Objective—To compare secretory responses to prostaglandin (PG) E2 in mucosa obtained from the proximal and distal portions of the colon of dogs.
Sample—Colonic mucosa from cadavers of 18 clinically normal adult dogs.
Procedures—Short-circuit current (ISC) and maximum change in ISC (ΔIsc) in response to administration of 1μM PGE2 were measured across mucosa obtained from the proximal and distal portions of the colon. Responses were evaluated in mucosa (n = 6 dogs) incubated in Ussing chambers with or without 1 mM amiloride or without chloride in the Ringer's bathing solution. Responses were also evaluated in mucosa (n = 9 dogs) incubated with or without pretreatment with 1 μM indomethacin, with or without amiloride in the subsequent bathing solution. Histologic changes in mucosa from 3 dogs were assessed over time.
Results—ISC and ΔISC were significantly reduced when chloride was removed from, but not when amiloride was added to, the bathing solution and were significantly reduced after pretreatment with indomethacin. The ΔISC was significantly greater in mucosa from the distal portion of the colon than in the proximal portion of the colon. Histologic changes after incubation for 3 hours were minimal.
Conclusions and Clinical Relevance—ISC and ΔISC resulted from electrogenic chloride secretion. Chloride secretion was reduced when release of PGs was prevented by indomethacin and was induced by administration of PGE2. Chloride secretion in response to PGE2 was greater in mucosa from the distal portion of the colon than in mucosa from the proximal portion of the colon.
Objective—To measure volatile fatty acid (VFA) concentrations
and pH in the gastrointestinal tracts of
healthy adult cats fed a commercial dry cat food.
Procedure—The gastrointestinal tracts were excised
immediately after euthanasia and divided into 6 sections
(stomach, duodenum, jejunum, ileum, proximal
portion of the colon, and distal portion of the colon).
Luminal contents were collected from each segment,
pH was measured, and contents were centrifuged.
The supernatant was analyzed for acetate, proprionate,
butyrate, isobutyrate, valerate, and isovalerate
concentrations by use of gas chromatography.
Results—Mean total VFA concentrations were lowest in
the stomach (20 mmol/L); increased through the duodenum,
jejunum, and ileum (30, 29, and 41 mmol/L, respectively);
and were greatest in the proximal and distal portions
of the colon (109 and 131 mmol/L, respectively).
Estimated mean total VFA amounts were low (< 600 μmol)
throughout all segments of the gastrointestinal tract; pH
values increased from the stomach through the ileum and
subsequently decreased in the colon.
Conclusions and Clinical Relevance—Total VFA
concentrations in the colon were comparable to values
reported for the forestomach of ruminants and
large intestines of monogastric animals, whereas values
in the small intestine were higher than reported
for other species. Total VFA amounts were low, consistent
with the short, nonvoluminous gastrointestinal
tract of carnivores. Luminal pH varied throughout
the gastrointestinal tract in a pattern similar to other
monogastric animals. Volatile fatty acids probably
contribute minimal metabolic energy in cats but may
be important in the maintenance of local mucosal
health. (Am J Vet Res 2000;61:359–361)
Objective—To compare guaranteed and measured concentrations of nutrients in commercial pet foods.
Sample Population—Annual inspection reports of pet food analyses from 5 states.
Procedures—Guaranteed and measured concentrations of crude protein (CP), crude fat (CF), crude fiber (CFb), moisture, and ash in pet foods were compared. The concentration difference for each nutrient was compared among types of food, target species, target life stages, manufacturers, and laboratories.
Results—The guaranteed and measured concentrations of nutrients were significantly different. For all foods, mean concentration differences were as follows: CP, 1.5%; CF, 1.0%; CFb, −0.7%; moisture, −4.0%; and ash, −0.5%. Crude protein difference for treats was significantly larger than differences for dry and canned foods. Crude fat difference for dry foods was significantly less than differences for canned foods and treats. Crude fiber and moisture differences for canned foods were significantly less than the corresponding differences for dry foods and treats. Only CFb differences differed among target species, life stages, manufacturers, or laboratories.
Conclusions and Clinical Relevance—Addition of 1.5% and 1% to the guaranteed minimums for CP and CF, respectively; subtraction of 0.7%, 4%, and 0.5% from the guaranteed maximums for CFb, moisture, and ash, respectively; and addition of 0.23 kcal/g to the asfed metabolizable energy value calculated by use of modified Atwater factors from guaranteed analyses provides a more accurate estimate of the nutrient and metabolizable energy content of commercial pet foods. Nevertheless, the actual composition of a food should be determined whenever possible.
