Cushing’s Disease in Dogs (Hyperadrenocorticism)
- Synonyms: Cushing’s syndrome, HAK, hypercortisolism
- Occurrence: rarer
- Location of disease: Abdomen/pelvis, General/Whole body
When to visit the vet?
Non-urgent see a veterinarian within 2–3 days
If the condition worsens / symptoms persist, consult a veterinarian.
Das Wichtigste auf einen Blick
Cushing’s syndrome in dogs is a hormonal disorder caused by excessive production of cortisol. Cortisol is an important hormone that regulates metabolic processes, immune response, and stress management. The most common cause is a benign tumor in the pituitary gland that increases ACTH production and thus stimulates the adrenal glands to produce more cortisol. Another, rarer cause is a tumor in the adrenal gland itself. Long-term use of corticosteroids can also trigger the syndrome. Symptoms include increased thirst and appetite, increased urination, hair loss, muscle weakness, and skin changes. Diagnosis requires a combination of clinical examination, blood tests such as the ACTH stimulation test, and imaging procedures. Treatment depends on the cause. For pituitary-dependent Cushing’s, trilostane is often used to inhibit cortisol production, while for adrenal tumors, surgical removal is considered. Regular follow-up is important to adjust therapy and monitor side effects. Prognosis varies depending on the form of the disease and the dog’s general health condition, but can be significantly improved through appropriate treatment. Preventive measures are limited due to unclear causes, but good health care and early detection can help maintain quality of life.
Ursachen
Cushing’s syndrome in dogs is an endocrine disorder characterized by excessive production of cortisol, a steroid hormone. Cortisol plays an important role in regulating metabolic processes, immune response, and stress management. It is produced in the adrenal glands, which are located above the kidneys.
The most common cause of Cushing’s syndrome in dogs is a benign tumor in the pituitary gland that increases production of adrenocorticotropic hormone (ACTH). This hormone stimulates the adrenal glands to produce cortisol. This form is called pituitary-dependent Cushing’s syndrome and accounts for approximately 80–85% of cases in dogs.
Another cause can be a tumor in the adrenal gland itself that directly increases cortisol production. This less common form is called adrenal-dependent Cushing’s syndrome. In rare cases, Cushing’s syndrome can also be caused by long-term administration of corticosteroids used to treat other conditions.
The exact causes of tumor development in the pituitary gland or adrenal glands are not fully understood. Genetic factors may play a role, as well as certain environmental factors that could increase the risk.
Symptoms
Symptoms of Cushing’s syndrome are varied and can differ from dog to dog. One of the most common signs is increased water intake and corresponding increased urinary urgency. This can lead to more frequent bathroom trips and occasionally accidents in the house.
Another common symptom is increased food intake, which often leads to weight gain and obesity. Dogs with Cushing’s syndrome tend to develop an enlarged abdominal region due to fat redistribution and muscle loss.
Skin changes such as thinning skin, hair loss, and an increased susceptibility to skin infections are also frequently observed. Some dogs may experience darkening of the skin or changes in hair growth.
Other symptoms may include lethargy, muscle weakness, and reduced exercise tolerance. In some cases, behavioral changes may also occur, such as increased irritability or apathy.
Diagnose
Diagnosis of Cushing’s syndrome requires a combination of clinical examination, blood tests, and imaging procedures. First, the veterinarian will take a thorough medical history and physically examine the dog to identify possible symptoms.
Blood tests are crucial to determine cortisol levels in the dog’s blood. A commonly used test is the ACTH stimulation test, which measures the adrenal glands’ response to an injection of ACTH. Another test is the dexamethasone suppression test, which helps distinguish between different forms of Cushing’s syndrome.
Imaging procedures such as ultrasound or MRI can be used to identify tumors in the pituitary gland or adrenal glands. These examinations are particularly important to determine the exact cause of the disease and plan appropriate treatment.
Therapie
Treatment of Cushing’s syndrome in dogs depends on the underlying cause. For the pituitary-dependent form, the medication trilostane is often used, which inhibits cortisol production in the adrenal glands. An alternative is mitotane, which destroys the adrenal cells that produce cortisol.
For an adrenal tumor, surgical removal of the affected tumor may be considered, provided the tumor is operable and the dog’s general condition allows it. In cases where surgery is not possible, medical therapy can also be applied.
If Cushing’s syndrome is caused by long-term administration of corticosteroids, the dose of these medications must be gradually reduced to restore hormonal balance.
Regular follow-up examinations are important to monitor treatment effectiveness and detect possible side effects. Adjustment of therapy may be necessary based on clinical signs and blood test results.
Prognose und Nachsorge
The prognosis for dogs with Cushing’s syndrome depends on various factors, including the form of the disease, the dog’s general health condition, and response to treatment. For many dogs, quality of life can be significantly improved through appropriate therapy.
Dogs with pituitary-dependent Cushing’s syndrome that respond well to medical treatment can often lead a relatively normal life. However, it is important to continue treatment lifelong and conduct regular veterinary follow-ups.
For dogs with adrenal tumors, the prognosis depends on the possibility of surgically removing the tumor. If the tumor can be completely removed and no metastases are present, the prognosis is generally better.
Long-term prognosis can be influenced by concurrent health problems or complications. Close collaboration with the veterinarian is crucial to develop the best treatment plan and maintain the dog’s quality of life.
Prävention
Since the exact causes of Cushing’s syndrome are not fully understood, there are no specific measures for prevention of the disease. However, general health care and regular veterinary examinations can help detect the disease early and begin treatment promptly.
If your dog requires long-term corticosteroids, it is important to carefully monitor dosage and adjust only under veterinary guidance. Long-term, high doses of such medications can increase the risk of developing Cushing’s syndrome.
A balanced diet, regular exercise, and a healthy body weight can also help to promote your dog’s general well-being and reduce the risk of hormonal imbalances.
Finally, it is important to pay attention to changes in your dog’s behavior or health and consult a veterinarian early if you suspect a health problem. Early intervention can help prevent complications and improve the long-term prognosis.
Ausblick auf aktuelle Forschung
Research is moving from “test-and-treat” toward precision medicine strategies. Genomic analyses of pituitary microadenomas and adrenal tumors identify mutation patterns and signaling pathways (e.g., cAMP/PKA, Wnt) that could enable targeted therapies in the future. In parallel, functional imaging is being refined: high-resolution ultrasound, contrast-enhanced CT/MRI, and—experimentally—PET tracers to distinguish active tumor components and plan therapy. In diagnostics, algorithmic combination approaches are gaining importance, integrating baseline values, stimulation tests, long-term monitoring, and clinical markers to better classify borderline cases and avoid overdiagnosis.
Therapeutically, trilostane remains standard, but studies are testing individualized dose control based on longitudinal cortisol profiles (home collection, dried blood cards) and digital progression markers (activity, panting frequency, drinking patterns). New substances target steroidogenesis enzymes or the pituitary axis, aiming to reduce side effects and prevent relapses. For surgical cases, minimally invasive procedures are being optimized, including perioperative risk stratification.
Another field is comorbidity medicine: metabolic syndrome, hypertension, thrombosis risk, skin barrier damage. Here, bundled therapies are emerging that systematically link endocrinology, dermatology, and cardiology. Finally, quality-of-life monitoring is taking center stage: validated questionnaires and sensors are intended to make therapy decisions patient-centered. Goal for the coming years: more precise diagnoses, tailored regimens, fewer side effects—and stable, measurably better quality of life.