Front Matter

Chapter 4 The Role of Nutrition in Canine Performance and Rehabilitation 75

calorimeter generates approximately 5.24 kcal.
Fat generates 9.16 kcal/g, and carbohydrate
4.26 kcal/g. This is the gross energy (GE) of
the substrate, and does not take into account
the energy lost in feces due to incomplete
digestion. This loss is reflected in the digestible
energy (DE). Metabolizable energy (ME) as
reported on pet food labels takes into account
energy lost in urine, deamination of amino
acids, and gases. ME is assumed to be signifi-
cantly less than the GE or DE. Protein and
carbohydrate are generally given a value of
4 kcal/g, and fat 9 kcal/g as calculated by the
Atwater equation when evaluating human
foods (Box  4.1). This equation is modified to
adjust for slightly less digestible ingredients in
a manufactured pet food, making protein and
carbohydrate approximately 3.5 kcal/g, and
fat 8.5 kcal/g (National Research Council,
2006a, 2006b).

Body condition, energy utilization at rest
and during exercise

The National Research Council (NRC) has set
forth energy and nutrient requirements for
dogs. Two equations are used to represent rest-
ing energy requirement (Box  4.2). The linear

equation closely mimics the results obtained

from the exponential equation until the sub-

ject’s weight reaches 25 kg, when the linear

equation diverges, overestimating the energy

requirements needed at rest. A multiplication

factor of 1.0–2.0, based on activity, is applied to

the linear equation’s initial calculation of

(30 × kg body‐weight) + 70, which is considered

the resting energy requirement (RER). The

exponential equation is (kg body‐weight)0.75

multiplied by 70, which is considered the

resting energy requirement. For activity, this

multiplication factor is increased up to approxi-

mately 140 to calculate maintenance energy

requirements (MER) for active pet dogs. These

equations are starting points for patients under-

going rehabilitation. When integrating exercise

into a therapeutic plan, 20–30 minutes of reha-

bilitation activity 3–4 times a week would likely

add in a negligible energy increase and should

be recognized when making a diet plan for a

rehabilitation patient.

Increasing physical activity and the effects of

training have been extensively studied in dogs

during treadmill exercise. The maximum oxy-

gen consumption during exercise (Vo2 max)

reflects the energy that can be generated via

oxygen utilization in the mitochondrial ETC.

An average 20‐kg Foxhound or Alaskan sled

ATP

ADP

Glucose

Hexokinase

Glucose-6-

phosphate

Glucose-1

phosphate

Glucose

Glucose

Glucose

Glycogen

synthase

PPi

UTP

glucoseUDP- UDP

Phospho-

glucomutase

Glucose

uridyl

tansferase

Figure 4.3 Glycogenolysis occurs when excessive glucose is taken into cells as reserve glucose stores, and is
eventually broken down for glucose when needed. UDP, uridine diphosphate; UTP, uridine triphosphate.