Laboratory Values and What They Mean
FULL BLOOD PANEL (sometimes referred to as a Canine Comprehensive SuperChem)
This blood panel will include all the liver function tests, CBC (complete blood count) plus T3, T4 and a Free T4, which are thyroid function tests. Reason for the full panel is to make sure that all values are within normal range and if isolated elevations are found, may warrant further evaluation. This is also to establish a baseline against which future laboratory results can be compared. However, by doing this panel at age 12 to 15 months, the AKK is mature enough that growth spurts are unlikely to render inaccurate liver function test results. Owners and breeders alike must also keep in mind that certain values can be slightly elevated due to stress on the dog going to the veterinarian and having the blood drawn. All of this must be taken into account when lab work is being evaluated.
Questions have arisen from AKKAOA members, and other AKK owners as to what blood work should be routinely measured on the Alaskan Klee Kai and what do the different values really mean? Of concern to some AKK people is liver disease, specifically, elevated ALT. Some owners have raised questions about the occurrence of thyroid disease, as well as questions about the potential for kidney disease in the Alaskan Klee Kai.
When checking for possible liver disease in my dog, what blood work should I get and why?
A Liver Panel, consisting of ALT (alanine aminotransferase), AST (aspartate aminotransferase), GGT (gamma-glutamyltransferase), AP (alkaline phosphatase), albumin, and TP (Total Protein) should be obtained. Remember that everything that enters the blood stream will pass thru the liver one or more times, and can influence test results. These include bacteria, antibiotics, food, hormones, etc.
ALT is elevated during infection, inflammation, antibiotic therapy, and liver pathology, among others. A laboratory value of greater than 3 times the upper limit of normal (Reference range of 10-100) a value of > 300 would indicate that further study is necessary to find the cause. It does not mean there is liver disease, as there is not enough information based on this one value and one laboratory parameter alone.
AST can be elevated because of age, obesity, pathology involving the liver as well as the biliary tract. AST is a less reliable indicator of liver disease, as other organ disease can cause a release of this enzyme. AST is present in muscle and other organs, and damage or disease in those extrahepatic areas can cause elevation. Thus, an elevated ALT and a ‘normal’ AST may not indicate liver disease at all. An elevated ALT with an elevated AST likely is liver disease, especially if they are >3x the upper limit of normal. Thus, an ALT of 182 and an AST of 106 are within acceptable ranges, because they are < 3x the upper limit of the reference range.
Depending upon the other liver enzyme levels, and what your veterinarian believes may be happening in your dog, further lab work may be indicated following treatment of any current infection with antibiotic therapy.
GGT comes primarily from the liver and can be elevated with liver disease, gallbladder disease, and pancreatitis. It can be increased by anticonvulsant and by glucocorticoid drugs.
AP is highly sensitive but not very specific for liver disease in dogs. But an elevation of GGT increases the specificity of AP(in dogs). (Thus, an elevation of GGT as well as AP is highly indicative of liver disease) AP is also elevated during growth spurts, especially in dogs. It is increased by the presence of infection, some antibiotics, anticonvulsants and glucocorticoids, and mildly elevated in both hypo and hyperthryoidism. Highest levels are seen in fatty liver disease.
Albumin may be decreased because of lessened liver function in hepatitis, or because of ascites. Hypoalbuminemia (decrease in albumin) is indicative of severe liver disease, or may be indicative of kidney disease, with protein losses across the basement membrane in the glomerulus in the kidney.
TP is a rather quick test to determine if there is a drop in total protein because of liver or kidney pathology, or if there is a malabsorption of food from the GI tract.
Rationale for doing a Liver Panel, rather than just one test:
No one component of the Liver Panel is diagnostic of liver disease, or of any other disease. Values from all components must be taken together to determine the cause for the elevation, whether or not it is of concern, and what further clinical evaluations are necessary. Because infection can cause an elevated ALT, your veterinarian will look at urine and other areas, perhaps treat with antibiotics, then follow up with repeat blood work after the course of therapy has been completed.
LIVER FUNCTION TESTS such as ALT and AST are affected by liver disease, but can be influenced by growth spurts as mentioned above, infection, and health conditions. ALT elevation without AST elevation does not indicate liver disease, but does indicate that there likely is an infection present, commonly a urinary tract infection. Usual reference range for both ALT and AST is around 10-100; clinicians do not generally become concerned until the values are greater than 3 times the upper limit of normal, or over 300. However, abnormal values do warrant “another look” or a “wait and watch”, for which the veterinarian may want to recheck certain lab tests.
THYROID PANEL is important because autoimmune thyroiditis, which has been found in our breed, is the most common cause of primary hypothyroidism in dogs. The disease has variable onset, but tends to clinically manifest itself at 2 to 5 years of age. Dogs may be clinically normal for years, only to become hypothyroid at a later date. The marker for autoimmune thyroiditis, thyroglobulin autoantibody formation, usually occurs prior to the occurrence of clinical signs. Therefore, since the majority of affected dogs will have autoantibodies by 4 years of age, annual testing for the first 6 years is recommended. After that, testing every other year should suffice. Unfortunately, a negative or normal report at any one time does not guarantee that the dog will not eventually develop thyroiditis.* But, a breeding pair that remains normal (neither male nor female develops autoantibodies) should produce offspring that are also normal.