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Why Won’t My Dog Eat In Heat? (Estrus & Loss of Appetite)

Last Updated: December 10, 2023

Is your dog not touching their food? Are there changes in their behavior? Do not worry, as there can be many reasons behind your dog not eating.

However, in the case of female dogs, they commonly stop eating because they are going through their Estrus cycle. But why?

Your dog won’t eat during their heat cycle (estrus) due to the severe hormone imbalance. Estrus makes female dogs temporarily lose their appetite because their inner biological urges make them prioritize mating. They may also be suffering from Pyometra (infected womb) which causes inappetence.

In this article, I shall explain one of the most crucial phases in a dog’s life, i.e., Estrus, and how to identify and take care of your dog going through an Estrus cycle and much more!

Let us first understand why your dog won’t eat when in season.

Why Won't My Dog Eat In Heat? A dog in season looking at its bowl of food.

Why Your Dog In Heat Isn’t Eating

It is very common for dogs to lose interest in food when they are in heat. Female dogs are likelier to lose interest in food during their heat cycle. The reasons are:

●     They are in their Estrus and Proestrus stages:

During these stages, there is a severe imbalance in hormones. It makes female dogs temporarily lose their appetite or focus less on food because their brains and inner biological urges make them prioritize mating above everything else during this timeframe. So it is common for female dogs to focus on mating and be oblivious to their daily activities and surroundings.

●     They are Suffering From Pyometra:

Pyometra is the name given to an infection that occurs in female dogs during their estrus cycle. Dogs usually have an imbalance in hormones during Estrus, which sometimes causes the uterus’s inner lining to thicken and develop cysts. This results in frequent urination, discharge of fluids from the uterus, lethargy, vomiting, diarrhea, and even weight loss.

Pyometra should never be taken lightly as it is potentially a fatal disease. So consult a vet asap as soon as you see the signs. Another essential thing to note is as long as dogs are not neutered or spayed, they have a high chance of developing Pyometra, especially if they are old and intact.

Possible Reasons Why Your Dog Isn’t Eating

As previously mentioned, if any dog stops eating and is showing signs of being in heat, it means they are going through a natural process called Estrus.

Furthermore, the following may also be reasons why your dog has a loss of appetite.

Sick Dog. Unwell dog resting under a blanket.

Sickness or Diseases

Both male and female dogs may stop eating if they are sick. For instance, old dogs often stop eating because of sickness or disease.

Therefore, your dog can stop eating due to a wide array of diseases and sicknesses, such as the following:

●     Injuries – If your dog was recently hurt or injured for whatever reason, it might not want to eat. It is completely natural. If you see any bruising or swelling, do not hesitate to contact your nearest vet and schedule an appointment. “Dogs are wise. They crawl away into a quiet corner and lick their wounds and do not rejoin the world until they are whole once more.” – Agatha Cristie.  

●     Dental Issues – Like humans, dogs, too, can suffer from rotting teeth and dental problems. Dogs with dental problems may refuse to eat or eat minimal amounts; they especially try to avoid dry foods at all costs.

●     Indigestion – This should be self-explanatory as almost all animals facing indigestion and digestive issues do not feel like eating.

●     Intestinal or stomach parasites – Worms and parasite infestation can cause your dog to feel full even though there is no food inside its stomach. If your dog’s belly is welling up, you should visit the vet as soon as possible.

●     Cancer, Organ Failure, etc. – While there are no telltale signs for this, I recommend seeing a vet as soon as possible if your dog has skipped meals for more than two days.

Behavioral Reasons

Anxiety in pets is common when there are disruptions in the dog’s routine and surroundings, such as the introduction of a new family member or pet, a move, or the presence of sound pollution, such as the ones associated with building construction, a storm, or fireworks.

Stress from even minor changes, such as the place or time of meals, can make sensitive dogs anxious and avoid food.

A dog may avoid eating if it is afraid of the other pets in the house. When eating, many dogs prefer to avoid eating in the company of humans because of the possible intimidation they may feel. In such a case, I suggest that dogs be fed at separate times.

