Dog heat cycle guide.

There are four stages of the heat cycle, Proestrus, Estrus, Diestrus and Anestrus.

It’s important to know when your dog it coming into heat and going out of heat. There are some clear signs and some subtle clues. Pay attention to your dog and learn her behavior. This will help you understand what’s going on when she 'does' come into heat.


Proestrus Stage

This stage of dog heat can last from 4-20 days. The average is 7-10 days. There are 3 common signs for a dog in heat during this stage:
Swollen Vulva: This is one of the best ways to spot the beginning of a dog heat cycle. The swelling is a significant difference over her “normal” appearance. Her teats may also swell slightly, but this is not a great heat indicator and can be tricky to spot.
Discharge: Your female may suddenly spend a lot of time licking herself. Take a tissue and wipe her vulva. If you notice red discharge, and her vulva is swollen, that’s a pretty good indicator that your dog is definitely coming into heat. It’s important to check this, since timing is everything when it comes to mating (or preventing a mating) your dog. The first day you notice the bloody discharge is called "DAY 1". Mark it on your calendar.
Suitors The third sign of heat is not found on your dog, but in the presence of other dogs. You may notice neighbor dogs hanging out around your house. They can smell your female's heat cycle. You may notice that your dog will tuck her tail often, protecting herself. She is not ready to accept a sire.


Estrus Stage

The Estrus Stage of the Dog Heat Cycle typically last from 5-14 days. The time your dog is fertile (her actual heat). At this stage, the discharge typically changes from red to straw colored. In many dogs it’s still somewhat pink, but you will notice a definite difference in color from the beginning of proestrus. This change usually occurs around day 8 or 9. Your dog will also be willing to accept a sire during this stage. She will switch her tail to the side. She may whimper and try to be outside more often than is normal for her. She is following her instinct to breed. Keep a close eye on her. Even if she is in a kennel, she can still end up pregnant.


Dogs get VERY creative during this stage. If you notice strange males in your yard, stay away from them. Bring your dog inside and wait for them to leave. When males are anxious to breed, they can be much more likely to bite. Don’t take your female to the pet store or the dog park. You can inadvertently cause problems that you really don’t want. It’s best just to keep her secluded to your yard and home. We have even seen a male sire impregnate a bitch through the holes in a chain link fence - so be very protective and cautious. Otherwise, you are going to be ordering DNA testing kits.


Diestrus Stage

The Diestrus Stage of the Dog Heat Cycle usually begins around day 24. This stage can last from 60-90 days. Your dog is no longer fertile at this point. Her discharge will change from straw colored to red and then stop completely. She still has a scent and can still attract unwanted attention, so wait until she has completely stopped bleeding before venturing into public places.


Anestrus Stage

This is the fourth and final stage of the dog heat cycle when your dog is “normal”. This stage last about 60-90 days, at the end of which, the entire heat cycle starts again.