Procedure—Venous blood was collected from each
horse prior to and 0.25, 0.5, 0.75, 1, 2, 3, 4, 4.5, 5, and
6 hours after IV administration of 250 mg (first experiment)
or 500 mg (second experiment) of furosemide.
Urine was collected hourly between 1 and 6 hours after
administration of furosemide at both doses.
Concentrations of furosemide were determined by use
of an ELISA. Concentration of furosemide and urine
specific gravity was modeled as a function of time,
accounting for inter- and intrahorse variabilities. On the
basis of pharmacokinetic and specific gravity data, the
probability of exceeding a concentration of 100 ng of
furosemide/ml as a function of time was determined,
using a semiparametric smooth functional averaging
method. A bootstrap approach was used to assess the
inherent variation in this estimated probability.
Results—The estimated probability of exceeding the
threshold of 100 ng of furosemide/ml and urine specific
gravity < 1.012 was approximately 0% between
4.0 and 5.5 hours after IV administration of 250 mg of
furosemide/horse, and ranged from 0 to 1% between
4 and 5.5 hours after IV administration of 500 mg of
furosemide/horse. The probability of a horse being
falsely identified as in violation of regulatory concentrations
was inversely associated with time.
Conclusions and Clinical Relevance—Coupling plasma
furosemide concentration with urine specific gravity
testing will greatly reduce the chance that some horses
are misclassified as being in violation of regulatory concentrations.
(Am J Vet Res 2001;62:1349–1353)
Objective—To estimate the probability for exceeding
a threshold concentration of furosemide commonly
used for regulatory purposes after IV administration
of furosemide in horses.
Animals—12 mature healthy horses (6 Thoroughbreds
and 6 Quarter Horses).
Procedure—Venous blood was collected from each
horse prior to and 0.25, 0.5, 0.75, 1, 2, 3, 4, 4.5, 5, and
6 hours after administration of 250 or 500 mg of
furosemide. Concentrations of furosemide were
determined, using an ELISA. Concentration of
furosemide was modeled as a function of time,
accounting for inter- and intrahorse variabilities. On
the basis of pharmacokinetic data, the probability for
exceeding a concentration of 100 ng/ml as a function
of time was determined, using a semiparametric
smooth functional averaging method. A bootstrap
approach was used to assess inherent variation in
this estimated probability.
Results—The estimated probability of exceeding the
threshold of 100 ng of furosemide/ml ranged from
11.6% at 4 hours to 2.2% at 5.5 hours after IV administration
of 250 mg of furosemide/horse and 34.2% at
4 hours to 12.3% at 5.5 hours after IV administration
of 500 mg of furosemide/horse. The probability of a
horse being falsely identified in violation of regulatory
concentrations was inversely associated with time
and positively associated with dose.
Conclusions and Clinical Relevance—Interhorse
variability with respect to pharmacokinetics of
furosemide will result in misclassification of some
horses as being in violation of regulatory concentrations.
(Am J Vet Res 2001;62:320–325)
OBJECTIVE To identify courses in which first-year veterinary students struggled academically and to survey veterinarians as to their opinions on existing prerequisite courses and proposed alternatives.
DESIGN Electronic surveys.
SAMPLE Associate deans for academic affairs at colleges of veterinary medicine and practicing veterinarians in North America and the Caribbean.
PROCEDURES Surveys were sent to associate deans of academic affairs seeking information on courses in which first-year veterinary students most commonly struggled academically. The 6 courses most commonly listed as prerequisites for admission to veterinary college were identified, and practitioners were asked to rank the relative importance of those courses for preparing students for veterinary college and to rank the importance of 7 potential alternative courses.
RESULTS Data were obtained from 21 associate deans and 771 practicing veterinarians. First-year veterinary students most commonly struggled academically in anatomy, physiology, and histology courses, but these courses were rarely included as prerequisites for admission. Practicing veterinarians agreed that anatomy and physiology should be considered as possible alternatives to 1 or more current prerequisite courses, such as organic chemistry and physics.
CONCLUSIONS AND CLINICAL RELEVANCE First-year veterinary students commonly encountered academic difficulties in anatomy, physiology, and histology. Because few surveyed veterinary colleges include these courses as prerequisites for admission, many students were exposed to this material for the first time as veterinary students, potentially adding to their academic difficulties and causing stress and anxiety. To help address this situation, veterinary colleges might consider replacing 1 or more current prerequisite courses (eg, organic chemistry and physics) with anatomy, physiology, and histology.
Objective—To determine the value of serial measurements of peritoneal fluid lactate concentration (PFL) for detecting strangulating intestinal lesions (SLs) in referred horses with signs of colic.
Design—Retrospective cohort study.
Animals—94 horses with signs of colic.
