Is Your Dog in Heat? Here's All You Need to Know

Pet care & safety
Dog in Heat

You’ve no doubt heard of a dog “going into heat” - but do you know what it means? Estrus, known as heat, is a stage in a female dog’s reproductive cycle. Mating with males occurs during this stage. Estrogen levels begin to increase and then quickly decrease. Mature eggs are then released from her ovaries.

When to Expect It and How Often Dogs Go Into Heat

If you got your furry companion as a puppy, you’re probably wondering when she will go into heat for the first time. Usually, this occurs between 6 and 24 months of agpuse, unless you get her spayed first. If you have a small breed, it can happen earlier. Larger dog breeds can take a little longer than 24 months. Your dog will typically go into heat at least twice per year.

How will you know when your dog is in heat?

You will likely know when your dog is in heat as it can get quite messy. Signs include:

  • Being more affectionate with you and noticing male dogs more

  • Menstrual bleeding

  • Excessive licking

  • Appetite changes

  • Temperature changes

  • Behavior change (agitated and/or anxious)

How long is a dog in heat?

You may think your dog is no longer in heat once she stops bleeding. However, that’s not true. Each heat cycle lasts three to four weeks, but bleeding is seen only during the first two weeks. The most fertile period is when the bleeding lessens and becomes clear or pink.

While bleeding is not something you want to deal with, it’s usually only a small amount, and you can use sanitary diapers for dogs. With some dogs, you may not even notice bleeding.

Watch Out for Pyometra

Around two to eight weeks after your dog’s heat cycle, she will be vulnerable to pyometra, which is a uterus infection. When your dog is in heat, her body is preparing to become pregnant (even if that’s the last thing you want). White blood cells that usually protect the uterus from infection aren’t present, allowing sperm to enter and thrive. Progesterone thickens the uterine lining and the cervix is open for sperm to enter. If your dog doesn’t become pregnant, she is now vulnerable to an infection. When the cervix is open, it’s known as an open pyometra infection. With a closed cervix, pus won’t be able to drain, which is even more life-threatening as it can lead to a distended belly.

So, how do you know if your dog has pyometra? She will show signs of diarrhea, vomiting, restlessness, and fever. If you notice any of these signs, contact the vet right away.

Why You Should Spay Your Dog and When

An unspayed dog has an increased chance of mammary cancer, which is the equivalent to breast cancer in dogs. Make a habit of checking your female dog for any lumps in her breast tissue from armpit to groin. Contact your vet if you feel anything out of the norm. You can get your pup spayed as soon as six weeks old, though many vets like to wait until six months or after. You must make sure your dog is not in heat during spaying as her uterus will be engorged and will bleed even more. Spaying your dog not only takes away the chance of pregnancy but will also protect her against pyometra and certain cancers.

It’s a personal decision to spay or not spay a dog. If you choose not to, be aware of potential health issues so you can protect your female pup to the best of your ability.