Recognizing Three Key Signs of Cushing's Disease in Dogs
Cushing's disease, medically referred to as hyperadrenocorticism, is a hormonal disorder that affects middle-aged and older dogs. It occurs due to excessive and prolonged exposure to cortisol, a hormone produced by the adrenal glands. The condition is often the result of a tumor in the pituitary or adrenal glands, or can be caused iatrogenically by long-term use of corticosteroids. Since Cushing’s disease develops gradually, early symptoms can be subtle and are often mistaken for normal signs of aging. Recognizing its key indicators early can make a significant difference in managing the condition and improving your dog’s quality of life.
1. Increased Thirst and Urination
One of the most noticeable early signs of Cushing's disease is polydipsia (increased thirst) and polyuria (increased urination). You might notice your dog drinking more water than usual and needing to go out for bathroom breaks more frequently, including multiple nighttime trips. House-trained dogs may suddenly begin having accidents indoors. These symptoms are a result of cortisol's effect on kidney function, leading to a reduced ability to concentrate urine.
2. Pot-Bellied Appearance
Another telling symptom is the development of a pot-bellied or swollen abdomen. This occurs due to a combination of factors: weakening of abdominal muscles, redistribution of fat to the abdomen, and enlargement of the liver. The dog's body conformation may change noticeably while the limbs remain thin, contributing to the distinctive round-bellied look.
3. Hair Loss or Thin, Fragile Skin
Dermatological changes are also common in dogs with Cushing's disease. Affected dogs may experience hair loss, slow hair regrowth, or thinning of the skin that can tear easily. The skin may develop dark patches or blackheads, and dogs are more prone to recurrent skin infections and slow healing of wounds due to impaired immune function and collagen breakdown.
Additional Symptoms to Watch For
- Increased appetite
- Excessive panting
- Muscle weakness or lethargy
- Frequent skin infections
- Weight gain or fat redistribution
- Behavioral changes
While many of these symptoms are also common with other health issues or aging, the combination of several signs, especially those noted above, should prompt a veterinary consultation.
Causes of Cushing's Disease
There are three primary causes:
- Pituitary-dependent: Caused by a benign pituitary tumor, accounting for up to 90% of cases.
- Adrenal-dependent: Results from a tumor on one of the adrenal glands, which can be benign or cancerous.
- Iatrogenic Cushing’s: Occurs when a dog is treated long-term with high doses of corticosteroids like prednisone.
Diagnosis and Treatment
If Cushing’s disease is suspected, your veterinarian will carry out a thorough physical exam and run diagnostic tests such as blood work, urine analysis, and hormone-specific tests like the ACTH stimulation and low-dose dexamethasone suppression (LDDS) tests. Imaging (ultrasound, CT, MRI) may also be needed to identify tumors.
Treatment depends on the type of Cushing’s disease and includes:
- Medications like trilostane (Vetoryl) or mitotane (Lysodren) to manage pituitary or adrenal forms.
- Surgery to remove adrenal tumors, if benign and operable.
- Gradual withdrawal of steroids under veterinary supervision in iatrogenic cases.
Monitoring and Long-Term Care
Dogs with Cushing’s disease need lifelong management, including frequent lab tests to adjust medication doses and monitor side effects. While the condition often can’t be cured, it can be effectively managed, allowing most dogs to live a comfortable life. Early recognition of the main symptoms—especially increased thirst and urination, pot-bellied appearance, and skin/hair issues—enables quicker diagnosis and initiation of treatment.
Conclusion
Understanding the subtle yet telling signs of Cushing’s disease is essential for dog owners. If your dog is showing any of these three key symptoms — excessive drinking/urination, pot-bellied look, or hair/skin issues — consult with your veterinarian as soon as possible. With proper care and timely intervention, dogs with Cushing’s can lead happy, active lives even after diagnosis.
