Cushing's Disease in Dogs: Symptoms and Treatment in the UK
Cushing's disease, or hyperadrenocorticism, is a hormonal disorder caused by chronically elevated cortisol levels in the body. It primarily affects middle-aged and older dogs, and because the symptoms develop gradually they are often mistaken for normal ageing. Left unmanaged it significantly affects quality of life, but with the right treatment most dogs do well for years.
Key takeaways
- Cushing's disease in dogs causes a distinctive cluster of signs including pot belly, hair loss and increased thirst — often mistaken for ageing.
- Diagnosis requires specific hormonal tests costing £150–£700 in total; ongoing management with trilostane costs £50–£120 per month.
- With appropriate treatment, most dogs with Cushing's disease maintain a good quality of life for several years.
What Causes Cushing's Disease?
In roughly 85 per cent of cases, Cushing's disease is caused by a small benign tumour in the pituitary gland (pituitary-dependent hyperadrenocorticism, PDH). The tumour causes the pituitary to overproduce ACTH, which stimulates the adrenal glands to produce excess cortisol. In the remaining 15 per cent, a tumour in one of the adrenal glands itself is responsible (adrenal-dependent hyperadrenocorticism, ADH).
A third form — iatrogenic Cushing's — is caused by prolonged use of corticosteroid medications. This reverses when the steroids are gradually withdrawn under veterinary supervision. Certain breeds are notably predisposed, including Poodles, Dachshunds, Boxers, Boston Terriers, Yorkshire Terriers and Staffordshire Bull Terriers.
Symptoms of Cushing's Disease in Dogs
Because cortisol affects almost every system in the body, Cushing's disease produces a wide range of symptoms. The most characteristic signs are a pot-bellied appearance (caused by muscle wasting and fat redistribution), symmetrical hair loss on the flanks and trunk, skin that becomes thin and wrinkled, increased thirst and urination, increased appetite, and lethargy.
The skin often becomes fragile and prone to bruising; some dogs develop calcinosis cutis — hard calcium deposits under the skin. Recurrent skin infections, urinary tract infections and muscle weakness causing difficulty climbing stairs are also common. Female dogs may show anoestrus (cessation of seasons), while male dogs may show testicular atrophy. Many owners attribute these changes to old age, so the diagnosis is frequently delayed — if you recognise a cluster of these signs, ask your vet to test for Cushing's.
Diagnosis and Costs
Diagnosing Cushing's requires specific blood tests because a routine biochemistry panel alone is not sufficient. The two main tests are the low-dose dexamethasone suppression test (LDDST) and the ACTH stimulation test — both cost roughly £80–£160 depending on the practice. Urine cortisol-to-creatinine ratio is a cheaper screening test (around £40–£60) but less definitive.
Once Cushing's is confirmed, abdominal ultrasound (£200–£400) is used to distinguish pituitary-dependent from adrenal-dependent disease — adrenal tumours often appear as masses on ultrasound. Some cases require referral to an internal medicine specialist for advanced imaging such as MRI or CT scanning (£1,500–£3,000 at a specialist centre) to assess pituitary tumour size, although this is not required for most dogs. Total diagnostic costs commonly range from £300–£700.
Treatment and Long-Term Management
The most widely used treatment for pituitary-dependent Cushing's in the UK is trilostane (Vetoryl), an adrenal enzyme inhibitor taken daily by mouth. It requires regular monitoring with ACTH stimulation tests — usually six to eight weeks after starting treatment and every three to six months thereafter — to ensure the dose is correct. Medication costs roughly £50–£120 per month depending on the dog's weight, with monitoring tests adding £80–£160 per visit.
Adrenal tumours may be treated medically in the same way, but surgical adrenalectomy (removal of the affected gland) is potentially curative and is carried out at specialist surgical centres at a cost of £3,000–£6,000. Medical management of PDH is lifelong. With good management, most dogs with Cushing's disease maintain a reasonable quality of life for several years. Pet insurance with a high annual limit and no sub-limits for hormonal conditions is the most useful cover for this diagnosis.
Find a Vet Near You
Managing Cushing's disease involves ongoing vet costs that can be significant over time. Use CompareMyVet at app.comparemyvet.uk to compare published consultation and test prices at practices near you, so you can plan your dog's care with confidence.
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Common questions
Pituitary-dependent Cushing's is not cured by medication but is effectively managed long-term. Adrenal-dependent Cushing's caused by a benign adrenal tumour can potentially be cured by surgical removal of the affected gland, though this carries surgical risks and is performed at specialist centres.
Both conditions cause increased thirst and urination, but Cushing's also produces a pot belly, skin and coat changes and muscle weakness. They can occur together, as Cushing's promotes insulin resistance. A vet will run specific tests to distinguish between them.
Untreated Cushing's progressively worsens, causing severe muscle wasting, increased susceptibility to infections, high blood pressure and risk of pulmonary thromboembolism. Quality of life deteriorates significantly, and the condition can become life-threatening if complications develop.
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