Cushing Disease in Cats
What is Cushing’s Disease?
Cushing’s disease, also known as hyperadrenocorticism, occurs when the adrenal glands overproduce certain hormones, particularly cortisol. The adrenal glands are two small organs near the kidneys, which play a crucial role in your cat’s overall health by producing hormones that control stress, metabolism, and their immune response.
There are three possible causes of Cushing’s disease:
1. Pituitary Gland Tumour: This is the most common cause, accounting for 85-90% of cases. A benign or malignant tumour on the pituitary gland (a small organ in the brain) stimulates the adrenal glands to produce excessive cortisol.
2. Adrenal Gland Tumour: In some cases, a tumour on the adrenal gland itself is the cause. If benign, surgical removal can cure the condition. If malignant, treatment may involve surgery, but the prognosis is less favourable.
3. Excessive Steroid Use (Iatrogenic Cushing’s): This type occurs when a dog has been on long-term steroid medications for another disease. Stopping or reducing the medication under veterinary supervision is the key to treating this form.
SIGNS & SYMPTOMS OF CUSHING'S
The clinical signs of Cushing’s disease can be subtle at first but become more obvious as the condition progresses. Common signs include:
• Increased appetite
• Excessive thirst and urination
• Lethargy or reduced activity levels
• Poor coat quality or hair loss – particularly on the sides and tail
• A “pot-bellied” appearance due to weakness of the abdominal muscles
• Thin skin, frequent infections, or poor healing of wounds
Other Concerns
Many cats with Cushing’s disease also have diabetes mellitus, which is linked to excess cortisol. These cats may require high doses of insulin to regulate their blood sugar. Chronic kidney disease, pancreatitis, and high blood pressure are also common in affected cats.
DIAGNOSIS OF CUSHING'S DISEASE
To diagnose Cushing’s disease, your veterinarian will conduct a thorough examination and review your dog’s history.
Based on these we will discuss the follow tests:
• Blood Tests: A complete blood count (CBC) and biochemistry profile can reveal signs that suggest Cushing’s.
• Urine Analysis: Cats with Cushing’s may have dilute urine or excess protein and glucose in their urine.
• Imaging: An ultrasound may be used to assess the size of the adrenal glands or identify the presence of tumours.
• Specific Hormone Tests: Tests such as the ACTH stimulation test and the low-dose dexamethasone suppression test are often used to confirm the diagnosis.
TREATMENT OPTIONS
Treatment varies depending on the cause of Cushing’s disease:
• Pituitary Tumour: The most common treatment is ongoing daily medication such as Trilostane which helps block excess hormone production.
• Adrenal Tumour: If the tumour is benign, surgery to remove it can be curative. If surgery is not possible, medication may help, but response rates can vary.
• Iatrogenic Cushing’s Disease: This type requires a gradual discontinuation of the steroid medication under your veterinarian’s supervision. Sudden withdrawal can lead to serious complications.
MANAGING CUSHING'S DISEASE IN CAT'S
Cats with Cushing’s disease require lifelong treatment and careful monitoring. Regular veterinary checkups, blood tests, and adjustments to medication will help manage the condition and minimise side effects. With consistent care, many cats can live comfortable and happy lives.
PROGNOSIS
The prognosis for dogs with Cushing’s disease depends on the type and severity of the condition, as well as how well it responds to treatment. In some patients, overall life expectancy is unfortunately reduced. With proper management however, most dogs can lead fulfilling lives, but ongoing medical supervision is critical to ensure the best outcomes.