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Applied Veterinary
Clinical Nutrition



Applied Veterinary
Clinical Nutrition
Editors

Andrea J. Fascetti, VMD, PhD, DACVIM, DACVN
Professor
Department of Molecular Biosciences
School of Veterinary Medicine
University of California
Davis, California

Sean J. Delaney, DVM, MS, DACVN
Assistant Clinical Professor—Volunteer
Department of Molecular Biosciences
School of Veterinary Medicine
University of California
Davis, California
Founder

Davis Veterinary Medical Consulting, Inc.
Davis, California

A John Wiley & Sons, Inc., Publication

This edition first published 2012
© 2012 by Andrea J. Fascetti and Sean J. Delaney
Illustrations by Catherine A. Outerbridge
© 2012 Catherine A. Outerbridge
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Library of Congress Cataloging-in-Publication Data
Applied veterinary clinical nutrition / editors,
Andrea J. Fascetti, Sean J. Delaney.
   p. cm.
  Includes bibliographical references and index.
  ISBN-13: 978-0-8138-0657-0 (hardcover : alk. paper)
  ISBN-10: 0-8138-0657-7
  1.  Pets–Nutrition.  2.  Pets–Diseases–Nutritional
aspects.  3.  Pets–Feeding and feeds.  I.  Fascetti,
Andrea J.  II.  Delaney, Sean J.
  SF414. A67 2012
  636.089'32–dc23

2011018148
A catalogue record for this book is available from the
British Library.
Wiley also publishes its books in a variety of electronic
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Set in 9.5/12 pt Times by Toppan Best-set Premedia
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1  2012

Designations used by companies to distinguish their
products are often claimed as trademarks. All brand


Contents
vii
ix

Contributors
Preface and Acknowledgments
  1

Integration of Nutrition into Clinical Practice
Sean J. Delaney, Andrea J. Fascetti, and Paul Brentson

3

  2

Basic Nutrition Overview
Sean J. Delaney and Andrea J. Fascetti

9

  3

Determining Energy Requirements
Jon J. Ramsey

23

  4

Nutritional and Energy Requirements for Performance
Richard C. Hill

47

  5

Nutraceuticals and Dietary Supplements
David A. Dzanis

57

  6

Using Pet Food Labels and Product Guides
Sean J. Delaney and Andrea J. Fascetti

69

  7

Feeding the Healthy Dog and Cat
Andrea J. Fascetti and Sean J. Delaney

75

  8

Commercial and Home-Prepared Diets
Andrea J. Fascetti and Sean J. Delaney

95

  9

Nutritional Management of Body Weight
Kathryn E. Michel

109

10

Nutritional Management of Orthopedic Diseases
Herman Hazewinkel

125

11

Nutritional Management of Skin Diseases
Catherine A. Outerbridge

157

12

Nutritional Management of Gastrointestinal Diseases
Nick Cave

175

13

Nutritional Management of Exocrine Pancreatic Diseases
Cecilia Villaverde

221

14

Nutritional Management of Hepatobiliary Diseases
Stanley L. Marks

235

15

Nutritional Management of Kidney Disease
Denise A. Elliott

251
v


vi

Contents

16

Nutritional Management of Lower Urinary Tract Disease
Joe Bartges and Claudia Kirk

269

17

Nutritional Management of Endocrine Diseases
Andrea J. Fascetti and Sean J. Delaney

289

18

Nutritional Management of Cardiovascular Diseases
Lisa M. Freeman and John E. Rush

301

19

Nutritional Management of Oncological Diseases
Glenna E. Mauldin

315

20

Enteral Nutrition and Tube Feeding
Jennifer A. Larsen

329

21

Parenteral Nutrition
Sally C. Perea

353

Index

375


Contributors

Andrea J. Fascetti, VMD, PhD, DACVIM, DACVN
Professor
Department of Molecular Biosciences
School of Veterinary Medicine
University of California
Davis, California

Joe Bartges, DVM, PhD, DACVIM, DACVN
Professor of Medicine and Nutrition
The Acree Endowed Chair of Small Animal Research
Department of Small Animal Clinical Sciences
College of Veterinary Medicine
University of Tennessee
Knoxville, Tennessee

Lisa M. Freeman, DVM, PhD, DACVN
Professor
Department of Clinical Sciences
Cummings School of Veterinary Medicine
Tufts University
North Grafton, Massachusetts

Paul Brentson, MBA
Hospital Administrator, Retired
Veterinary Medical Teaching Hospital
School of Veterinary Medicine
University of California
Davis, California

Herman Hazewinkel, DVM, PhD, DECVS, DECVCN

Department of Clinical Sciences and Companion
Animals
Section of Orthopaedics-Neurosurgery-Dentistry
Veterinary Faculty
Utrecht University
Utrecht, The Netherlands

Nick Cave, BVSc, MVSc, MACVSc, DACVN
Senior Lecturer in Small Animal Medicine
Centre for Companion Animal Health
Institute of Veterinary, Animal, and Biomedical Science
Massey University
Palmerston North, New Zealand
Sean J. Delaney, DVM, MS, DACVN
Assistant Clinical Professor—Volunteer
Department of Molecular Biosciences
School of Veterinary Medicine
University of California
Davis, California

Richard C. Hill, MA, VetMB, PhD, DACVIM,
DACVN, MRCVS
Associate Professor and Service Chief of Small Animal
Internal Medicine and Clinical Nutrition
Department of Small Animal Clinical Sciences
College of Veterinary Medicine
University of Florida
Gainesville, Florida

Founder

Davis Veterinary Medical Consulting, Inc.
Davis, California

Claudia Kirk, DVM, PhD, DACVN, DACVIM
Professor of Medicine and Nutrition Chair
Department of Small Animal Clinical Sciences
College of Veterinary Medicine
University of Tennessee
Knoxville, Tennessee

