What To Know About Dogs in Heat

There comes a time in the life of an intact female dog when they’re ready to breed. This period is called being in heat. The stage of heat, also called estrus or season, has distinct physical and behavioral signs. 

Many of the estrus factors, such as frequency, length of time, and severity, are dependent on your dog’s age and breed. Your dog may have symptoms that are particular to them. 

What Are the Signs?

Keep a leash handy, because your dog may have to urinate more when she’s in heat. You may also observe that her vulva is large, red, or swollen with some bleeding or blood-tinted discharge. 

Your dog will only bleed for around half of the total cycle, usually 7 to 10 days. Generally, bigger dogs bleed more than smaller dogs, but it varies between dogs. Some dogs bleed very little. If your dog prides themselves on their appearance and grooms themselves regularly, you probably won't find much blood spotting around the house. 

Your dog’s behavior will likely change as well. She may:

  • Be overly friendly with other dogs
  • Seek out male dogs
  • Mount or hump
  • Turn her tail to the side
  • Fidget or be nervous

Even though your dog will bleed, she isn't in pain during heat. However, being in heat can make your dog uncomfortable and fidgety. If her symptoms seem to be causing her pain, consult your vet

When Does Estrus Start?

This depends on your dog’s size. 

Smaller dogs can go into heat as soon as they are 4-months old. Larger breeds may not first go into heat until they are 18 to 24 months old. On average, the first heat begins at around 6 months of age. 

Even though they are old enough to get pregnant, your young dog’s eggs aren’t yet fully matured. Waiting until after the second estrus cycle will promote a healthy pregnancy.

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How Often Do Dogs Go Into Heat?

Similar to the start time, the exact frequency of estrus depends on your dog’s size, breed, and age. Female dogs who have not been spayed go into heat twice a year, around every 6 months. Each heat cycle lasts around 18 days, for generally anywhere from 2 to 3 weeks. 

The frequency depends on your dog, but her estrus cycles should be consistent. If these are inconsistent, your vet can determine if your dog has irregular seasons.

As your dog gets older, the frequency of her seasons may slow down. However, she will be going into heat for her whole life. Even though she goes into heat less often, she can still get pregnant.

The Estrus Cycle

The canine estrus cycle has four stages:

1.Proestrus: The beginning of heat lasts between 7 and 10 days. During this time, the vulva begins to swell and your dog begins to bleed. She will start attracting male dogs, but she isn’t ready to mate yet.

2.Estrus: This is the mating period of the estrus cycle. It lasts 5 to 10 days. Bleeding may reduce or stop. Your dog is ready to mate during this time. 

3.Diestrus: This period lasts anywhere from 10 to 140 days. Your dog is either pregnant during this time or she is in a period of rest.

4.Anestrus: This is the period of downtime before the next heat cycle, lasting around 6 months. 

Care

If your dog is in heat, she’ll require a bit of extra supervision and care. She’ll be feeling hormonal. Keeping her entertained and distracted will help relieve some of her anxiety and discomfort. Extra walks will also help her to reduce stress. 

Not only will she be attracting male dogs, but she’ll be attracted back! To avoid pregnancy, you’ll probably want to keep her away from other non-neutered dogs. This is true even in your own household. 

If you’re worried about your dog bleeding around the house, you can create a limited space for her to roam in. This usually means restricting her to easy-to-clean areas without carpeted floors or upholstered furniture. 

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Creating a nest for your dog to nap in with towels to catch the blood will help prevent any accidents from occurring. Doggie diapers can also help control bleeding accidents.

Your dog’s needs while she is in heat may vary. This can be a challenge and a big responsibility. If you want to avoid pregnancy, you can have your dog surgically sterilized before her first season. Since the timing of the first heat cycle varies, these procedures are recommended before she is 6-months old.

WebMD Medical Reference Reviewed by Kathleen Claussen, DVM on February 14, 2021

Sources

SOURCES:
AKC: “How Long Does a Dog Stay in Heat?,” ​”When Do Dogs Go Into Heat?”

Michelson Found Animals: “How Long Does a Dog Stay in Heat? (And Other Dog Period Questions Answered).”

MERCK MANUAL: “Breeding and Reproduction of Dogs.”

PDSA: “Dogs in heat/coming into season.”

VCA: “Estrous Cycles in Dogs.”

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