If you’ve just brought home your first female dog, you might be wondering: do dogs get periods? The short answer is yes—but it’s nothing like what humans experience. Female dogs go through a reproductive cycle called estrus, commonly called “going into heat.” It’s messy, it’s smelly, and it can be confusing if you don’t know what’s happening. As a vet tech who’s cleaned up more than my fair share of accidents, I’m here to walk you through exactly what to expect, how long it lasts, and what you can actually do about it.
Your female dog doesn’t menstruate the way you do. Instead, she experiences estrus—a hormonal cycle that makes her body ready to reproduce. During this time, she’ll have a bloody discharge, behavioral changes, and she’ll be attractive to male dogs from miles away. It’s nature’s way, but it’s also your cue to keep a close eye on her and understand what’s happening in her body.
Do Dogs Actually Get Periods?
Yes, female dogs do get periods, but we call it estrus or “going into heat.” It’s a natural reproductive cycle, not menstruation in the human sense. The key difference: female dogs shed the uterine lining only if they don’t get pregnant. If they do get pregnant, the cycle stops and they carry puppies instead. Humans menstruate whether or not they’re pregnant—totally different biological systems.
Here’s the real talk: when your dog is in heat, she’ll bleed. You might see blood spots on her bed, on your furniture, or on your floors. Some dogs are fastidious and clean themselves constantly, so you might not see much. Others? You’ll definitely notice. The bleeding typically lasts 7-10 days, though it can vary.
According to the American Kennel Club (AKC), understanding your dog’s reproductive cycle is crucial for responsible ownership, whether you’re planning to breed or simply want to keep her safe and healthy.
Pro Tip: Invest in washable dog blankets or pee pads for her favorite sleeping spots during her heat cycle. Trust me, this saves your couch.
The Estrus Cycle: What’s Really Happening
Your dog’s estrus cycle has four stages, and understanding each one helps you know what to expect. Think of it like a month-long hormonal roller coaster.
Proestrus (Days 1-9): This is the beginning phase. Her body is ramping up estrogen production. You’ll notice swelling of the vulva and bloody discharge. She might act slightly different—a bit more clingy or anxious—but she’s not quite ready to breed yet. If a male dog approaches, she’ll likely snap at him or move away.
Estrus (Days 10-14): This is the “fertile window.” Estrogen levels drop and progesterone rises. Her discharge becomes lighter and more watery. Most importantly, she’s now receptive to males. Her behavior changes dramatically—she might stand with her rear elevated, move her tail to the side, or actively seek out male dogs. This is when unwanted pregnancies happen if you’re not careful.
Diestrus (Days 15-26): Whether she got pregnant or not, her body shifts into this phase. If she’s pregnant, her body prepares for motherhood. If not, hormone levels gradually decrease. She becomes less interested in males, and her discharge dries up.
Anestrus (Days 27-60+): This is the “off” phase. No heat, no discharge, no interest in breeding. Her body is resting before the whole cycle starts again in about 6-12 months.
Signs Your Dog Is in Heat
Knowing the signs of heat is essential, especially if you have an intact (unspayed) female dog. Here’s what to watch for:
- Vaginal discharge: Bloody or blood-tinged discharge is the most obvious sign. It can be heavy or light depending on the dog.
- Vulvar swelling: Her vulva will be noticeably enlarged and may appear darker than usual.
- Behavioral changes: She might be more affectionate, anxious, restless, or clingy. Some dogs become slightly aggressive or irritable.
- Increased urination: She’ll pee more frequently, often in small amounts. This marks her territory and signals to males that she’s in heat.
- Tail positioning: During peak fertility, she’ll often hold her tail to the side or up, exposing her rear end.
- Flagging: She might stand with her rear end elevated and rear legs slightly spread—this is her way of saying “I’m ready.”
- Attraction to males: Male dogs will suddenly be very interested in her. You might notice them lingering around your yard or trying to mount her.
- Scent changes: Her pheromones change dramatically. You might notice a stronger smell, and males can detect it from incredibly far away.
- Licking the vulva: Excessive licking is normal as she keeps herself clean, but if it becomes obsessive, mention it to your vet.
Not all signs are obvious in every dog. Some are subtle; others are impossible to miss. If you’re unsure, your vet can confirm with a vaginal cytology test—basically a swab to check her cells.
