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Do dogs smell while in heat?

Dogs go through many changes when they are in heat. You may notice changes in their behavior, temperament, and appetite. You may also notice that they smell different. 

Do dogs smell while in heat?

The short answer is, yes. Dogs smell when they are in heat. The smell varies from dog to dog. Some owners say that the smell is barely detectable. Other owners claim the smell is quite pungent and unpleasant. 


When your dog is in heat, she experiences significant hormonal changes. These are similar to the fluctuations women experience during pregnancy. 

During the first stage of heat, known as proestrus, estrogen levels rise. Male dogs will be attracted to the female, but she won’t be receptive or fertile yet. The female typically begins bleeding during this stage. 

The estrus stage is next. This is when the female is receptive to males and can get pregnant. Estrogen levels begin to fall, and progesterone starts to rise.

The last stage is diestrus. Progesterone levels peak 3-4 weeks after this stage begins, then start to fall. Estrogen levels are low. 

These hormonal changes are responsible for many of the strange behaviors females display when in heat. They can also affect the way your dog smells. 

Species Survival

 Domestic dogs enjoy a long and safe lifespan. However, they still possess the biology and instincts of their wild ancestors. In the wild, dogs face predators and other challenges to survival. 

To keep the species alive, they must reproduce. To maintain population levels, they must reproduce quickly enough to replace each animal that dies. 

Most female dogs come into heat twice a year. This gives a fairly narrow window of time to procreate. From a survival perspective, it’s important that they breed during this time to keep the species alive.

Nature offers a helping hand by making the female smell when she’s in heat. Male dogs can smell this from miles away. They will go to great lengths to find and breed the female once they smell that she’s receptive. 

It’s a biological drive that is designed to keep the species going via reproduction. 

Why does my female dog smell fishy?

There are several reasons why your female dog may smell fishy. It can be a natural side effect of the heat cycle. It can also indicate a health problem. 


Owners that notice a strong smell from their dog in heat often say that she smells fishy. This seems to be the dog’s aphrodisiac. The smell and the associated pheromones are a signal to male dogs in the area that she can breed. 

Anal Glands

Male and female dogs have an anal sac on each side of their anus. When they poop, these glands are squeezed. This releases small amounts of fluid that coats the poop.

This fluid contains important information about your dog, including their age, health, and sexual status. This is why dogs smell each other’s poop. It’s essentially their version of a social media profile. 

However, dogs can also experience problems with their anal glands. This can cause a fishy smell. 

The most common problem with anal glands is a build-up of fluid. This typically happens when poop is too hard or soft, because it doesn’t express the anal glands fully. Over time, the fluid can build up and become hard. This is painful, and it can lead to infection in the glands. 

Anal gland abscesses and tumors are also possible, but less common. 


Pyometra occurs after a female’s heat cycle. The heat cycle opens the cervix to allow sperm to enter. Bacteria can also enter the uterus when the cervix is open. 

The uterus is normally inhospitable to bacteria. However, the uterine lining thickens during heat in preparation for pregnancy. After several heat cycles, this lining can thicken enough to be a breeding ground for bacteria. 

If the cervix is open when the infection develops, you will likely notice a foul-smelling discharge. If it is closed, the discharge can’t leave the body. This can make your dog sick very quickly. 

The stomach swells, appetite decreases, and the dog has no energy. They may also have vomiting or diarrhea. They may also drink more water in an effort to rid the toxins from their body. 

Bad Breath

That fishy smell you are noticing could be doggy breath. One cause of bad breath is simply your dog’s diet. It can also be caused by upset stomach, an oral infection, periodontal disease, and food stuck in your dog’s teeth. You may notice bleeding or swollen gums. Your dog may have difficulty eating or appear to have mouth pain. 

Kidney disease, diabetes, and tumors can also cause bad breath. If you notice pale gums, nausea, vomiting, or weight loss, you’ll need to take your dog to the vet. 


Vaginitis is inflammation of the vagina. It produces a fishy-smelling discharge. It can occur in all female dogs, whether spayed or intact. Male dogs are often attracted to females with vaginitis. It’s thought it smells similar to a female in heat to them. 

It’s often caused by a bacterial or viral infection of the vagina. Symptoms include increased urination, discharge, and scooting the vaginal area against the floor or an object. The vagina may appear red and swollen. 

Why does my female dog smell so bad?

