bluuebunny/crossref_metadata_2025 huggingface dataset:
Dual-energy X-ray absorptiometry measurement of bone-mineral density in the distal aspect of the limbs in racing Greyhounds
Authors: Emmerson Terrance D. , Lawes Timothy J. , Goodship Allen E. , Rueux-Mason Caroline , Muir Peter
Published: December 2005

Objective—To determine those bones in the distal aspect of the limbs of Greyhounds with fatigue fractures that have the greatest left-to-right differences in bone-mineral density (BMD).

Sample Population—Limbs obtained from 20 Greyhounds.

Procedure—Dual-energy x-ray absorptiometry (DXA) of the distal aspect of each limb and isolated bones from 10 dogs with a fracture of the central tarsal bone (CTB) of the right pelvic limb was performed. Highresolution scanning was performed on excised bones, and BMD measurements of CTB also were obtained from limbs of dogs without a CTB fracture.

Results—The BMD of the accessory carpal bone and calcaneus was not significantly different from the BMD of those bones in the contralateral limb. Although BMD of the CTB of the entire right pelvic limb and isolated bones from dogs with a CTB fracture was lower, compared with values for the entire left pelvic limb, values for isolated CTB from dogs without a CTB fracture were not significantly different. Metacarpal or metatarsal and thoracic or pelvic limb significantly affected BMD for measurements of the entire limb and isolated bones. Left-to-right differences in BMD were greatest for metacarpal 5.

Conclusions and Clinical Relevance—Asymmetric adaptive remodeling of metacarpal 5 can be detected by DXA. The potentially confounding effects of CTB fracture and unknown racing history made it difficult to interpret BMD changes in the CTB of these specimens. Densitometry could be developed as an in vivo assessment for risk of fractures in racing Greyhounds. (Am J Vet Res2000;61:1214–1219)
Effects of xylazine hydrochloride during isoflurane-induced anesthesia in horses
Authors: Steffey Eugene P. , Pascoe Peter J. , Woliner Michael J. , Berryman Edwin R.
Published: December 2005

Objective—To quantitate dose- and time-related anesthetic-sparing effects of xylazine hydrochloride (XYL) during isoflurane-induced anesthesia in horses and to characterize selected physiologic responses of anesthetized horses to administration of XYL.

Animals—6 healthy adult horses.

Procedure—Horses were anesthetized 2 times to determine the minimum alveolar concentration (MAC) of isoflurane in O2and to characterize the anestheticsparing effect (MAC reduction) after IV administration of XYL (0.5 and 1 mg/kg of body weight, random order). Selected measures of cardiopulmonary function, blood glucose concentrations, and urinary output also were measured during the anesthetic studies.

Results—Isoflurane MAC (mean ± SEM) was reduced by 24.8 ± 0.5 and 34.2 ± 1.9% at 42 ± 7 and 67 ± 10 minutes, respectively, after administration of XYL at 0.5 and 1 mg/kg. Amount of MAC reduction by XYL was dose- and time-dependent. Overall, cardiovascular and respiratory values varied little among treatments. Administration of XYL increased blood glucose concentration; the magnitude of change was dose- and time-dependent. Urine volume increased but not significantly.

Conclusions and Clinical Relevance—Administration of XYL reduced the anesthetic requirement for isoflurane in horses. The magnitude of the decrease is dose- and time-dependent. Administration of XYL increases blood glucose concentration in anesthetized horses in a dose-related manner. (Am J Vet Res2000;61:1225–1231)
Risk factors for outbreaks of disease attributable to white sturgeon iridovirus and white sturgeon herpesvirus-2 at a commercial sturgeon farm
Authors: Georgiadis Marios P. , Hedrick Ronald P. , Johnson Wesley O. , Yun Susan , Gardner Ian A.
Published: December 2005

Objective—To determine management, fish, and
environmental risk factors for increased mortality and
an increased proportion of runts for white sturgeon
exposed to white sturgeon iridovirus (WSIV) and
white sturgeon herpesvirus-2 (WSHV-2).