Objective—To determine characteristics of free-roaming
cats evaluated in a trap-neuter-return program.
Animals—5,323 free-roaming cats.
Procedure—Data collected included sex, maturity,
pregnancy status, number of fetuses per pregnancy,
cryptorchidism, and occurrence of complications or
Results—Adult cats represented 85% of the population,
and 57% were female. Overall, 19% of adult
females were pregnant, and mean litter size was 3.6
fetuses. Pregnancy rate peaked at 36 to 47% of all
females evaluated in March and April and decreased to
≤ 4% from October through January. Cryptorchidism
was observed in 1.9% of the males; 0.4% of the adult
females had pyometra. Only 1.9% of the cats were
already neutered. Euthanasia and unexpected death
rates were 0.4 and 0.3%, respectively. The most common
severe problems encountered included pyometra,
neoplasia, surgical complications, diaphragmatic hernia,
debilitation, and chronic inflammatory diseases.
Conclusions and Clinical Relevance—Neutering programs
for free-roaming cats should include preparations
to perform more spays than castrations. Typically,
almost half of the female cats trapped during spring
will be pregnant. Cryptorchidism is uncommon but is
encountered on a consistent basis, so care should be
taken to differentiate previous castration from retained
testicles. Euthanasia of debilitated cats for humane
reasons is rarely necessary, and unexpected deaths
occur at a low rate. It is feasible and safe to neuter
large numbers of free-roaming cats in large-scale clinics.
(J Am Vet Med Assoc 2002;221:1136–1138)
Procedure—Dogs were randomly assigned to 2
groups of 3 dogs in a crossover design. Diazepam
(0.5 mg/kg of body weight) was administered intravenously
to dogs in group 1 and intranasally to dogs
in group 2. Blood was collected from the jugular vein
of each dog into tubes containing lithium heparin
before and 3, 6, 9, 12, 15, 20, 30, 60, 120, 240, and
480 minutes following diazepam administration. After
a 4-day washout period, dogs in group 1 received
diazepam intranasally, dogs in group 2 received
diazepam intravenously, and blood was again collected.
Plasma concentration of BDZ was determined by
use of a fluorescence polarization immunoassay.
Results—Mean (± SD) peak plasma concentration of
BDZ following IV administration (1316 ± 216 µg/L)
was greater than that following IN administration
(448 ± 41 µg/L). Time to peak concentration was ≤ 3
minutes following IV administration and 4.5 ± 1.5
minutes following IN administration. Mean bioavailability
of BDZ following IN administration was
80 ± 9%.
Conclusions and Clinical Relevance—Diazepam is
rapidly and efficiently absorbed following IN administration
of the parenteral formulation. Plasma concentrations
match or exceed the suggested therapeutic
concentration (300 µg/L). Intranasal administration of
diazepam may be useful for treatment of seizures in
dogs by owners or when intravenous access is not
readily available. (Am J Vet Res 2000;61:651–654)
To evaluate the effects of a flotation vest (FV) and water flow rate (WFR) on limb kinematics of dogs swimming against a current.
7 (1 male and 6 female) healthy adult Siberian Huskies.
Dogs were habituated to swim with and without an FV beside an investigator in a continuous-flow pool against WFRs up to 2.9 km/h. During each of 4 experimental sessions in a repeated-measures study, markers were wrapped around the right carpus and tarsus, and a video was recorded while each dog swam with or without an FV for about 2 minutes at each of 7 WFRs between 0 and 2.9 km/h when the WFR was incrementally decreased or increased. Motion tracking software was used to measure stroke excursion and frequency.
Stroke excursion varied more than frequency among all dogs and in response to changes in experimental conditions. The male dog and 1 female dog were unable to complete the study. For the remaining 5 dogs across all experimental conditions, mean tarsus excursion was 30% that of the carpus. Mean total excursion (sum of the excursion-frequency products for the carpus and tarsus) decreased when an FV was worn and increased with WFR by 69% and 19% when WFR was incrementally increased and decreased, respectively.
CONCLUSIONS AND CLINICAL RELEVANCE
In dogs, range of motion during swimming was greater for the carpus than tarsus, when an FV was not worn, and increased more with WFR when WFR was incrementally increased. Those factors should be considered during swimming-based rehabilitation.