How Long Does a Dog’s Heat Cycle Last and How Often Does It Happen?
This is where individual variation matters. Most dogs go into heat twice a year, roughly every 6-12 months. Some breeds—particularly larger dogs—might only cycle once a year. Smaller breeds might cycle three times annually.
The entire estrus cycle lasts about 21 days on average, though it can range from 18-24 days. The bleeding phase typically lasts 7-10 days. After that, she might still be fertile for a few more days even without visible discharge.
Here’s the tricky part: your dog can get pregnant during her heat cycle, even if you think the bleeding has stopped. I’ve seen too many “surprise” litters because owners assumed the heat was over. It wasn’t.
Age matters too. Puppies usually have their first heat between 6-12 months old, though some large breeds don’t cycle until 18-24 months. As she ages, heat cycles might become less regular. Older dogs can still cycle, but it’s less predictable.
Safety Warning: Never assume your dog can’t get pregnant just because you don’t see discharge anymore. Keep her away from intact males for the full 3-4 week period to be safe.
Managing Your Dog During Her Heat Cycle
If you’re not planning to breed your dog, managing her heat cycle is about preventing unwanted pregnancies and keeping her comfortable. Here’s what actually works:
Keep Her Indoors: This is non-negotiable during estrus. Even a few seconds in the backyard can result in pregnancy if there’s an intact male nearby. Male dogs can smell a female in heat from up to a mile away. Yes, a mile. Keep her inside, especially during peak fertility (days 10-14).
Leashed Walks Only: If she needs to go outside, keep her on a short leash at all times. Don’t let her off-leash in parks or open areas. Even the friendliest dog might try to mount her during this time.
Use Dog Diapers or Pads: Washable dog diapers are a lifesaver. They prevent staining your furniture and make cleanup easier. Some dogs adjust quickly; others hate them. Start early and be patient. Alternatively, use washable pee pads on her favorite spots.
Clean Frequently: Bloody discharge can stain and smell. Wash her bedding regularly and spot-clean accidents immediately. A enzymatic cleaner helps remove the scent, which can attract males.
Provide Comfort: Some dogs experience cramping or discomfort during heat. Offer a comfortable, quiet space. Some benefit from a heating pad (on low, not high). Extra cuddles don’t hurt either.
Monitor for Complications: Watch for signs of infection, such as excessive discharge, foul odor, lethargy, or loss of appetite. These warrant a vet visit. Pyometra (a serious uterine infection) can develop during or after heat cycles, especially in older dogs.
According to PetMD, pyometra is a life-threatening condition that can develop in unspayed dogs, making spaying even more important for long-term health.
Spaying: The Permanent Solution
If you’re not breeding your dog, spaying (ovariohysterectomy) is the best option. It’s a surgical procedure that removes the ovaries and uterus, eliminating heat cycles permanently. No more bleeding, no more behavior changes, no more risk of unwanted pregnancy.
Most vets recommend spaying before the first heat cycle, ideally between 6-12 months old. Why? Because it significantly reduces the risk of mammary cancer and eliminates the risk of ovarian and uterine cancers entirely. The younger you spay, the greater the health benefits.
What to Expect: Spaying is a routine surgical procedure that typically takes 30-90 minutes, depending on your dog’s age and health. Your dog will be under general anesthesia. Recovery takes 10-14 days, during which she needs rest, pain management, and a protective collar (the infamous “cone of shame”) to prevent licking her incision.
Cost: Spaying costs vary widely depending on your location and vet, but typically ranges from $200-$500 for a healthy young dog. It’s more expensive for older dogs or those with health issues. Yes, it’s an investment, but it’s cheaper than raising a litter of puppies or treating reproductive cancers.
Behavioral Changes After Spaying: Most dogs become calmer after spaying. Some might gain weight more easily, so monitor her diet and exercise. She won’t lose her personality or become “less of a dog”—that’s a myth. She’ll just be a healthier, calmer version of herself.
The American Animal Hospital Association (AAHA) strongly recommends spaying and neutering as part of responsible pet ownership.
Health Risks of Leaving Dogs Unspayed
If you choose not to spay your dog, you need to understand the serious health risks involved. This isn’t fear-mongering—it’s veterinary reality.