Your female dog hops into your lap and you realize she smells very unpleasant. In addition to the causes listed above, there are a few potential reasons your canine companion suddenly smells like a dumpster. 


Metritis is an infection of the uterus. Pyometra occurs when a dog isn’t pregnant. Metritis occurs when the dog is pregnant, or after pregnancy. A pup that didn’t pass during birth, retained placenta, or fluid in the uterus are common causes. 

Symptoms of metritis include fever, loss of appetite, lethargy, and foul-smelling vaginal discharge. 

Skin infection

A skin infection can also cause your furry friend to smell bad. Yeast and bacterial infections are common. Allergies or skin irritation can increase the chances of developing a skin infection. 

These infections often have a musty smell. Some owners notice a smell similar to corn chips. 

Do dogs in heat have smelly urine?

Yes. The hormones in your dog’s body are present in urine. This is another way for the female to signal to males that she is ready to breed. It typically starts at the beginning of the heat cycle, and can intensify as she nears her fertile period. However, there are other potential causes for smelly urine as well. 


Just like humans, dogs are susceptible to urinary tract infections. The symptoms are similar to those of humans. They include painful urination, frequent urination, difficulty urinating, and incontinence.

The urine may become more concentrated, which will cause it to have a stronger smell. The bacteria causing the infection can also cause the urine to smell foul. 

Kidney Problems

Kidney problems can also cause your dog’s urine to smell, for similar reasons as a UTI. The urine may become too concentrated. 

Yeast Infection

A yeast infection can also cause your female dog’s urine to smell. The smell from yeast can be fishy. It can also smell like yeast. This smell is similar to bread or fermentation. 

What to do about my dog’s sudden smell?

The good news is, you don’t have to hold your breath around your dog due to a foul smell. There are ways to minimize or eliminate the smell. Of course, the first step is determining what’s causing the smell. 

Should You Visit the Vet?

Many causes of smelly dogs need to be treated by a veterinarian. These conditions include yeast infection, UTI, kidney problems, vaginitis, metritis, pyometra, and skin infections. 

Bad breath sometimes requires professional care as well. If it’s simply something in your dog’s diet or lack of oral hygiene, you can remedy these problems at home. However, if your dog’s gums are bleeding, swollen, or abscessed, you’ll need veterinary treatment. You’ll also need to visit the vet if your dog has a cavity, broken tooth, or lost tooth. If regular hygiene and dietary changes don’t solve the problem, take your dog to the vet to rule out other causes of bad breath. 

If the problem is anal glands, you can express them yourself. If they are very hard, hot to the touch, or painful, you’ll need to let your vet handle them. Otherwise, it’s a personal preference. Many owners prefer to avoid the job, because the smell can be quite pungent. 


If the smell is caused by your female companion being in heat, veterinary care isn’t needed, unless she’s showing signs of illness. 

Hormonal changes during heat can cause loss of appetite, mild nausea, and diarrhea. If these symptoms are severe or continue for more than a few days, take her for a checkup. If she’s showing signs of pain or difficulty urinating, these also require a vet visit. 

Masking Heat Smell

If you’ve got a female in heat, you may have noticed they have an unpleasant smell. Even if you don’t notice a smell, you can bet every male dog in the neighborhood does. It can be frustrating to deal with. Masking the heat smell will be helpful for you and any male dogs in the area. 

Many experienced dog owners give their dogs chlorophyll when in heat. It’s said to mask the smell, making the female less attractive to males. It works best if you give begin giving it at the first sign of heat. 

You may notice green stools when giving chlorophyll. It can also improve your dog’s breath. It’s supposed to help cleanse the system by removing toxins. 

Diapers are another option. They control the mess, so your dog won’t be bleeding on the furniture. They may also help mask the smell. To make it more effective, you can add a drop of essential oil to the outside of the diaper to further mask the smell. 

Bathing your dog can also help. Dogs emit odors from the oils on their skin. Urine that drips onto their fur can also smell, particularly during heat. Vaginal discharge during heat may also accumulate on their fur. 

Bathing your dog during heat can help keep them clean and reduce bacteria. Just be sure your dog is up for the bath. Heat is a stressful time, and hormonal changes can affect mood and behavior. 

You’ll also want to avoid overbathing. This can dry out their skin. If urine dripping or vaginal discharge is a problem, use pet wipes to keep their fur clean in between baths.