David A. Dzanis, DVM, PhD, DACVN
Regulatory Discretion, Inc.
Santa Clarita, California
Denise A. Elliott, BVSc (Hons), PhD, DACVIM, DACVN
Health and Nutritional Sciences Director—The Americas
Royal Canin SAS,
Aimargues, France
vii


viii

Contributors

Jennifer A. Larsen, DVM, PhD, Dipl ACVN
Assistant Professor of Clinical Nutrition
Department of Molecular Biosciences
School of Veterinary Medicine
University of California
Davis, California

Stanley L. Marks, BVSc, PhD, DACVIM (Internal
Medicine, Oncology), DACVN
Professor of Small Animal Medicine
Department of Medicine and Epidemiology
School of Veterinary Medicine
University of California
Davis, California
Glenna E. Mauldin, DVM, MS, DACVIM, DACVN
Western Veterinary Cancer Centre
Western Veterinary Specialist and Emergency Centre
Calgary, Alberta, Canada
Kathryn E. Michel, DVM, MS, DACVN
Professor of Nutrition
Dept of Clinical Studies-Philadelphia
Medical Director
M. J. Ryan Veterinary Hospital
School of Veterinary Medicine
University of Pennsylvania
Philadelphia, Pennsylvania
Catherine A. Outerbridge, DVM, MVSc, DACVIM,
DACVD
Assistant Professor of Clinical Dermatology
Department of Veterinary Medicine and Epidemiology
School of Veterinary Medicine
University of California
Davis, California

Sally C. Perea, DVM, MS, DACVN
Senior Scientist
P&G Pet Care Research and Development

8700 Mason-Montgomery Road
Mason, Ohio
Jon J. Ramsey, PhD
Professor
Department of Molecular Biosciences
School of Veterinary Medicine
University of California
Davis, California
John E. Rush, DVM, MS, DACVIM, DACVECC
Professor
Department of Clinical Sciences
Cummings School of Veterinary Medicine
Tufts University
North Grafton, Massachusetts
Cecilia Villaverde, BVSc, MS, PhD, DACVN,
DECVN
Servei de Dietetica i Nutricio
Fundacio Hospital Clinic Veterinari UAB
Edifici V-Campus UAB
Bellaterra, Spain
Unitat de Nutricio
Departament de Ciencia Animal i dels Aliments
Edifici V-Campus UAB
Bellaterra, Spain


Preface and Acknowledgments
overview of basic nutrition, energy requirements, and the
basics of product guides, pet foods, home-prepared diets,
and dietary supplements. The basic principles of these

foundation chapters are then underscored throughout the
remainder of the book, which addresses feeding principles
and practices in healthy dogs and cats, as well as those in
various disease states. The final two chapters provide guidance for assisted feeding in any patient using enteral and
parenteral nutrition.
We are extremely thankful to the editors and staff at
Wiley-Blackwell for their constant patience and encouragement with regard to this textbook. We are especially
grateful to Nancy Turner, Justin Jeffryes, Erica Judisch,
and Carrie Horn of Wiley-Blackwell and copy editor,
William Krol, for their efforts in seeing this book to
completion.
Without the contributions of many of our colleagues,
this book would not have been possible. We consider our
contributors to be the experts in their fields, so we are
extremely fortunate that they have been willing to share
their knowledge and experience through their respective
chapters.
None of this would have been possible without the love,
support, and guidance from many of our mentors, colleagues, friends, and family throughout the years. Each of
us would like to briefly acknowledge them.

Nutrition is rarely the first thing the practicing veterinarian
considers when making medical recommendations for
their patients. Yet eating is one of the only activities every
one of our patients does every day, thereby underscoring
the importance of the right diet and feeding practices. In
fact, appropriate food choices and feeding practices to
maintain a lean body condition are the only things in veterinary medicine proven to extend life expectancy in dogs
(Kealy et al. 2002). Given that overweight and obese cats
are at risk of developing diseases such as diabetes mellitus

and hepatic lipidosis that often shorten their life span, one
can confidently speculate that this finding may apply to
cats as well.
However, as of this writing, only about half of the veterinary schools or colleges in the United States have a
board-certified nutritionist as part of their faculty. This
means that approximately half of graduating veterinarians
never have consistent exposure to practicing nutritionists
during their didactic and clinical training so that they can
learn how to make appropriate nutritional recommendations to their patients.
The objective of this book is to provide clinically applicable nutritional advice that can be used every day in
practice. The foundation and science behind these recommendations is briefly explored, providing the reader with
extensive references for further reading if desired. Most of
the contributors to this text are nutritionists who are practicing day to day and providing practical solutions for their
patients and referring veterinarians.
We envision this text to be a resource not only for the
veterinary practitioner but also for students and residents
of multiple disciplines. Many veterinary schools and universities are now teaching a course in small animal clinical
nutrition, and this text will make a nice complement to
such lecture material. The book commences with an exploration of how nutrition can be integrated into everyday
practice in a manner that benefits both your patients and
your practice. The chapters that follow include a succinct

Andrea J. Fascetti:
From my days at the University of Pennsylvania, School
of Veterinary Medicine, I am grateful to Dr. Jim Orsini and
Dr. Mark Haskins for their insightful advice and encouragement to consider a career in research and education. I
will always be thankful to Dr. Glenna Mauldin for introducing me to the discipline of veterinary nutrition while
we were both at the Animal Medical Center in New York.
I don’t think I will ever be able to fully express my
gratitude to Dr. Quinton Rogers and Dr. Jim Morris for

