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Eﬀect of dietary fat source and exercise on odorant-detecting
ability of canine athletes
Eric K. Altom
, Gary M. Davenport
, Lawrence J. Myers
, Keith A. Cummins
Department of Animal and Dairy Sciences, College of Agriculture, Auburn University, AL 36849-5415, USA
Department of Anatomy, Physiology, and Pharmacology, College of Veterinary Medicine, Auburn University, AL 36849, USA
Accepted 13 February 2003
Eighteen male English Pointers (2–4 years of age, 23:94 0:54 kg body weight) were allotted to three diet and two physical
conditioning groups to evaluate the eﬀect of level and source of dietary fat on the olfactory acuity of canine athletes subjected to
treadmill exercise. Diet groups (6 dogs/diet) consisted of commercially prepared diets (minimum of 26% crude protein) containing
12% fat as beef tallow (A), 16% fat provided by equivalent amounts of beef tallow and corn oil (B), or 16% fat provided by
equivalent amounts of beef tallow and coconut oil (C). This dietary formulation resulted in approximately 60% of the total fatty acid
being saturated for diets A and C, while approximately 72% of the total fatty acids were unsaturated in diet B. One-half of the dogs
within each dietary group were subjected to treadmill exercise 3 times per week for 30 min (8.05 km/h, 0% grade) for 12 weeks. All
dogs were subjected to a submaximal exercise stress test (8.05 km/h, 10% slope for 60 min) every four weeks beginning at week 0.
Olfactory acuity was measured utilizing behavioral olfactometry before and after each physical stress test. Non-conditioned (NON)
dogs displayed a greater decrease (P<0:05) in olfactory acuity following exercise, while physically conditioned (EXE) dogs did not
show a change from pre-test values. A diet by treatment interaction (P<0:10) was detected over the course of the study. NON dogs
fed coconut oil had decreased odorant-detecting capabilities when week 4 values were compared with week 12 values. Feeding a diet
that is predominately high in saturated fat may aﬀect the odorant-detecting capabilities of working dogs. Additionally, these data
indicate that utilization of a moderate physical conditioning program can assist canine athletes in maintaining olfactory acuity
during periods of intense exercise.
Ó2003 Elsevier Science Ltd. All rights reserved.
Keywords: Dietary fat; Canine; Athlete; Odorant; Exercise; Olfaction; Fatty acid; Behavioral olfactometry
Acceptable performance of many working canines is
highly dependent on the olfactory acuity of the animal.
Currently, working canines provide a variety of services
to our society including the detection of narcotics, ex-
plosives, and other contraband. Additionally, these ca-
nine athletes are utilized in outdoor sporting events such
as hunting and ﬁeld trial competitions (Holloway, 1961).
Olfactory acuity is measured as the lowest concentration
of a selected odorant that can be detected by an or-
ganism. The olfactory acuity of dogs is exceptional
based on their ability to detect compounds that range in
concentrations from 1016 to 1018 M/L (Moulton and
Marshall, 1981; Myers, 1991a). Although limited re-
search is available, conditions such as canine distemper
(Myers et al., 1988a) and canine parainﬂuenza virus
infections (Myers et al., 1988b) may alter canine olfac-
tory acuity. Other clinical trials suggest that olfactory
sensitivity may be aﬀected by hypothyroidism, seizure
disorders, diabetes mellitus and head trauma (Myers,
Trainers have traditionally utilized high carbohydrate
diets in an eﬀort to maintain acceptable performance of
canine athletes. This practice is based on reports of en-
hanced levels of performance when humans athletes
consume high carbohydrate diets (Brotherhood, 1984;
Research in Veterinary Science 75 (2003) 149–155
Corresponding author. Fax: +1-334-844-1519.
E-mail address: email@example.com (K.A. Cummins).
Present address: Research and Development, The Iams Company,
P.O. Box 189, Lewisburg, OH 45338, USA.
0034-5288/$ - see front matter Ó2003 Elsevier Science Ltd. All rights reserved.
Coyle, 1992). In contrast, research using canine athletes
has shown several beneﬁcial eﬀects of feeding increased
dietary fat on physical performance. Dietary fat during
exercise spares blood glucose and muscle glycogen re-
serves (Kronfeld et al., 1994). Reynolds et al. (1995)
reported that trained sled dogs fed high fat diets relied
less on glucose oxidation to maintain intense physical
activity compared with sled dogs fed a high carbohy-
drate diet, and were able to sustain the intensity level of
physical activity for a longer period of time. While in-
creased dietary fat is a proven performance enhancing
tool in canine athletes, it is not known whether the di-
etary fat level and (or) dietary fatty acid composition
aﬀects olfactory acuity and odorant-detecting capabili-
ties of dogs.
