This chapter presents basic concepts related to avian clinical biochemistry. Avian medicine and surgery is recognized as an official specialty in veterinary medicine in three continents: Europe, Australia, and North America. The increasing demand for veterinary care for individual birds with a high sentimental or economical value and efforts to conserve endangered species facilitated this awareness. The introduction of micromethods in clinical laboratories and the public demand for veterinary care for individual birds have removed many obstacles of this field. This chapter begins with discussing how blood samples of birds can be collected in the most efficient way. The chapter then discusses starvation, flight, and postprandial effects. The chapter also elaborates the biochemistry of plasma proteins, renal function, and hepatobiliary disease in birds. The chapter emphasizes that all efforts should be made to obtain a blood sample before any treatment is given. Treatments administered before samples are collected may severely affect plasma chemical values, which may jeopardize a correct diagnosis at a later stage. The time interval between restraint and blood sampling should be kept to a minimum to prevent stress-associated changes in clinical chemistry parameters. Blood samples should be obtained before an extensive clinical examination is performed to avoid iatrogenic changes in the samples.

Avian Clinical Biochemistry

The acute phase response is a complex systemic early-defense system activated by trauma, infection, stress, neoplasia, and inflammation. Although nonspecific, it serves as a core of the innate immune response involving physical and molecular barriers and responses that serve to prevent infection, clear potential pathogens, initiate inflammatory processes, and contribute to resolution and the healing process. Acute phase proteins, an integral part of the acute phase response, have been a focus of many applications in human diagnostic medicine and recently have been identified in common animal species. Potential applications to diagnosis, prognosis, assessment of animal health, and laboratory animal welfare are readily apparent.

Acute phase response in animals: a review.

The acute phase response is a nonspecific inflammatory reaction of the host that occurs shortly after any tissue injury. The response includes changes in the concentration of plasma proteins called acute phase proteins (APPs), some of which decrease in concentration (negative APPs), such as albumin or transferrin, and others of which increase in concentration (positive APPs), such as C-reactive protein, serum amyloid A, haptoglobin, alpha-1-acid glycoprotein, and ceruloplasmin. Most positive APPs are glycoproteins synthesized mainly by hepatocytes upon stimulation by proinflammatory cytokines and released into the bloodstream. The acute phase response and clinical application of monitoring APPs in dogs and cats are reviewed in this article, including biochemical characteristics, assays developed for each individual APP, and preanalytic and analytic factors influencing APP results that should be taken into account for proper and adequate clinical interpretation. In addition, the diagnostic use of APPs and their possible application in monitoring treatment, which can be considered one of the most interesting and promising practical applications of these proteins, will be discussed. Finally, challenges and future developments of APPs in dogs and cats will be considered, because it is expected that new and cheaper automated assays for determination of the main APPs in small animals will contribute to a wider use of these proteins as biomarkers of infection and inflammatory lesions.

Acute phase proteins in dogs and cats: current knowledge and future perspectives

Tooth enamel is a unique mineralized tissue in that it is acellular, is more highly mineralized, and is comprised of individual crystallites that are larger and more oriented than other mineralized tissues. Dental enamel forms by matrix- mediated biomineralization. Enamel crystallites precipitate from a supersaturated solution within a well-delineated biological compartment. Mature enamel crystallites are comprised of non-stoichiometric carbonated calcium hydroxyapatite. The earliest crystallites appear suddenly at the dentino-enamel junction (DEJ) as rapidly growing thin ribbons. The shape and growth patterns of these crystallites can be interpreted as evidence for a precursor phase of octacalcium phosphate (OCP). An OCP crystal displays on its (100) face a surface that may act as a template for hydroxyapatite (OHAp) precipitation. Octacalcium phosphate is less stable than hydroxyapatite and can hydrolyze to OHAp. During this process, one unit cell of octacalcium phosphate is converted into two unit cell...