Animals—White sturgeon in 57 tanks at 1 farm and
observations made for fish at another farm.

Procedure—A prospective cohort study was conducted.
Data on mortality, proportion of runts, and
potential risk factors were collected. Five fish from
each tank were examined for WSIV and WSHV-2 via
inoculation of susceptible cell lines and microscopic
examination of stained tissue sections. An ANCOVA
was used to evaluate effects of risk factors on mortality
and proportion of runts.

Results—Major determinants of number of dead fish
(natural logarithm [ln]-transformed) were spawn,
source (90% confidence interval [CI] for regression
coefficient, 0.62 to 2.21), and stocking density (90%
CI, 0.003 to 0.03). Main predictors of proportion of
runts (ln-transformed) were spawn, mortality incidence
density (90% CI, 0.004 to 0.03), age (90% CI,
–0.012 to –0.004), and the difference in weight
between the largest and smallest nonrunt fish (90%
CI, 0.0002 to 1.24). Additional observations indicated
a possible protective effect attributable to previous
exposure to the viruses.

Conclusions and Clinical Relevance—Mortality and
proportion of runts for white sturgeon after exposure
to WSIV and WSHV-2 may be reduced for a farm at
which the viruses are endemic by selection of specific
broodstock, stocking with fish that survived outbreaks
of viral disease, using all-in, all-out production,
and decreasing stocking densities. (Am J Vet Res
2000;61:1232–1240)
Platelet aggregation in dogs with mitral valve regurgitation
Authors: Tanaka Ryou , Yamane Yoshihisa
Published: December 2005

Objective—To compare platelet aggregation in healthy dogs and dogs with mitral valve regurgitation (MVR) to determine whether regurgitation had an effect on platelet function.

Animals—32 dogs with MVR and 43 healthy dogs.

Procedure—Platelet aggregation was measured with an aggregometer, using adenosine 5'-diphosphate as the aggregating agent, and the maximum aggregation and the enhancement of platelet sensitivity (EPS) values were calculated.

Results—Platelet count and maximum aggregation were not significantly different between healthy dogs and dogs with MVR. However, EPS values in dogs with MVR were significantly higher than values in healthy dogs. Platelet count and maximum aggregation were not significantly different between dogs classified as New York Heart Association functional class I or II and dogs classified as functional class III or IV; however, EPS values were significantly higher in dogs classified as functional class III or IV.

Conclusions and Clinical Relevance—Results suggest that platelet aggregation is decreased in dogs with MVR and that the EPS value may be more sensitive to differences in disease severity than in measurement of maximum aggregation. (Am J Vet Res2000;61:1248–1251)
In vitro investigation of the effect of prostaglandins and nonsteroidal anti-inflammatory drugs on contractile activity of the equine smooth muscle of the dorsal colon, ventral colon, and pelvic flexure
Authors: Hoogmoed Linda M. Van , Snyder Jack R. , Harmon Faye
Published: December 2005

Objectives—To determine the in vitro effect of prostaglandin E2(PGE2), PGF2α, PGI2; and nonsteroidal anti-inflammatory drugs (NSAID; ie, flunixin meglumine, ketoprofen, carprofen, and phenylbutazone) on contractile activity of the equine dorsal colon, ventral colon, and pelvic flexure circular and longitudinal smooth muscle.

Animals—26 healthy horses.

Procedure—Tissue collected from the ventral colon, dorsal colon, and pelvic flexure was cut into strips and mounted in a tissue bath system where contractile strength was determined. Incremental doses of PGE2, PGF2α, PGI2, flunixin meglumine, carprofen, ketoprofen, and phenylbutazone were added to the baths, and the contractile activity was recorded for each location and orientation of smooth muscle.

Results—In substance P-stimulated tissues, PGE2and PGF2αenhanced contractility in the longitudinal smooth muscle with a decrease or no effect on circular smooth muscle activity. Prostaglandin I2inhibited the circular smooth muscle response with no effect on the longitudinal muscle. The activity of NSAID was predominantly inhibitory regardless of location or muscle orientation.

