🔍 Lab Clues for Cushing’s Syndrome in Dogs and Cats – A 2025 Vet’s Guide to Subtle Early Signs

By Dr Duncan Houston, BVSc

📋 Why Early Detection Matters

When a pet visits the clinic with subtle signs like panting, a pot-bellied appearance, or excessive thirst, a basic blood panel and urinalysis are often the first steps. These tests may reveal changes that hint at Cushing’s syndrome, even before specific tests are run. 🧬

🐕 Classic Lab Clues in Dogs

1. 🦠 The Stress Leukogram

This refers to changes in white blood cell counts triggered by high cortisol levels. Even if a dog isn’t visibly stressed, a stress leukogram may appear on the CBC (complete blood count):

• ⬆️ Increased neutrophils
• ⬇️ Decreased lymphocytes
• ⬇️ Decreased eosinophils

⚠️ When this pattern is present in a calm dog, elevated cortisol—possibly from Cushing’s—is a suspect.

2. 🧪 Elevated ALP (Alkaline Phosphatase)

This liver enzyme is often significantly increased in Cushing’s disease. ALP is induced by cortisol and may be elevated due to either natural overproduction or cortisone medications. 📈

3. 🩸 High Cholesterol

Increased fat mobilization from cortisol causes cholesterol to rise. This is common in many endocrine disorders but is especially suggestive when paired with other signs of Cushing’s. 🧈

4. 💧 Dilute Urine and Bladder Infections

Cushing’s dogs drink excessively and produce dilute urine (low specific gravity). The diluted urine, combined with immune suppression, increases the risk of silent urinary tract infections. Studies show up to 20% of Cushing’s dogs may have hidden bladder infections. 🔬

Urine culture is recommended when urine is dilute, even if white blood cells or bacteria aren’t seen under the microscope. 🧫

🐱 Cushing’s in Cats – Different Clues

Cushing’s syndrome is much rarer in cats and often presents differently. Cats with Cushing’s don’t typically show:

• ❌ Stress leukogram
• ❌ Elevated liver enzymes
• ❌ Increased cholesterol

Instead, look for:

• 😾 Poorly controlled diabetes mellitus
• 📉 High insulin doses with poor effect

If a diabetic cat requires large doses of insulin and glucose remains uncontrolled, underlying Cushing’s should be considered. 🎯

🧪 Summary of Laboratory Clues in Dogs

• ✅ Stress leukogram
• 📈 Elevated ALP (often significantly)
• 🧈 High cholesterol
• 💧 Dilute urine (specific gravity < 1.020)
• 🦠 Hidden bladder infection (suggested via culture)

🩺 What’s Next If Lab Clues Suggest Cushing’s?

If these hints are present, your veterinarian may recommend further testing to confirm the diagnosis:

• 💉 Low-Dose Dexamethasone Suppression Test (LDDST)
• 🧪 ACTH Stimulation Test
• 💧 Urine Cortisol:Creatinine Ratio (for screening)

📲 Ask A Vet for Lab Test Review

Wondering if your dog’s lab results point to Cushing’s disease? Need help interpreting a urine culture or enzyme reading? The Ask A Vet App connects you with real-time vet support. 📱🐾

Visit AskAVet.com or download the app to get answers from veterinary professionals today. 🐶🐱

✅ Summary: Key Takeaways

• 🧪 Cushing’s may be hinted at by routine bloodwork and urinalysis
• 🧬 Dogs often show specific lab changes (stress leukogram, ALP, cholesterol)
• 🐱 Cats typically show insulin-resistant diabetes instead of lab shifts
• 🔍 Suspicious lab findings should prompt targeted hormone testing

💬 Final Words from Dr Duncan Houston

Cushing’s syndrome isn’t always obvious—but subtle clues in blood and urine tests can light the path forward. If you or your vet notice a concerning pattern, further testing could make all the difference. 🐾

For real-time insights and professional interpretation, reach out through the Ask A Vet App or visit AskAVet.com. We’re here to help you uncover the truth behind the tests. 🧬📱