Cortisol and Chronic Stress in Dogs: Signs and Natural Support

Cortisol is often labeled the “stress hormone”—and for good reason. It’s a natural hormone produced by the adrenal glands to help your dog respond to short-term stress. But when cortisol levels stay elevated for too long, the effects can become damaging, not protective.

Cortisol gets talked about constantly in human health, especially in conversations about stress, poor sleep, weight gain, anxiety, inflammation, and feeling completely worn down. But dogs produce cortisol too.

Their bodies use it for many of the same basic reasons ours do: to respond to stress, mobilize energy, regulate blood sugar, influence inflammation, and help them survive an immediate threat. Cortisol itself is not the enemy. Your dog needs it.

The problem begins when the body keeps receiving the message that it needs to remain prepared for danger, whether that danger comes from fear, pain, illness, overstimulation, environmental stress, poor sleep, emotional trauma, or an unpredictable lifestyle.

The stressful event may end, but the dog’s body does not always get the memo.

Some dogs remain watchful, tense, reactive, restless, or physically unsettled long after the original trigger is gone. Over time, that repeated stress response may affect behavior, digestion, sleep, immune balance, inflammation, recovery, and overall resilience.

This is why I do not look at anxiety or reactivity as behavior problems alone. The nervous system, gut, immune system, hormones, pain levels, nutrition, environment, and emotional experiences are all connected.

Is Cortisol the Same in Dogs and Humans?

Dogs and humans both release cortisol through the hypothalamic-pituitary-adrenal axis, commonly called the HPA axis. Cortisol helps the body:

• Mobilize energy during stress

• Maintain blood sugar

• Influence metabolism

• Regulate aspects of immune activity

• Manage short-term inflammation

• Respond to pain, illness, fear, and physical demand

The broad purpose is similar in both species, but this article is specifically about dogs. Their behavioral clues, stressors, medical conditions, testing, nutritional needs, and appropriate support are not interchangeable with human cortisol advice.

Your dog cannot tell you that his stomach hurts every time he goes to daycare, that the construction next door is making him frantic, or that he has not slept deeply in weeks. He shows you through his body and behavior.

Our job is to notice.

A Cortisol Spike Is Not Always a Problem

Cortisol is meant to rise temporarily.

If your dog hears a frightening sound, encounters an unfamiliar dog, experiences pain, visits the veterinarian, or believes he is in danger, his body prepares him to respond. His heart rate may increase, energy is redirected, digestion may temporarily slow or change, and he becomes more alert and prepared to fight, flee, freeze, or seek safety.

Once the threat passes, the sympathetic fight-or-flight response should begin settling so the parasympathetic nervous system can guide the body back toward rest, digestion, repair, and recovery

A healthy stress response is not defined by never becoming stressed. It is defined partly by the dog’s ability to recover after stress.

Some dogs can shake off an upsetting moment, take a nap, eat dinner, and move on with their lives. Other dogs are still pacing three hours later.

That difference tells us something.

Fight, Flight, Freeze or Appease

When your dog senses danger, the sympathetic nervous system prepares the body to survive. Most people know this as the fight-or-flight response, but dogs may also freeze, shut down, avoid, appease, or become unusually clingy.

During this response, your dog’s body may:

• Increase heart rate and breathing

• Redirect blood flow toward the muscles

• Release stored energy

• Become more alert to sound, movement, and touch

• Temporarily reduce digestive activity

• Increase muscle tension

• React faster and think less clearly

This response is useful when the danger is real and temporary.

The problem begins when the dog repeatedly enters this survival state or has difficulty returning to a calmer rest-and-digest state afterward.

A dog stuck in fight-or-flight may pace, pant, scan the environment, bark at small noises, struggle to sleep, overreact to handling, or remain tense long after the trigger has passed.

A dog in a freeze or shutdown response may appear quiet, still, stubborn, disconnected, or “well behaved,” even though the nervous system is overwhelmed.

That distinction is important. Not every stressed dog looks frantic. Some become smaller, quieter, and less responsive.

The goal is not to prevent every stress response. It is to help the dog move through stress and return to a regulated state instead of remaining stuck in survival mode.

When Stress Becomes a Chronic Pattern

The concern is usually not one cortisol spike. It is the repeated activation of the stress response without enough opportunity for physical and emotional recovery.