Sleeping Dog. Dog Not Eating Due To Estrus Cycle.

Problems With Food

Picky eaters are always annoying, but what can you do? Regardless of how annoying picky eating dogs can be, you must give in to their demands because of the unconditional love you share.

However, sometimes there are problems with the food you provide to them, so your dog may refuse to eat them.

Some common problems dogs face with food are:

●     You switched brands or gave them something different

●     The food has expired

●     The food is too dry

●     The food was left out for too long

Miscellaneous Reasons

Some more reasons why your dog may refuse to eat include the following:

●     Hormonal Changes: Fluctuations and changes in hormones are common causes of loss of appetite in dogs.

●     Eating Outside: Dogs eat outside food just like humans. If your dog is allowed to roam freely, it’s likely to have eaten something outside. Then they might refuse to eat when back indoors.

●     Decrease In Activity: When dogs become less active, they require less food as they require less energy; this can result in a decrease in appetite.

●     Vaccinations: Vaccinations often cause a lack of appetite in dogs and animals and sometimes cause them to eat less or not.

●     The Dog Went Through Surgery: Dogs, like humans or other animals, will become weak and may skip a few meals after surgery.

What Is Estrus In Canines?

Canine estrus is a natural phenomenon that happens to all female dogs that are not spayed. For simplicity’s sake, think of this as the menstrual cycle for canines. To help you better understand Estrus, let us first begin with learning how to identify signs of Estrus in canines.

Identifying Signs of Estrus In Canines

The signs of Estrus are as follows:

●     The vulva of your dog will enlarge and swell.

●     Bloody discharge from the dog’s vagina.

●     Frequent urination.

●     Swelling of nipples.

●     Your dog will become more territorial, mark its territory or surroundings with urine, and use it to communicate. Yes, dogs can use urine to communicate among themselves, especially during Estrus!

●     Your dog may become overly friendly towards other dogs, especially males.

●     The dog will act nervous, agitated, and even anxious.

●     The dog may even start humping or mounting on objects.

●     The dog may develop nesting behavior.

●     The dog will lick their private parts more frequently.

●     There will be changes in its posture.

Now let us understand what the Estrus cycle is like for dogs.

Dog Not Eating When In Season

Estrus Cycle

The Estrus cycle in dogs consists of 4 major steps:


This is the stage dog owners most often notice and can easily identify that their dog is in heat. This stage lasts about 9 days on average; however, it can last for 0-27 days.

During this stage, the dog’s vulva will get swollen and develop a reddish color. It is then followed by red-tinted vaginal discharge.


During this stage of Estrus, the female dog usually becomes very receptive towards the opposite gender. This stage also lasts 9 days on average; however, it can last between 4-24 days.

During this stage, the female is the most fertile, and her vulva enlarges.

The vaginal discharge becomes less red and becomes a more light pinkish color. Moreover, the estrogen levels in the dog begin to drop, and on the other hand, their progesterone levels start rising.


During this stage, the females are not receptive to other male dogs anymore. Their estrogen levels remain low, whereas their progesterone levels peak. This stage of the cycle lasts for up to 60 days. After the initial 20-30 days, progesterone levels peak and slowly reduce by the end of this stage.


Think of this stage as the transitional phase between Diestrus and the beginning of the next proestrus cycle. This stage is usually about 150 days or 4 months; however, this duration is significantly longer in the case of larger dog breeds.

The dog’s vulva also returns to its normal state, the vaginal discharges stop altogether, and the dog’s body prepares it to get ready to get pregnant again.

Female Dog In Heat. A male dog sniffs a female on her heat cycle.

Frequency Of Estrus

The frequency of Estrus depends on a few factors, such as the size and breed of the dog. To give you an idea of the frequency of Estrus, here are some instances:

●     Dogs experience their first Estrus cycle after reaching puberty. They hit puberty around 6 months, but this varies depending on the breed.

●     Smaller breeds will experience this earlier when compared to larger breeds.

