Objective—To evaluate the efficacy of disinfectant-filled foot mats at reducing tracking of Salmonella enterica and overall bacterial contamination on floors in a veterinary teaching hospital.
Samples—Bacteria collected from floors before and after placement of disinfectant-filled foot mats.
Procedures—Foot mats filled with a phenolic-based disinfectant were placed at key transition areas in common-use corridors between the large animal hospital (LAH) and small animal hospital in a veterinary medical teaching hospital. Microbiological samples were collected for total bacterial counts and for the presence of S enterica at 14 designated sample sites in the veterinary medical teaching hospital. Samples were collected at regular intervals for 7 months before mat placement and for 13 months after mat placement.
Results—Median numbers of aerobic bacteria isolated before and after disinfectant mat placement were not significantly different for most sites sampled. For 3 of the 4 transition areas between the LAH and connecting common-use corridor, there was a significant difference in median bacterial counts on either side of the threshold. This difference was significant regardless of whether a disinfectant mat was present or not. Salmonella enterica isolates were cultured from several sites in the LAH and sites outside the LAH, irrespective of the presence of a disinfectant mat.
Conclusions and Clinical Relevance—Disinfectant-filled mats may not be uniformly effective in reducing the bacterial load on floors or in reducing mechanical tracking of S enterica from contaminated areas in a veterinary teaching hospital. Further studies are needed to determine effective measures to reduce mechanical transmission of bacteria on footwear in veterinary hospitals.
Procedure—Each horse was anesthetized twice.
Romifidine was administered IV, and anesthesia was
induced by IV administration of ketamine. Anesthesia
was maintained for 75 minutes by administration of
halothane (HA) or IV infusion of romifidine, guaifenesin,
and ketamine (TIVA). The order for TIVA or HA
was randomized. Cardiopulmonary variables were
measured 40, 60, and 75 minutes after the start of HA
Results—Systolic, diastolic, and mean carotid arterial
pressures, velocity time integral, and peak acceleration
of aortic blood flow were greater, and systolic,
diastolic, and mean pulmonary arterial pressure
were lower at all time points for TIVA than for
HA. Pre-ejection period was shorter and ejection
time was longer for TIVA than for HA. Heart rate was
greater for HA at 60 minutes. Minute ventilation and
alveolar ventilation were greater and inspiratory time
was longer for TIVA than for HA at 75 minutes. The
PaCO2 was higher at 60 and 75 minutes for HA than
Conclusions and Clinical Relevance—Horses
receiving a constant-rate infusion of romifidine,
guaifenesin, and ketamine maintained higher arterial
blood pressures than when they were administered
HA. There was some indication that left ventricular
function may be better during TIVA, but influences of
preload and afterload on measured variables could
account for some of these differences. (Am J Vet Res
Objective—To examine the effects of flunixin meglumine
and etodolac treatment on recovery of ischemicinjured
equine jejunal mucosa after 18 hours of reperfusion.
Procedure—Jejunum was exposed to 2 hours of
ischemia during anesthesia. Horses received saline
(0.9% NaCl) solution (12 mL, IV, q 12 h), flunixin meglumine
(1.1 mg/kg, IV, q 12 h), or etodolac (23 mg/kg, IV,
q 12 h). Tissue specimens were obtained from
ischemic-injured and nonischemic jejunum immediately
after ischemia and 18 hours after recovery from
ischemia. Transepithelial electric resistance (TER) and
transepithelial flux of tritium-labeled mannitol measured
mucosal permeability. Denuded villous surface
area and mean epithelial neutrophil count per mm2
were calculated. Western blot analysis for cyclooxygenase
(COX)-1 and -2 was performed. Pharmacokinetics
of flunixin and etodolac and eicosanoid concentrations
Results—Ischemic-injured tissue from horses treated
with flunixin and etodolac had significantly lower TER
and increased permeability to mannitol, compared with
that from horses treated with saline solution. Epithelial
denudation after ischemia and 18 hours after recovery
was not significantly different among treatments. Both
COX-1 and -2 were expressed in ischemic-injured and
nonischemic tissues. Ischemia caused significant
upregulation of both COX isoforms. Eicosanoid concentrations
were significantly lower in tissues from flunixin
and etodolac-treated horses, compared with that
from horses treated with saline solution.
