$50 .00
Biochemical Profiling in the Dog and Cat
A. H. Rebar, DVM, PhD, Diplomate ACVP G. Daniel Boon, DVM, MS, Diplomate ACVP John A. Christian, DVM, PhD
Clinical Handbook Series Published by The Gloyd Group, Inc. Wilmington, Delaware © 2004 by Nestlé Purina PetCare Company. All rights reserved. Printed in the United States of America. Nestlé Purina PetCare Company: Checkerboard Square, Saint Louis, Missouri, 63188 First printing, 1999.
This book is protected by copyright.
ISBN 0-9678005-4-4 Table of Contents
Introduction ...... 1
Part I Chapter 1 Biochemical Profiling Defined ...... 5 Chapter 2 Hemogram Interpretation ...... 7 Chapter 3 Urinalysis Interpretation ...... 11 Chapter 4 Acid-Base Balance ...... 15
Part II Biochemical Profiling Chapter 5 Clinical Pathology of the Urinary System ...... 27 in the Dog and Cat Chapter 6 Clinical Pathology of Hepatic Disease ...... 39 A. H. Rebar, DVM, PhD, Diplomate ACVP Chapter 7 G. Daniel Boon, DVM, MS, Diplomate ACVP Clinical Pathology of Exocrine Pancreatic Disease ...... 55 John A. Christian, DVM, PhD Chapter 8 Clinical Pathology of Gastrointestinal Disease ...... 63 Chapter 9 Clinical Pathology of Endocrine Disease ...... 71
Part III Chapter 10 Case Studies ...... 87
Part IV Table 1. Chemistry Reference Ranges for the Dog and Cat ...... 100 Table 2. Hematology Reference Ranges for the Dog and Cat ...... 101 Clinical Handbook Series Glossary of Terms ...... 102 Suggested Reading ...... 104 Subject Index ...... 107
Nestlé PURINA Biochemical Profiling in the Dog and Cat a6 Introduction
The goal of this text , Biochemical Profiling in the Dog and Cat , is to outline a systematic approach to the interpretation of large clinical chemistry profiles. It is not designed as an in-depth treatise on interpretive clinical chemistry but rather as an adjunct to such texts. To accomplish these objectives, an organ system and case- oriented format is used, following the style first introduced to veterinary medicine by Duncan and Prasse. 32 The book is divided into four sections, as described below.
Part I (Chapters 1 through 4) covers basic information on biochemical profiling as well as interpretation of the hemogram, urinalysis, and acid-base balance. Many of the tests used to evaluate acid-base balance are part of most large biochemical profiles; however, because acid-base disturbances are non-specific and can occur in diseases of many organ systems, acid-base balance is considered along with hemogram and urinalysis data.
In Part II (Chapters 5 through 9), each major organ system is discussed independently and a specific test panel is outlined for each. The specific panel represents a subset of the standard large chemistry profile and consists of those tests which should be evaluated first and as a unit whenever involvement of the given organ is suspected on the basis of history, clinical signs, and physical examination. The rationale for the use and interpretation of each test in the organ system panel is briefly outlined and a series of cases that illustrate the principles of interpretation for each organ system is then provided. (In some instances, the data have been modified for teaching purposes.)
Part III (Chapter 10) consists of a series of case studies presented as “unknowns.” The reader is encouraged to apply the principles outlined in Parts I and II to interpret the data presented. For each case, the authors’ interpretations are included.
Part IV includes important reference material: J Table 1. Chemistry Reference Ranges for the Dog and Cat* J Table 2. Hematology Reference Ranges for the Dog and Cat* J Subject Index J Suggested Reading J Glossary of Terms
* Reference values listed herein are from the Purdue University Veterinary Clinical Pathology Laboratory and are not intended as general reference values. Reference ranges may vary among other institutions and laboratories.
Nestlé PURINA Biochemical Profiling in the Dog and Cat 1 Nestlé Purina PetCare Company Checkerboard Square St. Louis, Missouri VET 6143 Part I
Nestlé PURINA Biochemical Profiling in the Dog and Cat 3 Chapter 1: Biochemical Profiling Defined
Biochemical profiling is defined as the use of multiple be extremely complex. Furthermore, interpretation of blood chemistry determinations to simultaneously assess results is often clouded by the fact that perfectly normal the health status of various organ systems. In addition to animals may have, indeed are expected to have an occa - standard chemistry tests, other parameters (ie, hemograms, sional abnormal test result. It is estimated that in a stan - urinalysis) are measured to give a more accurate and com - dard panel of 12 chemistry tests, approximately 46% of all plete picture of the overall health status of the patient. normal subjects will have at least one abnormal test result. Strictly speaking, hemograms and urinalysis are not part of Such abnormalities are usually associated with the way in clinical biochemical profiles; however, biochemical profiles which reference (or normal) values are determined. cannot be accurately interpreted without simultaneous eval - In order to establish the “normal range” reference values uation of the complete blood count (CBC) and urinalysis. for a given test, the procedure is performed on samples Biochemical profiling is a powerful diagnostic and moni - from a large population of clinically normal individuals. toring device used in ill patients and those receiving thera - The central 95% of the given results is identified and, if the py. It is also an important component of regular wellness data have a Gaussian distribution, a mean and a standard evaluations in healthy dogs and cats. Although biochemical deviation are determined based on the central 95%. The profiling offers exciting potential as a clinical tool, it is not reference values are then defined as those values falling a panacea. The following paragraphs illustrate some of the within the central 95%, ie, within 2 standard deviations more important difficulties encountered in the interpreta - above and below the mean ( see Fig. 1 ). Therefore, 5% of tion of clinical chemistry data. the values from a normal (ie, healthy) population fall out - Since standard chemistry screens may include from 12 side the defined “normal” reference interval for any given to 30 different test results, interpretation of these data may parameter.
Population 2.5% 95% 2.5% Reference intervals are established as all values Reference Interval falling between 2 standard deviations above and below the mean. By convention, therefore, 5% of the results from clinically normal individuals fall outside the reference interval for any given parameter.