Clandinin et al. (1985) reported that fatty acid con-
tent of the intestinal mucosa and adipose tissue was al-
tered by dietary fat consumption. Foot et al. (1983)
indicated that nutritionally adequate diets containing
various dietary fat sources altered the fatty acid content
and composition of lipids in the brain. Changes in
neurocellular membranes can alter the activity of lipid-
dependent enzymes required for neurotransmission
(Gerbi et al., 1994, 1993). Therefore, it is plausible that
altering the ratio of dietary saturated and unsaturated
fatty acids will alter the fatty acid composition of the
nasal epithelium of canine athletes resulting in altered
olfactory function. This hypothesis is based on research
that indicates diﬀerent sources of dietary fat alter the
fatty acid composition and functionality of various cel-
lular membranes (Campbell and Dorn, 1992; Periago
et al., 1990; Sebokva et al., 1990). No experiments have
been published that have evaluated the eﬀects of dietary
components on the odorant-detecting capabilities of
canine athletes. Therefore, the objective of this study
was to investigate the eﬀects of dietary fat (source and
level) and physical conditioning on the olfactory acuity
of canine athletes subjected to treadmill exercise.
2. Materials and methods
Eighteen healthy, performance bred, male pointers
(2–4 years of age, 23:94 0:54 kg body weight) were
selected from kennels from across the Southeast region
of the United States. All dogs received complete physical
examinations by the project clinician and were pro-
nounced to be in normal health prior to entering the
study. No dog had received regular physical condition-
ing or ﬁeld training for at least 6 months prior to initi-
ation of the study. Dogs were housed individually in
USDA approved kennel facilities located at the Auburn
University College of Veterinary Medicine campus for
the duration of the study. All procedures were pre-ap-
proved by the Institute Animal Care and Use Commit-
tee for Auburn University and were in accordance with
the Guide for the Care and Use of Laboratory Animals
(National Research Council, 1996). All dogs successfully
completed this study.
2.2. Diets and feeding regimes
The term ‘‘diet’’ refers to the formulation of the
feed presented to each dog during the study. All dogs
were given free access to fresh water and fed a com-
plete and balanced dry diet (Diet A, control) con-
taining a minimum of 26% crude protein and 12%
crude fat (comprised of beef tallow), during a four
week acclimation period prior to the initiation of the
study. This control diet formulation was selected for
this study because a similar diet was being commer-
cially marketed as an appropriate diet for adult ath-
For the experiment, dogs were allotted to one of the
three diet groups (6 dogs/diet group). The diets were
formulated based on Association of American Feed
Control Oﬃcials nutrient requirements for adult dogs
Ingredientb(as-fed) Diet Ac
Ground yellow corn 36.0 29.1 29.1
Soybean meal 15.4 17.8 17.8
Corn gluten meal 13.5 16.0 16.0
Rice bran 11.0 11.0 11.0
Beef tallow 8.0 4.0 4.0
Corn oil —8.0 —
Coconut oil —— 8.0
Beef and bone meal 6.5 2.0 2.0
Wheat 6.0 6.0 6.0
Brewers yeast 1.0 1.0 1.0
Dog vitamin pre-mix 0.7 0.7 0.7
Salt 0.6 0.7 0.7
Dicalcium phosphate 0.5 1.6 1.6
Calcium carbonate 0.3 1.1 1.1
Trace mineral pre-mix 0.2 0.2 0.2
Lysine 0.2 0.2 0.2
Potassium 0.1 0.1 0.1
Choline 0.05 0.05 0.05
Manufactured by Ralston–Purina, St. Louis, MO.
Values reported as percentage of total diet mixture.
Diet A (control): 12% crude fat (4% beef tallow added internally in
diet mixture, 4% beef tallow added externally as a sprayed product
following extrusion, and remaining 4% dietary fat derived from basal
Diet B (unsaturated): 16% crude fat (4% beef tallow added inter-
nally in diet mixture, 4% beef tallow and 4% corn oil added externally
as a sprayed product following extrusion, and remaining 4% dietary fat
derived from basal ingredients).
Diet C (saturated): 16% crude fat (4% beef tallow added internally
in diet mixture, 4% beef tallow and 4% coconut oil added externally as
a sprayed product following extrusion, and remaining 4% dietary fat
derived from basal ingredients).