serving as my graduate mentors. Together your patience,
ix


x

Preface and Acknowledgments

scientific integrity, and knowledge are characteristics I will
strive to emulate throughout my career. It has been a privilege and an honor to work with you both.
I am very thankful to be at a veterinary school where
the administration has had the vision to institute and maintain an active clinical and basic research program in nutrition. I am also fortunate to have two amazing colleagues,
Dr. Jennifer Larsen and Dr. Jon Ramsey, who share my
love of teaching, research, and service in this discipline.
Special thanks to Debbie Bee and Dr. Zengshou Yu: Your
tremendous efforts in our research facilities make much of
what we do possible.
Dr. Delaney, you are a great friend and colleague, and
I am very grateful that we worked together to make this
book a reality. It has been a long collaboration, but one
that has been enjoyable every step of the way thanks to
your tireless enthusiasm and efforts.
I think that it is through our relationships with others
that we find meaning in life, and no relationships are more
important to me than those with my family. My parents,
Shirley and Alfred Fascetti, raised me to believe that anything is possible. I am grateful for the sacrifices they made
to ensure my success and for their unwavering love and
support. I also want to express a heartfelt thanks to my
brother, Michael, and sister-in-law, Sara, for their constant
support. I am very fortunate to be able to share my passion

for learning and research with my husband, Dr. Greg Pasternack. He has been a continual source of encouragement,
support, and love throughout this process; and I can’t
imagine my life without him. To my sons, Noah and Ari,
thank you for reminding me every day that it is the little
things in life that matter and that we sometimes need to
slow down to really appreciate what we have. I also want
to say thank you to the many animals that have shared my
life and were an inspiration for my career choice: my cats
Travis, Beaver, Mario, and Simon, and my dogs, Bandit
and Hetchy.
Sean J. Delaney:
I would like to thank the following people who have supported and/or taught me over the years and by doing so
made my contribution as co-author and co-editor of this
book possible:
• The many wonderful and dedicated educators, especially Ms. Roman, my third-grade teacher, for teaching
me patience; Ms. Ziegler, my fifth-grade teacher, for
supporting my interest in science; Sister Margaret, the
Our Mother of Good Counsel elementary school principal, who instilled in me the importance of following

rules; Mr. Burghdorf, my Glendale High School English
teacher, who was one of the many folks over the years
who showed me that teaching others can be a high
calling; “Sr.” Gallagher, my AP Spanish teacher, for
introducing me to the concept of “molinos de viento” via
Cervantes’ Don Quixote; Ms. Daniels, my Glendale
Community College calculus instructor, who reminded
me of the importance of doing my homework and tutored
me so that I could successfully transfer to UCSB; Dr.
Walker, who freely gave of his time to share his passion
for veterinary medicine with an eager Boy Scout 25

years ago; Dr. Gayek of UCLA for his support in my
application to vet school after warning me about the
challenges associated with the profession; Dr. Perdue,
an equine veterinarian who generously shared his knowledge with a city kid aspiring to be a small animal veterinarian; Dr. Kuris, my UCSB invertebrate zoology
professor, for helping me get into the graduate nutrition
program while in vet school, years after many academicians would have forgotten a former undergraduate
student; Dr. Rogers, my UCD MS major professor, for
his guiding hand in my first foray into research and for
continual support for my training as a nutritionist;
Doctors Griffin, Bowers, and Kerner for their many
efforts to advance my training during my first year in
practice; Dr. Fascetti, my residency mentor, colleague,
co-author, co-editor, and friend with whom I have been
able to share my passion for clinical nutrition for a
decade; and, finally, Aniel Santos, Dr. Larsen, and Dr.
Perea, my partners at Davis Veterinary Medical Consulting, Inc., as well as the many pet lovers, veterinarians,
and veterinary nutritionist users of the Balance IT® software and products, who along with the dedicated folks
at Natura Pet Products, Inc., remind(ed) me regularly
how much I still have to learn about nutrition.
• My family starting with my great-grandparents, especially my great-grandfathers, whom I never met but who
likely provided some influence on my chosen career path
(one was an optometrist [love of medicine and science],
a cavalry officer [love of animals], a grocer and tortilla
factory owner [love of food and food making], and a
cooper [love of mastering a specialized skill]). My
grandparents, Ed, Connie, Gordon, and Mercedes, who
deeply loved my parents as children, and thus showed
my parents how to be loving to me. My parents, Mike
and Mercedes, my first teachers, a constant source of
encouragement and love, and who suggested my first job

with animals (cleaning up the neighborhood dogs’ backyards) and the idea of further training in nutrition. My
sister, Mercedes, and her family, Mark and Mason, for




Preface and Acknowledgments
their love. My beautiful, caring, and brilliant wife,
Siona, who has supported my dreams and made
many of my projects over the past 16 years better, possible, and, many times, fun. And my young and joyous
daughters, Maya and Ruby, who will hopefully one
day read this acknowledgment and remember that all of
life’s accomplishments are made possible by the gifts
others share with you. And although they are not
people, I also want to specifically thank the many kind

xi

animal companions with whom I have shared a home
over the years: Jolie (I-III), Lady, Moseley, Ginger, and
Billie.
REFERENCE
Kealy, R.D., D.F. Lawler, J.M. Ballam et al. 2002. “Effects
of diet restriction on life span and age-related changes in
dogs.” Journal of the American Veterinary Medical Association 220(9): 1315–1320.



Applied Veterinary
Clinical Nutrition

Integration of Nutrition into
Clinical Practice

Sean J. Delaney, Andrea J. Fascetti, and Paul Brentson
INTRODUCTION
A vast majority of veterinarians are forced by necessity to
concurrently be businesspeople. This reality, which for
many is undesirable, causes many clinical approaches to
be at least partially viewed through a “fiscal filter.”
Although this filter should not be fine enough to strain out
appropriate medical decisions, it certainly requires that the
economics associated with certain medical practices be
considered. Therefore, this introductory chapter will
discuss the “business” of nutrition in clinical practice, as
to not do so may prevent the reader from being able to
afford to implement the knowledge contained in the rest
of this textbook.

1

who do not choose to feed them) can easily double gross
profits from food sales with minimal additional effort or
expenditures. Theoretically, revenues and profits could be
increased more than fivefold based on the low compliance
found in a study by the American Animal Hospital Association (AAHA 2003). Thus, many practices could earn up
to $100,000 in gross profits from therapeutic pet food sales
if they engaged in full compliance.

