BLOOD TEST AND CHEMISTRY PROFILES

JUST WHAT DO THEY TELL US?

PART ONE

Mary Lou Gerace

We all know that every dog should receive a thorough veterinary examination once a year.  As part of this yearly exam, most of us are advised to obtain a blood count and serum chemistry profile.  We are told that these tests will provide invaluable information about OUR dog for the future.  That when your dog is in a healthy state, the blood tests will establish normal levels that your veterinarian can refer back to, should your dog get become ill in the future. This month I will discuss the “Normal Complete Blood Count Values”, what the “numbers” mean and how to know if your dog is within the  “normal” range.

A complete blood count (CBC) is taken to indicate the quantity and quality of cells in the blood.

Every laboratory that does blood work will have its own level of ranges of what they consider normal.  These values will vary and are dependent upon the particular laboratory equipment being used.  Normal readings are established by taking a certain number of dogs and analyzing their blood and then averaging it out.  You should ask your veterinarian how the norms are established for the laboratory that he uses.  If you are using blood chemistry to work out a diagnosis, do not use several different laboratories.  Stay with one for consistent results.

If you work with your veterinarian on a yearly basis, you can establish the normal levels of blood chemistry for your dog.  Establishing norms prior to any health problems is just “good” preventative medicine. 

Below is a chart that shows  “NORMAL” Complete Blood Count Values and an explanation of the values.  Keep in mind, however, that there may be a variation in the “norm” depending on the laboratory used.

Test                                                                                                      Range

RBC count                                                                                           5.5 - 8.5 X 100,000/L

PCV (Hematocrit)                                                                                37 - 55 percent

Hemoglobin (Hb) g/L                                                                            120-180

Reticulocyte count                                                                                0-1.5%

Platelet count    x 100000/ul                                                                  2-9

WBC count                                                                                          6.0 - 17 x 1000/L

Neutrophils (seg) x 1000/ul                                                                   3.6-11.5

Neutrophils Bands                                                                                0.0-0.3

Lymphocytes    x 1000/ul                                                                      1.0-4.8

Eosinophil x1000/ul                                                                              0.01-1.25   Monocytes x 1000/ul                                                                                 0.15-1.35

Basophils /ul                                                                                         0-150

RBC-RED BLOOD CELL COUNT—Red blood cells transport oxygen and carbon dioxide between the lungs and the body tissues.  They are produced in the bone marrow and are under the control of chemicals that are secreted by the kidneys.  The red blood cells have various component parts:

PVC (PACK CELL VOLUME/HEMATOCRIT) is the most commonly used expression of red cell numbers and is measured as a percentage of blood composed of red blood cells. 

“DECREASED” levels of RBC or PCV is commonly termed “anemia” and have three (3) basic cause

·        Reduced bone marrow production that can be from an iron deficiency, a vitamin B12 deficiency, or chronic kidney or liver disease;

·        Loss of blood from the body such as external or internal hemorrhage, or parasites;

·        Destruction within the body called hemolytic anemia (breaking down of red blood cells).

“INCREASED” levels of RBC or PCV are usually the result of dehydration.  It can also be the result of the bone marrow over-producing red blood cells, but this is rare.  Over-use of vitamin/mineral products can also cause increases in hematocrit levels.

HEMOGLOBIN (Hb) is the essential oxygen carrier of the blood.  It is found within the red blood cells and is responsible for the red color of the blood.  It is essentially equivalent to the PVC.

“DECREASED” levels indicate the presence of hemorrhage and anemia.

“INCREASED” levels indicate a higher than normal concentration of red blood cells.

RETICULOCYTES are immature red blood cells that have been released from the bone marrow prematurely.

“DECREASED” count, if associated with chronic anemia, indicates a lowered red blood cell production by the bone marrow.

“INCREASED” count is associated with chronic hemorrhage or hemolytic anemia (destruction of RBCs).

PLATELET COUNT test indicates the blood clotting ability of the dog.  Platelets, also called thrombocytes, are derived from the bone marrow. 

“DECREASD” numbers of platelets occur in bone marrow depression, autoimmune hemolytic anemia, systemic lupus (a blood clotting disorder), severe hemorrhage or intravascular coagulation.

“INCREASED” numbers of platelets occur sometimes when there is a fracture, a blood vessel injury or if the bone marrow is overproducing (cancer).

WBC is the total number of white blood cells.  WBC’s are often called leucocytes.  There are different kinds of white blood cells and the figure shown on the chart is reached by combining the total of these various kinds of white cells together.  The different kinds of cells are called neutophils, neutrophil bands, lymphocytes, eosinophils, monocytes and basophils.

“DECREASED” levels of WBCs may indicate developmental or metabolic disorders, an overwhelming infection, especially from viruses, or drug and chemical poisoning.

“INCREASED” levels of WBCs can be seen in infections, especially bacterial in nature, as well as emotional upsets and blood disorders.

NEUTROPHILS are white blood cells that go to work in the face of inflammation.  They consume foreign material and destroy bacteria. 

“DECREASED” numbers of neutropils might indicate viral infection, starvation, drug reactions, or an overwhelming bacterial infection.

“INCREASED” numbers would indicate a local bacterial infection and inflammation, stress, tissue destruction such as abscesses or tumors, or the use of steroid drugs. 

NEUTROPHIL BANDS are immature neutrophils that are prematurely released from the bone marrow when there is an immediate need for them, such as at the site of the inflammation. 

“INCREASED” numbers of bands indicate that the bone marrow has the infection or it has the inflammation under control.  If the band cells are greater than 10 percent of the mature neutrophils, and the total WBC is normal or low, then it would show that the bone marries is losing the battle.

LYMPHOCYTES function along with the immune system.  They recognize antigens (enzymes, toxins or foreign substances) and produce antibodies (protein substances) that fight the antigens.

“DECREASED” numbers are seen from stress, steroid use or cancer chemotherapy drugs.

“INCREASED” numbers result from a strong stimulus to the immune system such as chronic inflammation, recovery from acute infections and under active adrenal glands (Addison’s disease). 

EOSINOPHILS are the detoxifiers of histamine.  Histamine is a substance released by the body whenever tissue is damaged.

“DECREASED” numbers occur with stress, steroid use, or an overactive adrenal gland (Cushing’s Disease).

“INCREASED” numbers occur during an allergic reaction to something in the environment, or when parasites are in the system or with an under active adrenal gland (Addison’s Disease).

MONOCYTES are single cells that are immature forms of macrophages.  Macrophages are the cells that “eat” foreign bodies and cellular debris.

“DECREASED” numbers are not regarded as “important”.

“INCREASED” numbers occur with chronic fungus infections, dying tissue, chronic inflammatory and immune diseases.  They also increase with a stress reaction from using steroid medications and Cushing’s Disease. 

BASOPHILS contain both histamine and heparin.  Heparin is a blood clotting inhibitor.  These cells start the inflammatory response after the body is injured.  Basophils are not commonly found on the blood smear of dogs. 

“DECREASED” numbers can be an indicator of an under active thyroid.

“INCREASED” numbers of these cells are associated with high levels of fact in the blood, heartworm disease, Cushing’s Disease, thrombus formation (blood clot within the blood vessels) and ulcerative colitis.

Next month I will discuss the blood chemistry profile (Serum Chemistry Profile) and what those numbers mean.  As always, the above information is based on my personal research.  References include: http://www.thepetcenter.com/pha/cp.html

http://www.bichonfriseusa.com/caninebloodwork.htm

http://www.petscorner.com.my/articles/article-blood_count.html

As always, comments welcome! 

boomer@trianglenet.net

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