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How Long Does a Dog Stay in Heat

How Long Does a Dog Stay in Heat

Whether you're a first-time breeder or an excited new pet owner, understanding your dog's heat cycle is important. You may be asking yourself: How often do dogs go into heat? How long does a dog stay in heat? Find the answers to your questions and learn more about your dog's heat cycle!

How Often Do Dogs Go Into Heat?

Most female dogs go into heat, or experience estrus, for the first time when they are about 6 months old. This can be earlier for small-breed dogs and later for large-breed dogs. Most dogs will go into heat about every 6 months, although this can vary depending on the breed and the dog. Smaller breeds may go into heat more often, while larger breeds may go into heat less often.

It may take a year or two for a dog's cycle to become regular. Female dogs will go into heat throughout their entire lives, although they will probably go into heat less often as they get older.

If you plan on breeding your dog, you should talk with your veterinarian about when your dog is ready to be bred. Many vets advise not breeding young female dogs during their first or second cycle.

Before breeding your dog, you should consider giving her a pre-breeding supplement, like Breed Heat from Thomas Pet. This formula is designed to support reproductive health, help regulate hormones, and bring female animals into normal heat cycles.

Symptoms of a Dog in Heat

When a dog is in heat, she's receptive to mating and experiences hormonal changes that indicate she's in heat, including a swollen vulva, bloody vaginal discharge, and more frequent urination. Female dogs are often more nervous, alert, and easily distracted during their heat cycle.

When the discharge decreases in amount and blood, the female often becomes receptive to males. She may elevate her hindquarters toward male dogs when they approach while holding her tail to the side.

How Long Does a Dog Stay in Heat?

Heat cycles in female dogs usually last between 2 to 3 weeks. Some dogs may be in heat for a shorter or longer period. You'll know the heat cycle is over when there's no more bleeding or discharge and her vulva returns to its normal size. It's important to note that female dogs aren't usually receptive to males during their whole cycle.

Many people wonder when their dog is most fertile to increase their chances of a successful breeding. Generally, dogs are most fertile after the proestrus stage, which is about 9 days long, and during the first 5 days of the estrus stage of the cycle. Understanding the Reproductive Cycle in Dogs There are 4 stages of a female dog's reproductive cycle.

Understanding the reproductive cycle in dogs is important for determining the best time to breed a dog and calculating conception dates. The 4 stages are proestrus, estrus, diestrus, and anestrus. Dogs experience different symptoms during each stage.

  • Proestrus: The first stage of a dog's reproductive cycle lasts about 9 days. The symptoms of this stage include bloody discharge and swelling of the vulva. Although females will start to attract males during this time, most of them will reject the male until the next stage.
  • Estrus: The second stage generally lasts about 9 days, but can last anywhere from 4 to 21 days. This is the stage when the female is most fertile, and she will be receptive to the male. The signs of estrus include a soft, enlarged vulva and a decrease in blood in the discharge. The discharge may become straw-colored.
  • Diestrus: This is the final stage of the heat cycle. The signs of diestrus include the vulva returning to normal and the discharge decreasing and stopping. The female will no longer be receptive to males during this stage.
  • Anestrus: This is the timeframe between heat cycles, and it usually lasts around 4 to 6 months, although it can last much longer.

If your female becomes pregnant, you may not notice any visible signs at first. Some early signs of pregnancy in dogs may include loss of appetite, fatigue, and vomiting. If you think your dog might be pregnant, you should visit with your veterinarian. Your vet can perform a variety of tests to confirm if your dog is pregnant.

The Importance of Nutrition

If your vet determines your dog is pregnant, having a healthy litter and successful whelping experience is the goal. This requires taking proper care of the momma dog during her pregnancy. Meeting the nutritional requirements of your pregnant dog is essential for a healthy pregnancy and puppies.

In addition to feeding your dog a nutritional diet, there are supplements that can help support dogs during pregnancy. A prenatal vitamin, like Bitch Pills, can help cover nutritional gaps in your momma dog's diet and help support the needs of developing puppies.

Preventing Your Dog From Going Into Heat

The only way to prevent your dog from going into heat is by having her spayed. If you aren't planning on breeding your dog, it's highly recommended to get her spayed, which can have numerous health and behavioral benefits. Your vet can help you determine the best time to spay your dog.

Looking Ahead

Now that you know the answer to, "How long does a dog stay in heat?", you can focus on taking care of your momma dog and preparing for whelping.

Thomas Labs® understands that preparing for whelping can be overwhelming if you aren't sure what to expect or what supplies you'll need. Familiarizing yourself with the whelping process and planning ahead will help make the experience a lot smoother for you and your dog!


The materials and information provided on this website are not intended to replace the medical advice or services of your veterinarian or other pet healthcare professional. Consult your own veterinarian if you have medical questions concerning diagnosis, treatment, therapy, or medical attention.

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