Emotional and Behavioral Stressors

• Chronic anxiety or fear

• Noise sensitivity

• Separation distress

• Reactivity toward dogs, people, movement, or handling

• Previous trauma

• Poor early socialization

• Conflict with another animal in the home

• Repeated exposure to situations the dog cannot comfortably manage

Physical Stressors

• Pain or an undiagnosed health condition

• Digestive discomfort, nausea, or reflux

• Skin irritation and constant itching

• Illness, surgery, injury, or prolonged recovery

• Excessive exercise without enough recovery

• Poor-quality or frequently interrupted sleep

• Medication effects

• Blood-sugar instability or inadequate nutrition

Environmental and Lifestyle Stressors

• An unpredictable household or daily routine

• Frequent boarding, daycare, grooming, or travel

• Repeated confinement

• Lack of appropriate movement or decompression

• Constant household noise

• Busy windows, fence-line activity, or repeated barking

• Too many outings, visitors, training sessions, or social demands

• Strong fragrances, cleaning products, or other environmental exposures

One dog may tolerate a busy household, frequent visitors, daycare, training classes, and weekend travel. Another dog may find that same lifestyle completely overwhelming.

Stress is not determined only by what happened. It is also determined by how that individual dog experienced it.

Signs Your Dog May Be Stuck in a Stress Cycle

There is no single behavior or symptom that proves your dog has chronically elevated cortisol. What we can identify are patterns suggesting that the nervous system is struggling to settle, regulate, or recover.

Behavioral and Emotional Clues

You may notice:

• Restlessness or frequent pacing

• Hypervigilance or constantly scanning the environment

• Difficulty settling even when the house is quiet

• Startling at ordinary sounds

• Overreacting to small triggers

• Increased barking, whining, or vocalizing

• Clinginess or inability to relax away from you

• Hiding, avoidance, or emotional withdrawal

• Increased irritability

• Becoming more reactive as the day progresses

• Difficulty thinking or responding once aroused

• Trouble recovering after guests, walks, training, grooming, or travel

• Sleeping lightly or appearing to “sleep with one eye open”

A dog who cannot settle is not necessarily stubborn, dramatic, spoiled, or poorly trained. His nervous system may genuinely be struggling to shift gears.

For a closer look at how anxiety affects both behavior and physical health, read How Anxiety Affects Dogs.

Physical Clues

Chronic stress may also show up through the body:

• Panting during stressful situations or long after activity has ended

• Muscle tension or difficulty becoming physically comfortable

• Stress-related soft stool or diarrhea

• Stomach gurgling, nausea, reflux, or appetite changes

• Repeated digestive flares during travel, boarding, storms, or household disruption

• Licking, chewing, scratching, or other repetitive behaviors

• Poor-quality sleep

• Fatigue after stressful experiences

• Reduced tolerance for exercise, handling, or stimulation

• Increased sensitivity to pain

• Recurring symptom flares during periods of emotional stress

These symptoms can have many causes. Stress should not become the new answer we slap onto everything. However, when symptoms predictably worsen during emotional or environmental stress, that pattern deserves attention.z

Can Chronic Stress Contribute to Anxiety, Reactivity, or Aggressive Responses?

Yes. Cortisol is only one part of the stress response, but repeated activation of that system may leave a dog closer to his threshold.

A dog who is painful, frightened, overstimulated, sleep-deprived, physically uncomfortable, or unable to recover between stressful events may react faster and more intensely. He may become more sensitive to sounds, movement, handling, unfamiliar dogs, visitors, or being left alone.

That response may look like:

• Pacing, panting, whining, or inability to settle

• Barking or lunging at triggers

• Growling, snapping, or biting when overwhelmed

• Avoidance, hiding, or shutting down

• Becoming unusually clingy

• Panicking when a caregiver prepares to leave

• Destructive behavior or vocalizing during separation

• Taking hours—or even days—to return to baseline after a difficult event

Chronic stress does not automatically cause aggression, and cortisol should not become the explanation for every behavior problem. Genetics, pain, medical conditions, learning history, trauma, environment, sleep, nutrition, and prior experiences may all contribute.

But when the nervous system is already working overtime, the dog may have far less capacity to cope before moving into fight, flight, freeze, or appeasement.

