What does your pet’s blood work tell us?

Albumen (ALB): Albumen is a small protein produced in the liver. The protein acts as a force to keep fluid in the blood vessels. If the albumen is deficient, fluid begins to leak out of the vessels and into surrounding tissues causing edema. Low albumen levels can occur with liver disease causing decreased production, through losses in the urine secondary to kidney disease or losses from damaged intestines. An increase in albumen is seen with dehydration.

Alk. Phos. (ALP): Alkaline Phosphatase is an enzyme which originates from many parts of the body but primarily in the liver and bones. Increases in this enzyme can be an indicator of liver or bone disease. In young dogs there is often a mild increase due to growing bones. The same increases can be seen after sustaining a trauma to the bones. Mild increases in ALP are more significant in cats than dogs. Large increases in ALP can be seen with liver disease, Cushing’s disease (Hyperadrenocorticism), or drug therapy such as cortisone or phenobarbital.

Amylase and Lipase: Amylase and Lipase are enzymes produced by the pancreas to break down components of ingested food. Increases in the circulating blood levels of these enzymes can occur with inflammation of the pancreas (pancreatitis) or sometimes pancreatic cancer.

Bilirubin: Bilirubin is a yellowish brown substance found in bile. It is produced when the liver breaks down old red blood cells. Bilirubin is excreted from the body in the feces giving it it's brown color. Increases in bilirubin can be an indicator of liver or gall bladder disease or an obstruction to the bile duct.  Increases in bilirubin will also happen with the abnormal, rapid destruction of red blood cells.  An increase in bilirubin will often result in a yellow tinge to the skin, eyes or gums called jaundice.

Blood urea nitrogen (BUN): BUN is a measure of the urea nitrogen which is a product of protein metabolism. It is formed in the liver and excreted by the kidneys. Increases in this level are usually attributed to kidney dysfunction, although small increases can be seen with dehydration as well. A low BUN could be supportive of a liver problem.

Calcium: Calcium in the bloodstream comes from the bones. The Parathyroid Hormone controls the fluctuation of calcium in and out of the bloodstream and bones. Increases in calcium can be secondary to kidney disease, increased parathyroid activity, bone disease and certain types of cancer. There are also certain types of rat poisons that can cause an increase in calcium. A low calcium level can lead to tremors, muscle problems and heart arrhythmias. Low calcium can occur secondarily to an under-active parathyroid gland, malnutrition or depletion from pups nursing on the mother.

Complete Blood Count (CBC): The complete blood count looks at the numbers and types of white blood cells present in the blood stream. It also looks at red blood cell numbers and any abnormalities in their appearance. Increases in white cells can happen with infections or severe allergies. Low white cell numbers can indicate certain viral infections. Abnormal white or red cells can be seen with certain forms of cancer and can sometimes be the only indicator that there is a problem.

Creatinine: Creatinine is a waste product of muscle metabolism. It is excreted by the kidneys. An increase in creatinine usually indicates a problem with the kidneys. Like the BUN, small increases can occur with dehydration.

Glucose: Glucose is blood sugar. Small increases in blood sugar can occur with stress (such as having blood drawn). Large increases are usually indicative of diabetes mellitus. If we are unsure if an elevated glucose is significant or not, the presence of glucose in the urine can lend support to diabetes. Low blood sugars can occur secondarily to malnutrition, pancreatic cancer, sepsis, or an overdose of insulin.

Phosphorus: Phosphorus, like calcium, originates in the bones and is controlled by the parathyroid hormone. It is commonly elevated with kidney disease. In general the higher the phosphorus the worse the long term prognosis. If there is an increase in the bun, creatinine and phosphorus simultaneously, at least 75% of the kidney function is compromised.

Potassium: Potassium is both an electrolyte and a mineral. It is essential to the proper functioning of muscles and nerves. Low potassium levels can lead to muscle weakness and is often seen with kidney failure or other diseases causing a lack of appetite. Increased potassium levels can cause diarrhea, low blood pressure and heart arrhythmias which can even become fatal. Increased potassium can result from acute kidney failure or Addison’s disease (hypoadrenocorticism).

Sodium: Like potassium, sodium is both an electrolyte and a mineral. It is also essential to the proper functioning of muscles and nerves. Sodium and potassium levels often change simultaneously. When sodium levels go up potassium levels usually decrease and when sodium levels are decreased potassium levels usually go up.  Increased sodium levels, usually related to the intake of high salt foods, can lead to high blood pressure. This is especially a concern in patients with heart disease. Low sodium levels are more uncommon but will often occur in patients on diuretics or patients with gastrointestinal diseases or Addison’s disease.

T4, FreeT4, TSH: These values help us to evaluate thyroid function.  Low thyroid values can be seen in dogs (and rarely in cats). These animals are often overweight and have poor hair coats or excessive shedding and fur loss. Supplements can be given to adjust for low thyroid function. High thyroid values can be seen in cats. Excessive thyroid hormones can result in weight loss (often with increased appetite), vomiting, increased heart rates and blood pressure. Medications can be given to suppress the excessive production of thyroid hormones.

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