Front Matter

78 Canine Sports Medicine and Rehabilitation

and there is a greater chance for body condition
loss during extended activity, a body condition
score of 4–5 may be ideal before competition
due to the potential for weight loss during
competitive racing (Hinchcliff et al., 1998).

Nutrition for performance

Dietary protein—beyond energy

In addition to essential amino acids supplied in
the diet (Table  4.1), dogs can synthesize non‐
essential amino acids through amidation,
deamination, and carboxylation reactions that
convert carbon precursors and essential amino
acids into nonessential amino acids. Nitrogen
retention studies rely on nitrogen balance as the
measure of adequacy; however, most canine
nitrogen retention studies have never exam-
ined the consequences for lean mass. The NRC
states that only 20 g/1000 kcal of protein is min-
imally required for maintenance, equating to
approximately 10–12% crude protein in a typi-
cal dry commercial product.
Dietary protein helps maintain muscle integ-
rity and appropriate total protein, albumin and
red blood cell status. The hematocrit and serum
albumin tend to decrease with training and rac-
ing, and such decreases appear to be a result of
overtraining syndrome (Kronfeld et al., 1989;
Wakshlag et al., 2010). This syndrome can be
correlated to the acute phase response whereby
the liver changes its protein production profile
to proteins such as haptoglobin and C‐reactive

protein, possibly at the expense of albumin

(Wakshlag et al., 2010; Kenyon et al., 2011). The

mechanism for these changes is poorly under-

stood, but is thought to be due to acute inflam-

mation of exercise and potential cytokine

alterations resulting in accompanying decreases

in red blood cell counts (Kronfeld et al, 1989;

Wakshlag et al., 2010; Kenyon et al., 2011).

Adequate protein intake may be helpful in

ameliorating this condition.

Studies examining protein consumption

and its role in maintaining red blood cell

counts and hematocrit in training sled dogs

have postulated that approximately 30% of

the metabolizable energy (70–80 g pro-

tein/1000 kcal) should come from highly

digestible animal‐based protein (Kronfeld

et al., 1989). Four groups of sprint racing sled

dogs exercising approximately 60 km in field

work per week, plus treadmill training each

week, on four diets comprising 18% ME pro-

tein (48 g/1000 kcal), 24% ME protein (60

g/1000 kcal), 30% ME protein (75 g/1000

kcal), and 36% ME protein (90 g/1000 kcal)

from an initial diet of approximately 26% ME

protein were examined. After 12 weeks of

feeding each diet, routine complete blood

counts, serum chemistries, Vo2 max and physi-

cal assessment were performed. Six of eight

dogs in the lowest protein diet (18% ME)

sustained musculoskeletal injuries and

showed a 25% drop in Vo2 max. Dogs in the

highest protein group displayed a 10%

increase in plasma volume, and there was a

linear correlation between hematocrit, hemo-

globin, and total blood volume and protein

intake (Reynolds et  al., 1999). Querengaesser

Figure 4.5 Appropriate body condition score (BCS) for a
working sled dog—current BCS 4 of 9. Note that the
musculature is defined and ribs are visible, which may
not be the case in heavier coated dogs.

Table 4.1 Essential and non‐essential amino acids

Dietary essential amino

acids

Dietary non‐essential

amino acids

Isoleucine

Leucine

Lysine

Methionine

Phenylalanine

Tryptophan

Valine

Histidine

Threonine

Arginine

Alanine

Tyrosine

Aspartic acid

Asparagine

Glutamine

Glutamic acid

Glycine

Serine

Cysteine

Proline