What Are the Signs of a Female Dog in Heat?

There's something special about female dogs. They're fiercely loyal, they can be unbelievably sweet, and they definitely have their very own personalities. When you have a female dog, though, there's one extra bit of care with which you need to be familiar. If your dog isn't spayed, then being able to recognize the signs of a dog in heat can help you to keep her safe and healthy.

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What Are the Signs of a Female Dog in Heat?
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Dog heat frequency

The good news is that dogs don't go into heat too frequently, so you don't need to worry about female dog in heat behavior all that often. If you don't plan on breeding your dog, then spaying her can put an end to unwanted dog in heat symptoms.

According to VCA Hospitals, your female dog will experience her first heat cycle when she reaches sexual maturity, which is around six months of age. Dogs come into heat about twice per year, though small breed dogs may experience three heat cycles per year. Giant breed dogs may only have one heat cycle every 12 to 18 months. Young dogs may initially experience irregular cycles.

Your dog's heat cycle will last for about two to three weeks on average. The exact duration of her heat cycle can vary, too, so it's best to know how to identify signs of a dog in heat to better monitor your dog.

Dog in heat symptoms

When your dog goes into heat, she will progress through three stages: proestrus, estrus, and diestrus. You may be trying to track your dog's heat cycles in order to breed her, or you may want to monitor your dog's first heat cycle with plans of having her spayed. The different heat stages will bring about different heat symptoms in your dog, so knowing just what to look for can help you track the progression of your dog's heat cycle.

Proestrus symptoms

The earliest stage of heat is the proestrus stage, which lasts about nine days. According to Banfield Pet Hospital, dogs in proestrus may have a vulva that looks more swollen than normal. Your dog may hold her tail close to her body and may be clingy and stick by your side.

Breeding Business notes that you may see some bloody discharge during this stage. Some dogs are fastidious about cleaning themselves, though, so this is a symptom on which you shouldn't rely.

During proestrus, your dog will not allow a male to mate. Male dogs will be attracted to your dog, but she may react aggressively if they try to mate. The proestrus stage allows a female dog's body to get ready for mating, but her body won't be completely ready until she enters the second stage of heat.

Estrus symptoms

When your dog enters estrus, she will be ready to breed. According to Banfield Pet Hospital, your dog's discharge may change from bloody to a clear or brown color. As your dog's hormones fluctuate, she'll start to move her tail to the side, signaling to male dogs that she is ready to breed. This is the point at which your veterinarian can test your dog to determine the best time to breed her.

During estrus, which lasts about nine days, female dogs produce pheromones. Male dogs can smell these pheromones from miles away and are attracted to the scent. When your dog is in estrus, you need to be particularly careful about her safety around other dogs since male dogs will be interested in her, and she will usually allow them to mate with her. Multiple males may fight over your female when she's in heat. Female dogs may be aggressive toward your female, and she may fight back at them.

If you're not planning to breed your dog, it's best to keep her separated from other dogs while she's in estrus. This is usually the best way to keep her from potentially being involved in a dog fight, and it's important to be extra vigilant about her safety during this time.

Diestrus symptoms

Banfield Pet Hospital explains that during the final stage of heat, diestrus, your dog will no longer be interested in mating. Her vulva will gradually return to its normal size, and the vaginal discharge will stop.

Concerning dog in heat symptoms

Most of the time, heat cycles go perfectly fine. They're a typical part of life for a female dog. However, a complication can result after estrus. Pyometra is an infection of your dog's uterus, and it can be very serious. It's important to spot the symptoms of pyometra early and immediately seek veterinary help for your dog.

According to VCA Hospitals, pyometra results because of a combination of conditions that your dog's estrus cycle creates. While your dog is in estrus, your dog's progesterone levels stay elevated for about two months. This causes the lining of the uterus to thicken, preparing for a potential pregnancy.

If your dog doesn't get pregnant for several heat cycles, the uterine lining gets thicker, and cysts sometimes develop. The thickened lining then secretes fluids, making an environment that is ideal for growing bacteria. This environment, paired with the fact that your dog's progesterone levels don't allow the uterine muscles to contract and expel the fluids, can lead to infection.

Pyometra risk

According to VCA Hospitals, pyometra most often occurs in sexually intact older dogs, though a dog of any age can experience the condition. If your dog is not spayed, then it's important to carefully monitor her for this condition.

In some cases, you may notice pus draining from your dog's vagina if she has developed pyometra. Your dog may also have a fever, be lethargic, or be depressed. In other cases, the pus cannot drain to the outside and results in a distended abdomen, and she will be listless and depressed and may vomit or have diarrhea. Your dog may drink more water regardless of whether a pus discharge is present.

Pyometra progresses quickly, and it is vital that you seek veterinary help immediately. Left untreated, this infection can kill your dog. Generally, your vet will perform a spay and remove your dog's infected uterus and ovaries. Your dog will probably be given antibiotics for two weeks after the surgery to help clear up any lingering infection.

Preventing pregnancy

If your dog is in heat, Dogster recommends that she should stay away from male dogs for at least three to four weeks. This means no trips to dog parks, doggie day cares, or other situations where your dog may interact with male dogs. If your female dog lives with intact dogs in the house, it can be stressful for all of the dogs, so it's best to keep them separated while your female is in heat. If you have relatives or friends nearby, it may be best to send one of the dogs to live with them until your female's heat cycle is over.

The most effective way to prevent pregnancy in your dog is to have her spayed. If your dog is actively in heat, your vet may suggest that you wait until she is out of heat before performing the surgery. Spaying a dog is a relatively routine surgery, and it will prevent your dog from becoming pregnant and from going into heat in the future. Additionally, spaying your dog reduces her chances of developing mammary cancer and eliminates the chance of her developing pyometra.