STRATEGIES TO INCREASE PRODUCT SALES
Recommending an Effective Therapeutic Food
The surest way to increase compliance and therapeutic pet
food sales is to recommend an effective one. This sounds
simple enough but can be quite challenging in practice. To
start, one must make the correct diagnosis and select a
food that can be measurably shown to, or perceived to,
improve the pet’s condition or disease management. For
example, clients feeding a “weight loss” food that does not
result in weight loss and/or a reduction of or relief in any
comorbidity are likely to stop feeding the ineffectual food.
Similarly, trying to sell a food that a pet will not eat is
unlikely to be successful. Therefore, establishing expectations, monitoring the patient response, and providing a
variety of options is vital for client compliance.

AVERAGE REVENUE FROM FOOD
SALES AND THE POTENTIAL
In 2003, the average food revenue was 4% of total veterinary practice revenue in the United States (Landeck 2006).
At the same time, average total revenue earned by practices in 2005 was U.S. $1,078,087. Assuming that the vast
majority of food sales were for therapeutic foods that typically have a markup of 40–45%, food sales represent U.S.
$43,123, in revenue or gross profits ranging from $17,249
to $19,405. Since net income (before any owner compensation) averaged 25.5% of revenues in 2005, food sales
roughly represent between 6.3% and 7.1% of an average
practice’s gross profits. This value, while relatively significant, can be higher as practices that focus more on the
large compliance gap with therapeutic food recommendations (this gap includes both veterinarians who do not
actively recommend medically needed foods and clients

Establishing Expectations
Many clients choose not to start feeding a recommended
therapeutic food, or choose to stop feeding one, because

they do not clearly understand what is expected from the
food. Creating expectations requires going over the mechanism by which the food is to prove helpful. For example,

Applied Veterinary Clinical Nutrition, First Edition. Edited by Andrea J. Fascetti, Sean J. Delaney.
© 2012 Andrea J. Fascetti and Sean J. Delaney. Published 2012 by John Wiley & Sons, Inc.

3


4

Applied Veterinary Clinical Nutrition

BOX 1.1
Few recommendations hold as much weight with
clients about what to feed their pet as a veterinarian’s
recommendation. Many pet food companies are aware
of this and invest heavily in the veterinary community,
vying for the veterinarian’s awareness of their products
and, ideally, their recommendation. Unfortunately, the
resulting influx of generous support is increasingly
viewed by some as creating a conflict of interest for
veterinarians and resulting in a bias with dietary recommendations. This perception is increased by veterinarians who have limited recommendations beyond the
products, brands, and/or companies they stock. Therefore, the goal of this chapter is not to increase the
perception among some that veterinarians sell food just
to make more money. Instead this chapter’s goal is to
assist the veterinarian in methods to ensure they can
afford to provide the best medical care for their patients
and clients by fully integrating nutrition into their clinical practice.

clients who understand that higher dietary phosphorus can
cause progression of renal damage in kidney insufficiency,
and that most dietary phosphorus comes from protein-rich
ingredients, are less likely to feed a higher protein- or
phosphorus-containing over-the-counter food. Not surprisingly, clients (in the form of human patients) have better
retention of medical information when verbal information
is accompanied with written information (Langdon 2002).
Therefore, client handouts can be a very useful adjunct to
verbal client education. Equally helpful can be reinforcement with repetition of key points by veterinary staff at
checkout or discharge, assuming that the staff has already
become familiar with all standard client handouts. In some
practices, veterinary staff can play an instrumental role in
drafting these client handouts as they often can relate to
the lay audience and are also aware of the common questions and issues that should be addressed.
Monitoring Patient Response
Although many therapeutic foods can be quite effective,
not all foods work for every patient. A food’s failure may
be defined as simply as a patient being unwilling to eat the
food. Therefore, monitoring the response to a newly recommended food is crucial to improving compliance. Initially, the greatest risk to compliance is food refusal. Often
this can be managed with appropriate recommendations
for transitioning to the new food, as well as planned and

periodic follow-up in the form of an email, phone call, or
in-person office visit to address any issues that arise.
Follow-up is equally important to reinforce the importance
of the dietary recommendation. Recommendations that
have no follow-up are likely to be perceived as not being
as crucial or important. Finally, checking on progress provides an opportunity to discuss and select an alternative
but still appropriate food if the first recommendation does
not work. At times there can be a reluctance to perform

follow-up since it often is “unbillable” time; however,
follow-up can be tiered and veterinary support staff can be
leveraged to assist with follow-up. Many of the outbound
calls can be conducted by reception staff with elevation to
licensed veterinary technicians and the attending veterinarian as needed. This “triaging” of sorts can increase
efficiency, and often is welcomed by staff members who
feel both entrusted and empowered.
Providing a Variety of Options
Since no food will work in every situation, it is important
to have additional options for the client. A ready and specific alternative recommendation should reduce the likelihood that the client may select a food by themselves,
resulting in the potential for an inappropriate food to be
selected and the potential loss of a medically justified sale.
The tendency to stock only one “house brand”—while
convenient from an inventory management perspective—
decreases the ability to readily offer alternatives and can
lead to a perception that there is only one option, or worse
yet, that the recommendation is made solely on the basis
that that particular brand is all the veterinarian sells. Certainly, carrying every therapeutic food available (which
now number in the hundreds) is not feasible in all but a
few referral settings; therefore, a selection of foods used
for the management of diseases seen frequently at the
practice along with a willingness to special order, or even
identify direct delivery options for clients, is probably the
best approach. Additionally, the stocking of more smallersized bags can help increase the variety of foods offered
without substantially increasing the “carrying cost of
inventory.” Small bags also can be useful for a trial, and
once an acceptable option has been found a standing order
for that patient in larger sizes can be created. Such standing orders then help to increase the number of inventory
turns, thereby improving cash management. This “small
bag” approach might also assist with reducing the labor

involved in stocking larger bags as well as increasing the
storage capacity of a facility by increasing the height at
which food can be stored. Most therapeutic food manufacturers will accept return of inventory that has expired. For




