Reading about your dog’s Cushing’s disease can lead you to information about people with a condition of the same name. The connection begins with cortisol and the glands that control it. Understanding that shared system, then looking carefully at the names and figures used for each species, gives the comparison a clearer shape.
The Same Hormone in Both Species
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) explanation of Cushing’s syndrome starts with too much cortisol over a long period. In its account of the human body, cortisol helps with the response to stress, blood pressure, blood sugar, inflammation and turning food into energy. The adrenal glands, above the kidneys, make it. The familiar phrase “stress hormone” describes only part of its work.
The control system involves a sequence of signals. The hypothalamus, a part of the brain, releases CRH. That tells the pituitary gland to release ACTH, which tells the adrenal glands to make cortisol. When cortisol rises enough, it switches off the CRH signal, and ACTH and cortisol fall. NIDDK also describes a daily pattern: cortisol production normally drops just after a person falls asleep, whereas in Cushing’s syndrome it does not.
A 2025 review of Cushing’s disease across animal species describes this hypothalamic-pituitary-adrenal system as evolutionarily conserved. That shared chain of signals is the starting point for comparing dogs and people. Keep the human description of the sleep-related dip in its human context, rather than turning it into a way to interpret your dog’s sleep or behavior.
One Name, Two Meanings
In the human NIDDK explanation, Cushing’s disease means the pituitary form: a pituitary tumor makes too much ACTH, which in turn stimulates cortisol production. Cushing’s syndrome is the broader name. The same account also describes tumors in an adrenal gland that make too much cortisol. The gland involved is therefore an important part of the meaning, even when the shorter name sounds familiar.
For an owner moving between canine and human reading, the useful distinction is between the broad subject and the particular form being discussed. A heading that says only “Cushing’s” leaves that distinction unstated. Keep the species and full term together as you read. The guide to terminology in veterinary records provides the vocabulary for the canine side of the comparison.
How Common Is It?
Frequency figures need their labels. NIDDK gives estimates of about 40 to 70 people per million for endogenous Cushing’s syndrome. Here, “endogenous” means the cause comes from inside the body. That estimate is about the syndrome, with that qualification; it is not a figure for every possible use of the name Cushing’s.
MedlinePlus Genetics describes Cushing disease, the pituitary form, as affecting up to 2.4 in 1,000,000 people each year. Keep “each year” with that number. It refers to a different named condition and includes a time period, so it should not be treated as a second estimate of exactly the same thing as the NIDDK figure.
On the canine side, Schofield and colleagues’ study in the Journal of Small Animal Practice, published in 2022, examined records for 905,544 dogs under UK primary veterinary care. Including existing and newly identified cases during 2016, the researchers estimated a one-year period prevalence of 0.17%. Increasing age was associated with higher odds in their analysis.
That finding places the canine figure in a defined veterinary population and year. It does not provide a worldwide rate or an estimate for your own dog. Nor do these differently defined human and canine figures establish a precise ratio between species. For an owner of an older dog, the age association is useful background about the study group, rather than an explanation of any individual animal’s condition.
Medicines as a Cause
The NIDDK account of the causes of Cushing’s syndrome says that, in people, the most common cause is long-term, high-dose use of cortisol-like medicines. This is distinct from its discussion of causes arising inside the body. The broader syndrome name therefore covers both internally arising and medicine-related causes.
This also explains why the word “endogenous” matters in the frequency estimate above. A figure limited to an internal cause leaves medicine-related cases outside that definition. When comparing information, keep that boundary in view alongside the species, the full condition name and the time period. Otherwise, similar-looking figures can appear to disagree simply because they describe different groups.
Why Dogs Matter to Research
In their 2025 review in the International Journal of Molecular Sciences, Massardi and colleagues describe dogs as the most studied animal form of Cushing’s disease. They report strong molecular and clinical similarities with the human pituitary condition. The review considers naturally occurring forms in several species as well as experimental animal models.
The authors also identify practical and ethical limits on the experimental use of companion animals. Both parts of that account matter: dogs offer a scientifically informative comparison, and there are limits to how companion animals can be involved in research. The paper is a review of models and their strengths and limitations, rather than a care plan for an individual dog.
What This Means for You and Your Dog
The comparison is most useful as a guide to language and basic body science. Follow the chain from brain signals to adrenal cortisol, then check what a source means by disease, syndrome and endogenous. With a frequency figure, keep the population and time period beside the number. These distinctions make the reading more precise without requiring you to apply a human account to your dog.
Your dog’s individual care belongs with your veterinarian. Human signs differ, and only a doctor can assess them. This comparison does not provide medical advice for people.