{"id":2011,"date":"2025-09-18T09:05:29","date_gmt":"2025-09-18T16:05:29","guid":{"rendered":"https:\/\/www.sbahvet.com\/blog\/?p=2011"},"modified":"2025-09-18T09:05:30","modified_gmt":"2025-09-18T16:05:30","slug":"how-long-are-dogs-in-heat","status":"publish","type":"post","link":"https:\/\/www.sbahvet.com\/blog\/how-long-are-dogs-in-heat\/","title":{"rendered":"How Long Are Dogs in Heat?"},"content":{"rendered":"
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\"Female<\/figure>\n<\/div>\n\n\n

At Sunrise Boulevard Animal Hospital, we recommend that most dogs be spayed for a variety of health reasons (and to reduce the number of homeless pets). However, should you choose to breed your dog, or if you have adopted a dog who has not yet been spayed, you\u2019ll want to know what to expect in terms of her heat cycles. Keep reading to find out how long unspayed female dogs are in heat.<\/p>\n\n\n\n\n\n\n\n

Across Your Dog\u2019s Lifetime<\/h2>\n\n\n\n

Your dog\u2019s size and breed will affect when she reaches sexual maturity and experiences her first reproductive cycle<\/a>. Smaller dogs may go into heat for the first time around 4 or 5 months, but larger breeds may not experience this until they are as old as 2. That\u2019s why your veterinary team<\/a> might have very specific recommendations on when a female dog should be spayed<\/a>.<\/p>\n\n\n\n

An unspayed dog will go into heat twice per year, and this can last until her senior years. Unlike humans, dogs have the ability to get pregnant even into their senior years (but they might be less fertile as they get older).<\/p>\n\n\n\n

What is One Heat Cycle?<\/h2>\n\n\n\n

A dog\u2019s heat cycle has 4 distinct stages<\/a>:<\/p>\n\n\n\n

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  1. Proestrus <\/em>is when a dog produces estrogen, leading to tell-tale bloody discharge and swelling of the genitalia. This lasts about 1 to 1 \u00bd weeks. Male dogs will often demonstrate interest in female dogs during this stage, but females will not be ready to breed.<\/li>\n\n\n\n
  2. During estrus<\/em>, the female dog is ready to breed, and this stage can range from just 1 day all the way up to 3 weeks. She will experience hormonal changes that prepare her for pregnancy. You might notice her discharge change from bloody to yellowish as a signal that she has entered estrus. If you are not planning for puppies, this is the most vital time to keep your girl away from unneutered males!<\/li>\n\n\n\n
  3. In diestrus<\/em>, she will no longer be ready for pregnancy, though hormonal changes might make you think she is pregnant. She may be swollen or bloated, and she might even produce milk. If you are unsure about whether your dog is carrying puppies, please feel free to reach out to us<\/a>.<\/li>\n\n\n\n
  4. Finally, anestrus <\/em>occurs at the end of the heat cycle when reproductive hormones are at their lowest until she begins her cycle again in six months or so.<\/li>\n<\/ol>\n\n\n\n

    How To Care for Your Dog While She Is in Heat<\/h2>\n\n\n\n

    Caring for a dog in heat involves both physical and emotional support:<\/p>\n\n\n\n