Chapter 1 / Integration of Nutrition into Clinical Practice 

those manufacturers where such is not the case, this
approach can minimize “perishable shrink” by reducing
the cost of any expired bag that cannot be returned.
From the veterinary practitioner’s viewpoint, the greatest value of carrying and recommending a variety of products for the same condition can be increasing one’s
familiarity with different products. Clinical experience
with each product increases the likelihood of making the
best initial recommendation, as well as increasing one’s
comfort with changing to an alternative product if the
initial recommendation proves unsuccessful.
Recommending Therapeutic Treats
A growing category within veterinary product offerings is
therapeutic treats. These treats often pair with a “matching” therapeutic food to give the client a nutritionally
appropriate option when treating is desired. These treats
often take the form of a biscuit-shaped version of the corresponding dry kibble. Therefore, treats generally do not
offer anything novel to the nutritional management of the
condition or disease, but rather assist with compliance by
encouraging the pet’s interest in the new dietary approach
while preventing some other treat, which might be inappropriate, from being given. The same process outlined
above should be used when recommending an effective
therapeutic food.
Recommending Nutraceuticals

and Dietary Supplements
For a full discussion on this subject please see Chapter 5
on nutraceuticals and dietary supplements.
From a financial perspective, stocking certain dietary
supplements should be considered. Although the margin
on such products can vary greatly, they generally take up
much less shelf space than food and treats. Typically, products that are only sold through veterinarians should be
considered unless carrying nonexclusive products adds
overall “value” for the client due to convenience. Caution
should be taken when recommending or offering products
for sale at a premium when comparable human supplements of equal or even greater quality or potency are
available for a similar or lower price. If such products are
available from other retailers, whether “brick and mortar”
or online, it is in the best interest of solid client relations
to refer clients to that retailer, while being sure to give a
specific product and retailer recommendation for clarity
and convenience. If a product is widely available only
online, then clients are generally willing to purchase such
products directly from the veterinarian who can compete
on the basis of reduced delivery time and cost.

5

CREATING OR INCREASING REVENUE
FROM NUTRITIONAL ADVICE
Veterinarians’ time is limited for both their own continuing
education and client education. Therefore, there is an
“opportunity cost” associated with spending time on nutrition. If a veterinarian earns more income from learning
about and performing surgery, for example, than learning
about and advising on nutrition, there is a financial incentive to focus on surgery and a disincentive to focus on

nutrition. Certainly the generalist cannot pick and choose
only the aspects of veterinary medicine that are most
profitable but recognizing the potential for fiscal disparity
provides context for a discussion on nutritional advice
revenue.
Not only is veterinarians’ time limited, the value of
nutritional advice can be diluted by the perception that
they lack the expertise to make nutritional recommendations. This perception can be increased by the appearance
of bias for a particular brand or company’s food in one’s
recommendation(s) as discussed above or by a variety of
compounding factors. One of these factors is the belief that
nutrition is a pseudoscience. This belief can largely be
dispelled by ensuring that the application of nutrition is
testable. If a veterinarian forgoes “testing” a nutritional
recommendation by neglecting to monitor patient response,
then one can hardly blame clients for feeling that their own
beliefs about feeding are equally correct. This can be especially true when inappropriate feeding regimens may not
manifest as problems immediately. Unfortunately, clients
are not aware that veterinarians who recommend a particular therapeutic food often choose to do so because such
recommendations are based on scientifically proven strategies or have, in fact, actually been tested for the condition
or disease in question. Certainly many therapeutic veterinary foods are in need of additional clinical study (Roudebush et al. 2004); however, they are largely based on very
sound science. Clients may also believe that nutrition is
simple, after all, as they likely have successfully fed themselves for most of their lives. While providing adequate
calories to meet (and often exceed) caloric requirements
is thankfully relatively simple in the developed world,
ensuring that the nutrients delivered with these calories are
optimal is not always straightforward. The field of nutrition is also beset by self-proclaimed “nutritionists” who
have little, if any, medical or nutritional training. At the
same time, many veterinarians received an abridged veterinary nutrition education in veterinary school or college,
and subsequently little additional education postgraduation. This has led to a level of discomfort for many on the

subject, rather than the expertise or mastery many feel on


6

Applied Veterinary Clinical Nutrition

other veterinary medical topics. Thus, a climate exists
where veterinarians acquiesce in the nutritional management of their patient, or at least fail to take a very active
role unless intervention is absolutely necessary, such as in
the cases of hepatic lipidosis or food allergy. Therefore,
the following recommendations are for practitioners who
take, or wish to take, an active role in the management of
all their patients’ diets.
Nutritional Advice for Healthy Patients
The number one obligation of the veterinarian when advising clients about an appropriate diet for a healthy pet is to
ensure that it maintains an ideal body condition (please see
Chapter 9 on the nutritional management of body weight
for further discussion on this topic). Keeping dogs lean is
the only proven intervention to increase both the quantity
and quality of life (Kealy 2002). Although unproven in
cats, caloric restriction has repeatedly been shown to
extend lifespan in mammals (Sohal 1996; Barja 2004) and
would thus be expected to do so in cats as well. Therefore,
avoidance of overweight and obesity should be a goal for
the feeding of every patient a practitioner sees.
In addition to weight management, an appropriate food
should have an appropriate nutritional adequacy statement
for the patient. This means that the food is appropriate for
the patient’s species, age, and reproductive status if the

patient is a reproducing female. As would be expected,
many foods meet these criteria, and further discrimination
should be based on both client and patient preference. For
a client, convenience, cost, and personal nutritional philosophy may be important in deciding which foods they
select. For patients, ingredients and their associated impact
on palatability along with texture (i.e., dry, wet, semimoist) and macronutrient distribution (e.g., protein, fat,
and carbohydrate percentages) play key roles in the foods
they choose to consume when given a choice. Recognizing
that no one food can meet all of these preferences and
needs helps to give a perspective on why so many brands
and varieties exist and what needs to be considered when
advising clients about food options.
It can often be useful to have the client select a few
foods they like and review these products with them
during wellness visits. This method helps to narrow down
the field of foods to consider and often provides an opportune time to exhibit some expertise, as well as an openness
to discuss nutrition. If the client has no preconceived
notions, then it should be suggested that companies be
recommended that actually make their own food and
employ nutritionists. Such companies are more likely to
have the technical expertise to address any issues that