150 E.K. Altom et al. / Research in Veterinary Science 75 (2003) 149–155
(1996) and fed as an extruded dry product manufactured
by Ralston–Purina Company, St. Louis, MO (Tables 1
and 2). Diet B contained a minimum of 26% crude
protein and 16% crude fat provided by equal amounts
of beef tallow and corn oil. Diet C contained a minimum
of 26% crude protein and 16% crude fat provided by
equal amounts of beef tallow and coconut oil. Diet
formulations resulted in diet B containing predomi-
nately unsaturated fatty acids, while diet C contained
predominately saturated fatty acids (Table 3). Nutrient
composition of each diet was analyzed utilizing the
methods approved by the Association of Oﬃcial Ana-
lytical Chemists (16th edition, 1995).
2.3. Physical conditioning program
Dogs from each diet group were allotted to two
conditioning groups (physically conditioned and non-
conditioned). Physically conditioned dogs (EXE) were
exercised three times weekly on a motorized treadmill
(Parker Treadmills, Auburn, AL) at a rate of 8.05 km/h
(0% slope) for 30 min/day on non-consecutive days.
Non-conditioned dogs (NON) were exercised at
8.05 km/h (0% slope) for 10 min/day one day per week to
ensure familiarity with the treadmill. Duration of the
physical conditioning program was 12 weeks. The
physical conditioning program was developed to closely
simulate traditional techniques utilized by performance
ﬁeld dog trainers to condition their competitors (Tar-
rant, 1977; Wehle, 1964).
2.4. Physical stress testing
All dogs were subjected to a submaximal exercise
stress test on weeks 0, 4, 8 and 12 of the study. During
the two-stage exercise test, dogs were initially exercised
at a rate of 8.05 km/h (5% slope) for 15 min, and then at
a rate of 8.05 km/h (10% slope) for 45 min. The physical
test was concluded at 60 min or when the dog refused to
2.5. Odorants and subject preparation
Olfactory acuity is measured as the lowest concen-
tration of a selected odorant which is detectable by an
Composition analysis of test dietsa
4085 4322 4321
Moisture (%) 7.3 5.3 5.0
Protein (%) 26.5 26.6 26.0
NFE (%) 46.1 42.5 42.5
Fat (%) 12.6 16.9 16.8
Fiber (%) 1.3 1.3 1.3
Ash (%) 5.8 6.4 6.4
Calcium (%) 1.0 1.0 1.0
Phosphorus (%) 0.8 0.8 0.8
Sodium (%) 0.3 0.3 0.3
Potassium (%) 0.6 0.6 0.6
Chloride (%) 0.5 0.5 0.5
Manufactured by Ralston–Purina, St. Louis, MO.
Fatty acid composition of test dietsa
Fatty acidbDiet Ac(control) Diet Bd(unsaturated) Diet Ce(saturated)
Caprylic 8:0 —— 2.9
Capric 10:0 —— 2.5
Lauric 12:0 —0.3 21.5
Myristic 14:0 1.9 1.0 9.7
Palmitic 16:0 20.8 15.4 14.9
Palmitoleic 16:1 2.1 1.0 1.0
Margaric 17:0 1.0 0.5 0.5
Stearic 18:0 14.2 7.3 7.9
Oleic 18:1 36.5 29.6 21.2
Linoleic 18:2, n6 17.2 40.0 13.9
-Linolenic 18:3, n3 0.9 1.1 0.7
Total saturated fatty acids 37.9 24.5 59.9
Total unsaturated fatty acids 56.8 71.7 36.8
Remaining fatty acids 5.3 3.8 3.3
Omega 6:3 19.1:1 36.4:1 19.9:1
Manufactured by Ralston–Purina, St. Louis, MO.
Values reported as percent of total fat contained in the diet.
Diet A (control): 12% crude fat (4% beef tallow added internally in diet mixture, 4% beef tallow added externally as a sprayed product following
extrusion, and remaining 4% dietary fat derived from basal ingredients).
Diet B (unsaturated): 16% crude fat (4% beef tallow added internally in diet mixture, 4% beef tallow and 4% corn oil added externally as a sprayed
product following extrusion, and remaining 4% dietary fat derived from basal ingredients).
Diet C (saturated): 16% crude fat (4% beef tallow added internally in diet mixture, 4% beef tallow and 4% coconut oil added externally as a
sprayed product following extrusion, and remaining 4% dietary fat derived from basal ingredients).
