Biochemical Blood Testing
 

Biochemistry of the blood gives us an indication of what is happening with in the body. When different tissues are damaged the damaged cells release specific enzymes which our equipment detects as abnormal levels. This then helps localise the problem. Also if certain organs are not eliminating certain waste products this can tell us they are not functioning properly.

Below is a list of many of the variuos tests avaiable and a little of what they reveal to us.

BUN or Blood Urea Nitrogen

  • Urea is an end product of protein metabolism and is excreted by the kidneys. Any condition that reduces kidney filtration rates or increases protein breakdown results in increased BUN levels. Some examples besides the various kidney diseases would be heart and circulation conditions where there is a decreased flow of blood to the kidneys. Decreased levels can be seen in some genetic conditions. 

 Creatinine:

  • Creatinine is a waste product that originates from muscles and is eliminated from the body by the kidneys. An elevation of creatinine is due to kidney disease or dehydration. Both creatinine and BUN increase in the bloodstream at the same time in patients with kidney disease.

Phosphorous:

  • Is another indicator of kidney disease.
  • When the BUN, Creatinine and Phosphorous are all elevated then we know we have a problem with the kidneys. If only 1 is elevated it does not necessarily means kidney disease/failure

Glucose:

  • Blood glucose levels are influenced by diet, liver function and by utilization rates. Excessively high glucose levels may be caused by Diabetes Mellitus. Hypoglycemia(low glucose) may be caused by a pancreatic cancer, Adrenal disease or severe exertion.

Bilirubin:

  • Bilirubin is a bile pigment derived from the breakdown of haemaglobin release when red blood cells are destroyed or removed normally by the body. Increase levels can indicate liver disease, haemolytic disease (abnormal destruction of red blood cells)

ALT:

  • Is present in liver cells. Damage to these cells such as in liver disease leads to the enzyme being released into the blood stream where we can detect its increase. It is a good indicator of liver problems whether primary (infection, cancer etc.) or secondary (circulation disturbance to the liver for instance)

Amylase :

  • This enzyme is produced in the pancreas and gut. Along with lipase can indicate pancreatic disease. High levels of amylase can occur with obstruction of the bowel and other severe bowel disease.

Lipase:

  • Produced only in the pancreas so is a good indicator of pancreatic disease

Alkaline Phosphatase:

  • Produced in both the liver and bone so high levels suggests problems in these areas

Thyroid Hormone:

  • Low levels is called Hypothyroidism and can result in hair coat changes, weight gain along with many other signs. High levels occur in Hyperthyroidism- a potentially fatal condition usually seen in old cats.

Cortisol:

  • Indicates how the adrenal glands are functioning. High or low levels can indicate possible serious disease such as Cushings Syndrome and Addisons Disease

Cholesterol

  • Cholesterol is a form of fat. Cholesterol can be increased in the bloodstream for many reasons in dogs. It is much less common for cats to have increased cholesterol. Some of the diseases that cause elevated cholesterol are hypothyroidism, Cushing's disease, diabetes and kidney diseases that cause protein to be lost in the urine. High cholesterol does not predispose dogs and cats to heart and blood vessel disease as it does in people.

Creatinine kinase

  • Creatinine kinase (CK) is released into the blood from damaged muscle. Elevation of creatinine kinase therefore suggests damage to muscle including heart muscle. It is always elevated with snake bites in Australia

Bile Acids

  • Bile acids are produced by the liver and are involved in fat breakdown. A bile acid test is used to evaluate the function of the liver and the blood flow to the liver. Patients with abnormal blood flow to the liver, a condition known as portosystemic shunt will have abnormal levels of bile acids. The bile acid test measures a fasting blood sample and a blood sample two hours after eating.

Calcium

  • Calcium in the bloodstream originates from the bones. The body has hormones, which cause bone to release calcium into the blood and to remove calcium from the blood and place it back into bone. Abnormally high calcium in the blood occurs much more commonly than low calcium. High blood calcium is most commonly associated with cancer. Less common causes of elevated calcium are chronic kidney failure, primary hyperparathyroidism which is over-function of the parathyroid gland, poisoning with certain types of rodent bait and bone disease. 
  • Low blood calcium may occur in dogs and cats just before giving birth or while they are nursing their young. This is called eclampsia and occurs more commonly in small breed dogs. Eclampsia causes the animal to have rigid muscles which is called tetany. Another cause of low blood calcium is malfunction of the parathyroid glands which produce a hormone (PTH) that controls blood calcium levels. Animals poisoned with antifreeze may have a very low blood calcium.

Total Protein

  • Total protein includes albumin and larger proteins called globulins. Included in the globulins are antibodies which are protein molecules. Total protein can be increased if the dog or cat is dehydrated or if the pet's immune system is being stimulated to produce large amounts of antibody. Total protein is decreased in the same situations which reduce albumin or if the pet has an abnormal immune system and cannot produce antibodies.