BLOOD: FACTS YOU NEED TO KNOW
©2002, Barbara Bouyet, all rights reserved. Barbara is a long-time member of the GHC Committee and a renowned authority on the Akita. This section is excerpted from her Book entitled Akita Treasure of Japan, Vol II. We thank her for her generosity in allowing us to use it. For order information: http://www.akitabook.com/
Blood brings nutrients and oxygen to every part of the body, while removing the waste products from cells. It is part of the immune system as well as the circulatory system. Because blood circulates throughout the body, any alterations in normal blood physiology can have widespread adverse consequences throughout the body.
Briefly, let us look at the structure of this vital fluid. Blood is an extremely complex fluid composed of both formed elements (red cells, white cells, platelets), and plasma. All of these cells are different in structure and function but they begin in the bone marrow from a common progenitor cell called a stem cell. The red cells carry oxygen from the lungs to body tissues by attaching the oxygen to hemoglobin, a pigmented substance in red cells that contains iron. When the amount of hemoglobin or the total amount of red cells falls below a certain number, the possibility of anemia exists. There are many types of anemia, some are caused by vitamin or mineral deficiencies or an inability to absorb certain nutrients; destruction of red blood cells, inherited abnormalities in the blood, or the failure of the bone marrow to manufacture sufficient numbers of red blood cells. Cancers like leukemia (cancer of the blood), or lymphoma (cancer of the lymph system), and chronic diseases like lupus, hepatitis or polyarthritis, ulcerative colitis and hypothyroid disease can all be underlying causes of anemia. Reactions to vaccines, drugs and toxins can also cause anemia.
Red blood cells have a normal life span of up to 120 days. The bone marrow continually produces red cells throughout life but when these cells are destroyed prematurely, it is called hemolytic anemia. In this disease, the red cells break down faster than the bone marrow can replace them. Remember, red cells carry oxygen and nutrients to every cell in the body, while removing waste. When these cells break down faster than they can be replaced, the body can die without treatment.
In Akitas, hemolytic anemia is often caused by an inherited autoimmune reaction, and it is called autoimmune hemolytic anemia. Antibodies, produced by the immune system to protect the body against foreign invaders, mistake the red cells as foreign and bind to the red cells causing their destruction. It is difficult to treat and often fatal. There is an inherited predisposition to this disease.
Another form of hemolytic anemia, acquired hemolytic anemia, is caused by the body’s reaction to vaccines, medications, infections and toxins. This type of anemia is usually temporary and will resolve after a few months but may require supportive therapy. There may be an inherited predisposition to this form of anemia since most Akitas receiving the same drugs or vaccines, will not suffer from a hemolytic anemia in response.
Aplastic anemia is a failure of the bone marrow to produce red blood cells. It is rare but is a medical emergency requiring a blood transfusion to sustain life. In most cases, this form of anemia is caused by drugs or exposure to toxic substances. Pesticides including lindane, used to treat fleas, chlordane, diazinon and malathion, have all been implicated as a cause of aplastic anemia's. Organic solvents like benzene and those used in cleaning fluids, especially fluids made to clean metals, metal parts, automobile engines, computer parts or other metal surfaces are also causes of aplastic anemia.
Polycythemia is an acquired disease of red blood cells known to occur in the Akita. This disease is a precursor to leukemia where the bone marrow begins over producing red cells. Polycythemia has been linked to exposure to chemicals used in agriculture and household pesticides. In animal studies, this blood abnormality has been linked to an inert ingredient in the weed killer Roundup™, to the chemicals chlordane and mirex (used for fire ants), the phenoxy herbicides, and diflubenzuron (an ingredient in household cleansers).
Ehrlichiosis is a tick-born parasite that mimics autoimmune hemolytic anemia and thrombocytopenia. Babesiosis is a tick-borne infection caused by the malaria-like protozoan Babesia microti. The protozoan inhabits red blood cells and can result in severe hemolytic anemia. These diseases are treatable in the early stages.
Platelets, or thrombocytes, are tiny disk-shaped cells crucial to normal blood clotting, also called coagulation. Platelets are manufactured in the bone marrow; they can survive for about 10 days and are constantly renewed by the bone marrow. Disorders affecting platelets are often found along with red blood cell disorders. For example, a dog with autoimmune hemolytic anemia may also have thrombocytopenia because the abnormal immune system response will attack both red blood cells and platelets. This combination, called “Evans syndrome,” is a disease of genetically predisposed individuals, and therefore, these dogs should not be used for breeding.
