Dog Adrenal Gland Problems: Signs and What They Mean

The signs of adrenal gland problems in dogs fall into two opposite patterns: too much cortisol, which looks like heavy drinking and urinating, a bigger appetite, a pot-bellied shape, panting at rest and thinning hair, or too little cortisol, which looks like vague weakness, a picky appetite, vomiting, diarrhea, shaking and episodes of collapse. If your dog is showing anything from that second group, especially weakness, repeated vomiting or collapse, call your veterinarian right now or go straight to an emergency clinic, because a low-cortisol crisis can become life threatening within hours. Any dog with a lasting change in thirst, appetite, coat or stamina needs an exam and bloodwork rather than a wait-and-see week at home.

Adrenal disease is one of the easiest things in canine medicine to mistake for normal aging, and one of the most rewarding to catch early. Below is what each pattern looks like, how the two differ, and what happens once you walk into the clinic with your concerns.

What the adrenal glands actually do

Your dog has two adrenal glands, each sitting just in front of a kidney. They are small, but they manufacture hormones the body cannot run without. Cortisol regulates blood sugar, inflammation, the stress response and how protein is broken down and rebuilt. Aldosterone controls the balance of sodium and potassium, which in turn drives blood pressure and hydration. The glands also produce small amounts of sex hormones and adrenaline.

Almost every case of dog adrenal issues comes down to a quantity problem. The glands make too much of these hormones or too little. Too much cortisol is called hyperadrenocorticism, better known as Cushing's disease. Too little is called hypoadrenocorticism, better known as Addison's disease.

Research suggests cortisol excess in dogs arises in two distinct ways: a small tumor in the pituitary gland at the base of the brain that keeps telling the adrenals to work harder, or a tumor in one of the adrenal glands itself. There is also a third, entirely man-made version, caused by long courses of steroid medication given for another condition. If that applies to your dog, do not stop or reduce a prescribed medication on your own. Steroid doses have to be tapered by the prescribing veterinarian, because stopping abruptly can trigger a sudden cortisol deficiency.

Signs that point to too much cortisol

Cushing's disease creeps. Owners often say, looking back, that the first changes seemed like an older dog slowing down. Watch for:

• Drinking noticeably more water and asking to go out more often, sometimes with overnight accidents in a previously reliable dog
• A ravenous appetite, counter surfing or scavenging that is out of character
• A pot-bellied or sagging abdomen, often with visible muscle loss along the spine and hind legs
• Thinning coat, symmetrical hair loss over the flanks and trunk, and hair that is slow to grow back after clipping
• Thin, papery skin with visible blood vessels, blackheads, or hard chalky white plaques in the skin
• Panting at rest, including at night in a cool room
• Skin infections and urinary tract infections that keep returning
• Lethargy, reluctance to jump onto furniture, and a generally flat mood

The pattern matters more than any single sign. A dog that is drinking more, eating more, losing coat and panting is telling you something specific, and it is not simply age. Cushing's is most often picked up in middle-aged and senior dogs, and it is frequently discussed in breeds such as poodles, dachshunds, beagles, Boston terriers and Yorkshire terriers, though any dog can develop it.

There is a practical reason not to delay. Excess cortisol raises blood pressure, encourages urinary infections, worsens diabetes risk and increases clotting risk, so the longer it runs unaddressed, the more secondary problems stack up. If you have ticked two or three boxes on the list above, that is a bloodwork conversation this week, not next season.

Signs that point to too little cortisol

Addison's disease has earned its nickname, the great pretender. The signs are vague, they come and go, and they often improve for a while after a visit to the clinic for fluids, which makes the underlying problem easy to miss. Look for:

• Intermittent vomiting and diarrhea, sometimes with blood, that resolves and then returns weeks later
• A reduced or unpredictable appetite and gradual weight loss
• Weakness, exercise intolerance and a dog that tires far sooner than it used to
• Shaking or shivering that is not about temperature
• Increased thirst and urination in some dogs, which confusingly overlaps with the opposite condition
• A clear link to stress: flares around boarding, travel, thunderstorms, a house move or a grooming appointment
• A slow heart rate, dehydration, dark stools or collapse during an episode

A dog that is weak, collapsing, vomiting repeatedly or unable to stand needs emergency veterinary care immediately, because an adrenal crisis can drop blood pressure and push potassium to levels that interfere with the heart. That is not a signs-of-adrenal-issues-in-dogs checklist item to monitor. That is a drive to the emergency clinic.

Addison's is often diagnosed in young and middle-aged dogs, which is part of why it gets overlooked in an otherwise healthy looking animal. It is reported more frequently in standard poodles, Portuguese water dogs, bearded collies, Nova Scotia duck tolling retrievers, West Highland white terriers and Great Danes, among others. Breed is a prompt to test sooner, never a reason to rule anything out.

