What Does the Adrenal Gland Do in Dogs? (Key Signs)

When to call the vet. If your dog is weak, wobbly, collapsing, vomiting repeatedly, having diarrhoea alongside deep lethargy, shaking, cold to the touch or has crashed suddenly after a stressful event, treat it as an emergency and go to an emergency veterinary hospital straight away. A dog whose adrenal hormones fail can lose blood pressure and electrolyte balance fast, and that is not something to watch over a weekend. Book a prompt, non-emergency appointment if you are seeing slower changes: drinking and urinating much more than usual, a bottomless or a vanished appetite, a pot-bellied shape, symmetrical hair loss, thin or bruising skin, panting at rest, hind-leg weakness or repeat infections.

A dog's adrenal glands are two small hormone factories, one sitting just in front of each kidney. They make cortisol, which governs the stress response, blood sugar, immune activity and inflammation; aldosterone, which controls sodium, potassium, blood pressure and fluid balance; adrenaline and noradrenaline, which drive the fight-or-flight surge; and small amounts of sex hormone precursors. Together those hormones keep a dog's internal chemistry stable when life is not. When the glands produce too much cortisol, the result is Cushing's disease. When they produce too little cortisol and aldosterone, the result is Addison's disease. Both are real, testable conditions, and both belong in a veterinarian's hands.

Yes, dogs have adrenal glands, and here is how they are built

Every dog has two adrenal glands. They are easy to overlook on an ultrasound screen because they are small, pale and tucked against the front edge of each kidney. Size is a poor guide to importance. Without adrenal hormones a dog cannot hold blood pressure, cannot mobilise glucose under stress, and cannot keep sodium and potassium inside the narrow range the heart depends on.

Each gland has two distinct parts that behave almost like separate organs.

The outer layer, the cortex, is arranged in three zones. The outermost zone produces aldosterone, the mineralocorticoid that tells the kidneys to hold onto sodium and shed potassium, which in turn sets blood volume and blood pressure. The middle zone produces cortisol, the glucocorticoid that raises blood sugar, dampens inflammation, modulates immune activity and shapes how a dog uses protein and fat. The innermost zone makes small quantities of sex hormone precursors such as androstenedione.

The inner core, the medulla, is nervous tissue in all but name. It releases adrenaline and noradrenaline on demand: heart rate up, airways open, blood redirected to muscle. That is the surge you see in a dog that has just heard the doorbell.

Cortisol release is not random. The hypothalamus signals the pituitary gland at the base of the brain, the pituitary releases ACTH, and ACTH instructs the adrenal cortex to produce cortisol. Rising cortisol then feeds back and quietens the signal. This loop, the HPA axis, is where most canine adrenal disease goes wrong. The large majority of Cushing's cases in dogs begin with a small, usually benign pituitary tumour that keeps sending the ACTH signal, rather than with a tumour in the adrenal gland itself. That distinction changes how the disease is managed.

The signs owners usually notice first

Adrenal disease rarely announces itself. It arrives as a set of changes that look like ordinary ageing until you line them up side by side.

With too much cortisol (hyperadrenocorticism, or Cushing's disease), owners typically notice drinking and urinating far more than usual, a bottomless appetite, a pot-bellied or sagging abdomen, symmetrical thinning of the coat along the flanks and trunk, thin skin that bruises or scabs easily, heavy panting, weakness through the back legs, and repeated skin or urinary infections.

With too little cortisol and aldosterone (hypoadrenocorticism, or Addison's disease), the picture is vaguer and more dangerous. Addison's is called the great pretender for a reason: intermittent vomiting, diarrhoea, poor appetite, weight loss, shaking, weakness and lethargy that come and go, often worse after a stressful event. An Addisonian crisis, where electrolytes and blood pressure collapse, is a true emergency and needs immediate veterinary care rather than a watch-and-wait weekend.

Tumours of the adrenal medulla (pheochromocytoma) are less common and can cause episodic panting, pacing, a racing heart, high blood pressure and collapse that resolves as abruptly as it started.

What you see	Too much cortisol (Cushing's)	Too little cortisol (Addison's)
Thirst and urination	Markedly increased	Variable, often with dehydration
Appetite	Ravenous, food-obsessed	Poor, picky, skipping meals
Body shape	Pot belly, muscle loss over spine and hips	Weight loss, general wasting
Coat and skin	Symmetrical hair loss, thin skin, recurrent infections	Usually unremarkable
Energy pattern	Steady decline, panting at rest	Waxing and waning, crashes after stress
Typical age	Middle-aged to older dogs	Often young to middle-aged adults
Urgency	Schedule testing soon	Can become an emergency quickly

If more than one row rings true, book the appointment. Adrenal disease is diagnosed on bloodwork, not on appearance, and the sooner testing starts, the less collateral damage the hormones do.

When adrenal signs become an emergency

Most adrenal changes build slowly, but a dog with low adrenal hormone output can decompensate quickly, and that is the scenario to be ready for. Go to an emergency veterinary hospital, rather than waiting for a routine appointment, if your dog collapses or cannot stand, is vomiting repeatedly or cannot keep water down, has bloody diarrhoea, is shaking, is cold to the touch, has pale gums, is breathing fast or heavily at rest, seems confused or unresponsive, or has had a sudden crash in the hours after a boarding stay, a car journey, a house guest or any other stressor.