Stress Stacking: When Small Events Become One Big Problem

Dogs do not necessarily begin each day with an empty stress bucket.

A poor night’s sleep, upset stomach, sore hip, loud delivery truck, tense encounter on a walk, missed nap, grooming appointment, and thunderstorm may each seem manageable alone. Stack them together, and the dog may run out of coping capacity.

This is often when pet parents say:

“He exploded over nothing.”

It probably was not nothing.

It may have been the final small demand placed on a nervous system that had already been working overtime.

Stress hormones do not necessarily disappear the moment the trigger ends. A dog may need real recovery time after an upsetting event. Piling more excitement, outings, training, visitors, or intense exercise onto an already activated dog can make regulation harder rather than easier.

Sometimes the most therapeutic activity is not another enrichment game.

Sometimes it is sleep.

Cortisol, the Vagus Nerve, and Recovery

The vagus nerve is a major communication pathway between the brain and organs throughout the body, including the heart and digestive tract. It plays an important role in parasympathetic activity—the side of the nervous system associated with rest, digestion, recovery, and restoration.

When a dog remains in a repeated state of alert, the body may have difficulty transitioning back toward that calmer state. This can affect:

• The ability to rest deeply

• Digestive movement and comfort

• Heart-rate regulation

• Emotional resilience

• Immune communication

• Recovery after stressful events

• The ability to think and learn during behavior work

Supporting the vagus nerve is not about performing one magical reset and declaring the dog fixed. It is about repeatedly giving the nervous system experiences that encourage safety, predictability, healthy sensory input, appropriate movement, physical comfort, and recovery.

My article Understanding the Vagus Nerve in Dogs explains this connection in greater detail and includes practical ways to support nervous-system regulation.

The Gut-Brain-Stress Connection

The digestive system and brain are in constant communication.

Stress can affect appetite, stomach acid, digestive movement, bowel habits, microbial balance, and how comfortably a dog processes food. At the same time, digestive pain, dysbiosis, nausea, reflux, and inflammation can make a dog feel more anxious, restless, reactive, or unable to settle.

This relationship can create a frustrating loop:

1. Stress affects digestion.

2. Digestive discomfort creates additional physical stress.

3. The uncomfortable dog sleeps poorly or becomes more reactive.

4. Poor sleep and reactivity create more stress.

5. The cycle continues.

This is why I do not separate behavior support from nutrition and physical health. A dog cannot always “train through” a body that feels awful. And a beautiful fresh-food diet may not be enough by itself if the dog remains frightened, painful, sleep-deprived, or chronically overstimulated.

Both sides of the conversation need attention.

Read How Your Dog’s Gut Influences the Brain and Behavior for a deeper look at digestion, the microbiome, anxiety, reactivity, and the gut-brain connection.

How Chronic Stress May Affect the Whole Dog

When the stress response is repeatedly activated, we may begin to see effects beyond obvious anxiety.

Digestion

Stress may contribute to changes in appetite, stomach acid, digestive movement, stool quality, reflux, nausea, and digestive comfort. Some dogs experience predictable gastrointestinal flares during boarding, travel, storms, schedule changes, or emotionally difficult events.

Immune and Inflammatory Balance

Short-term cortisol activity helps regulate inflammation and immune responses. Ongoing stress, however, may interfere with normal immune regulation and recovery.

This does not mean every ear infection, allergy flare, urinary issue, or inflammatory condition is caused by cortisol. It means stress may be one piece of a larger pattern that also includes nutrition, microbiome health, environmental exposure, medications, genetics, and underlying disease.

Pain and Physical Tension

Stress, inflammation, discomfort, poor sleep, and pain can reinforce one another. A painful dog may be unable to settle. A sleep-deprived dog may become more sensitive to pain. An uncomfortable dog may have less tolerance for ordinary handling, noise, activity, or frustration.

Sleep and Recovery

Deep, restorative sleep is essential for physical and emotional recovery. A hypervigilant dog may appear to sleep for many hours while never fully relaxing. He may wake at every sound, follow every movement, change positions constantly, or remain prepared to react.

Sleep quantity and sleep quality are not the same thing.

Learning and Behavior

A dog in a high state of arousal has less access to thoughtful decision-making. This is one reason behavior work becomes much harder when the dog is already frightened, painful, nauseated, exhausted, or overwhelmed.