Molecular Mechanisms of Dental Enamel Formation

Excretion of infused 14C-steroid hormones via faeces and urine in domestic livestock

T.B. Farver, Concepts of Normality in Clinical Biochemistry. J.G. Hauge, DNA Technology in Diagnosis, Breeding, and Therapy. J.J. Kaneko, Carbohydrate Metabolism and Its Diseases. M.L. Bruss, Lipids and Ketones. J.J. Kaneko, Serum Proteins and the Dysproteinemias. L.J. Gershwin, Clinical Immunology. J.W. Harvey, The Erythrocyte: Physiology, Metabolism, and Biochemical Disorders. J.J. Kaneko, Porphyrins and the Porhyrias. J.E. Smith, Iron Metabolism and Its Disorders. W.J. Dodds, Hemostasis. J.G. Zinkl and M.B. Kabbur, Neutrophil Function. J.W. Kramer and W.E. Hoffmann, Clinical Enzymology. B.C. Tennant, Hepatic Function. D.F. Brobst, Pancreatic Function. W.E. Hornbuckle and B.C. Tennant, Gastrointestinal Function. G.H. Cardinet III, Skeletal Muscle Function. D.R. Finco, Kidney Function. G.P. Carlson, Fluid, Electrolyte, and Acid-Base Balance. J.A. Mol and A. Rijnberk, Pituitary Function. A. Rijnberk and J.A. Mol, Adrenocortical Function. J.J. Kaneko, Thyroid Function. L-E. Edqvist and M. Forsberg, Clinical Reproductive Endocrinology. T.J. Rosol and C.C. Capen, Calcium-Regulating Hormones and Diseases of Abnormal Mineral (Calcium, Phosphorus, Magnesium) Metabolism. R.B. Rucker and J.G. Morris, The Vitamins. M. Haskins and U. Giger, Lysosomal Storage Diseases. B.R. Madewell, Tumor Markers. C.S. Bailey and W. Vernau, Cerebrospinal Fluid. J.R. Turk and S.W. Casteel, Clinical Biochemistry in Toxicology. W.F. Loeb, Clinical Biochemistry of Laboratory Rodents and Rabbits. J.T. Lumeij, Avian Clinical Biochemistry. Appendixes. Index.

Clinical biochemistry of domestic animals

The pentose cycle as a pathway for glucose metabolism in intact lactating dairy cows.

Influence of dietary vitamin E on the red cells of ozone-exposed rats

Digoxin was administered orally and intravenously to seven healthy adult mares and geldings in two separate trials. At a dose of 44 microgram digoxin/kg body weight, the oral study was characterized by an absorption phase with a mean (+/- 1 standard deviation) peak serum digoxin concentration of 2.21 ng/ml (+/- 0.45) at a mean of 2.29 h (+/- 1.52) after administration. A second rise in serum digoxin concentration started about 6-8 h after administration and extended to about 20 h after administration. The mean bioavailability (F) was 23.38% (+/- 5.96). At a dose of 22 microgram digoxin/kg body weight, the intravenous study was characterized by a two-compartment model with the following mean pharmacokinetic measurements: distribution rate constant (alpha), 1.391 h-1 (+/- 0.1909); zero-time serum digoxin concentration determined from the distribution phase (A), 21.247 ng/ml (+/- 5.6614); elimination rate constant (beta), 0.0409 h-1 (+/- 0.0069); zero-time serum digoxin concentration determined from the elimination phase (B), 3.82 ng/ml (+/- 0.433); apparent specific volume of distribution uncorrected for protein binding (Vd beta), 5.003 l/kg (+/- 0.5177). The mean beta corresponded to a biological half-life (T1/2 beta) of 16.9 h. Based upon results of this study, theoretically achievable steady-state serum digoxin concentrations were calculated for maintenance doses given by oral and intravenous routes of administration with appropriate two-compartment, multiple-dose formulae. Loading doses were also calculated for each route. It is the opinion of the authors that the oral route of administration of digoxin is effective in the horse and may preclude the potential risks posed by the high serum digoxin concentrations immediately following intravenous administration.

A pharmacokinetic study of digoxin in the horse.

http://science.sciencemag.org/content/sci/137/3531/673.full.pdf

Jiro J. Kaneko

Papers

Clinical biochemistry of domestic animals

The pentose cycle as a pathway for glucose metabolism in intact lactating dairy cows.

Influence of dietary vitamin E on the red cells of ozone-exposed rats

A pharmacokinetic study of digoxin in the horse.

Erythrocyte Life Span in the Guanaco