SIRS stands for Systemic Immune Response Syndrome. It is a complex cascade of a heightened immune response that involves both the immune and coagulation systems. SIRS can be caused by a variety of infectious and non-infectious causes. Simply put, it is whole body inflammation that can quickly advance to organ failure. If left unmanaged, the patient mortality rate is very high.

Sepsis is inflammation caused by an infection (technically SIRS plus an infection although this is more of a research definition than a practical one). Often confused with bacterimia (an infection of the blood), sepsis may be systemic or localized such as an internal abscess or a kidney infection.

Severe Sepsis is the progression of sepsis when organ failure begins to occur. The reason sepsis has such a high mortality rate is not because of the infection but rather an over active immune response that leads to organ failure.

Septic Shock occurs when there is a rapid loss of blood pressure (hypotension) and organ failure is imminent. The rapid loss of blood pressure can be due to fluid loss associated with the severe inflammation.

WBC stand for White Blood Cell count and is the absolute number of leukocytes which includes all types of white cells such as neutrophils and lymphocytes.

Left Shift or "bands" are the immature form of neutrophils. During an inflammatory state the body often puts out more neutrophils resulting in a higher percentage of immature forms.

Leukocytosis is simply a high WBC count. In an infection a patient may have either leukocytosis or leukopenia (low white cell count).
Inflammation is the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Common signs of inflammation are leukocytosis, leukopenia, left shift, fever, rapid breathing, or rapid heart rate.

Inflammation is the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Common signs of inflammation are leukocytosis, leukopenia, left shift, fever, rapid breathing, or rapid heart rate. Inflammation is a protective attempt by the dog to remove the injurious stimuli as well as initiate the healing process for the tissue. Inflammation is not a synonym for infection.

Immune Mediated Diseases are auto-immune disorders where the body attacks itself. The most common in dogs are immune - mediated hemolytic anemia (IMHA) and immune- mediated thrombocytopenia (ITP) in which the body's own immune system attacks its red blood cells (IMHA) or platelets (ITP).

Neoplasia is the uncontrolled, abnormal growth of cells or tissues in the body, and the abnormal growth itself is called a neoplasm or tumor. It can be benign or malignant. Benign neoplasms do not grow aggressively, do not invade the surrounding body tissues, and do not spread throughout the body. Malignant neoplasms, on the other hand, tend to grow rapidly, invade the tissues around them, and spread, or metastasize, to other parts of the body. The word "tumor" or "mass" is often used to describe the actual swelling or other physical appearance of a neoplasm. The word "cancer" is often confused with neoplasia, but only malignant neoplasms are truly cancers.

Necrosis is the premature death of cells and living tissue. Non-infectious necrosis is caused by external factors, such as toxins or trauma.

Culture refers to the laboratory growing of microorganisms from suspected infected body material. Almost any material from the body can be cultured although the success rate falls rapidly with difficult to grow fungus, anaerobes, or contaminated material. Cultured material often has a high false positive and false negative rate.

Vascular Endothelium Cells are the thin layer of cells that line the interior surface of blood vessels forming an interface between circulating blood in the lumen and the rest of the vessel wall. The endothelium acts as a selective barrier between the vessel lumen and surrounding tissue, controlling the passage of materials and the transit of white blood cells into and out of the bloodstream. Vascular Dilating is the dilation of the blood vessels allowing increased permeability. Excessive or prolonged increases in permeability of the endothelial monolayer, as in cases of chronic inflammation, may lead to tissue edema/swelling and fluid loss. Pronounced fluid loss can lead to hypotension (see septic shock).

In-Vivo is Latin for "within the living". It refers to what happens within the body either naturally or as part of an experiment such as a clinical trial. Alternatively, in-vitro (Latin for "within the glass") refers to that which occurs in a controlled environment such as a test tube or in a laboratory.