Pyometra: This is the big one. Pyometra is a life-threatening bacterial infection of the uterus that can develop during or after heat cycles. Signs include excessive discharge (sometimes pus-like), lethargy, loss of appetite, vomiting, and excessive thirst. It’s an emergency requiring immediate surgery and antibiotics. Without treatment, it’s fatal. It’s more common in older, unspayed dogs, but it can happen at any age.
Mammary Cancer: Unspayed dogs have a significantly higher risk of developing breast cancer. The risk increases with each heat cycle. Spaying before the first heat reduces this risk by 99%. After the first heat, the risk reduction drops to about 90%. After the second heat, it’s only about 50%.
Ovarian and Uterine Cancers: These are rare but serious. Spaying eliminates these risks entirely.
Unwanted Pregnancy: Even if you’re careful, accidents happen. Raising a litter is expensive, time-consuming, and comes with health risks for the mother dog. Pregnancy and labor complications can be life-threatening.
Behavioral Issues: Intact females can become more aggressive or anxious during heat cycles. Some become escape artists, desperately trying to find males.
According to research published on the National Center for Biotechnology Information (NCBI), spaying significantly improves long-term health outcomes in female dogs.
Real Talk: I’ve seen too many emergency surgeries for pyometra. I’ve watched owners spend thousands on treatment that could have been prevented with a $300 spay surgery. Don’t wait. Get your dog spayed.
Frequently Asked Questions
At what age do female dogs get their first period?
– Most female dogs have their first heat between 6-12 months old. Large breed dogs might not cycle until 18-24 months. There’s no “normal” age—it varies by individual and breed. If your dog hasn’t had her first heat by 2 years old, mention it to your vet.
Can a dog get pregnant during her first heat?
– Yes, absolutely. Even though she’s young, her body is biologically capable of reproducing. This is why keeping her away from intact males during her first heat is crucial. Pregnancy in young dogs carries health risks, including complications during labor.
How can I tell if my dog is pregnant after her heat cycle?
– Signs of pregnancy include enlarged nipples, weight gain, nesting behavior, and lethargy. Your vet can confirm pregnancy with an ultrasound around 25-30 days after mating or a blood test for relaxin hormone. If you suspect pregnancy, see your vet immediately. Learn more about canine abortion options if needed.
Is it normal for my dog to hump during her heat cycle?
– Dogs might hump during heat for various reasons—hormonal changes, dominance, or just excitement. It’s not necessarily sexual behavior. If it’s excessive or bothering you, redirect her to appropriate activities. For more details, check out why female dogs hump.
Can I use human period products on my dog?
– No. Human pads aren’t designed for dogs and can cause irritation. Use dog-specific diapers or washable pee pads instead. They’re made to fit properly and won’t irritate her skin.
Does spaying affect my dog’s growth or development?
– Spaying won’t stunt growth if done after she’s fully grown (typically 12-18 months for most breeds). If spayed very early, some studies suggest slightly increased risk of certain joint issues, but the benefits still outweigh the risks. Discuss timing with your vet based on your dog’s breed and size.
Will my dog’s personality change after spaying?
– No. Spaying removes her ovaries and uterus, not her brain. She’ll still be the same goofy, loving dog you know. She might be calmer during heat cycles, but her core personality remains unchanged. Learn more about female dog terminology and facts.
Can my dog go into heat while pregnant?
– No. Pregnancy stops the heat cycle. Her body focuses on maintaining the pregnancy instead of cycling. If she’s pregnant and showing signs of heat, something is wrong—contact your vet immediately.
How long after heat ends can my dog still get pregnant?
– This is tricky. While the fertile window is typically days 10-14 of the cycle, sperm can survive for several days. To be completely safe, assume she can get pregnant for the entire 3-4 week heat cycle. Don’t let her near intact males until you’re absolutely certain her cycle is over.
Is there a non-surgical alternative to spaying?
– There are hormonal options like injections or implants that temporarily prevent heat cycles, but they’re not permanent and come with their own risks. Spaying remains the gold standard. Talk to your vet about what’s best for your dog’s specific situation.
What if my dog seems to be in pain during her heat cycle?
– Some discomfort is normal, but excessive pain isn’t. If she’s crying, unable to walk, or showing other signs of distress, contact your vet. It could indicate pyometra or another complication. Never give her over-the-counter pain medication without vet approval.