might arise, as well as the knowledge to make nutritionally
sound and safe products.
From a fiscal perspective, such a review of potential
foods or nutritional recommendations should not result in
a unique charge for the client but rather should be captured
in the office visit fee. This assumes that any requested
review does not require additional research and analysis
outside the office visit. In cases where it does, time should

be charged either on an agreed upon flat rate or on a perunit of time basis up to some pre-established maximum.
Clients who do not wish to pay for the veterinarian’s time
should be advised that the evaluation is accordingly
limited. Some veterinarians find it difficult to charge for
researching an issue but if the research is specific for a
patient, most clients will accept that it is appropriate when
it is raised with confidence and the resolve that one’s
professional time is of value. It should be noted that a
veterinarian’s review often involves dietary supplements,
as the variety of novel and often unconventional supplements greatly exceeds the number of pet foods, which are,
in practice, more closely regulated.
At times, veterinarians have difficulty distinguishing the
continuing self-study required as a veterinary medicine
professional and the work involved in researching unique
supplements or foods. The best way to distinguish this in
one’s own mind is that the veterinarian is not charging for
the knowledge on how to interpret and find information,
but rather the act of applying their critical thinking and
scientific knowledge to the patient’s and/or client’s specific products and/or needs. An analogy might be that one
does not charge for the time it takes to learn a surgical
procedure but rather charges for using the resulting skills
and knowledge to perform the surgery on particular
patients.
Nutritional Advice for Unhealthy Patients
Most, if not all, diseases and conditions can be affected by
diet. For some conditions and diseases this may simply be
related to the adverse effects of inadequate caloric intake
associated with hyporexia or anorexia of illness. For many
other conditions and diseases, there are specific nutritional
management interventions that are the subject for most of

the rest of this textbook. For these sick patients, it is generally easier to generate revenue through veterinary therapeutic foods, treats, and/or parenteral solution sales, or
through procedures (such as feeding tube placement) to
provide compensation for the specific nutritional guidance
and/or advice involved in their selection. However, it
should be noted that for board-certified veterinary nutritionists who consult on cases, but who may not share in




Chapter 1 / Integration of Nutrition into Clinical Practice 

or receive credit for such sales or procedures, one should
expect to compensate them specifically for their time for
such advice. The veterinarian should be able to realize
adequate revenue through product sales, nutrition-related
procedures, and nutritional counseling to justify the full
integration of nutrition into clinical practice to the benefit
of healthy and unhealthy patients.
BOX 1.2  WHAT IS A BOARD-CERTIFIED
VETERINARY NUTRITIONIST?
A board-certified veterinary nutritionist is a licensed
veterinarian who has undergone additional education
and training in the field of veterinary nutrition. This
typically involves additional graduate coursework and/
or graduate degrees in nutrition along with residency
training at the secondary or tertiary referral level under
the supervision of a board-certified veterinary nutritionist. Following completion of residency training and
publication of animal nutrition related research in peerreviewed scientific journals, candidates for certification
often submit case reports along with their credentials
to indicate their mastery of the discipline. Upon acceptance of these materials, candidates are allowed to sit

for a multipart multiday intensive examination on
veterinary nutrition. Candidates who pass all parts of
the examination and are voted into the specialty can
refer to themselves as board-certified veterinary nutritionists or “diplomates.” There are currently two veterinary nutrition specialty colleges in the world, the
American College of Veterinary Nutrition (ACVN™;
www.acvn.org; also the basis for most of the summary
above) and the European College of Veterinary Comparative Nutrition (ECVCN). Members of the ACVN
can be found in North America, the Carribean, the
United Kingdom, Europe, and Australasia, while most
ECVCN diplomates are found in Europe. The majority
of diplomates are employed in academia, with the
remainder in industry, private practice, or the government. Attending veterinarians and specialists in other
disciplines typically refer cases to diplomates of the
ACVN or ECVCN in academia or at large referral
hospitals.

7

It is expected that the reader of the rest of this textbook
should be able to better advise clients about the nutritional
management of unhealthy patients and recognize when
referral to a board-certified veterinary nutritionist is indicated. It is recommended that when a board-certified veterinary nutritionist needs to be consulted, the referring
veterinarian charges for their time specifically if they act
as the “conduit” for the consultation, similar to how clinical pathology reports may be handled. Accordingly, many
veterinary nutritionists and veterinary nutrition consulting
services will bill the referring veterinarian directly rather
than the client so that the referring veterinarian can apply
the necessary charges for their time to the client’s final
invoice. Occasionally, product sales and consulting fees
will not be available as methods to compensate the generalist or referring veterinarian. In those cases, a veterinarian

should charge for their time or set up an office visit specifically to address an unhealthy patient’s nutritional needs
and educate the client accordingly.
REFERENCES
AAHA (American Animal Hospital Association). 2003. The
Path to High-Quality Care. Lakewood, CO: American
Animal Hospital Association Press.
Barja, G. 2004. “Aging in vertebrates, and the effect of caloric
restriction: A mitochondrial free radical production-DNA
damage mechanism?” Biological Reviews of the Cambridge Philosophical Society 79(2): 235–251.
Kealy, R., D. Lawler, J. Ballam et al. 2002. “Effects of diet
restriction on life span and age-related changes in dogs.”
Journal of the American Veterinary Medical Association
220(9): 1315–1320.
Landeck, E. 2006. Financial & Productivity Pulsepoints, 4th
edition. Lakewood, CO: American Animal Hospital Association Press.
Langdon, I., R. Hardin, and I. Learmonth. 2002. “Informed
consent for total hip arthroplasty: Does a written information sheet improve recall by patients?” Annals of The Royal
College of Surgeons of England 84(6): 404–408.
Roudebush, P., T. Allen, C. Dodd et al. 2004. “Application of
evidence-based medicine to veterinary clinical nutrition.”
Journal of the American Veterinary Medical Association
224(11): 1765–1771.
Sohal, R.S., and R. Weindruch. 1996. “Oxidative stress,
caloric restriction, and aging.” Science 273(5271): 59–63.