Dogs already diagnosed with an adrenal condition deserve a lower threshold for calling. If a dose of prescribed medication has been missed or vomited back up, if your dog is due for a monitoring recheck and is off colour, or if something simply looks wrong, phone the clinic and describe it. It is far easier for a veterinary team to stabilise a dog early than to rescue one that has been sliding for two days. Keep your veterinarian's number and the nearest emergency hospital's number somewhere you can find them without searching.

Why 'adrenal fatigue' does not appear in a veterinary chart

Search for dog adrenal fatigue and you will find a great deal of confident content. It is worth being blunt: adrenal fatigue is not a recognised veterinary diagnosis. It is a wellness-industry concept borrowed from human alternative medicine, where reviews of the available evidence have not supported it either. There is no accepted test for it in dogs and no agreed definition of what it would even be.

What is real is adrenal insufficiency, adrenal excess, and the atypical presentations in between, all of which are identified through specific hormone testing. The risk of the adrenal fatigue framing is not that it sounds appealing, it is that it is slow. A dog whose owner spends six months chasing an unmeasurable problem is a dog whose actual endocrine disease went untested for six months. If your dog is tired, drinking more, losing coat or losing muscle, that is a testing conversation with your veterinarian.

How a veterinarian confirms and manages adrenal disease

Diagnosis starts broad and narrows. Physical exam, complete blood count, chemistry panel, urinalysis and blood pressure come first. Patterns such as a raised alkaline phosphatase, persistently dilute urine, or a sodium to potassium ratio that has slipped out of range point the way.

From there come adrenal-specific tests. A urine cortisol to creatinine ratio, collected at home to avoid clinic stress, is useful mainly for ruling Cushing's out. An ACTH stimulation test measures how the glands respond when they are prompted to produce cortisol, and it is a standard tool both for diagnosing Addison's and for monitoring treatment. A suppression test checks whether the feedback loop shuts cortisol production down the way it should. Abdominal ultrasound shows whether both glands are symmetrically enlarged or whether one carries a mass, which separates pituitary-dependent disease from an adrenal tumour.

Treatment is prescription territory. For a dog producing too much cortisol, your vet may prescribe medication and adjust it using repeat testing, and a single adrenal tumour may be assessed as a surgical candidate, with that decision belonging to the veterinarian or surgeon. For a dog producing too little, treatment is usually lifelong hormone replacement that your vet prescribes and monitors, with regular rechecks to confirm the plan still fits the dog. Research suggests many dogs on a stable, well-monitored plan do well day to day, but results vary from dog to dog.

None of that is optional, and none of it can be substituted with anything bought over the counter. If your dog is on prescribed medication, do not change, skip or stop a dose on the strength of an article, including this one. Dose decisions belong to the veterinarian holding the monitoring results.

What to watch at home and what to tell your vet

The most useful thing an owner can bring to an appointment is a record. Adrenal disease is a pattern condition, and patterns are invisible from inside a single fifteen-minute consult. A simple phone note is enough.

Worth tracking:

• Water. Fill the bowl with a measured jug and note roughly how much goes in over a full day, including any bowls in other rooms.
• Urination. How often, how large the puddles, any new accidents overnight or in the house in a previously reliable dog.
• Appetite and weight. Meals finished or refused, scavenging, begging, stealing food, and body shape changes such as a dropping belly or a spine and hips becoming more prominent.
• Energy. Which walks are refused, whether the dog struggles on stairs or in the car, and whether bad days follow stressful events.
• Coat and skin. Where hair is thinning, whether both sides match, bruising, slow-healing scabs, recurring ear or skin infections.
• Episodes. Date, time, what happened, how long it lasted, what the dog had been doing beforehand, and how fast it recovered. Short phone videos of panting, trembling, pacing or weakness are genuinely valuable.

Bring a full list of everything your dog receives: prescribed medication, flea and worm products, chews, treats, anything given by another household member, and anything bought without a prescription. Some products can influence hormone test results or how medications are processed, so your veterinarian needs the whole picture before a cortisol test day. Also mention recent steroid courses of any kind, including creams and ear or eye preparations, and any upcoming stressors such as boarding, travel or surgery, since those are the moments a vulnerable dog is most likely to destabilise.

Key Takeaways

• Dogs have two adrenal glands, one in front of each kidney, producing cortisol, aldosterone, adrenaline and sex hormone precursors.
• Cortisol manages blood sugar, inflammation and the stress response; aldosterone manages sodium, potassium and blood pressure.
• Too much cortisol is Cushing's disease; too little cortisol and aldosterone is Addison's disease, which can become an emergency.
• Collapse, repeated vomiting, bloody diarrhoea, shaking, pale gums or a sudden crash after stress means emergency care now, not tomorrow.
• Adrenal fatigue is not a recognised veterinary diagnosis and has no accepted test in dogs.
• Diagnosis relies on bloodwork, stimulation or suppression testing and ultrasound, and treatment is prescription-based and vet-monitored.
• A home record of water intake, appetite, energy, coat changes and episode timing makes the appointment far more productive.

The adrenal glands are a small piece of anatomy doing an outsized job, and when they drift in either direction the whole dog shows it. Your veterinarian owns the diagnosis and the treatment plan: the testing, the prescription, the monitoring schedule and the timing of any change to it. Your job at home is observation, consistency with the plan as written, and knowing which signs mean the car keys rather than the calendar.

Nothing in this article treats, cures or prevents any condition; every decision about your dog's care belongs with your veterinarian.

Related guides: Senior Dog Bloodwork : What a Senior Blood Panel Shows and Why Is My Senior Dog Drinking So Much? (Warning Signs).