Conclusions and Clinical Relevance—In the equine large intestine, exogenous prostaglandins had a variable effect on contractile activity, depending on the location in the colon and orientation of the smooth muscle. The administration of NSAID inhibited contractility, with flunixin meglumine generally inducing the most profound inhibition relative to the other NSAID evaluated in substance P-stimulated smooth muscle of the large intestine. The results of this study indicate that prolonged use of NSAID may potentially predispose horses to develop gastrointestinal tract stasis and subsequent impaction. (Am J Vet Res2000;61:1259–1266)
Mutational analysis of tumor suppressor gene p53 in feline vaccine site-associated sarcomas
Authors: Nambiar Prashant R. , Haines Deborah M. , Ellis John A. , Kidney Beverly A. , Jackson Marion L.
Published: December 2005

Objectives—To investigate the role of tumor suppressor gene p53 mutation in feline vaccine site-associated sarcoma (VSS) development and to evaluate the relationship between p53 nucleotide sequence and protein expression.

Sample Population—Formalin-fixed paraffinembedded tissues of 8 feline VSS with dark p53 immunostaining (high p53 expression) and 13 feline VSS with faint or no staining (normal p53 expression).

Procedure—DNA was extracted from neoplastic and normal tissue from each paraffin block. The following 3 regions of the p53 gene were amplified by polymerase chain reaction: 379 base pair (bp) region of exon 5, intron 5, and exon 6, 108 bp region of exon 7, and 140 bp region of exon 8. Amplified p53 products were sequenced and compared with published feline p53. The p53 mutations identified were correlated with p53 mutations predicted by immunostaining.

Results—Neoplastic cells of 5 of 8 (62.5%) VSS that had high p53 expression harbored single missense mutations within the p53 gene regions examined. The p53 gene mutations were not detected in the 13 tumors with normal p53 immunostaining. Nonneoplastic tissues adjacent to all 21 VSS lacked mutations of these p53 gene regions.

Conclusions—The p53 gene mutations were restricted to neoplastic tissue and, therefore, were unlikely to predispose to VSS. However, p53 mutations may have contributed to cancer progression in 5 of the 21 VSS. There was very good (κ quotient = 0.67 with a confidence limit of 0.3 to 1.0), although not complete, agreement between prediction of mutation by p53 immunostaining and identification of mutations by sequencing of key p53 gene regions. (Am J Vet Res2000;61:1277–1281)
Effect of a 30-minute infusion of dobutamine hydrochloride on hind limb blood flow and hemodynamics in halothane-anesthetized horses
Authors: Raisis Anthea L. , Young Lesley E. , Blissitt Karen J. , Walsh Karen , Meire Hylton B. , Taylor Polly M. , Lekeux Pierre
Published: December 2005

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 Res2000;61:1282–1288)
Comparison of tear proteins of llamas and cattle
Authors: Gionfriddo Juliet R. , Melgarejo Tonatiuh , Morrison Elizabeth A. , Alinovi Catherine A. , Asem Elikplimi K. , Krohne Sheryl G.
Published: December 2005

Objective—To analyze and compare contents of the preocular tear films of llamas and cattle.

Animals—40 llamas and 35 cattle.

Procedure—Tear pH was determined by use of a pH meter. Total protein concentration was determined by use of 2 microtiter methods. Tear proteins were separated by use of electrophoresis and molecular weights of bands were calculated. Western blot immunoassay was used to detect IgA, lactoferrin, transferrin, ceruloplasmin, α1-antitrypsin, α1-amylase, and α2-macroglobulin. Enzyme electrophoresis was used to detect proteases.

Results—The pH of llama and cattle tears were 8.05 ± 0.01 and 8.10 ± 0.01, respectively. For results of both methods, total protein concentration of llama tears was significantly greater than that of cattle tears. Molecular weights of tear protein bands were similar within and between the 2 species, although llama tears had a distinct 13.6-kd band that was not detected in cattle. Lactoferrin, IgA, transferrin, ceruloplasmin, α1-antitrypsin, α1-amylase, α2–macroglobulin, and proteases were detected in both species.