E.K. Altom et al. / Research in Veterinary Science 75 (2003) 149–155 151
organism. Olfactory thresholds were determined for all
dogs prior to the initiation of this study by behavioral
olfactometry utilizing eugenol (Sigma Chemical Com-
pany, St. Louis, MO) as the odorant (Ezeh et al., 1992;
Myers and Pugh, 1985). Dilutions of ascending con-
centration of eugenol from 1018 to 101M/L of stock
solutions of eugenol (6.52 M) in propylene glycol (Fisher
Scientiﬁc Company, Fair Lawn, NJ) were utilized to
determine odorant-detecting thresholds 30 min prior to
the treadmill physical stress test and 30 min following
the conclusion of the physical stress test. Eugenol was
selected as the test odorant based on its ability to
stimulate olfactory nerve activity with little or no eﬀect
on trigeminal activation (Doty, 1989). One milliliter of
each dilution was stored in a separate sealed 12 75 mm
borosilicate test tube (Fisher Scientiﬁc Company, Fair
Lawn, NJ). Odorless blanks were used that contained
1 mL of pure propylene glycol. Care was taken to pre-
vent any cross-contamination of the sample vials.
Subjects were prepared according to previously de-
scribed techniques for behavioral olfactometry (Ezeh
et al., 1992; Myers and Pugh, 1985). Dogs were blind-
folded and lightly restrained in a right lateral recum-
bency and allowed to acclimate for a minimum of 5 min
to the environment before the evaluation was initiated.
Eﬀorts to create a stimulus-neutral environment (Myers,
1991a) within the testing room included adequate ven-
tilation, temperature control (25 1°C), white noise to
prevent excessive auditory stimulus, and odor control
(no perfume, cologne, or smoking allowed, and baking
soda bags were utilized as odor absorbents). All dogs
were calm prior to odor presentation, as indicated by
minimal spontaneous body movement.
2.6. Olfactory function evaluation
Baseline odorant-detecting thresholds for eugenol
were established for each dog using triplicate measure-
ments on non-consecutive days using previously de-
scribed techniques (Ezeh et al., 1992; Myers and Pugh,
1985). The same evaluators performed all olfactory
threshold measurements throughout the study. The av-
erage of these values was determined to be the baseline
odorant-detecting threshold value for each dog. The
olfactory acuity for all dogs was determined to be within
normal ranges (Myers, 1991b) prior to inclusion in the
study. Normal range was determined to be the detection
of an odor concentration less than 109M/L eugenol
Each olfactory evaluation test was initiated by pre-
senting the blind-folded dog with the empty test tube
holder, a sample blank (pure propylene glycol), and then
the individual test tray containing the serial dilution set
with three additional blanks randomly placed in the set.
The method of presenting the samples was similar to
that previously described (Ezeh et al., 1992; Myers and
Pugh, 1985). Each individual sample tube was opened
and placed approximately 2 cm ventral to the tip of the
dogÕs nose. Each dilution was presented for 10 s, with-
drawn for 15 s, and then followed by the next sample in
the serial dilution set. Thresholds for odorant-detection
were determined to be the lowest eugenol concentration
that evoked an observable, reﬂexive behavioral re-
sponse. Behavioral responses were videotaped and an-
alyzed by four observers trained to detect the
appropriate behavioral response. A positive olfactory
response was determined by the presence of a pre-de-
termined typical behavior pattern of a sniﬀ. Observers
independently agreed in every case of response or lack of
response to odor stimuli at a given concentration. The
18 tenfold dilutions were recorded as the negative log of
the dilution with 1 being the most concentrated and 18
being the least concentrated. A score of 0 was recorded
for lack of response. This study was conducted as a
2.7. Statistical analysis
Dogs were allotted randomly to diet and conditioning
groups. Data were analyzed as a double split plot over
time design, with diet, conditioning, week, and time as
main eﬀects. The experimental unit was dog within diet
and conditioning group. Initial olfactory estimates col-
lected at week 0 were utilized as covariates to assess
changes in olfactory acuity during the experimental pe-
riod. The general linear model (GLM) procedure of SAS
(Statistical Analysis Systems Version 6.12, SAS Institute,
Cary, NC) was utilized for statistical analyses. Diﬀerences
among treatment least squares means were separated
utilizing the PDIFF option of SAS when protected by a
signiﬁcant (P<0:10) F-test. Initially a complete model,
including all three-way interactions, was used to analyze
these data. However, three-way interactions that were not
signiﬁcant (P>0:10), as determined by ANCOVA, were
eliminated from the ﬁnal analysis.