Procedures—Medical records of horses evaluated between September 2006 and February 2010 because of signs of colic were reviewed. All included horses had ≥ 2 peritoneal fluid samples collected, including one at admission and another within 1 to 6 hours after admission. Of the 94 horses, 26 were assigned to the SL group on the basis of findings at surgery or necropsy and 68 were assigned to the nonstrangulating intestinal lesion group because their signs of colic resolved with medical management. Peritoneal fluid lactate concentration was measured by use of a handheld lactate monitor. Data were analyzed by use of univariable and multivariable logistic regression analysis.
Results—PFL at admission > 4 mmol/L, an increase in PFL over time, and especially an increase in PFL over time in horses with a PFL < 4 mmol/L at admission (OR, 62; sensitivity, 95%; specificity, 77%) were significant predictors of horses with an SL.
Conclusions and Clinical Relevance—Serially determined PFL was a strong predictor for differentiating horses with SLs from horses with nonstrangulating intestinal lesions. Given the high OR, sensitivity, and specificity of these tests, serially determined PFL may have potential as a screening test for identifying horses with SLs. Further evaluation of the clinical value of PFL for predicting SLs in a prospective, multicenter study is warranted.
OBJECTIVE To evaluate the effect of volume of IV regional limb perfusion (IVRLP) on amikacin concentrations in synovial and interstitial fluid of horses.
ANIMALS 8 healthy adult horses.
PROCEDURES Each forelimb was randomly assigned to receive IVRLP with 4 mL of amikacin sulfate solution (250 mg/mL) plus 56 mL (total volume, 60 mL) or 6 mL (total volume, 10 mL) of lactated Ringer solution. Horses were anesthetized, and baseline synovial and interstitial fluid samples were collected. A tourniquet was placed, and the assigned treatment was administered via the lateral palmar digital vein. Venous blood pressure in the distal portion of the limb was recorded. Additional synovial fluid samples were collected 30 minutes (just before tourniquet removal) and 24 hours after IVRLP began; additional interstitial fluid samples were collected 6 and 24 hours after IVRLP began.
RESULTS 30 minutes after IVRLP began, mean amikacin concentration in synovial fluid was significantly greater for the large-volume (459 μg/mL) versus small-volume (70 μg/mL) treatment. Six hours after IVRLP, mean concentration in interstitial fluid was greater for the large-volume (723 μg/mL) versus small-volume (21 μg/mL) treatment. Peak venous blood pressure after large-volume IVRLP was significantly higher than after small-volume IVRLP, with no difference between treatments in time required for pressure to return to baseline.
CONCLUSIONS AND CLINICAL RELEVANCE Study findings suggested that large-volume IVRLP would deliver more amikacin to metacarpophalangeal joints of horses than would small-volume IVRLP, without a clinically relevant effect on local venous blood pressure, potentially increasing treatment efficacy.
To evaluate the prophylactic efficacy of triclosan-coated (TC) suture in preventing surgical site infections (SSIs) in dogs and cats undergoing surgical procedures.
862 animals (794 dogs and 68 cats).
Incidences of SSI of surgical wounds closed with TC suture and surgical wounds closed with non-TC suture occurring between the time of surgery and 1 month postoperatively were compared. Animals were randomly assigned to TC or non-TC suture groups. When TC suture was assigned, all suture available as TC material was used rather than non-TC suture. Presence of an SSI was determined by an owner questionnaire or direct examination.
Overall, 50 of 862 (5.8%) animals developed SSIs. Incidence of SSI was 6% (24/428) in the non-TC suture group and 6% (26/434) in the TC suture group. No significant difference was found in the incidence of SSI between groups. No significant difference was detected in the incidence of incisional problems (eg, redness, dehiscence, and seroma formation) between animals in which TC suture was used and those in which non-TC suture was used. On multivariable analysis, other factors were associated with increased SSI rates, including an incision length > 10 cm, surgery performed by the soft tissue surgery department, and anesthesia duration of > 240 minutes.
CONCLUSIONS AND CLINICAL RELEVANCE
No significant difference in incidence of SSI was detected between animals undergoing surgical procedures performed with non-TC versus TC suture.
Objective—To evaluate fecal concentrations of
selected genera of colonic bacteria in healthy dogs,
and to investigate effects of dietary fructooligosaccharides
(FOS) on those bacterial populations.
Animals—6 healthy adult Beagles.
Procedure—Dogs were randomly assigned to 2
groups of 3 and fed an unsupplemented diet for 370
days. After 88 days, fecal samples were collected.
Another fecal sample was collected from each dog
282 days later. Group A then received a diet supplemented
with FOS, and group B continued to receive
the unsupplemented diet. Twenty-eight to 29 days
later, fecal samples were collected. Diets were
switched between groups, and fecal samples were
collected 31 and 87 days later. Concentrations of
Bifidobacterium spp, Lactobacillus spp, Clostridium
spp, Bacteroides spp, and Escherichia coli in freshly
collected feces were determined. Effects of diet and
time on bacterial concentrations were compared
Results—Bifidobacterium spp and Lactobacillus spp
were inconsistently isolated from feces of dogs fed
either diet. Sequence of diet significantly affected
number of Bacteroides spp subsequently isolated
from feces, but diet had no effect on numbers of
Clostridium spp or E coli.
