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Adrenal Fatigue In Pets- Are We Missing It?

by Marlene Siegel, DVM

Despite the advancements in modern veterinary medicine, we have the sickest pet population in history. If we include cancer, autoimmune disease, arthritis, obesity, allergies and gastrointestinal disorders, nearly 100% of our fur family are affected with some form of chronic degenerative disease that is related to adrenal gland dysfunction.

In veterinary medicine we are trained to recognize the 2 major adrenal dysfunctions once they have advanced past the early adrenal dysfunction stage - what is recognized as adrenal fatigue:

  1. Hyperadrenalcortism (also called Cushing’s Disease) which is an excess production of cortisol which could occur from a tumor in the pituitary gland, adrenal gland or the over usage of exogenous steroids (Iatrogenic).

  2. Hypoadrenalcortism (also called Addison’s disease) is an autoimmune disease in which the body attacks the outer layers of the adrenal glands. This leads to a deficiency in key hormones (cortisol- glucocorticoids and aldosterone- mineralocorticoids) which regulates the body’s organ responses to stress and water/electrolyte balance. Addison’s disease can also be caused by destruction of the adrenal gland, either by a metastatic tumor, hemorrhage, infarction, granulomatous disease, adrenolytic agents like the drug mitotane, or a drug like trilostane that inhibits adrenal enzymes.

There is little information discussing Adrenal Fatigue in animals.

Chronic stress and the resultant inflammation play a major role in the etiology of “Adrenal Fatigue”

The immune system is a complex mechanism that integrates and impacts every cell of the body. There are massive amounts of information discussing how 70% of the immune system lives in the gut and is impacted by the microbiome and lifestyle.

Though intermittent stress is positive, chronic stress, chronic inflammation and “Adrenal Fatigue” negatively impact the immune system. Stress is one of the mechanisms the ancestors used to help them survive challenging times and come through it more resilient. But there is an equally important mechanism of recovery and repair that is necessary to shift from surviving to thriving, which is the ultimate goal of life.

Autonomic Nervous System:

Sympathetic vs Parasympathetic

As information comes into the brain (through sight, sound, feel, taste and smell) it is processed through the amygdala, an area of the brain that contributes to emotional processing. Depending on how the message is received and interpreted, one (of the 2) branches of the autonomic nervous system (ANS) will be activated. If the message is danger, it sends a distress signal to the hypothalamus. This area of the brain functions like a command center, communicating with the rest of the body through the ANS to activate the sympathetic branch for a fight or flight response. When the sympathetic branch is activated, it sends a signal to the adrenal gland. Cortisol and adrenaline are released, energy and blood supply increase to the muscles, stored sugars are released into the blood for immediate energy, and the fight/flight response takes over (the urge to run away from the danger or fight to survive).

The parasympathetic branch of the ANS that regulates rest, repair, digestion and detoxification is shut down by high sympathetic tone. This is critically important, because all resources need to be diverted for survival during times of danger. Once the danger/threat is gone, then it is important to repair, regenerate and detoxify.

The Hypothalamic-Pituitary-Adrenal Axis

(HPA axis)

The collaboration of the adrenal gland, pituitary and hypothalamus is known as the hypothalamic-pituitary-adrenal axis (HPA axis). Their joint activities help control the body’s reactions to stress, (physical or psychological). They also help regulate digestion, the immune system, and energy usage.

When a perceived danger is received, there is an initial surge of epinephrine. When this surge begins to subside, the hypothalamus activates the second component of the stress response system: the HPA axis. The HPA axis relies on a series of hormonal signals to keep the sympathetic nervous system activated.

If the brain continues to perceive something as dangerous, the hypothalamus releases corticotropin-releasing hormone (CRH), which travels to the pituitary gland, triggering the release of adrenocorticotropic hormone (ACTH). This hormone travels to the adrenal glands, prompting it to release cortisol. This process allows the body to stay in high alert.

If there is no danger, the vagus nerve stimulates the parasympathetic branch of the ANS so the body can rest, repair, digest and detoxify.

Stress and Heart Rate Variability (HRV)

Stress, whether real or perceived, increases heart rate, breathing rate, and blood pressure. When the threat is over, the body relaxes, heart rate, breathing and blood pressure reduce, and there is a return to the resting state.

Heart rate variability (a measure of the variability between heartbeats) is a metric of how the body is recovering (the ability to adapt) from stresses throughout the day and an evaluator of overall fitness. Low heart rate variability is considered a sign of current or future health problems because it shows the body is less resilient and struggles to handle changing situations. Low HRV may be an early indicator of adrenal fatigue.

