Objective—To compare large intestinal transit time (LITT) in dogs of various body sizes and determine whether fecal quality was correlated with LITT.
Animals—6 Miniature Poodles, 6 Standard Schnauzers, 6 Giant Schnauzers, and 6 Great Danes.
Procedure—LITT was calculated as the difference between total (TTT) and orocecal transit time (OCTT). Minimum and mean OCTTs were determined by use of the sulfasalazine-sulfapyridine method. Minimum TTT was estimated by use of chromium and ferric oxide as color markers, and mean TTT was calculated from the recovery from feces of ingested colored plastic beads. Fecal moisture content was determined and fecal consistency was scored during the same period.
Results—Large-breed dogs had higher fecal moisture content and more watery fecal consistency. No association between body size and OCTT was detected, but there was a positive correlation between body size and mean TTT. Mean LITT increased significantly with body size, from 9.1 ± 1.1 hours in Miniature Poodles to 39.4 ± 1.6 hours for Giant Schnauzers. Significant correlations were detected among mean LITT, mean TTT, and fecal scores, whereas no correlation was observed between fecal moisture content and TTT or LITT.
Conclusions and Clinical Relevance—LITT was correlated with fecal consistency in dogs of various body sizes. Mean LITT can be predicted from values for mean TTT in healthy dogs.
Objective—To evaluate the effect of dietary fat and
energy density on body weight gain, body composition,
and total energy expenditure (TEE) in neutered
and sexually intact cats.
Animals—12 male and 12 female cats
Procedure—Male cats were castrated (castrated
male [CM]) or underwent no surgical procedure (sexually
intact male [IM]). Female cats underwent
ovariectomy (spayed female [SF]) or laparotomy and
ligation of both uterine tubes without ovary removal
(sexually intact female [IF]). Cats were fed either the
low-fat (LF) or high-fat (HF) diet for 26 weeks, with the
final allocation consisting of 8 groups: IF-LF, IF-HF, SF-LF,
SF-HF, IM-LF, IM-HF, CM-LF, and CM-HF. Mean
food intake for each group was recorded daily, and
body weight was monitored weekly throughout the
study. Body composition and TEE were measured
before surgery in week 0 and at the end of the study
(week 26) by isotope dilution (double-labelled water).
Results—Neutered cats gained significantly more
body fat and body weight (53.80 ± 5.79%) than sexually
intact cats (27.11 ± 5.79%) during the study. Body
weight gain of neutered cats fed the HF diet was
greater than those fed the LF diet. Following correction
for body composition, TEE was similar in all
groups and no pattern towards increased food intake
Conclusions and Clinical Relevance—Weight gain
in neutered cats was decreased by feeding an LF, low
energy-dense diet. To prevent weight gain in cats after
neutering, a suitable LF diet should be fed in carefully
controlled meals rather than ad libitum. (Am J Vet
Objective—To compare orocecal transit time (OCTT)
as assessed by use of the sulfapyridine appearance
time in plasma after oral administration of sulfasalazine
in dogs of varying age and body size and
determine whether OCTT correlates with fecal
Animals—6 Miniature Poodles (MP), 6 Standard
Schnauzers (SS), 6 Giant Schnauzers (GS), and 6
Great Danes (GD).
Procedure—Determinations of OCTT were made at
12, 22, 36, and 60 weeks of age. Dogs were fed sulfasalazine
mixed with a meal. Blood samples were
then collected for 6 hours. The OCTT was the time
from ingestion of the meal to detection of sulfapyridine
in plasma. Fecal moisture content and consistency
were recorded during the same periods.
Results—Mean OCTT decreased during growth of
GS and GD dogs. No correlation was found between
OCTT and fecal variables during growth in the 4
breeds. Effect of body size was observed at 12 and 22
weeks of age, with a longer OCTT in GS and GD than
in MP and SS dogs. Similar OCTTs were observed at
36 and 60 weeks of age in all breeds, although GS
and GD dogs had poorer fecal quality during those
Conclusions and Clinical Relevance—An effect of
age on OCTT was observed only in large-breed dogs,
with longer transit times in puppies (12 weeks old)
than in adults (60 weeks old). Mean OCTT is not correlated
with body size in adult dogs. No relationship
was detected between OCTT and fecal variables in
healthy dogs. (Am J Vet Res 2003;64:1105–1109)
Objective—To compare gastric emptying time, smallintestinal
transit time (SITT), and orocecal transit time
(OCTT) of radiopaque markers in dogs varying in age
and body size and to determine whether fecal variables
(ie, consistency and moisture content) are related
to gastrointestinal tract transit times in dogs.
Animals—24 eight-week-old female puppies, including
6 Miniature Poodles, 6 Standard Schnauzers, 6
Giant Schnauzers, and 6 Great Danes.
