Can Being In Heat Make A Dog Sick

Can Being In Heat Make A Dog Sick?

Last Updated: August 18, 2023
correct answerThe Short Answer is:

In the heat, a dog’s hormones will undergo certain changes causing both physical and behavioral changes. It is possible that she may become ill or erratic during this time and will need special attention. Female dogs experience the heat cycle throughout their lives, and getting them spayed at the right age is the only way to ensure they live a long and healthy life without the stress of the heat cycle.

In this article you will know the answer to the query “Can Being In Heat Make A Dog Sick?“.

Have you ever lived with a dog experiencing an unpleasant heat cycle? Do you have an intact female dog? In the heat female dogs can be very uncomfortable and stressed and it is not uncommon for them to get sick. 

Can Being In Heat Make A Dog Sick

During heat dogs may vocalize more cry a little bleed and behave differently. The entire process is often very unpleasant for both the pet parent and the dog. However if you understand whats going on better you can make your dog feel much better. 

What do we mean by “being in heat”?

Whenever a dog is in heat it means she is getting ready to reproduce or she is already fertile. An intact female dog is in heat when she has reached sexual maturity and is ready to mate and give birth to puppies. In most dog breeds female dogs experience their estrus cycle or “will be in heat” once or twice a year but for some breeds it can be as often as every four months.   

How do you know if your dog is in heat?

Both physical and hormonal changes occur during a dogs heat period and the changes in their hormones trigger changes in a dogs behavior. When your female dog is in heat you will notice all these changes. Every stage of a dogs estrus cycle is characterized by certain physical and behavioral changes. 

Here are some things to expect from a female dog in heat;

  1. An estrus cycle begins with the proestrus stage which is marked by a swollen vulva frequent urination bloody discharge from the vulva and excessive licking of the genital area. It is possible that she becomes more nervous and clingy.
  2. This second stage of the estrus cycle (which is called estrus) is characterized by the clear or straw-colored discharge from the vulva tail flagging and flirty behavior toward male dogs because she is fertile and ready to mate.
  3. When the dogs reach the diestrus stage they are no longer fertile or interested in mating. As a result the vulva will shrink to its normal size and the vaginal discharge will cease. 

How long does “being in heat” last?

The dogs estrus cycle lasts between 2 and 4 weeks. During the entire heat phase the dog lasts about 28 days. During the second stage of the heat cycle when he becomes fertile and begins to mate the dog lasts for a total of 3 to 9 days. 

Depending on the breed the length of the dogs estrus cycle and the age at which it begins to vary. Small dog breeds usually mature faster undergoing their first heat cycle around six months whereas large dog breeds become sexually mature between 12 and 18 months or 24 months for very large dogs. 

In addition small dog breeds have their estrus cycle every four months while large dog breeds have their cycle every eight or twelve months; and how long each heat cycle lasts depends on the breed and size of the dog. 

Why might a dog in heat be vomiting?

Normally vomiting is not a symptom of a dog in heat however hormonal changes can cause minor digestive problems in female dogs. 

When a dog is in heat it may experience mood swings and mild stomach upsets but severe symptoms such as vomiting lethargy and lack of appetite need to be addressed by a veterinarian. The symptoms of pyometra which is an infection of the uterus include vomiting lethargy and frequent urination. 

If left untreated Pyometra can be fatal. Dogs with this condition require immediate veterinary care and the cure is the surgical removal of the uterus. Dietary indiscretion organ damage or parasitic infections like worms are the most common causes of vomiting in dogs. 

As a consequence vomiting in a dog in heat may result from an underlying disease or dietary indiscretion instead of being solely the result of the heat cycle. Be sure to consult your veterinarian if you observe that your dogs condition is very unusual. 

Why might a dog in heat suffer from diarrhea?

Female dogs may experience some sickness during or after their heat cycle as a result of hormonal changes in their bodies. The dog may have slight gastrointestinal upset but symptoms like vomiting or diarrhea are not common during an estrus cycle since these are not normal symptoms. 

A dogs estrus cycle is usually stressful and confining your young lady might also add to her stress levels which may in turn lead to gastrointestinal upsets. 

In addition if there is a loose bowel movement expect symptoms to last for only a day and anything longer or more severe with other disturbing signs such as fever lethargy increased thirst pus from the vulva can be caused by a potentially deadly infection in the uterus; pyometra.

How else might the behavior of a dog in heat change?

