FrançaisThe four liver values on your dog’s report
None of these enzymes measures how well the liver works. Function is assessed with other tests, such as bile acids, albumin, glucose, urea or cholesterol, and with imaging [1, 5].
| Line | What it reflects | Our detailed guide |
|---|---|---|
| ALT (ALAT, GPT) | An enzyme inside liver cells that leaks into the blood when they are injured [1]. | High ALT in dogs |
| ALP (ALKP, SAP) | Rises with slowed bile flow, growing bone, and in dogs with steroids or the body’s own cortisol [2]. | High ALP in dogs |
| GGT | Another marker of bile flow; steroids and phenobarbital can also raise it in dogs [3]. | Read with ALP |
| Bilirubin (TBIL) | A yellow pigment from the breakdown of red blood cells, cleared by the liver into bile [4]. | Read with the blood count |
How to read a liver line: the bilirubin example
Every line follows the same structure. Bilirubin is a good example because a small number can matter.
- Abbreviation TBIL is total bilirubin. Some reports also split it into direct (conjugated) and indirect bilirubin [4].
- Result Three times the upper limit in this illustrative line.
- Unit mg/dL in the United States; µmol/L in Europe (about × 17.1).
- Laboratory interval The example uses the dog interval of the Merck Veterinary Manual [6]. Your laboratory’s interval applies.
- Flag H: above the interval. A high bilirubin can come from the destruction of red cells, from the liver itself or from blocked bile flow [4].
Reading the pattern: which enzyme rises most
Vets compare how many times each value exceeds its upper limit. When ALT rises much more than ALP and GGT, injury to liver cells is likely the main process. When ALP and GGT rise much more than ALT, slowed bile flow or enzyme induction (by steroids, for example) comes first [1].
| Pattern | What it can suggest | What usually follows |
|---|---|---|
| ALT ≫ ALP | Liver cell injury: inflammation, toxins, medicines, chronic hepatitis [1, 5]. | Review of medicines and exposures, repeat test, imaging or further tests. |
| ALP and GGT ≫ ALT | Slowed bile flow, or induction by steroids or the body’s cortisol [2, 3]. | Medicine review; sometimes cortisol testing such as an ACTH stimulation test. |
| ALP alone, young dog | Growing bone [2]. | Usually no action, age-adapted reading. |
| Bilirubin high, red cells low | Destruction of red cells (hemolysis) rather than liver disease [4]. | Blood count and smear; see anemia in dogs. |
| Bilirubin high with high ALP/GGT | Reduced bile excretion by the liver or the bile ducts [4]. | Imaging and further liver tests. |
How common, and how serious?
Raised liver enzymes are frequent on dog blood work, and many dogs with a mild increase have no liver disease. In a study of dogs whose liver lesions were confirmed by biopsy, ALT, ALP or both were increased in up to 90% of cases, but the same enzymes also rise with many problems that start outside the liver [7].
Some breeds are predisposed to chronic hepatitis, a condition in which an unexplained, persistent rise in ALT can be one of the first laboratory signs. The ACVIM consensus cites, among others, Labrador Retrievers, Doberman Pinschers, Bedlington Terriers, Dalmatians and English Springer Spaniels [5].
What can change liver enzymes without liver disease
- Medicines. Corticosteroids (including creams and drops), phenobarbital and several others can raise ALP, GGT or ALT [2, 3].
- The body’s own cortisol. Prolonged stress, chronic illness or an adrenal gland disorder induce a dog-specific form of ALP [2].
- Age. Puppies have a much higher ALP because of bone growth [2].
- Sample issues. Under-filled heparin tubes can raise GGT, and some analysers read bilirubin falsely high in haemolysed or lipaemic samples [3, 4].
Where to go next
To check how well the liver works, rather than whether it is injured, vets use the bile acids test. Cats read their liver enzymes differently: see high liver enzymes in cats.
En français : enzymes du foie élevées chez le chien.
Questions to ask your veterinarian
- Which enzymes are raised, by how many times the upper limit, and which rises most?
- Could any medicine, cream or drops explain the pattern?
- Is the bilirubin raised, and does the blood count suggest red cell destruction?
- Do we need a liver function test such as bile acids, or an ultrasound?
- When should we repeat the tests, and what change would alter the plan?
Get your dog’s liver values explained together, with the rest of the report.
AI DiagAnimals reads ALT, ALP, GGT and bilirubin side by side with your laboratory’s intervals, highlights the pattern and prepares the questions for your vet. The service opens soon: leave your email to be told first.
Frequently asked questions
What is the most common cause of elevated liver enzymes in dogs?
There is no single cause. Medicines, the effect of steroids or the body’s own cortisol on ALP, problems starting outside the liver and primary liver disease are all frequent. The pattern of the enzymes and the history help your vet tell them apart [1, 2, 7].
What does it mean if my dog has high alkaline phosphatase?
ALP rises with slowed bile flow, bone growth, steroid medicines and prolonged stress or illness in dogs. See our detailed guide to high ALP in dogs [2].
What is an alarming ALT level in dogs?
More than 10 times the upper limit is described as a marked increase, but a moderate increase that persists can also matter. A dog that is unwell needs prompt attention whatever the number [1, 5].
How long can a dog live with very high liver enzymes?
The enzymes do not predict life expectancy. It depends on the cause, which is why the next step is to find it with your vet.
What should I not feed a dog with high liver enzymes?
Keep the usual diet and avoid supplements, human foods and anything containing xylitol until your vet advises otherwise: diet changes depend on the cause.
Sources
- eClinPath, Cornell University College of Veterinary Medicine. Alanine aminotransferase (ALT). eclinpath.com/chemistry/liver/liver-injury/alanine-aminotransferase
- eClinPath, Cornell University College of Veterinary Medicine. Alkaline phosphatase (ALP). eclinpath.com/chemistry/liver/cholestasis/alkaline-phosphatase
- eClinPath, Cornell University College of Veterinary Medicine. Gamma-glutamyl transferase (GGT). eclinpath.com/chemistry/liver/cholestasis/gamma-glutamyl-transferase
- eClinPath, Cornell University College of Veterinary Medicine. Bilirubin. eclinpath.com/chemistry/liver/cholestasis/bilirubin
- Webster CRL et al. ACVIM consensus statement on the diagnosis and treatment of chronic hepatitis in dogs. J Vet Intern Med. 2019;33(3):1173-1200. doi.org/10.1111/jvim.15467
- Merck Veterinary Manual. Serum biochemical analysis reference ranges. merckvetmanual.com/reference-values-and-conversion-tables/reference-guides/serum-biochemical-analysis-reference-ranges
- Assawarachan SN et al. A descriptive study of the histopathologic and biochemical liver test abnormalities in dogs with liver disease in Thailand. Can J Vet Res. 2020;84(3):217-224. pubmed.ncbi.nlm.nih.gov/32801457
Laboratory methods and reference intervals vary. This article explains; it does not diagnose. For a decision about your pet, use the original report and talk to your veterinarian. Our editorial policy.