Procedure—Gastrointestinal tract transit time experiments
were performed at 12, 22, 36, and 60 weeks of
age. Dogs were fed 30 small radiopaque markers
mixed with a meal. Abdominal radiographs were
taken. The time at which 50% of the markers had left
the stomach (T50) and the time at which the first
marker reached the colon were calculated. Fecal
moisture content and scoring on the basis of fecal
consistency were recorded during the same periods.
Results—Puppies had a shorter mean T50 than
adults, and mean OCTT decreased significantly only
during growth of large-breed dogs. However mean
fecal moisture content significantly increased with
age, except in Giant Schnauzers. No effect of body
size on T50 was found regardless of age, and no difference
was observed between OCTT of small- and
large-breed adult dogs. The effect of age on the mean
SITT was not significant for any breed. However, a
strong positive correlation was recorded between
body size and fecal moisture content (r2 = 0.77) or
fecal scores (r2 = 0.69) in adult dogs.
Conclusions and Clinical Relevance—Age affects
T50 in small- and large-breed dogs and OCTT in largebreed
dogs. However, body size does not affect T50
or OCTT. A relationship does not exist between gastrointestinal
tract transit time and fecal variables in
healthy dogs. (Am J Vet Res 2002;63:677–682)
Objective—To evaluate effects of age and body size
of dogs on intestinal permeability (unmediated diffusion)
as measured by the ratio of urinary lactulose to
L-rhamnose (L:R) and absorption (carrier-mediated
transport) as measured by the ratio of urinary D-xylose
to 3-O-methyl-D-glucose (X:MG) and to determine
whether these variables correlated with fecal quality.
Animals—6 Miniature Poodles, 6 Standard
Schnauzers, 6 Giant Schnauzers, and 6 Great Danes.
Procedure—A solution that contained lactulose and
rhamnose or xylose and 3-O-methyl-D-glucose was
administered orally to dogs that were 12, 22, 36, and
60 weeks old. Urine was collected 6 hours later, and
urinary L:R and X:MG were calculated. Fecal moisture
and scoring were recorded during the same periods.
Results—Age and breed did not affect intestinal
absorption, and we did not detect a relationship
between X:MG and fecal variables. In contrast, we
detected significant effects of age and body size on
intestinal permeability. Puppies (12 weeks old) and
large dogs had higher intestinal permeability than adult
(60 weeks old) and small dogs. The increased intestinal
permeability in large dogs was associated with
lower fecal quality as indicated by the significant positive
correlations between L:R and fecal moisture (r,
0.61) and L:R and fecal scores (r, 0.86) in adult dogs.
Conclusion and Clinical Relevance—These results
indicate that age and body size should be considered
when assessing intestinal permeability by use of the
L:R urinary excretion test in dogs. High intestinal permeability
could be a possible cause of poor fecal quality
in large dogs. (Am J Vet Res 2002;63:1323–1328)
Objective—To evaluate energy expenditure (EE) in
dogs by estimating rate of CO2 production (rCO2).
Procedure—Food was withheld for 24 hours, and all
dogs received an IV infusion of 13C sodium bicarbonate
for 8 hours. Breath samples were collected before
infusion and at 30-minute intervals from 4 to 8 hours,
and 13C enrichment in breath CO2 was measured,
using gas chromatography-isotopic ratio mass spectrometry.
Food was withheld from 6 dogs, and rCO2
and O2 consumption were measured, using a conventional
indirect calorimeter. The CO2 production and
O2 consumption were measured by use of indirect
calorimetry in 6 other fed dogs that were injected
with 2H2O and H218O. Blood samples were collected
before tracer injection, 4 hours later, and on days 4, 7,
and 11. Deuterium and 18O enrichments in plasma
water were determined.
Results—Mean rCO2 measured by indirect calorimetry
was 516 ± 34 and 410 ± 16 µmol/kg0.75/min in 6 fed
and 6 food-deprived dogs, respectively. The rCO2 calculated
from 13C-bicarbonate dilution was 482 ± 30
µmol/kg0.75/min. Mean rCO2 determined by use of the
double-labeled water method was 1,036 ± 46
mmol/kg0.75/d. Mean energy expenditure calculated
from rCO2 determined by infusion of 13C bicarbonate,
indirect calorimetry in fed and food-deprived dogs, and
infusion of double-labeled water was 386 ± 39, 379 ±
25, 338 ± 14, and 552 ± 25 kJ/kg0.75/d, respectively.
Conclusion and Clinical Relevance—Energy
expenditure calculated by indirect calorimetry in
unfed dogs can be considered representative of basal
metabolic rate. (Am J Vet Res 2002;63:111–118)