When The Lion Is ALWAYS In Pursuit

The brain does not distinguish between the threat of the lion chasing you and the S.A.D. day (Standard American Day, though it is not just in America that these stressors exist). The S.A.D. includes the S.A.D. Diet (Standard American Diet). Other stressors for humans include being sleep deprived, having persistent financial concerns, lockdowns, processed foods, toxins, nutrient deficiencies, EMF pollution and FEAR (Future Events Appearing Real). Animals also experience stress from processed foods, toxins, nutrient deficiencies and EMF. One of the biggest contributors to animal stress is entraining (absorbing) stress from their human companions.

High cortisol, whether it is naturally produced by the adrenal glands in response to stressors or from prescription medications, creates a risk for blood sugar imbalances, contributes to leaky gut, perpetuates high inflammation and hormone imbalances. Signs of persistent cortisol elevation include weight gain, low energy and poor vitality.

Adrenal Fatigue

Adrenal fatigue begins when the body is unable to properly respond to “threats”, whether real or perceived, with the appropriate steroids. This usually occurs when the body gets “stuck” in sympathetic tone (stays in fight/flight) and is unable to shift into parasympathetic (rest, repair, digest and detoxify). Early warning signs of adrenal fatigue in pets mimic “allergy” symptoms such as sneezing, itching, excessive eye tearing or licking of the paws. The western practitioner lumps these under “allergies” and prescribes a pharmaceutical (steroids, Apoquil, Cytopoint) so the symptom goes away (temporarily) and the owner is happy…but the root cause has not been addressed and the use of steroids further suppress the adrenal glands ability to properly produce steroids.

Other symptoms of adrenal fatigue may include waxing and waning gastrointestinal signs, a finicky appetite, inappropriate response to stressors and generalized lethargy. Again, the western practitioner addresses the symptoms (often prescribing a steroid) but not the underlying dis-ease. Again, the use of steroids further suppress the adrenal glands ability to properly produce steroids. The pet improves…until the next episode.

Eventually the pet relapses or the condition worsens into a chronic degenerative disease or an autoimmune condition like Addison’s Disease where the adrenal gland is no longer able to produce the steroids needed to maintain life.

Prescribed steroids are the most overused and abused drugs in the conventional veterinarian’s pharmacy.

Glucocorticoid hormones (either naturally produced or from prescribed medications) stimulate the adrenal medulla.

Addressing The Root Cause

Solving the immune challenges and improving autonomic nervous system balance for our fur children is a family effort. We the pet parents must change the lifestyle factors that are contributing to adrenal stress and immune dysfunction in our fur kids.


  1. Feed species appropriate grass fed/finished balanced raw diet with the appropriate proportions of meat, fat, organs and bone.

  2. Provide highly filtered structured water.

  3. Provide the Essential Vitamins/Minerals and Fatty Acids in plant based bioavailable organic form.

  4. Clean the environment with organic products, essential oils or other natural cleaners.

  5. Use only organic personal body care products on the pet.

  6. All laundry products should be natural and organic.

  7. Monitor the home air quality.

  8. Mitigate EMF. Hard wire when possible, turn off routers when sleeping or leaving the house, no smart appliances, use EMF mitigating devices.

  9. Create mindfulness practices. Meditate, go outside and do grounding with your pets. Exercise together and do deep belly breathing (as you become more parasympathetic, your pet will relax too).

  10. Detoxify the 6 organs of elimination (kidneys, colon, lungs, liver, skin and lymphatics).

  11. Heal the leaky gut.

  12. Support the microbiome and its diversity with fermented foods.

  13. Incorporate Hormetic Stressors (rectal ozone, intermittent fasting, temperature extremes) into your life and your pets.

  14. Use Adaptogenic herbs and Sodium Ascorbate.

  15. Be open to learning. At my website I have resources and biohacking tools that work with sound, light and vibration to restore balance to the ANS and improve HRV.

The Choice To Heal Is Ours

The veterinary pharmaceutical medicine market is a $44 billion dollar market currently dominated by vaccines, flea and tick repellents and anti-infectives!

With the health statistics as they are, we are clearly not suffering from a deficiency of pharmaceuticals.

The holistic and integrative veterinarians are leading the movement to address the root cause of dis-ease and support the body's innate intelligence to heal. Mitigate as many factors that compromise the immune system as possible by reducing stress, healing the leaky gut and lowering inflammation. This practice, along with supplying the essential nutrients the body needs to function, is the foundation for health and longevity for our fur fam and us.


Dr. Siegel is best known for integrating holistic treatment options with traditional veterinary medicine. Since 1987, she has relentlessly pursued the cause of disease in animals and formulated treatment regimens that literally save lives. It's not a stretch to say that Dr. Siegel has given back decades of life to the animals she has treated. Dr. Siegel is committed to creating healthy lifestyles for animals and the people that love them.

Dr. Siegel gained national recognition after being featured on the Truth About Cancer Project in 2019, and in the same year, launched EvoLove Raw - her proprietary raw pet food for dogs and cats.

Dr. Siegel continues to treat pets at her practice in Lutz, Florida and is also a frequent speaker and lecturer across the country.


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