There are many tell-tale signs a female dog is about to go into heat. From physical developments like a swollen vulva to a noticeable discharge to being more agitated or needy – even a different tail position can give signs a dog is coming into season or either in heat. If you really want a heads up as to when heat is coming, or if you are a professional, responsible breeder, you’ll begin checking hormone levels, which are the very first sign heat is coming.
This pivotal moment in a dog’s life means more work for you than for them, so let’s investigate what you need to know about a dog’s reproductive cycle.
Things You Need to Know about a Female Dog Going Into Heat
There are four stages of a female dog’s reproductive cycle that owners need to help them through. Male dogs don’t go through any kind of reproductive cycle. At five months old, they can start being fertile, and sexual maturity hits around the year mark. After that, they are always “ready to go” if they are not neutered (and some don’t lose the urge even when they do get fixed.)
Female dogs can reach sexual maturity as early as six months old. This is when you need to start watching even closer for changes to the dog’s behavior. Larger breeds of dogs might not reach sexual maturity until after the year mark. It’s important to ask your vet what to expect for your particular pet.
Signs A Dog Is Coming Into Season
Proestrus: 7-10 Days
This stage is the earliest you’ll notice a dog going into heat. The first sign to look for is a swollen vulva. She’s going to need to potty more often and might lick her genitals obsessively. The dog will develop a discharge, anywhere from light-colored to blood-tinted to dark red. Her estrogen hormone is surging.
There are doggy diapers you can buy if you don’t want a mess on your carpet or furniture. You can buy disposable or reusable diapers. You can even get fashionable designs for your favorite girl.
The rub-on this part of the process is that the female’s scent will attract male dogs, but she’s not going to let them mount her. She could get aggressively defensive about it. It’s important to keep your female dog away from male dogs during any part of the heat cycle unless you intend on breeding.
Estrus: 5-10 Days
FUN FACT: Estrus stems from the Latin word meaning “Frenzy”
This is when “all systems go.” Estrus is the same thing as being in heat. The dog is ready to mate. The bloody discharge will stop. Remember all that urinating the dog was doing during the first phase? That was her letting all the male dogs know she’s ripe for action.
When the discharge from proestrus becomes clear instead of blood-tinted, this is a sign the dog is entering estrus. She’s most fertile at this stage. Keep in mind if she does tie with another dog, the sperm can live a week in her reproductive system, so pregnancy is possible during any point of this stage.
The female dog at this point will move her tail to the side to allow easier access to the potential male breeder. Male dogs at this point can smell a dog in heat and even if they have a generally chill disposition, they might become aggressive trying to get to her. It’s just nature, folks. Studies show a male dog can smell a female dog in heat up to three miles away.
If you don’t want your female dog to become pregnant, it’s imperative you NEVER let her run off-leash during this time. You should have her under a short lead at all times and limit her time outdoors. Even running in the backyard off-leash can create a problem as a male dog will do whatever it takes to get through that fence.
Should unwanted mating happen, there is little you can do when the dogs are “tied?” They are essentially locked together and no amount of calling, cold water, or shouting is going to break them up. DO NOT pull them apart as this can result in injury. Contact your vet immediately afterward.
Diestrus: Day 10-140
This is the calm time after heat when either a dog is pregnant, or not pregnant and also not fertile. The discharge lessons and the vulva returns to regular size. Males will still try to mount, but she’s not having it.
You can resume normal activities, but it’s best to work with your vet to make sure the dog is actually out of the heat, especially early on in this stage.
One thing to look out for in this phase is “phantom pregnancy” or, as the American Kennel Club (AKC) calls it – false pregnancy. The dog isn’t pregnant, but her body is producing milk, or her nipples are swollen.
This is an uneventful period as far as reproduction goes. This is after diestrus but before the next heat cycle.
Shouldn’t I Get My Dog Spayed Before Going Into Heat?
For a long time, general guidance was to have a dog spayed or neutered at six months old, safely preventing any unwanted pregnancies. Many shelters won’t let a dog go home until it is fixed.
New research suggests it’s best to let a female dog go through one heat cycle before being spayed so she can reach full maturity. Waiting allows the growth plates to close so the dog is fully developed. Doing it earlier can keep that growth plate open and cause growth and size issues that you might not see visually, but it could cause problems with bones, hips, and joints down the road.
What if My Dog Ties and it’s an Unwanted Pregnancy?
First, don’t feel too bad about it. The natural instinct of dogs to mate is not something you can easily control. It does happen and there are ways to terminate a pregnancy in the first few days.
Female dogs have pregnancies that only last 2-3 months, so time is of the essence. You will need to immediately notify your veterinarian to explore the options, as there can be adverse side effects of the medicines given to stop the pregnancy.
Will a Neutered Dog Try to Tie with a Female Dog in Heat?
Once a male dog has been neutered, his testosterone levels go down, so he has little interest in mating. Even if your guy is a hamper, that doesn’t always mean they are sexually searching for a mating that will never happen. Sometimes it’s a reaction to stress or it just feels really good.
All that said, the neutered male CAN tie with a female in heat. It’s the same process as mating, and when they tie, don’t try to stop it. The only difference is a pregnancy will not result from mating.
It’s important to note about 6.3 million unwanted pets are brought to animal shelters each year nationwide. Almost a million of those don’t live to be adopted. Breeding should be done responsibly and intentionally, so take all steps you can to avoid unwanted pregnancy by being cognizant of the signs a female dog is in heat.