What Does GGT Mean in Dogs and Cats?
Quick answer
GGT is an enzyme associated with the bile ducts. It tends to rise when bile flow is slowed or the bile ducts are irritated. Vets often read GGT with ALP: when both rise together, bile flow is more likely involved. GGT is especially useful in cats, where it can help separate different liver patterns.
What is GGT?
Gamma-glutamyl transferase is found in bile duct cells, among other tissues, and increases with bile flow problems.
Reference range
[Range pending sourced table] Reference ranges vary by lab and species. Use the range printed on your pet's report.
What can raise GGT
- Slowed bile flow
- Bile duct or gallbladder conditions
- Steroid medications (dogs)
- Some liver conditions
What can lower GGT
- Low values are rarely significant
Dogs vs cats
In dogs
Steroids can raise GGT in dogs along with ALP.
In cats
In cats, the balance of GGT and ALP can help vets narrow down liver patterns.
Why one value rarely tells the whole story
GGT points toward bile flow but needs ALP, bilirubin, and imaging to explain why. Hydration, recent meals, stress during the visit, medications, and how the sample was handled can all shift a result. Vets look at the whole panel, your pet's symptoms, and the trend across tests over time.
Conventional interpretation
Vets read GGT with ALP and bilirubin; persistent rises may prompt imaging.
Whole-pet context
Watch appetite, especially fat tolerance, and any yellow tinge to gums or eyes.
Supportive options are not a cure. Check with your veterinarian before adding any supplement.
Questions to ask your vet
- Do GGT and ALP point toward bile flow?
- Would an ultrasound of the gallbladder help?
- Could medications play a role?
- How does this compare with my pet's previous results?
Frequently asked questions
Is GGT the same as ALP?
- No, but both relate to bile flow and are usually interpreted together.
Why does my vet care about GGT in my cat?
- In cats, GGT relative to ALP can help distinguish between different liver problems.
What is a normal GGT range?
- Reference ranges vary by laboratory, analyzer, and species. Use the range printed on your pet's report and ask your vet how your pet's result compares.
Should GGT be rechecked?
- Your veterinarian decides based on how far from range the value is, your pet's symptoms, and other results. Trends over time are often more useful than one result.
Related lab values
Related guides
Educational support only. Not a diagnosis or substitute for veterinary care.
Have your pet's report?
Upload a PDF or photo and see GGT and every other value plotted against its range.
Upload a lab report