Objectives—To determine effect of α-tocopherol
supplementation on serum vitamin E concentrations
in Greyhounds before and after a race.
Animals—8 adult racing Greyhounds.
Procedure—Dogs were given 2 capsules of α-tocopheryl
acetate (total, 680 units [0.5 g]) with food that
contained ≤ 15 mg of vitamin E/kg each morning for 7
days. Dogs were exercised in a 30 × 30-m grass paddock
for 15 minutes twice a day and raced for 500 m
twice a week. Blood samples were collected before
and 5 minutes after a race, before supplementation
was begun, and after 7 days of supplementation.
Blood and diet samples were analyzed for tocopherols
and α-tocopheryl acetate.
Results—Before supplementation, serum α-tocopherol
concentration after racing (mean ± SD,
6.7 ± 2.4 mg/L ) was significantly lower than before
racing (12.2 ± 3.1 mg/L). After supplementation, α-
tocopherol concentrations were significantly higher
overall, although values obtained before (26.6 ± 5.2
mg/L) and after (29.8 ± 3.6 mg/L) racing were not significantly
Conclusions and Clinical Relevance—Supplementation
with α-tocopheryl acetate increased serum
α-tocopherol concentrations and eliminated the
decrease in α-tocopherol concentration that was
detected after a race, which may decrease oxidation
during exercise and improve performance or recovery.
(Am J Vet Res 2001;62:1118–1120)
Objective—To develop a multiplex polymerase chain
reaction (PCR) assay for the detection of Toxoplasma
gondii and Neospora caninum DNA in canine and
feline biological samples.
Sample Population—Biological samples from 7 cats
with systemic (n = 4) or CNS (3) toxoplasmosis, 6 dogs
with neospora- or toxoplasma-associated encephalitis,
and 11 animals with nonprotozoal disease.
Procedure—Primers for T gondii, N caninum, and the
canine ferritin gene (dogs) or feline histone 3.3 gene
(cats) were combined in a single PCR assay. The DNA
was extracted from paraffin-embedded brain tissue,
CSF, or skeletal muscle. The PCR products with positive
results were cloned, and sequence identity was
Results—Of 7 cats and 4 dogs with immunohistochemical
or serologic evidence of toxoplasmosis, PCR
results were positive for all cats and 3 dogs for T gondii,
and positive for T gondii and N caninum for 1 dog.
Another dog had negative PCR results for both parasites.
Of 2 dogs with immunohistochemical or serologic
evidence of neosporosis, PCR results were positive
for 1 for N caninum and positive for the other for
T gondii. All negative-control samples yielded negative
results for T gondii and N caninum on the PCR assay.
Conclusions and Clinical Relevance—Standard tests
for toxoplasmosis or neosporosis associated with the
CNS rely on serologic, histologic, or immunohistochemical
analysis and can be difficult to interpret. The
multiplex PCR assay with built-in control reactions
could be a complementary clinical tool for the antemortem
diagnosis of toxoplasmosis or neosporosis
associated with the CNS. (Am J Vet Res 2003;64:1507–1513)
Objective—To determine whether mild restriction of
food intake affects clinicopathologic variables, body
composition, and performance of dogs undertaking
intense sprint exercise.
Animals—9 trained healthy adult Greyhounds.
Procedure—Dogs were offered food free choice
once daily for 9 weeks until body weight and food
intake stabilized. Dogs were then randomly assigned
to be fed either 85% or 100% of this quantity of food
in a crossover study (duration of each diet treatment
period, 9 weeks). Dogs raced a distance of 500 m
twice weekly. Clinicopathologic variables were
assessed before and 5 minutes after racing; food
intake, weight, body composition, body condition
score, and race times were compared at the end of
each diet period.
Results—Compared with values associated with
unrestricted access to food, there were significant
decreases in mean body weight (by 6%) and median
body condition score (from 3.75 to 3.5 on a 9-point
scale) and the mean speed of the dogs was significantly
faster (by 0.7 km/h) when food intake was
restricted. Body composition and most clinicopathologic
variables were unaffected by diet treatment, but
dogs given restricted access to food had slightly
fewer neutrophils, compared with values determined
when food intake was unrestricted.
Conclusions and Clinical Relevance—Results indicate
that the common practice among Greyhound
trainers of mildly restricting food intake of racing dogs
to reduce body weight does improve sprint performance.
A body condition score of approximately 3.5
on a 9-point scale is normal for a trained Greyhound in
racing condition. (Am J Vet Res 2005;66:1065–1070)