Conclusions and Clinical Relevance—Flunixin and
etodolac treatment retarded recovery of intestinal
barrier function in jejunal mucosa after 18 hours of
reperfusion, whereas tissues from horses treated
with saline solution recovered baseline values of TER
and permeability to mannitol. (Am J Vet Res
Objective—To use Doppler ultrasonography and singlefiber
laser Doppler flowmetry (LDF) to evaluate blood
flow in the dependent and nondependent hind limbs of
anesthetized horses and to evaluate changes in femoral
arterial blood flow and microvascular skeletal muscle
perfusion in response to administration of phenylephrine
hydrochloride or dobutamine hydrochloride.
Animals—6 healthy adult horses.
Procedure—Horses were anesthetized and positioned
in left lateral recumbency. Doppler ultrasonography
was used to measure velocity and volumetric flow in
the femoral vessels. Single-fiber LDF was used to
measure relative microvascular perfusion at a single
site in the semimembranosus muscles. Phenylephrine
or dobutamine was then administered to decrease or
increase femoral arterial blood flow, and changes in
blood flow and microvascular perfusion were recorded.
Results—Administration of phenylephrine resulted in
significant decreases in femoral arterial and venous
blood flows and cardiac output and significant
increases in mean aortic blood pressure, systemic
vascular resistance, and PCV. Administration of dobutamine
resulted in significant increases in femoral
arterial blood flow, mean aortic blood pressure, and
PCV. Significant changes in microvascular perfusion
were not detected.
Conclusion and Clinical Relevance—Results suggest
that Doppler ultrasonography and single-fiber LDF can
be used to study blood flows in the hind limbs of anesthetized
horses. However, further studies are required
to determine why changes in femoral arterial blood
flows were not associated with changes in microvascular
perfusion. (Am J Vet Res 2000;61:286–290)
Objective—To evaluate the hemodynamic effects of
dobutamine hydrochloride (0.5 µg/kg of body
weight/min) in halothane-anesthetized horses.
Animals—6 adult Thoroughbred horses.
Procedure—Anesthesia was induced by use of romifidine
(100 µg/kg) and ketamine (2.2 mg/kg), IV.
Anesthesia was maintained by halothane (end-tidal
concentration 0.9 to 1.0%). Aortic, left ventricular, and
right atrial pressures were measured, using cathetermounted
strain gauge transducers. Cardiac output
(CO), velocity time integral, maximal aortic blood flow
velocity and acceleration, and left ventricular preejection
period and ejection time were measured from aortic
velocity waveforms obtained by transesophageal
Doppler echocardiography. Velocity waveforms were
recorded from the femoral vessels, using Doppler ultrasonography.
The time-averaged mean velocity and early
diastolic deceleration slope (EDDS) were measured.
Pulsatility index (PI) and volumetric flow were calculated.
Microvascular perfusion was measured in the
semimembranosus muscles by laser Doppler flowmetry.
Data were recorded 60 minutes after induction of
anesthesia (control) and at 15 and 30 minutes after
start of an infusion of dobutamine (0.5 µg/kg/min).
Results—Aortic pressures were significantly
increased during the infusion of dobutamine. No
change was observed in the indices of left ventricular
systolic function including CO. Femoral arterial flow
significantly increased, and the PI and EDDS
decreased. No change was observed in the femoral
venous flow or in microvascular perfusion.
Conclusions and Clinical Relevance—At this
dosage, dobutamine did not alter left ventricular systolic
function. Femoral blood flow was preferentially
increased as the result of local vasodilatation. The lack
of effect of dobutamine on microvascular perfusion
suggests that increased femoral flow is not necessarily
associated with improved perfusion of skeletal
muscles. (Am J Vet Res 2000;61:1282–1288)
Objective—To determine the accuracy of cytologic diagnosis, compared with histologic diagnosis, in determination of disease in ultrasound-guided fine-needle aspirates of splenic lesions.
Sample Population—Splenic specimens from 29 dogs and 3 cats.
Procedures—Records were searched for dogs and cats that had undergone ultrasound-guided splenic aspiration. Criteria for inclusion were ultrasonographic identification of splenic lesions and cytologic and histologic evaluation of tissue from the same lesion. Cytologic samples were obtained by fine-needle aspiration, and histologic specimens were obtained via surgical biopsy, ultrasound-guided biopsy, or necropsy.
