White blood cells, also known as leukocytes, are categorised into neutrophils, lymphocytes, monocytes, eosinophils, and basophils. The differences between them are related to the site of production, the period of circulation in the bloodstream, and the factors that trigger their proper function within the complex network of blood vessels. The normal white blood cell count also varies between species. Leukocytosis refers to an elevation in the number of circulating white blood cell, while leucopoenia is a drop in their numbers. Apart from an overall rise or drop in white blood cells, it is possible to diagnose disorders by monitoring the relative increases or decreases in specific kinds of white blood cell.
Leukograms are blood tests that calculate the amount of different white blood cells within the bloodstream. This test also enables your veterinarian to gain insight into the disease, thus diagnosing a wide range of disorders.
Neutrophilia is a condition associated with an elevation in the neutrophile count in the bloodstream, as a result of inflammation. Changes in the outer structure of neutrophils, also known as toxic changes, may take place if there is extreme inflammation. On the other hand, neutropenia is a reduction in the number of neutrophils in the bloodstream. This can be due to white blood cells adhering to the walls of broken blood vessels, destruction of neutrophils, or drop in production in the bone marrow. An overwhelming bacterial infection or poor reactions to medication may also trigger Neutropenia, or even pan-cytopenia (deficit in red and white blood cells and platelets).
Eosinophilia relates to a boost in the number of eosinophils, which influence allergic responses and parasite control. Factors that cause these increases include allergic reactions, particular antibodies, parasitic infections, and an inflammation of the intestines, kidneys, lungs, or skin. Conversely, a reduction in eosinophils is referred to as eosinopenia, and is a common response to stress or corticosteroids treatment.
Basophils, which are not common in domestic animals, are responsible for producing histamine, dealing with allergic reactions and parasite control. Though basophilia (an increase in basophils) is rare, some dogs with heartworm disease do experience it.
Lymphocytosis is a rise in the number of lymphocytes present in the bloodstream. It is a result of numerous factors such as specific hormones, infections that stimulate the immune system, chronic diseases like arthritis, and leukaemia. Lymphopenia is a decline in lymphocyte levels, mostly due to corticosteroids (either natural or administered as treatment). Decreased manufacture of lymphocytes, specific viral infections, and genetic diseases can also bring about lymphopenia.
Monocytosis is a condition that increases monocyte levels and may be linked with long-term inflammation.
Leukaemia and Lymphoma
Leukaemia is a malignant cancer that is denoted by an elevation in abnormal white blood cell levels. Lymphoma is a similar cancer that affects specific white blood cells, though it originates from lymph nodes and tissues. Leukaemia should be immediately suspected when there is an elevation in the white blood cell count in the bloodstream.
Gray Collie Syndrome
It is also known as cyclic haematopoiesis, and is a genetic immune-system deficiency that affects only gray Collies. Symptoms of this syndrome include a substantial decrease in neutrophils that happens in 12‑day cycles, devastating repetitive bacterial infections, bleeding, a pale coat and nose colour. The disease is understood to be a flaw in the development of the cells in the marrow that make up red and white blood cells, and platelets. Growth factors and hormones that influence cellular growth also have a cyclic pattern.
Most puppies born with this syndrome usually don’t survive past their first week, with older dogs dying by 6 months of age. Dogs that do survive may end up stunted and weak, with severe bacterial infections when neutrophil numbers are low. They also accumulate an abnormal protein called amyloid, a condition known as amyloidosis.
Your veterinarian can identify the disease using the symptoms and blood test results. Effective treatment involves a bone marrow transplant at an early age.
This hereditary condition develops from abnormal maturation of white blood cells, with most dogs not showing any symptoms of illness. A rare and fatal variety of the disease also creates skeletal deformities and high vulnerability of infection. Pseudo-Pelger-Huët abnormality is an acquired defect in white blood cell growth that is due to long-term infection, viral disease, drug therapy, and some tumours.