Understanding Liver Levels in Dogs

Liver levels in dogs are one of the most important tools that you as the owner have in determining whether your pet's liver function is at proper levels. When vets refer to "liver levels," they generally mean the quantity or reading for different hormones that are naturally found in the liver. The disturbance of the usual balance of these hormones is often one of the best indicators about how your pet's liver is functioning; having too much or too little of any particular hormone will usually throw off the functioning of your dog's liver.

Why Liver Levels are Important

Dogs with liver problems can display a huge host of different symptoms. These may include, but are not limited to, the following:

  • Jaundice
  • Vomiting and diarrhea
  • Loss of weight
  • Loss of appetite
  • Increase in appetite
  • Increased thirst and urination frequency
  • Distended abdomen
  • Lethargy
  • Weakness

Of these symptoms and the others that typically characterize liver problems in dogs, only the first one, jaundice, is unique to liver issues. This means that your pet can display a range of symptoms having to do with his liver and it can still be very difficult to determine, based on those symptoms alone, what the problem is. That's why testing his liver levels is such an important indicator of how his liver is functioning.

What Liver Levels Mean

There are four primary types of liver enzymes that your vet will commonly test for when he's considering your dog's liver function. Between these four different enzymes, your vet will typically be able to make an informed diagnosis or prediction about what the liver damage is and what condition your pet is suffering from, if any. These four enzymes are referred to as ALT, AST, SAP and GGT.


ALT is one of the best indicators of abnormal liver function, because the levels of ALT in your pet's bloodstream are directly related to the number of liver cells that have died as a result of infection or some other unnatural phenomenon. As those cells die, the system releases ALT into the blood. It's not uncommon for the ALT levels to vary widely from dog to dog, and most vets will not be alarmed unless your pet's ALT levels are at least 3 times the normal rate on multiple readings.


A slight increase in the enzyme AST can be indicative of very serious liver problems like cirrhosis and cancer.


SAP levels are closely linked with cancer of the liver. Increases in this enzyme level are strongly linked to the presence of cancerous cells in your pet's liver.


An increase in the levels of GGT in your pet's liver typically indicates a problem with the liver that is a result of plugged or blocked bile ducts in the liver.

Between these various enzymes, you and your vet will have a much better idea of what exactly is causing your pet's liver problems and how to best remedy them. Speak with your vet with any additional questions you may have or for more information.