86 Canine Sports Medicine and Rehabilitation
Some hypothesize that use of antioxidant
cocktails has the ability to quench free radicals
more effectively than single agents, and there
have been two separate studies examining this
concept. The first study used a mixture of 475
IU of alpha‐tocopherol, 706 mg of vitamin C,
and 5.1 mg of beta‐carotene per kilogram of
food for 3 weeks. The other study used 400 IU
of alpha‐tocopherol, 3 mg of beta‐carotene, and
20 mg of lutein per kilogram of food for 4 weeks
(Baskin et al., 2000; Piercy et al., 2000). Both
studies found no association with decreased
muscle damage as evaluated by CK and limited
antioxidant potential during recovery, while
serum concentrations increased for all of the
supplemented antioxidants. Other single agent
studies examining astaxanthin (a carotenoid)
and blueberries (flavonoids) have shown
increased antioxidant potential in serum with
no association with improved performance
(Dunlap et al., 2006; Reynolds et al., 2010). Based
on the limited information and lack of benefits
for performance, supplementation is not rec-
ommended at the time of writing.
Feeding strategies in canine athletes
Feeding patterns can affect performance.
Frequency and time of feeding become impor-
tant not only to decrease fecal bulk, but also to
maximize metabolites that are typically used
for the activity. Sprinting dogs running for less
than 10 minutes during a single bout of exercise
will benefit from modest feed restriction
24 hours prior to exercise (decreasing total meal
by 20%) during single‐day events to decrease
fecal bulk. Although some advocate small
carbohydrate meals before exercise to provide
glucose as fuel for impending exercise, there
are few data to support this strategy in dogs
(Hawley et al., 1997). Sprinting and intermedi-
ate athletes, particularly agility and field trial
dogs that perform multiple bouts of exercise in
a day, may benefit from carbohydrates in small
amounts immediately after a bout of exercise
when expected to undertake another bout
within 2–3 hours. If repetitive bouts are close to
together this may not be advised to avoid
vomiting or regurgitation (Hill, 1998). During
multiple days of competition, post‐exercise gly-
cogen repletion is advised within 30 minutes of
the last bout of exercise for the day to replenish
muscle glycogen.
Intermediate athletes exercising typically
once a day for 20 to 120 minutes typically rely
on both glycogen and fat for energy generation;
therefore it is recommended that they be fed
diets moderate in fat (50% of ME) and carbohy-
drate (20% ME), and high in protein (30% ME).
This diet allows adequate muscle glycogen
repletion during training and helps increase
mitochondrial volume. Fat will be used as a
primary fuel at rest and within 20 minutes of
exercise allowing for glycogen sparing when
these athletes are asked to run above 60% of
Vo2 max. These athletes will benefit from post‐
exercise carbohydrate supplementation to
restore muscle glycogen concentrations par-
ticularly during multiple‐day events (Reynolds
et al., 1997; Wakshlag et al., 2002b). In an effort
to promote fat use and lipolysis, feeding a
single meal each day may be advantageous
with that meal about 2 hours post exercise.
Modest feed restriction (20% of meal) the day
before racing will prevent defecation during
exercise, promote lipolysis, and decrease fecal
bulk (Hill et al., 1999; Toll & Gillette, 2010). Care
should be taken not to feed larger meals imme-
diately after exercise particularly in larger,
deep‐chested breeds prone to gastric dilatation
and volvulus.
Endurance athletes (i.e., Foxhounds and sled
dogs) tend to be fed one or two large meals each
day during training, which will typically need
to be approximately 300–500 kcal/kg0.75 during
heavy training (Ordway et al., 1984; Musch
et al., 1985; Decombaz et al., 1995; Hinchcliff
et al., 1997b). These meals should be approxi-
mately 30% ME protein, 60–70% ME fat, and
negligible carbohydrate (<10% ME). The ration
will likely comprise over 50% commercial dog
food, with the rest as high‐fat meat. This is
necessary to achieve the caloric density and
digestibility needed for competitive racing and
hunting. As training intensifies there are back‐
to‐back runs of 60 miles or greater on different
terrains, thus increasing caloric demands.
These are often met by using high‐fat meats in
small chunks during rest periods on the trail.
Little is known about the nutrient composition,
but these tactics appear successful during
competitive endurance sled dog training and
racing. During racing, dogs are fed significantly
larger meals during 4–8‐hour or longer rest
stops. Since carbohydrate is not a primary fuel
for exercise in these athletes, post‐exercise
carbohydrate supplementation for glycogen