🧪 Vet Internal Medicine 2025: Elevated Liver Enzymes in Dogs — Causes, Testing & What to Do Next

Has your dog’s bloodwork shown elevated liver enzymes? This is a common finding during wellness checks, pre-anesthetic screens, or when a pet feels off. But what does it really mean? I’m Dr Duncan Houston BVSc, and in this 2025 guide, I’ll walk you through what liver enzymes are, why they rise, what tests to expect, and when action is truly needed. 🐶

1. What Are Liver Enzymes?

Liver enzymes are proteins made by liver cells and released into the bloodstream. Two primary ones we assess in dogs are:

• ALT (Alanine Aminotransferase): Rises with liver cell injury
• ALP (Alkaline Phosphatase): Rises with bile duct inflammation, stress, bone growth (in young dogs), or some medications

Other markers include:

• AST (Aspartate Aminotransferase): Less specific, may rise with muscle damage
• GGT (Gamma-Glutamyl Transferase): Useful in some liver diseases

2. Why Are These Enzymes Elevated? 🔍

Enzymes increase when liver cells are stressed, damaged, or reacting to disease elsewhere. Causes include:

• ⚕️ Liver disease (chronic hepatitis, copper storage disease)
• 💊 Medications (e.g., steroids, phenobarbital, NSAIDs)
• 🦠 Infections (leptospirosis, bacterial hepatitis)
• 🧬 Breed-related issues (e.g., copper buildup in Bedlington Terriers)
• 🧪 Hormonal diseases (Cushing’s, diabetes, thyroid issues)
• 🫀 Gallbladder or bile duct obstruction
• 🍽️ Fatty liver or metabolic stress

3. Age and Breed Matter 🧬

• 🐕 Puppies: Often have high ALP due to bone growth—usually not concerning
• 🐾 Older dogs: May show changes due to benign liver aging (vacuolar hepatopathy)
• 🐕‍🦺 Breed risks: Dachshunds (Cushing’s), Labs, Dobermans, Westies (chronic hepatitis), Shelties and Cocker Spaniels (gallbladder issues)

4. Should I Worry If My Dog Has No Symptoms? 🤔

Sometimes yes. Many liver conditions are silent early on. Elevated enzymes—especially ALT—may be your first clue that something is starting. It’s far better to investigate early than to wait until irreversible damage occurs. 🚨

5. Additional Testing 🧪

If liver enzymes are elevated, your vet may suggest:

• 🧫 Bile acids test: Evaluates liver function
• 🧴 Bilirubin: High levels suggest impaired bile flow or severe anemia
• 🩻 Abdominal ultrasound: Looks for liver shape, gallbladder issues, or tumors
• 🧬 Special bloodwork: Check for infections, copper, or hormone problems

6. When Is a Liver Biopsy Needed? 🔬

A liver biopsy gives definitive answers about the cause of enzyme elevation. It’s usually recommended if:

• ALT remains elevated over time
• The dog has clinical signs (vomiting, jaundice, lethargy)
• Ultrasound shows abnormal liver structure

Biopsies can be done via:

• 🧷 Needle biopsy (ultrasound-guided)
• 🔬 Laparoscopy (minimally invasive surgery)
• 🩺 Open surgery (for larger samples or complicated cases)

7. What Can You Do at Home While You Wait? 🏠

Your vet may recommend a trial of:

• 🧴 Antioxidants: Vitamin E, SAMe (Denamarin®)
• 💊 Ursodiol: Helps bile flow and reduces liver inflammation
• 🦠 Antibiotics: Short course if infection is suspected
• 🥩 Low-copper or liver-support diets

8. Monitoring & Rechecking 🔄

Typically, we recheck bloodwork in 2–4 weeks. If values return to normal—great! If not, we may need imaging or biopsy. Persistence is key to preventing long-term damage. 🩺

9. Prognosis and Next Steps ✅

Outcomes vary depending on the cause. Many dogs with mild elevations live long, healthy lives with monitoring and supplements. Others with chronic hepatitis or structural problems benefit greatly from early treatment.

10. Ask A Vet: Ongoing Support

Need clarity on your dog’s liver enzymes or biopsy plan? Connect with licensed vets at AskAVet.com. We review lab reports, answer your concerns, and help guide treatment decisions 24/7. 📱

11. Summary Table

12. Final Thoughts

Elevated liver enzymes aren’t always an emergency—but they’re not something to ignore. They can be early warning signs of a liver problem that’s still treatable. With the right tests and a proactive approach, we can protect liver health and keep your pet thriving. 🐕🫀

— Dr Duncan Houston BVSc

Need help interpreting liver labs? Visit AskAVet.com or download the Ask A Vet app. We’re here to guide you through every step. 💙