No diﬀerences were detected in baseline olfactory
acuity prior to the initiation of the study, and mean
acuity (expressed as the negative log of the minimum
eugenol concentration needed to elict a behavioral re-
sponse) was 16:31:2 (SEM). In contrast, physical
conditioning aﬀected olfactory acuity (P<0:05) fol-
lowing the one hour of physical stress test with dogs
receiving physical conditioning three days per week
(EXE) having greater odorant-detecting capabilities
compared with NON dogs (Table 4). NON dogs had a
64% reduction in olfactory acuity following the physical
stress test based on pre and post-exercise values. How-
ever, pre and post-exercise values for EXE dogs were
152 E.K. Altom et al. / Research in Veterinary Science 75 (2003) 149–155
similar (P>0:10). NON dogs fed coconut oil had de-
creased (P<0:10) olfactory acuity when pre-test
threshold values obtained at week 4 were compared with
values subsequently obtained at week 12 (Table 5).
Likewise, EXE fed the control diet had signiﬁcantly
(P<0:10) lower olfactory acuity when values obtained
at week 4 were compared with values obtained at week
12. All remaining diet–physical conditioning combina-
tions were similar (P>0:10) across the study period. No
evidence of olfactory function was present in NON dogs
fed coconut oil at week 12 values (Table 5). It is im-
portant to note that these values were obtained prior to
any physical exertion. The calculated percent change
between pre-test olfactory values and post-test olfactory
values indicated that EXE dogs and NON dogs fed diets
B and C were not diﬀerent (P>0:10).
The sport of ﬁeld trials is one of the fastest growing
outdoor activities in the United States. However, since the
beginning of ﬁeld competitions, trainers have searched for
methods to improve canine performance. Holloway
(1961) reported that 85% of hunting dog owners surveyed
indicated some type of olfactory problem. Although the
source of these conditions was not determined, olfactory
function remains a primary concern for trainers of canine
athletes. Myers and coworkers (1988a, 1988b, 1991b)
have documented several conditions which aﬀect the ol-
factory function of canines. These conditions include ca-
nine distemper and parainﬂuenza viral infections.
However, these conditions are not believed to be the cause
of impaired olfactory function in this study due to the fact
that precautionary physical examinations, an aggressive
vaccination program, and baseline olfactory measure-
ments were performed prior to the initiation of the pro-
ject. Additionally, all dogs were examined throughout the
study and none displayed clinical signs of any upper re-
spiratory or viral infection.
While some anecdotal evidence exists in the popular
press, these data are the ﬁrst to indicate scientiﬁcally a
beneﬁcial eﬀect of physical conditioning on the olfactory
acuity of canine athletes when subjected to moderate
exercise. Behavioral olfactometry measurements re-
vealed canine athletes enrolled in a physical condition-
ing program were able to maintain a greater olfactory
acuity compared with dogs that were not physically
conditioned. Non-conditioned dogs displayed a 63.6%
decrease in olfactory acuity following treadmill exercise,
while EXE dogs showed no signiﬁcant changes (Table
4). These data may possibly be explained by altered re-
spiratory function of the dogs during exercise. Dogs that
are not in adequate physical condition breathe more
through the mouth during periods of intense exercise as
opposed to breathing through the nose when exposed to
intense physical exertion. Because of increased heat load
during exercise, dogs force more air through the lungs
and out of the mouth to regulate body temperature. It is
highly probable that decreasing the amount of airﬂow
through the nasal passage reduces the amount of
odorants passing over the olfactory membranes. This
Olfactory acuity of canine athletes pre and post-treadmill exercise1
No. of dogs 9 9
Pre-stress test 10:71:3ac 7:81:4ac
Post stress test 3:91:4ad 8:11:2bc
Percent change (%)3)63.6 3.8
LSMeans SEM. Values represent the negative log of the mini-
mum eugenol concentration that elicited a behavioral response.