Training still has a place. But training works better when the body has enough capacity to participate.

When It May Be More Than Stress

This article is about stress-related cortisol patterns, not primarily about Cushing’s disease. However, some physical changes should not be blamed on anxiety or nervous-system dysregulation without appropriate medical investigation.

Contact your veterinarian if your dog develops:

• Excessive thirst

• Significantly increased urination

• A dramatic increase in appetite

• A persistent pot-bellied appearance

• Noticeable muscle weakness or wasting

• Thin or fragile skin

• Symmetrical hair loss

• Repeated skin or urinary infections

• Unexplained bruising

• Persistent panting without an obvious trigger

• Rapid or significant physical changes

These symptoms can occur with Cushing’s disease, diabetes, liver disease, thyroid disorders, medication effects, pain, and other medical conditions.

Stress may be part of the picture, but it should not become a reason to overlook disease.

Can Cortisol Be Tested in Dogs?

Cortisol can be measured, but a single result does not always explain the complete situation.

Veterinary visits, restraint, pain, fear, unfamiliar surroundings, illness, and medications may influence cortisol activity. Testing intended to investigate Cushing’s disease is also different from trying to understand whether a dog is living under excessive emotional or environmental stress.

Depending on the symptoms, your veterinarian may consider:

• Complete blood count

• Blood chemistry

• Urinalysis

• Thyroid testing

• Urine cortisol-to-creatinine ratio

• ACTH stimulation testing

• Low-dose dexamethasone suppression testing

• Additional endocrine testing

• Imaging

• Review of current and past steroid exposure

Testing should be selected based on the dog’s symptoms and medical history—not because “high cortisol” has become the internet’s explanation for everything this month.

Mineral testing, microbiome testing, nutritional assessment, pain evaluation, and a detailed behavior history may provide additional information, but they do not diagnose Cushing’s disease or replace appropriate veterinary testing.

How to Reduce Your Dog’s Overall Stress Load

You cannot simply suppress cortisol and call the problem solved.

The more useful question is:

Why does your dog’s body believe it needs to remain on alert?

The answer may involve one issue or several overlapping ones.

Start With Physical Comfort

Before assuming a dog has a purely emotional or training problem, consider whether something hurts.

Possible contributors include:

• Joint or spinal pain

• Dental pain

• Ear discomfort

• Skin irritation

• Digestive pain

• Nausea or reflux

• Urinary discomfort

• Hormonal or endocrine changes

• Reduced vision or hearing

• Medication effects

• Poor recovery after illness or surgery

Pain changes behavior. A dog who suddenly becomes restless, reactive, avoidant, clingy, irritable, or sensitive to touch deserves a physical-health review.

Protect Sleep and Recovery

Many dogs need far more uninterrupted rest than they receive.

Create realistic opportunities for your dog to sleep without children, visitors, other animals, televisions, doorbells, constant handling, or pressure to participate. After a stressful event, reduce additional demands.

That may mean:

• Taking a quieter walk

• Skipping daycare

• Avoiding unnecessary visitors

• Reducing training pressure

• Allowing extra sleep

• Offering a calm chewing or licking activity

• Choosing sniffing and decompression over intense exercise

• Giving the dog physical and emotional space

Rest is not laziness. Recovery is part of the plan.

Reduce Sensory Overload

Take an honest look at your dog’s environment:

• Is the television or music constantly playing?

• Does your dog spend the day guarding a busy window?

• Is there repeated barking from nearby dogs?

• Are plug-ins, candles, fragrance sprays, or strong cleaners used throughout the home?

• Are entrances and exits chaotic?

• Is your dog repeatedly exposed to known triggers?

• Does your dog have a quiet, protected resting area?

• Are there too many outings, visitors, classes, or social obligations?

Some dogs do not need more stimulation.

They need less chaos.

Build Predictability

Meals, walks, sleep, medication, quiet time, and interaction do not need to happen at the exact minute every day. But a dog living in constant uncertainty may remain more watchful than a dog who generally understands what comes next.

Predictability can be especially helpful for rescue dogs, noise-sensitive dogs, senior dogs, dogs with separation distress, dogs recovering from illness, and dogs experiencing major household changes.

Feed for Stability and Resilience

Nutrition does not erase trauma or replace behavior support. But a poorly nourished, inflamed, uncomfortable, or metabolically unstable body has fewer resources available for emotional regulation and recovery.