Results—Cytologic diagnoses corresponded with histologic diagnoses in 19 of 31 (61.3%) cases and differed in 5 of 31(16.1%) cases, and 1 aspirate was inadequate for evaluation. In 7 of 31 (22.6%) cases, histologic evaluation of tissue architecture was required to distinguish between reactive and neoplastic conditions. On the basis of histologic diagnosis in 14 animals with nonneoplastic conditions, the cytologic diagnosis was correct in 11 cases, not definitive in 2 cases, and incorrect in 1 case. In 17 animals with malignant neoplastic diseases, the cytologic diagnosis was correct in 8 cases, not definitive but consistent with possible neoplasia in 5 cases, and incorrect in 4 cases. Multiple similar-appearing nodules were significantly associated with malignancy, whereas single lesions were more often benign.
Conclusions and Clinical Relevance—Ultrasound-guided aspiration of splenic lesions is a minimally invasive tool for obtaining specimens for cytologic evaluation. Although cytologic diagnoses often reflect histologic results, if missampling or incomplete sampling occurs or tissue architecture is required to distinguish between reactive and neoplastic conditions, accurate diagnosis with fine-needle aspiration may not be possible.
Objective—To determine nonenteric sites associated
with Escherichia coli isolates in dogs and the antimicrobial
susceptibilities of the isolates.
Sample Population—17,000 canine specimens.
Procedure—Medical records of 17,000 canine specimens
submitted for bacteriologic culture were examined
and the number of isolations of E coli was determined.
For these cases, records were further examined
with respect to body system involvement, sex,
concurrent infection with other species of bacteria,
and antimicrobial susceptibility.
Results—674 E coli isolates (424 from urine, 62 from
the skin, 52 from the respiratory tract, 45 from the
ear, 43 from the female reproductive tract, 25 from
the male reproductive tract, and 23 from other organ
systems) were identified. There was a significantly
higher proportion of isolates from urine specimens
from spayed females than from sexually intact
females or males. Escherichia coli was isolated in
pure culture from 65.9% of the specimens. Most E
coli isolates were susceptible to norfloxacin (90%),
enrofloxacin (87.5%), gentamicin (90.7%), and
Conclusions and Clinical Relevance—Most nonenteric
E coli infections in dogs involve the urinary tract.
Amikacin, gentamicin, norfloxacin, and enrofloxacin
have the highest efficacy against canine E coli isolates.
For E coli isolates from dogs, in vitro susceptibility
to commonly used antimicrobial agents has
remained fairly stable during the past decade. (J Am
Vet Med Assoc 2001;218:381–384)
Procedure—Cardiac output was measured in 6 anesthetized
horses as lithium dilution cardiac output
(LiDCO), thermodilution cardiac output (TDCO), and
transesophageal Doppler echocardiographic cardiac
output (DopplerCO). For the LiDCO measurements,
lithium chloride was administered IV, and cardiac output
was derived from the arterial lithium dilution curve.
Sodium nitroprusside, phenylephrine hydrochloride,
and dobutamine hydrochloride were used to alter cardiac
output. Experiments were divided into 4 periods.
During each period, 3 LiDCO measurements, 3
DopplerCO measurements, and 3 sets of 3 TDCO
measurements were obtained.
Results—70 comparisons were made between
LiDCO, DopplerCO, and triplicate TDCO measurements
over a range of 10 to 43 L/min. The mean
(± SD) of the differences of LiDCO – TDCO was –0.86
± 2.80 L/min; LiDCO = –1.90 + 1.05 TDCO (r = 0.94).
The mean of the differences of DopplerCO – TDCO
was 1.82 ± 2.67 L/min; DopplerCO = 2.36 + 0.98
TDCO (r = 0.94). The mean of the differences of
LiDCO – DopplerCO was –2.68 ± 3.01 L/min; LiDCO =
–2.53 + 0.99 DopplerCO (r = 0.93).
Conclusions and Clinical Relevance—These results
indicate that lithium dilution is a suitable method for
measuring cardiac output in horses. As well as being
accurate, it avoids the need for pulmonary artery
catheterization and is quick and safe to use.
Monitoring cardiac output during anesthesia in horses
may help reduce the high anesthetic mortality in this
species. (Am J Vet Res 2000;61:731–737)