Basic Nutrition Overview

Sean J. Delaney and Andrea J. Fascetti

INTRODUCTION
While the vast majority of this text is focused on the
application of veterinary nutrition in clinical practice, this
chapter centers around basic nutrition. Although the
chapter is not exhaustive, it should provide enough depth
to enable the applied veterinary clinical nutrition portion
of the text to be used with a strong understanding of key
underlying nutrition principles.

2

3.5 kcal/gram (g) for protein, 8.5 kcal/g for fat, and
3.5 kcal/g for carbohydrate. These values are slightly
lower than those used for human foods (i.e., 4 kcal/g for
protein, 9 kcal/g for fat, and 4 kcal/g for carbohydrate) due
to the typically lower digestibility of ingredients commonly used in pet food (assumed average apparent digestibility for protein is 80%, 90% for fat, and 84% for
carbohydrate).
All three macronutrients’ energy must ultimately be used
to create adenosine triphosphate (ATP) through phosphorylation as ATP is the “energy currency” of the body. For
protein this means conversion to glucose via gluconeogenesis with ATP generation via glycolysis and the Krebs or
tricarboxylic acid (TCA) cycle during cellular respiration.
Gluconeogenesis is the metabolic pathway by which glucogenic amino acids (lysine and leucine excluded) are
converted to glucose. Glucose is then converted to pyruvate
during glycolysis, which produces ATP and the potential
for more ATP if pyruvate enters the TCA cycle. For fat,
ATP is typically produced via beta oxidation where ATP
is produced from acetyl-CoA in the TCA cycle. Generated
glucose or glucose from the breakdown of glycogen or
starch and from sugars in the diet can be used to generate
ATP via glycolysis and the TCA cycle as well. It should

be noted that the TCA cycle produces substantially more
ATP than glycolysis that solely generates pyruvate, but the
TCA cycle cannot occur in the absence of oxygen, and thus
the importance of breathing and the intake of oxygen in
the production of energy by the body. However, lactic acid
produced during anaerobic glycolysis (typically in muscle)
can be converted to glucose by the liver in the Cori cycle.

ENERGY
After oxygen and water, the next most important component for any animal to gain from its environment is energy.
Energy is available from only three types of macronutrients: protein, fat, and carbohydrate. Each of these macronutrients provides a specific amount of energy that can be
measured in kilocalories or kiloJoules or Calories. The
amount of energy is determined by knowing the mass of
the macronutrient in a food or diet and the corresponding
energy conversion factor. Energy conversion factors are
standardized values for the amount of energy available
from a gram of the specified macronutrient. Currently the
most commonly used unit for measuring energy is the preInternational System (SI) metric unit, kilocalories (kcal),
which is equal to “Calories” (with an uppercase “C”) seen
on human food labels in certain countries like the United
States (1,000 kcal is often written as “Mcal,” the abbreviation for Megacalorie). The less commonly used SI unit for
energy, kiloJoule (kJ), is converted from kilocalorie or
Calorie by multiplying by 4.185 (1 kcal or Calorie = 4.185
kJ). For pet foods, the energy conversion factors that are
used are referred to as modified Atwater factors. They are

Applied Veterinary Clinical Nutrition, First Edition. Edited by Andrea J. Fascetti, Sean J. Delaney.
© 2012 Andrea J. Fascetti and Sean J. Delaney. Published 2012 by John Wiley & Sons, Inc.

9

10

Applied Veterinary Clinical Nutrition

It is also worth noting that any protein consumed in
excess of needs for anabolic pathways such as protein
synthesis will be used as a source of energy as there is no
body store for amino acids. This is different from excessive fat, which will be stored in adipose tissue, and glucose,
which can be stored as glycogen. All protein, fat, and
carbohydrate that exceed energy needs can end up being
stored in adipose tissue. Unlike glycogen, theoretically
there is no limit in the amount of energy that can be stored
in adipose tissue, although there may be adverse health
consequences with extreme levels of storage as seen with
obesity.
Energy Requirements
Dogs and cats eat to meet their energy needs. Unlike some
species that have “specific hungers” for certain nutrients
(e.g., ruminants for certain minerals), dogs and cats will
not seek out certain foods or nutrients in the face of specific nutrient deficiencies. This makes sense teleologically
for a carnivore like the cat or a species that has some
carnivorous roots or tendencies like the dog. From an
evolutionary perspective, there was (or is) no penalty for
the inability to seek out specific nutrients, as the search for
and consumption of specific evolutionary prey species
should inherently provide the right balance and types of
essential nutrients. The only risk for deficiency is really
related to inadequate consumption of prey. Therefore,

determining a dog’s or cat’s energy requirement is very
important.
Pet foods are generally formulated with a certain amount
of nutrient per unit of energy. This ensures that essential
nutrients are provided to the dog or cat at appropriate
levels when fed to meet the pet’s energy requirement.
Consequently, this means that pets that are fed such foods
below their energy requirement are in danger of nutritional
deficiencies. Pets fed above their energy requirement are
in danger of receiving excessive amounts of nutrients (this
latter case really only represents a risk of obesity or potentially urolithiasis). For further discussion on determining
a dog’s or cat’s energy requirement as well as different
energy terms such as gross energy, digestible energy,
metabolizable energy, and net energy, the reader is referred
to Chapter 3 on energy requirements.
ESSENTIAL NUTRIENTS
Essential nutrients are organic compounds and nonorganic
elements that cannot be produced by the body but are
needed to support life. Essentiality is different for different
species, although for mammalian species such as the dog
and the cat, there are many similarities in what is essential;