A thoughtful nutrition plan may include:

• Fresh, minimally processed food

• Adequate high-quality protein

• Appropriate fat

• Balanced minerals

• Omega-3 fatty acids

• Digestive support when indicated

• Microbiome support when indicated

• Consistent meals for dogs who struggle with long gaps between food

• Removing foods that worsen itching, digestive discomfort, or inflammation

The goal is not to throw every calming supplement into the bowl. The goal is to build a body with enough resources to respond, regulate, and recover.

For practical nutritional and lifestyle considerations, continue with Natural Ways to Support Your Dog’s Stress.

Choose Exercise Carefully

Exercise can be helpful, but more is not always better.

Intense fetch, repetitive ball chasing, chaotic dog parks, high-arousal daycare, or relentless physical activity may produce exhaustion without true nervous-system regulation.

Balance higher-intensity activity with:

• Sniffing walks

• Gentle exploration

• Slow movement

• Appropriate strength and mobility work

• Chewing and licking

• Foraging

• Quiet outdoor time

• Rest days

• Bodywork

• Activities the individual dog genuinely enjoys

A tired dog is not automatically a regulated dog.

Sometimes he is simply a tired, overstimulated dog.

Use Training to Build Safety

Training can help a dog develop confidence, predictability, communication, and coping skills. But a dog who is repeatedly pushed over threshold does not learn that the world is safe. He learns that his warning signals are ignored.

Behavior work should account for the dog’s:

• Physical health

• Pain

• Digestive comfort

• Sleep quality

• Current arousal level

• Environment

• Reinforcement history

• Trauma history

• Trigger intensity and distance

• Ability to recover

Obedience alone does not regulate a nervous system.

Natural Support Options to Consider

Natural tools may be useful, but they should be selected for the individual dog and used as part of a broader plan—not stacked together because they all have the word “calming” on the label.

Essential Oils

Essential oils may be incorporated into routines that support grounding, relaxation, sleep, emotional balance, and a calmer home environment.

Oils commonly considered include:

• Lavender: Often selected for general relaxation and emotional tension

• Frankincense: Commonly used for grounding and emotional steadiness

• Cedarwood: May be useful when a dog has difficulty settling

• Vetiver: Often considered for overstimulation and a busy nervous system

• Roman Chamomile: May be helpful for emotional sensitivity and tension

Selection, quality, dilution, method of use, age, health conditions, medication use, and the dog’s individual response all matter. Never force a dog to remain near an aroma he is trying to avoid.

My article Essential Oils for Dog Anxiety provides more specific guidance on selecting oils based on how anxiety presents.

Herbs and Adaptogens

Herbs such as ashwagandha, valerian, skullcap, passionflower, lemon balm, and milky oats may be considered depending on the dog’s pattern, medications, constitution, and reason for stress.

Not every calming herb is appropriate for every dog. Some are better suited to acute situations, while others may be considered for broader nervous-system support. Medication interactions and underlying health conditions must be considered.

Homeopathy

Homeopathy may be considered when the dog’s emotional and physical symptom pattern points clearly toward an appropriate remedy.

Aconite is not automatically the remedy for every frightened dog. Ignatia is not automatically the remedy for every grief response. The individual picture still matters.

CBD

CBD may help some dogs with discomfort, sleep, emotional regulation, or the intensity of their response to stress.

Results depend on:

• Product quality

• Formulation

• Amount used

• Timing

• Consistency

• The reason for use

• The individual dog

“CBD did nothing” sometimes means the product, amount, timing, or expectation did not match the situation.

PEMF, Red Light, Massage, Reiki, and Bodywork

These modalities may support relaxation, physical comfort, circulation, mobility, recovery, and a calmer sensory experience.

A dog who is less painful and more physically comfortable may have more capacity for emotional regulation. The dog should always be allowed to participate willingly. More treatment is not automatically better treatment.

Raindrop Technique and Aromatic Bodywork

When appropriately adapted for the dog, aromatic bodywork may be incorporated into a broader relaxation and wellness routine.

I use these sessions as one possible layer—not as a replacement for veterinary care, nutrition, behavior support, pain evaluation, or environmental changes.

Breed, Temperament, and Life Experience

Some dogs appear more sensitive to environmental stimulation, movement, noise, pressure, and changes in routine.

