts up to 2 weeks)
- Estrus (4 to 8 days)
- Diestrus (6 to 10 weeks)
- Anestrus (around 15 weeks)
The Proestrus
The signs of the proestrus cycle are obvious:
- Vaginal pink discharge
- Bleeding
- Swelling of the vulva
- Increased urination
A dog in heat is also more agitated than usual and you may also notice a lot of dogs interested in mating with her. The female releases pheromones that will attract males from a considerable distance. However, during the proestrus, the female dog will reject any approaching male.
This stage of the cycle will last 4 to 14 days, according to the size and breed of the dog.
The Estrus
The estrus is the stage of the heat cycle when the female dog may get pregnant. The female dog accepts males at this stage and is friendlier.
The estrus is signaled by the stopping of bleeding and discharge; the dog also releases eggs. This stage lasts 4 to 8 days. If the dog gets pregnant, the pregnancy lasts for 9 weeks on average.
If you want to prevent the pregnancy, the female dog needs to be spayed before her first heat cycle or as soon as possible. Some vets prefer spaying during the first estrus.
The Diestrus
The diestrus is the third stage of the heat cycle and takes 6 to 10 weeks. During this stage, there are many hormonal changes, the dog will be easily irritable and have shifting moods.
Dogs that haven't been fertilized may present signs of false pregnancy:
- Swollen mammary glands
- Production of milk
- Affectionate behavior towards humans or toys
- Moaning, whining
- Looking for secluded placed to build a nest
- During the diestrus, the female will not be interested in mating.
The Anestrus
The anestrus lasts for 15 weeks and is the last stage of the heat cycle. This stage doesn't present any hormonal activity; the dog will have a normal behavior, no vaginal discharge and no interest in mating.
If the female dog is not spayed, the anestrus stage will be followed by the entire heat cycle.
Benefits of Spaying
If you choose to spay your dog, this is a simple procedure that involves removing the uterus and the ovaries. A spayed dog lives a healthier and longer life and you don't have to worry about unwanted puppies.
In addition, spaying can also prevent ovarian cysts, tumors in the ovaries or uterus, uterus infections or mammary cancer. The dog will have no more mood swings and bleeding. Ideally, spaying should be performed before the first heat cycle (6 to 14 months, depending on the breed).