Blood coagulation or clotting is a complex process that requires many substances in addition to platelets. These substances are called coagulation factors. The process starts when platelets initiate the coagulation process by aggregating (clumping together) or combining the factors. The end result of this process is the formation of a clot to terminate a hemorrhage after injury. The most common cause of a low platelet count is destruction of platelets by the immune system.
The Akita on the left is affected with thrombocytopenia and may live a normal life with treatment. Thrombocytopenia is a deficiency of platelets and can be caused by a decrease in the number of platelets produced by the bone marrow as in the case of leukemia or aplastic anemia. There can be a destruction of platelets which occurs in lymphoma, lupus, blood poisoning, infections, tick-borne parasitic diseases, or a reaction to drugs, vaccines or toxins.
With some Akitas, the platelet numbers are normal but they do not function to produce coagulation because of an inherited clotting disorder like von Willebrand’s disease (vWD) or a response to vaccines, drugs or toxins. vWD is the most common inherited disorder causing a failure of clotting. The von Willebrand’s factor is one of coagulation factors mentioned above. It is found in plasma, platelets and blood vessel walls. When this factor is missing or defective, platelets cannot adhere to the vessel wall at the site of a hemorrhage or injury and clotting does not occur. As a result, bleeding does not stop.
vWD is inherited as an autosomal trait with incomplete dominance. This means offspring may inherit the disorder if either parent carries the gene, but not all offspring will be affected to the same extent. Dogs with type I disease have reduced but measurable levels of Von Willebrand factor (1 to 60 per cent). Animals that inherit the gene for type I vWD from both parents (homozygotes) die before birth or shortly thereafter.
There is now a very accurate test to diagnose carriers of the vWD gene as well as affected dogs. A sample of blood can be taken and shipped under refrigeration to a qualified veterinary research center. Normal dogs show proper levels of the vWD protein. Carriers or afflicted dogs have significantly lower levels of the vWD protein. Test results on severely affected dogs may indicate vWD protein levels only one-sixth as high as normal.
Since there is an accurate test to determine the presence of vWD, in time all Akita breeders will offer puppy buyers a certification that both sire and dam are free from the inherited form of vWD. Furthermore, increased testing for genetic vWD carriers by responsible breeders can lessen the impact of this deadly disease. To prove this point, Dr. Jerold S. Bell of Tufts University, writes in his article “Popular Sire Syndrome and Concerns of Genetic Diversity,”
By supporting research into autoimmune diseases, both financially and by donating DNA from your Akita, we will one day be able to erase inherited forms of hemolytic anemia and other blood disorders found in the Akita.
Unique Akita Blood
*An unusual feature of the blood that is seen in some Akitas is microcytosis, the presence of abnormally small red blood cells and a high potassium level. No correlation between high potassium levels and microcytosis has been found, and not all Akitas show these traits. The presence of microcytosis in the Akita has not been associated with any physical problem, though microcytosis, in general, is associated with certain anemias. Other Japanese breeds may also show microcytosis.
The Akita has been found to have RBCs with high potassium content. The condition is called pseudohyperkalemia. All other canines have red cells with low potassium content. This high potassium content has not been linked to any disease, but it can cause a problem during routine blood panels if your veterinarian is not familiar with this anomaly. The Akita and other Japanese breeds have a permeable erythrocyte sodium-potassium membrane pump, which means their red cells leak potassium into the serum producing pseudohyperkalemia. (This peculiarity makes these dogs more susceptible to onion poisoning.) If the blood is not spun immediately, there can be a false indication of Addison's disease syndrome.”
White Blood Cells
The last formed element making up the blood and manufactured from stem cells in the bone marrow are white blood cells which function to protect the body from foreign organisms—virus, bacteria, any disease causing agents. Because of this function, the body will produce more white cells than normal in response to infections. These changes show up as elevated white cells on a blood test. White blood cell numbers can increase in response to inflammation, allergies, and infection or even stress. In cancers like leukemia, either the numbers of white blood cells are increased or their appearance is abnormal, or both.
A decrease in white blood cells may indicate an overwhelming infection like Parvo virus which results in a steep drop of white blood cells characteristic of this disease; with bone marrow disorders, or a decrease can be a reaction to drugs or a toxic chemical.
Neutrophils, monocytes, eosinophils, basophils and lymphocytes are white blood cells, each with its own function:
The following links will open in a new browser window. They will give you more information on blood and disorders that affect the blood:
Updated on 09/18/2008