In a dog in heat look out for the following behavioral changes;

Anxiety: During the first few days of your female dogs estrus cycle you will notice some behavioral changes. During this period puppies tend to get anxious because they can sense the changes taking place in their bodies which causes them to become a little nervous and clingier to their owners. 

Decreased energy: The first phase of the heat cycle can be characterized by low energy levels and extra laziness in female dogs. Some bitches will become extra restless and nervous whereas others will be extremely lazy. It is important to look for a significant change in one direction or a radical change in behavior. For example if your dog is normally clingy and affectionate she may become snobbish and grumpy while a usually high-spirited dog may become very lazy. 

Increased appetite: A dog in heat also has a greater appetite for food as her body prepares for a possible pregnancy and needs to be nourished for her puppies when they are born. It can also be the other way around some female dogs have reduced appetites and eat very little.

Tail movement: During the first phase of the heat period female dogs tuck their tails and fight off any advances from male dogs. During the second estrus stage females will wag their tails and flirt with males to get their attention and communicate their desire to mate. 

How can you help your dog in heat to feel better?

It can be confusing and unpleasant for a teenage dog to be in heat and she may act extra cuddly or erratic. The following tips can help your female pup get through her estrus cycle if you decide not to breed her.

Pay more attention

Your dog may not be seeking your attention during her heat period but she definitely needs you. It is your responsibility to make sure she is properly cleaned up when she expels liquid discharge to avoid getting your living space dirty. In addition to trimming the hair surrounding her genital area you may need to get her some dog diapers to contain the discharge if she has a long-haired breed.

Give her more treats

When your dog eats very little during this period she will need extra treats to make sure shes getting the healthy amount of calories she needs to keep her energy level up. Provide her with toys or bones she can chew on to help stabilize her mood.

Take her on more walks

Taking our dog for daily walks with a leash can help her work off some anxiety and relax better if she becomes restless during her heat period. You do not need to walk her on a leash or use a tracking GPS device to prevent her from running off.

What are the advantages of having a female dog neutered?

In case you’re wondering whether or not to spay your bitch here are a few good reasons.

It prevents pyometra

The uterus is infected with pyometra which can be deadly. Approximately 25% of intact middle-aged female dogs will have this condition in which the uterus is filled with toxic pus that can be fatal if not surgically removed. A spayed dog is completely protected from this condition.

It increases the lifespan of your dog

The benefits of spaying your dog include a longer healthier and happier life. Science has proven that neutered pets tend to live longer than intact ones because they are less susceptible to certain infections tumors and behavioral problems. Dogs that are spayed before their first estrus cycle are less likely to develop mammary cancer.  

It prevents heat cycle and pregnancy

In spite of the fact that the heat cycle and pregnancy are both natural parts of female dogs’ lives they can both be very stressful. Being in heat isnot fun for the dog or the owner so having your pet spayed will spare you both the stress of being in heat.

A dog spayed at the wrong age or without proper safety precautions can develop some unpleasant lifelong consequences. When sex at a young age some health problems can occur such as hip dysplasia torn ligaments bone cancer and urinary incontinence. Make sure your dog is of the right age for the surgery; this varies for different breeds.


In human females “being in heat” can be compared to the menstrual cycle however dogs experience the estrus cycle which does not occur nearly as frequently as in humans. In the heat a dogs hormones will undergo certain changes causing both physical and behavioral changes. 

It is possible that she may become ill or erratic during this time and will need special attention. Female dogs experience the heat cycle throughout their lives and getting them spayed at the right age is the only way to ensure they live a long and healthy life without the stress of the heat cycle.

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Amanda Dogs Trainer

Amanda (Author)

With over a decade of experience, Amanda is a distinguished dog trainer. Her expertise in canine behavior has transformed countless lives, fostering harmonious human-canine connections. Through compassionate and personalized approaches, she empowers owners to understand and connect with their furry companions, creating a legacy of joyful tails and transformed lives.

Osvaldo Maciel Dogs Trainer

Osvaldo Maciel (Content Reviewer)

Osvaldo Maciel, a stalwart in the field with 14 years of experience, is a revered dog trainer. His journey is defined by a profound understanding of canine behavior, shaping unbreakable human-canine bonds. Osvaldo guides owners to connect with their beloved pets, leaving an indelible mark of happiness and transformation. His legacy shines through the countless lives he has touched.

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