differences are mainly in the amount needed. In addition,
there are nutrients that are required only at certain times
or under the right circumstances. These nutrients are
referred to as “conditionally essential nutrients.” An
example of a conditionally essential nutrient that also
exemplifies interspecies differences in essentiality is the
amino acid taurine. In premature human infants, taurine,
which is essential for cats but not dogs, is conditionally

essential. Premature neonates are not metabolically mature
enough to produce adequate amounts of taurine from the
normal sulfur amino acid precursors, methionine and
cystine.
Cystine is a good example of another category of nutrients that are called “sparing.” Sparing nutrients are able to
decrease the amount of essential nutrient needed in the
diet. Thus, cystine decreases by up to 50% the amount of
methionine needed in the diets of both dogs and cats.
Cystine is not considered essential as it is not needed in
the diet when adequate methionine is present. Methionine
itself is sparing for choline as it can also serve as a source
of methyl groups. Therefore, methionine is both an essential and a sparing nutrient. The other commonly encountered sparing nutrient is tyrosine, which spares the amino
acid phenylalanine and has been shown to be important in
maximal melanin synthesis in black cats (Yu 2001).
List of Essential Nutrients for Dogs and
Cats by Group
1. Protein
a. Amino Acids
i. Arginine
ii. Histidine
iii. Isoleucine
iv. Leucine
v. Lysine
vi. Methionine (spared by cystine)
vii. Phenylalanine (spared by tyrosine)
viii. Threonine
ix. Tryptophan
x. Valine
xi. Taurine (cat, not dog)
2. Fat

a. Linoleic acid
b. Arachidonic acid (cat, not dog)
c. +/− Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)
3. Minerals
a. Macrominerals (required at ≥100 mg/Mcal, or
approx. ≥400 ppm)
i. Calcium (Ca)




Chapter 2 / Basic Nutrition Overview

ii. Phosphorus (P)
iii. Magnesium (Mg)
iv. Sodium (Na)
v. Potassium (K)
vi. Chloride (Cl)
b. Trace minerals or microminerals (required
at < 100 mg/Mcal, or approx. < 400 ppm)
i. Iron (Fe)
ii. Copper (Cu)
iii. Zinc (Zn)
iv. Manganese (Mn)
v. Selenium (Se)
vi. Iodine (I)
4. Vitamins
a. Fat-soluble vitamins
i. Vitamin A, retinol
ii. Vitamin D3, cholecalciferol

iii. Vitamin E, α-tocopherol
iv. +/− Vitamin K3, menadione (also vitamin K1,
phylloquinone) (cat, not dog)
b. Water-soluble vitamins
i. Thiamin, vitamin B1
ii. Riboflavin, vitamin B2
iii. Pyridoxine, vitamin B6
iv. Niacin, vitamin B3
v. Pantothenic acid, vitamin B5
vi. Cobalamin, vitamin B12
vii. Folic Acid, vitamin B9
viii. Biotin, vitamin H or B7
ix. Choline
As cited in the list above, the cat as a true carnivore
requires nutrients that the dog as an omnivore does not.
The following is a list of the cat’s unique metabolics:
• Unable to convert carotenoids to adequate vitamin A/
retinol
• Inadequate synthesis of vitamin D (even if hairless and
exposed to sunlight/UV radiation)
• Unable to use tryptophan for niacin synthesis
• Unable to synthesize adequate amount of taurine from
sulfur amino acids, methionine, and cysteine
• Unable to synthesize citrulline (needed for the urea
cycle; as a result, a single arginine-free but proteincontaining meal can cause death)
• Glutamic acid (high in plants and low in animals)
intolerance
• Reduced ability to conserve nitrogen
• Reduced ability to desaturate long-chain PUFAs (therefore, needs arachidonic acid since cats are unable to
make it from linoleic acid)

11

• Metabolically adapted to low carbohydrate diet (e.g.,
less activity of enzymes involved in glucose metabolism
like glucokinase, which is the enzyme needed for the
first step in deriving ATP from glucose)
Protein and Amino Acids
Protein provides nitrogen and amino acids in the diet.
Amino acids are either essential or nonessential (aka dispensable). Essential amino acids for dogs and cats include
arginine, which is not essential for humans; therefore, arginine or a protein rich in it (e.g., whey) may be added to
human enteral diets when fed to dogs or cats. In addition
cats require taurine (as noted above), unlike dogs and
humans who can make adequate amounts from sulfur
amino acid precursors. In commercial pet foods, taurine,
like several other commonly limiting amino acids, is supplied as a purified amino acid. Essential amino acids
(except taurine) can potentially come in two isoforms:
L-amino acids and D-amino acids. L-amino acids are the
commonly encountered form, while D-amino acids are
less common and at times less available or unavailable for
use by the body. For example, D-lysine cannot be used by
dogs and cats the way L-lysine can be. However,
D-methionine can be used to meet up to 50% of the methionine requirement. Therefore, one should not see a dog or
cat food supplemented with D-lysine but can see one supplemented with DL-methionine.
Methionine, in addition to enabling urine acidification,
is also used in pet foods that derive a large portion of their
protein content from legumes such as soy, which are “limiting” in sulfur amino acids. Limiting means that the particular essential amino acid is closest to the requirement
of the species. Therefore, when the species’ requirement
for that essential amino acid is met, all other essential
amino acids the protein provides are in excess of the

requirement. Thus, it can be more cost effective for a pet
food manufacturer to add a single limiting amino acid in
its purified form (likely to be a DL-amino acid) than to
simply increase the amount of protein-rich ingredients to
meet a single amino acid requirement. In addition to sulfur
amino acids that are limiting in legumes, lysine is typically
limiting in grains. Ancestral peoples recognized this in a
limited way and combined legumes and grains (e.g., “rice
and beans”) in meals to ensure a complete and balanced
amino acid profile.
There are several ways to assess an ingredient’s or a
food’s protein content. The typically required and reported
crude protein value does not give any indication of how
well a food will meet a dog’s or cat’s protein or amino acid
requirements, although higher crude protein values are