Conclusions and Clinical Relevance—Some genera
of bacteria (eg, Bifidobacterium) believed to be common
components of colonic microflora may be only
sporadically isolated from feces of healthy dogs. This
deviation from expected fecal flora may have implications
for the effectiveness of supplementing diets
with prebiotics. (Am J Vet Res 2000;61:
Objective—To evaluate sensitivity and specificity of a
multiplex polymerase chain reaction (PCR) assay for
simultaneous detection of Rhodococcus equi and differentiation
of strains that contain the virulence-associated
gene (vapA) from strains that do not.
Sample Population—187 isolates of R equi from
equine and nonequine tissue and environmental
specimens and 27 isolates of bacterial species genetically
or morphologically similar to R equi.
Procedure—The multiplex PCR assay included 3
gene targets: a universal 311-bp bacterial 16S ribosomal
RNA amplicon (positive internal control), a 959-bp
R equi-specific target in the cholesterol oxidase gene
( choE ), and a 564-bp amplicon of the vapA gene.
Duplicate multiplex PCR assays for these targets and
confirmatory singleplex PCR assays for vapA and
choE were performed for each R equiisolate. An additional
PCR assay was used to examine isolates for the
Results—Results of duplicate multiplex and singleplex
PCR assays were correlated in all instances, revealing high specificity and reliability (reproducibility)
of the vapA multiplex assay. Of the pulmonary isolates
from horses with suspected R equi pneumonia,
97.4% (76/78) yielded positive results for vapA. Seven
of 50 (14%) human isolates of R equi yielded positive
results for vapA. Six human R equi isolates and 1
porcine isolate yielded positive results for vapB. No
isolates with vapA and vapB genes were detected.
Conclusions and Clinical Relevance—The multiplex
PCR assay is a sensitive and specific method for simultaneous
confirmation of species identity and detection
of the vapA gene. The assay appeared to be a useful
tool for microbiologic and epidemiologic diagnosis and
research. (Am J Vet Res 2005;66:1380–1385)
Objective—To determine the effect of azithromycin chemoprophylaxis on the cumulative incidence of pneumonia caused by Rhodococcus equi, age at onset of pneumonia, and minimum inhibitory concentration (MIC) of azithromycin for R equi isolates cultured from fecal and clinical samples.
Design—Controlled, randomized clinical trial.
Animals—338 foals born and raised at 10 equine breeding farms; each farm had a history of endemic R equi infections.
Procedures—Group 1 foals were control foals, and group 2 foals were treated with azithromycin (10 mg/kg [4.5 mg/lb], PO, q 48 h) during the first 2 weeks after birth. Foals were monitored for development of pneumonia attributable to R equi infection and for adverse effects of azithromycin. Isolates of R equi were tested for susceptibility to azithromycin.
Results—The proportion of R equi–affected foals was significantly higher for control foals (20.8%) than for azithromycin-treated foals (5.3%). Adverse effects of azithromycin treatment were not detected, and there were no significant differences between groups for the MICs of azithromycin for R equi isolates cultured from fecal or clinical samples.
Conclusions and Clinical Relevance—Azithromycin chemoprophylaxis effectively reduced the cumulative incidence of pneumonia attributable to R equi among foals at breeding farms with endemic R equi infections. There was no evidence of resistance to azithromycin. Nonetheless, caution must be used because it is possible that resistance could develop with widespread use of azithromycin as a preventative treatment. Further investigation is needed before azithromycin chemoprophylaxis can be recommended for control of R equi infections.
Objective—To determine sex, breed, and age distributions in a population of horses with cervical vertebral compressive myelopathy (CVCM), compared with contemporaneous control horses.
Design—Retrospective case-control study.
Animals—811 horses with CVCM and 805 control horses.
Procedures—The Veterinary Medical Database was searched to identify horses with CVCM and contemporaneous control horses registered between July 1974 and August 2007. Admission date, admitting institution, sex, breed, age at the time of registration in the database, weight, and discharge status (alive, died, or euthanized) were recorded for each case and control horse.
Results—On the basis of results of multivariable logistic regression analysis, geldings and sexually intact males had a significantly higher likelihood of having CVCM than females (odds ratio [OR], 2.0 [95% confidence interval, 1.5 to 2.6]; and OR, 2.4 [95% confidence interval, 1.8 to 3.2], respectively). Thoroughbreds, Tennessee Walking Horses, and Warm-bloods were overrepresented in the CVCM group, compared with Quarter Horses. Horses that ranged from < 6 months to < 7 years of age had significantly higher odds of having CVCM, compared with horses ≥ 10 years of age.
Conclusions and Clinical Relevance—Sex, breed, and age predilections were detected in horses with CVCM. Improved understanding of these factors will aid clinical recognition of the disease in groups that may have a high prevalence of CVCM or were previously not recognized to be commonly affected. The results may also stimulate future investigations to further delineate etiopathogenesis, such as breed-related genetic causality.