When talking about liver values in dogs, the enzymes ALT, AST, ALP, GGT, and GLDH are usually meant. Elevated levels may indicate liver disease. However, they also vary according to age and race.
So don’t be surprised if you find a wide variety of reference values on various websites and specialist books.
To measure the liver values, the vet takes some blood and then has it tested in the laboratory. In particular, the following 5 enzymes are measured in dogs:
- ALT = Alanine Aminotransferase
- AST = Aspartate Aminotransferase
- ALP = Alkaline Phosphatase
- GGT = Gamma Glutamyl Transferase
- GLDH = Glutamate Dehydrogenase
The measurement of the liver values alone does not replace the examination of the liver function. In addition, other blood values such as bilirubin or LDH are often examined.
The liver is one of the dog’s largest organs and has numerous functions. It detoxifies and is essential in the production of certain substances.
Liver values of healthy dogs should be between 10-130 U/L for ALT, 10-34 U/L for AST, 24-147 U/L for ALP, 0-24 U/L for GGT and GLDH below 9 U/L located. Depending on the table, different information can also be found.
Importance of Liver Values
Paradoxically, not all liver enzymes are liver-specific. Abnormal liver values can therefore also indicate other diseases.
The liver enzyme “alanine aminotransferase” was formerly usually referred to as “GPT” or “SGPT”. The old version is still used in some older laboratories.
Of all the liver enzymes, ALT is the most liver-specific. As a rule, increased values here indicate damage to the liver cells.
However, this damage does not necessarily have to be of a permanent nature. Because the liver has a very strong ability to regenerate itself.
The liver value “aspartate aminotransferase” was once primarily abbreviated to “GOT” and “SGTO”. In contrast to ALT, however, it is significantly less specific.
Because in addition to damaged liver cells, muscle diseases can also cause this enzyme to rise sharply. It does not necessarily indicate liver disease.
An investigation is nevertheless useful. If only one enzyme deviates from the liver values in the table, then there is no reason to panic.
“Alkaline phosphatase” is an umbrella term for various sub-enzymes. We are talking about liver ALP here. But there are other forms:
- Bone ALP
- Intestinal ALP
- Placenta ALP
Elevated ALP levels in the liver, on the other hand, can indicate inflammation, gallbladder disease, hormonal imbalances, diabetes, or certain medications.
The “gamma-glutamyl transferase” is an enzyme that can indicate diseases of the liver and bile ducts when it is elevated.
Together with ALT, it is one of the most reliable liver values from the table to draw conclusions about existing liver diseases.
Because of this, dogs with elevated ALT levels often have elevated GGT levels as well. However, the liver enzymes alone do not necessarily say anything about liver function.
Although the liver enzyme “glutamate dehydrogenase” is found in all organs, it is more concentrated in the liver. Significantly increased values can therefore indicate problems.
This is because when liver cells die, the enzyme gets out of the cells and into the blood. Inflammation of the liver in particular therefore increases GLDH very strongly.
Poisoning, cirrhosis of the liver, jaundice, or liver cancer can also increase the values significantly. But it can also indicate diseases outside of the liver.
If the liver values ALT, AST, ALP, GGT, and GLDH deviate from the reference values in the table, this can indicate existing liver problems. Since not all enzymes are liver-specific, other causes are also possible.
Significance of Elevated Liver Values
Just because your dog has elevated liver values doesn’t necessarily indicate liver disease. Possible causes are here:
- Heat stroke
- Cushing’s Syndrome
- Viral infections
- Heart failure
- Bacterial inflammation
If the problems actually have their origin in the liver, then other symptoms usually also become noticeable. Typical examples are here:
- Loss of appetite
- Yellow gums
- Nausea and vomiting
- Loss of appetite
- Blood in the stool
- Lack of coordination
- Increased thirst
- Yellowish eyes
The treatment depends primarily on the suspected cause. For more harmless problems, supplements and dietary adjustments may be sufficient.
In more serious cases, however, medication or even surgical interventions may be necessary. Here you should always follow the recommendations of the veterinarian.
If the dog’s liver values are far above the normal values in the table, this may indicate existing liver diseases. This can usually be recognized by jaundice, chronic vomiting and an unusually strong thirst.