Conditioning: NON, non-conditioned; EXE, physically condi-
Percent change in olfactory acuity between pre-stress test values
and post stress test values.
abIndicate diﬀerences within time period. Means within the same time
period lacking a common superscript diﬀer (P<0:05).
cdIndicate diﬀerences within conditioning group. Means within the
same conditioning group lacking a common superscript diﬀer
Eﬀects of dietary fat source and physical conditioning on the olfactory thresholds of canine athletes throughout the project test period1
Diet A Diet B Diet C
NON EXE NON EXE NON EXE
No. of dogs 3 33333
Week 4 18.0a12.0a11.0a11.3a18.0a12.0a2.9
Week 8 13.7a7.7a;b10.3a5.3a11.3a6.3a2.9
Week 12 15.0a4.7b4.7a6.0a0.0b11.0a2.9
LSMeans SEM. Values represent the pre-stress test, values reported as the negative log of the minimum eugenol concentration, that elicited a
Diets: Diet A, control containing 12% fat as beef tallow; Diet B (unsaturated), containing 16% fat (8% beef tallow and 8% corn oil); Diet C
(saturated), containing 16% fat (8% beef tallow and 8% coconut oil).
Conditioning: NON, non-conditioned; EXE, physically conditioned.
a;bIndicated diﬀerences within diet-conditioning group. Means within the same diet-conditioning group lacking a common superscript diﬀer
E.K. Altom et al. / Research in Veterinary Science 75 (2003) 149–155 153
mechanism could substantially reduce the ability of the
athlete to detect odors both during and following peri-
ods of intense exercise. Likewise, increased dehydration
of the nasal mucosal layer of poorly conditioned dogs
would contribute to the altered function of the olfactory
system due to total body dehydration.. It is highly
probable that dehydration of the nasal mucosal mem-
brane would result in decreased enzyme activity and
decreased membrane ﬂuidity. These conditions could
alter neuro-signal transduction and odorant receptor
function in the olfactory mucosal layer, thereby poten-
tially impairing olfactory function in canine athletes.
Conversely, a canine in top physical condition would be
able to reduce the amount of air breathed through the
mouth. Hydration status following exercise was not
quantitatively measured in this experiment. Although
the complete mechanism for decreased odor detection in
non-conditioned canine athletes was not fully deﬁned in
this experiment, a combination of decreased airﬂow
across the nasal membranes and/or decreased hydration
status of the mucosal layer may signiﬁcantly decrease
odor detection capabilities in these canine athletes.
Several studies report alterations in functionality of
organ and tissues in response to diﬀerent dietary fat
sources. Therefore, these diet-induced responses may
also aﬀect nasal epithelial composition and function
when dogs are fed various fat sources. MacDonald et al.
(1996) reported altered brain membrane phospholipid
concentrations in rats during long term feeding of sat-
urated versus unsaturated fatty acids. They reported
that a diet comprised of saturated fatty acids resulted in
a deﬁciency of 18:3 fatty acids in the brain. Membrane
phospholipids provide a hydrophobic barrier between
the environment and the cell (MacDonald et al., 1996).
The fatty acid composition of membrane phospholipids
dictates the ﬂuidity and permeability of the membrane
(Couture and Hulbert, 1995). Therefore, alteration of
the membrane fatty acid composition may alter the
function of the membrane due to changes in ﬂuidity
which, in turn, alters the function of membrane en-
zymes. While the complete olfaction mechanism is not
deﬁned, major components that mediate the molecular
events of olfaction include one or more odorant-binding
proteins, odorant-sensitive adenylate cyclase, and sodi-
um-potassium ATPase. Sodium–potassium ATPase is
one enzyme in brain synaptic membranes that has been
reported to be altered by dietary fat (Gerbi et al., 1994).
Our data show a possible diﬀerential response to di-
etary fat source and exercise. Dietary fat source and(or)
level did not alter the olfactory acuity of the physically
conditioned (EXE) dogs. However, NON dogs fed co-
conut oil showed no evidence of odor detecting ability at
week 12 of the study (Table 5). Similarly, EXE dogs fed
the control diet had signiﬁcantly reduced olfactory
function prior to exercise when values obtained at week
4 were compared to values obtained at week 12 of the
study. No diﬀerences were detected among the remain-
ing diet-conditioning groups.
Physical conditioning of canine athletes prevented a
reduction in olfactory acuity following one hour of
treadmill exercise. Although further studies are required,
these data indicate a beneﬁcial eﬀect of regular physical
conditioning for canine athletes that are engaged in ac-
tivities which require quality odorant-detecting capa-
bilities. Additionally, feeding increased levels of
saturated fatty acids to unconditioned dogs could result
in poor olfactory detecting performance. While further
investigations are warranted, data derived from this
study suggest that high levels of saturated fat can further
reduce the odorant-detecting capabilities of poorly
conditioned canines. These factors should be considered
when developing a training program for canine athletes.
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