Working and herding breeds may remain highly aware of everything happening around them. Sensitive sporting breeds may react strongly to household tension or environmental changes. Dogs bred for guarding may be naturally vigilant. Small dogs may experience a world where they are frequently picked up, crowded, startled, or handled without warning.

Rescue dogs may also carry the effects of poor early socialization, unstable housing, confinement, frightening handling, neglect, repeated rehoming, or experiences we may never fully know.

Breed can offer clues, but it should not become an excuse.

“He is a Border Collie” does not mean he should live in a permanent state of hyperarousal.

“She is a rescue” does not mean chronic fear must simply be accepted forever.

Their history helps explain the pattern. It also helps us build a more appropriate plan.

Dana’s Thoughts

I see many dogs labeled anxious, reactive, stubborn, dramatic, aggressive, or bad when the real picture is far more complicated.

Sometimes the dog is painful. Sometimes he is nauseated. Sometimes he has not slept deeply in months. Sometimes the household is far more stimulating than anyone realizes. Sometimes his food is not working for him. Sometimes his gut is inflamed. Sometimes training has repeatedly pushed him past the point where he can think. Sometimes the dog has learned that nobody listens until he explodes.

And sometimes several of those things are happening at once.

This is why I ask so many questions. I want to know when the behavior began, what was happening around that time, whether it changes throughout the day, how quickly the dog recovers, what the stool looks like, how the dog sleeps, what medications have been used, whether pain has been evaluated, what the dog eats, what changed in the home, and what else the body may be trying to tell us.

Cortisol may be part of the picture. But the real goal is not to chase one hormone.

The goal is to understand why the dog’s body keeps responding as though it is under threat—and determine what can be changed to help that dog feel and function better.

Five Things You Can Start Today

1. Track the Pattern

For several days, write down:

• What happened before the reaction

• The time of day

• Food and treats

• Sleep quality

• Stool or digestive changes

• Exercise and activity

• Pain or physical symptoms

• How long the dog took to recover

Patterns are easier to see on paper than in the middle of a difficult day.

2. Protect One Real Rest Period

Create at least one predictable period each day when your dog can sleep without interruption, handling, visitors, household chaos, or pressure to participate.

3. Reduce One Known Stressor

Do not try to fix everything tonight. Choose one repeated source of stress and reduce its intensity, frequency, or duration.

4. Replace Intensity With Regulation

Trade one high-arousal activity for a sniffing walk, calm outdoor time, gentle bodywork, or another activity that helps your dog settle rather than simply crash.

5. Look at the Whole Dog

Consider behavior, pain, digestion, sleep, nutrition, medications, environment, past experiences, and medical history together.

That is often where the missing information has been hiding.

When You Need an Individualized Plan

If your dog remains anxious, reactive, restless, uncomfortable, unable to settle, or physically unwell despite your efforts, it may be time to stop adding random calming products and take a closer look at the complete pattern.

My work may include reviewing:

• Nutrition and digestive health

• Medical history and lab work

• Pain, mobility, and sleep

• Daily routine and environmental exposure

• Stress, trauma, and behavior patterns

• Essential oils, herbs, homeopathy, and CBD

• Minerals, mushrooms, and microbiome support

• Bodywork and energy modalities

• Additional testing considerations

Sometimes the answer is simple. Sometimes it is complex.

The important part is choosing the next step based on your dog—not simply grabbing the first “calming” product that appears in a search result.

Reach our for an Inquiry Chat — we can talk about both sides of the equation — Nutrition + Wellness & Behavioral Support Techniques.

Continue Learning

These articles expand directly on the systems and support strategies discussed above:

• How Anxiety Affects Dogs
  Learn how anxiety can affect behavior, digestion, sleep, and physical health.

• Understanding the Vagus Nerve in Dogs
  Explore how the nervous system shifts between stress, digestion, rest, and recovery.

• How Your Dog’s Gut Influences the Brain and Behavior
  Learn how digestive health, the microbiome, and the nervous system influence one another.

• Natural Ways to Support Your Dog’s Stress
  Review nutritional, environmental, and lifestyle considerations for stressed dogs.

• Essential Oils for Dog Anxiety
  Learn how different anxiety patterns may influence the selection and use of essential oils.