Question

can i get a summery of heat cycle and a step by step on what it is or do please

Answer 1

Heat cycle

When a female dog is receptive to mating, she is in a stage of her reproductive cycle known as being in heat. Each dog differs in length of heat, discharge amount and hormonal changes. Dogs typically have two heats per year beginning between six months to one year of age. The heat cycle of the female lasts from 18 to 21 days. The heat cycle vary depending on the breed and size of the dog. Smaller dogs tend to have their first heat cycle earlier and large breed dogs later.

There are 4 stages of the dog heat cycle

They are proestrus, estrus, diestrus and anestrus. These 4 stages has different signs related to physical or clinical changes, behavior, hormonal changes, cytologic (vaginal smear) and physiologic changes.  

General description of the various stages and the changes associated with each stage

1. Proestrus

The first stage is called proestrus. It shows the symptoms that the dog is in heat. This stage lasts for an average of 9 days, but many dogs experience from 0-27 days. The first sign of this stage is the swelling of the vulva and best symptom that the beginning of a dog heat cycle. This is accompanied by a bloody vaginal discharge and she may urinate more often. when males dogs will be attracted to the female, but she will not be receptive. The estrogen levels will peak and the follicles will develop. The dog may display changes in behavior such as

A personality change: A female dog will become more affectionate and clingy.

Appetite changes: It’s not unusual for a dog to go off her food a bit during this first week, or she may get hungrier.

Swelling of the vulva: Dog’s vulva will look swollen or larger than normal.

Tail tucking: Whenever another dog approaches it guard the vulva, either by tucking the tail between the leg or sitting down.

2. Estrus

This is the stage where the dog becomes ready to breed typically last from 3-21 days and lasts 9 days on average. This is the time the dog is is in actual heat (fertile) and where the ovaries begin to release eggs for fertilization. The vaginal discharge may change from bloody to a clear or brownish discharge. The dog move her tail to the side, making herself available to a male dog. This is known as “flagging” a sign that she is fertile. This will determine if this is the best time to breed. Some changes occurs during this period, they are

Lightened discharge: Previously bright red, the discharge now lightens to be somewhat pink.

Softening of the vulva: Initial swelling subsides just enough to make the vulva soften enough for penetration.

Sometimes a very serious complication that can occur after estrus called pyometra ie., an infection of the uterus. This is an emergency situation and could even cause death.

3. Diestrus

As diestrus takes over, the fertile part of the heat cycle comes to an end and the female is no longer receptive to the male. This stage can last from 60-90 days and at this point, the dog is no longer fertile. When the Estrogen levels are low and the progesterone peaks 3 to 4 weeks after the start of diestrus period and then declines to basal levels by the end of diestrus period. This increase and then decrease in progesterone will occur if the dog is pregnant. Signs of the diestrus stage include:

Gradual disappearance of vulva swelling: Most of the swelling is gone within one week’s time, but the vulva may remain slightly enlarged.

4. Anestrus

Anestrus is the final stage or resting stage of the dog heat cycle. This is the longest phase of a dog’s heat cycle, from 100-150 days. It is the time between diestrus and the next proestrus. There is no vaginal discharge and no swollen vulva.