Comparing the two patterns side by side

What you notice	Too much cortisol (Cushing's)	Too little cortisol (Addison's)
Thirst and urination	Markedly increased, often the first clue	Sometimes increased, usually less dramatic
Appetite	Increased, often ravenous	Reduced, picky, skipped meals
Body shape	Pot belly with muscle wasting	Weight loss, thin, poor condition
Coat and skin	Thinning hair, fragile skin, repeat infections	Usually normal
Energy	Lethargic but still eating and drinking	Weak and episodic, worse after stress
Stomach signs	Uncommon	Common: vomiting, diarrhea, sometimes blood
Typical age at diagnosis	Middle-aged to senior	Young to middle-aged
Urgency	Needs a planned diagnostic workup	Can become a same-day emergency

When dog adrenal problems become an emergency

Most cortisol-excess cases are worked up on a normal appointment schedule. Cortisol deficiency is the one that turns sharply. Go to an emergency veterinarian now if your dog is collapsing or cannot rise, is vomiting repeatedly, has bloody or black tarry stool, feels cold with pale gums, is breathing oddly, or has suddenly become profoundly weak after a stressful event.

The same applies to a dog on long-term steroid medication whose doses were missed or stopped suddenly. That dog can be short of cortisol at exactly the moment the body needs it most.

In the hospital, the first steps are usually intravenous fluids, electrolyte correction and blood tests, with hormone testing to follow once the dog is stable. The diagnosis can wait a few hours; the stabilisation cannot. If you are unsure whether what you are seeing crosses the line, call the clinic and describe it. Triage over the phone costs you nothing, and veterinary teams would far rather hear about a dog who turns out to be fine.

How veterinarians diagnose and manage adrenal disease

Diagnosis starts broad, then narrows. Expect a physical exam, a complete blood count, a chemistry panel, electrolytes and a urinalysis. Certain findings raise suspicion straight away: dilute urine, elevated liver enzymes and high cholesterol can point toward cortisol excess, while a low sodium to potassium ratio, low blood sugar and unexplained anemia can point toward deficiency.

From there, your vet may run a specific hormone test. A baseline cortisol measurement is commonly used as a first screen for deficiency, with an ACTH stimulation test to confirm. For suspected excess, a low-dose dexamethasone suppression test, an ACTH stimulation test or a urine cortisol to creatinine ratio may be chosen, depending on the dog and the clinical picture. Abdominal ultrasound helps show whether one adrenal gland is enlarged, both are, or a mass is present. Advanced imaging is sometimes used when a pituitary tumor is suspected.

Management depends on the diagnosis. Cortisol excess driven by the pituitary is usually controlled with long-term oral medication that reduces cortisol production, with repeat blood tests to keep levels in a safe window. A tumor confined to one adrenal gland may be a surgical case. Steroid-induced cases are managed by a carefully supervised taper of the original medication. Cortisol deficiency is managed with lifelong hormone replacement, typically a mineralocorticoid plus a glucocorticoid, adjusted using follow-up bloodwork and increased around stressful events on veterinary advice.

Two honest caveats. First, results vary from dog to dog, in how quickly signs settle and how much monitoring each dog needs. Second, diagnostic and monitoring costs vary widely by clinic and region, so ask for an estimate of the full workup up front rather than being surprised test by test. If something in the plan is unclear, talk to your vet and ask them to walk you through what each test rules in or out.

Key Takeaways

• Adrenal problems in dogs come in two opposite forms: too much cortisol (Cushing's) and too little (Addison's).
• Excess cortisol looks like heavy drinking, a bigger appetite, a pot belly, muscle loss, thinning coat, panting and repeat infections.
• Deficiency looks like weakness, poor appetite, vomiting, diarrhea, shaking and episodes that flare under stress.
• Collapse, repeated vomiting, bloody stool or profound weakness means emergency care immediately, not a morning appointment.
• Diagnosis relies on bloodwork plus specific hormone testing and often ultrasound; the pattern of signs is what triggers the testing.
• Both conditions are manageable long term with veterinary treatment and regular monitoring, and results vary from dog to dog.
• Never stop or change a prescribed steroid medication without the prescribing veterinarian's guidance.

Where adrenal care begins

Adrenal disease is a diagnosis that belongs entirely to your veterinarian. Hormone disorders cannot be identified by appearance, by breed or by a symptom list on a website, and two dogs with opposite problems can look similar across a room. The job of an article like this one is to help you recognise a pattern early enough to act on it, and then to hand the question over to someone who can run the tests, interpret them in context and build a monitoring plan around your specific dog.

Bring notes to the appointment. Water bowl refills per day, appetite changes, photos of coat loss over the past few months, and dates of any episodes of weakness or vomiting are genuinely useful clinical data, and they often shorten the path to the right test. Diet, exercise and general wellness care all matter for an aging dog, but they sit alongside a diagnosis and a treatment plan, never in place of one.

If you are still weighing whether what you are seeing needs an appointment this week or a trip to the emergency clinic tonight, Dog Emergency Signs covers the symptoms that should never be slept on, and your veterinary team is always the right first phone call.