Chemistry

Cystatin C is a small (13 kD) protein that is used as a marker of glomerular filtration rate (GFR) or kidney function, particularly in chronic renal disease (CKD). Serum cystatin C is generally considered superior to creatinine as a marker of GFR in dogs (Ghys et al 2014 review) but not in cats (Ghys et al 2016). Physiology Cystatin […]

Serum amyloid A (SAA) is an acute phase protein and α-globulin that is produced in the liver in response to inflammatory cytokines.  It is considered a major acute phase protein in domestic species, except for the pig, in that low values are present in normal animals with marked increases (100-1000 fold) occurring within 24-48 hours with

Here we provide quick guides (tables and algorithms) to interpreting changes in acid-base results from a standard chemistry panel. Simple disturbances Respiratory disturbances The following table provides a summary of the changes in the blood gas (pH, pCO2) with primary respiratory acid-base disturbances, based on the type of disturbance. Note, that a respiratory disturbance cannot

Iron panels consist of serum iron, total iron binding capacity (TIBC, an indirect measurement of transferrin) and percentage saturation of transferrin measurement. Below is a table on guidelines for interpretation of this test panel. Interpretation of common changes in iron panels Iron TIBC % saturation transferrin Disorders ↓ N ↓ Any cause of low iron.

Sodium Increased   Artifact Water loss from blood sample (inadequate capping) Iatrogenic Hypertonic fluid administration Water deficit Excess water loss: Panting, fever, hyperventilation, diabetes insipidus Inadequate intake: Water deprivation, primary adipsia/hypodipsia Hypotonic fluid loss and inability to conserve water or drink: Renal: Osmotic/chemical diuresis, renal failure Non-renal: Gastrointestinal, cutaneous, third space losses Salt gain Excess

Acute phase proteins (APPs) are defined as proteins that change their serum concentration by >25% in response to inflammatory cytokines (IL-1, IL-6, TNFα). The acute-phase response is considered part of the innate immune system, and APPs play a role in mediating such systemic effects as fever, leukocytosis, increased cortisol, decreased thyroxine, decreased serum iron, and

Physiology Total calcium as measured on the chemistry panel includes a large component that is protein-bound and does not necessarily reflect the status of the biologically active ionized form. Free ionized calcium (iCa2+) is the form of calcium that is readily available to cells, and measurement of iCa2+ is a more accurate reflection of the

Bone marrow is the main hematopoietic tissue in the body and is composed of roughly equal amounts of hematopoietic cells and fat.  Most hematopoiesis in adults occurs in flat bones and at the end of long bones.  The bone marrow is composed of multiple cell types: Hematopoietic precursors: Myeloid, erythroid, megakaryocytic, lymphoid: These develop in

Serum protein electrophoresis (SPE) separates proteins into multiple bands using an electrical field and can be done in various media, including cellulose acetate (largely replaced), agarose gel or liquid within a capillary tube (capillary zone). These all separate the proteins into distinct bands or fractions. The fractions are separated by charge and size. Albumin is

Disease of the kidney can be generally classified as acute or chronic. A diseased kidney could be functioning normally leading to no clinical pathologic abnormalities, but the disease can also lead to a loss of ability to concentrate or dilute tubular filtrate (requires 2/3 loss of functional mass), to eliminate nitrogenous wastes (requires loss of