●     Unspayed female dogs will experience Estrus twice yearly.

●     Unspayed female dogs may experience Estrus 3-4 times yearly.

●     The frequency of Estrus in older and bigger dogs is less frequent.

●     Dogs will experience Estrus their whole lives.

However, dogs may have irregularities in their Estrus cycles, so a simple vet consultation can help determine if that is the case.

How To Care For Your Dog During Estrus?

Your dog needs extra care and attention when they are in heat. Thus, you should ensure the following if your dog is going through an Estrus cycle.

Set Up A Cozy Environment

Dogs in heat are always uncomfortable. So it becomes your duty to make things easier for them as much as possible. Setting up a cozy environment is one of the best things you can do for them.

A few ideas include:

●     Adding extra clean and comfy blankets

●     Chewing toys

●     Soft and slow music

●     Keeping your dog indoors

●     Avoiding loud and abrupt noises in the house

Providing Company and Support

Talk to your dog, and give the good girl some pets and scratches. Spend as much quality time with her as possible. It will distract her and simultaneously calm her down because she knows she has you by her side.

Dogs tend to get very hormonal when going through heat cycles. So providing enough distractions and entertainment will make things much easier for them and allow them to bear and tolerate the discomfort and anxiety they are going through.

Taking Precautionary Measures

Taking preventive measures is a must when handling dogs in heat.

As soon as you see signs of your dog being in heat, you should do the following:

●     Stock up on doggy diapers.

●     Stock up on cleaning supplies.

●     Stock up on their favorite treats and food.

●     Restrict their movement around the home.

●     Keep male dogs away from them.

●     Set up a cozy environment.

●     Ensure that they have no way of leaving the house.

A Bulldog in Heat.

Monitoring Her Constantly

This includes observing her routinely. Do not hesitate to visit your nearest vet if you see any alarming signs.

Animals tend to become sick abruptly, so always be prepared to take the trip to the vet at any given moment for your dog.

If you see any abnormalities such as the ones listed below, then please make that visit to the vet immediately:

●     Decrease in activity

●     Lethargic and sluggish movement

●     Not drinking enough water

●     Appearing weak or breathing too heavily

●     Skipping meals for more than two days

Some Useful Tips And Suggestions

Here are some useful tips and suggestions:

Controlling Your Dog In Heat

The best way to control your dog in heat is by distracting them. Distracting them includes spending more time with them, engaging in games and activities, giving them new toys, changing their environment, and much more. The main purpose of this is not to let your dog remain idle and away from male dogs.

Balancing Exercise And Rest

Remember always to maintain a healthy balance between exercising and resting, as overdoing so could result in dire consequences.

Understanding Common Behavior

“Dogs do speak, but only to those who know how to listen.”– Orhan Pamuk.

Experienced or bonded dog owners can understand their dog’s vocabulary and tones. When you develop that understanding with your dog, you can notice the tone of their barks and body language and understand what they are trying to say or how they feel.

Creative Ways of Getting Your Dog To Eat

There are lots of creative ways to get your dog to eat. For instance, you can get puzzle-solving toys that reward your dog with treats for completing the puzzle. 

I love the Outward Hound Dog Brick Interactive Treat Puzzle Toy from Amazon. This brain teaser encourages your doggo to find kibble or treats in the flip-lid compartments, which makes feeding times fun and engaging.

Or you can even make special bread and baked treats for your dogs. There are lots of ready-to-bake mixes for dogs available on the market, or you can even mix up random things your dog loves and bake them into a treat.


Sharon Waddington
Sharon Waddington is the founder of World of Dogz. With over 30 years of experience working with dogs, this former Police Officer has seen it all. But it’s her trusty German Shepherd, Willow, who steals the show as the inspiration behind this website. As Sharon’s constant companion Willow has played a pivotal role in shaping her passion for dogs. Recently, Sharon has become deeply passionate about the plight of rescue dogs and is an active advocate for dog rescue, striving to make a difference in the lives of dogs in need.

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