Conclusions and Clinical Relevance—Llama tears have significantly greater total protein concentration than cattle tears, whereas pH is similar between species. Because little variation was detected within species for the number and molecular weight of protein bands, pooling of tears for analysis is justified. Results suggest that lactoferrin, ceruloplasmin, transferrin, α1-antitrypsin, α2-macroglobulin, α1-amylase, and IgA are present in the tears of llamas and cattle. (Am J Vet Res2000;61:1289–1293)
Detection of lysozyme in llama, sheep, and cattle tears
Authors: Gionfriddo Juliet R. , Davidson Harriet , Asem Elikplimi K. , Krohne Sheryl G.
Published: December 2005

Objective—To determine whether the tears of llamas, sheep, and cattle contain lysozyme and compare lysozyme concentrations in tears among these species.

Animals—40 llamas, 5 sheep, and 36 cattle.

Procedure—Electrophoresis, western blot immunoassay for lysozyme, a spectrophotometric assay to detect tear lysozyme by its ability to lyse a suspension ofMicrococcus lysodeiticus, and a microtiter plate colorometric assay were performed.

Results—A 13.6-kd protein band was detected by use of electrophoresis and western blot immunoassay in llama and sheep tears but not cattle tears. Results of spectrophotometric assay suggested that llama and sheep tears had high concentrations of lysozyme, whereas cattle tears had low concentrations. Results of the microtiter plate colorometric assay suggested that llama tears had high concentrations of lysozyme, whereas concentrations in sheep and cattle tears were lower.

Conclusions and Clinical Relevance—Lysozyme concentrations in tears may vary among species and this variability may contribute to differing susceptibilities to ocular diseases such as infectious keratoconjunctivitis. (Am J Vet Res2000;61:1294–1297)
In vitro comparison of metaphyseal and diaphyseal placement of centrally threaded, positive-profile transfixation pins in the equine third metacarpal bone
Authors: McClure Scott R. , Hillberry Ben M. , Fisher Kate E.
Published: December 2005

Objective—To evaluate in vitro holding power and associated microstructural and thermal damage from placement of positive-profile transfixation pins in the diaphysis and metaphysis of the equine third metacarpal bone.

Sample Population—Third metacarpal bones from 30 pairs of adult equine cadavers.

Procedure—Centrally threaded positive-profile transfixation pins were placed in the diaphysis of 1 metacarpal bone and the metaphysis of the opposite metacarpal bone of 15 pairs of bones. Tensile force at failure for axial extraction was measured with a materials testing system. An additional 15 pairs of metacarpal bones were tested similarly following cyclic loading. Microstructural damage was evaluated via scanning electron microscopy in another 6 pairs of metacarpal bones, 2 pairs in each of the following 3 groups: metacarpal bones with tapped holes and without transfixation pin placement, metacarpal bones following transfixation pin placement, and metacarpal bones following transfixation pin placement and cyclic loading. Temperature of the hardware was measured with a surface thermocouple in 12 additional metacarpal bones warmed to 38 C.

Results—The diaphysis provided significantly greater resistance to axial extraction than the metaphysis. There were no significant temperature differences between diaphyseal and metaphyseal placement. Microstructural damage was limited to occasional microfractures seen only in cortical bone of diaphyseal and metaphyseal locations. Microfractures originated during drilling and tapping but did not worsen following transfixation pin placement or cyclic loading.

Conclusions and Clinical Relevance—Centrally threaded, positive-profile transfixation pins have greater resistance to axial extraction in the diaphysis than in the metaphysis of equine third metacarpal bone in vitro. This information may be used to create more stable external skeletal fixation in horses with fractures. (Am J Vet Res2000;61:1304–1308)
Effects of 3-methylindole production and immunity against bovine respiratory syncytial virus on development of respiratory tract disease and rate of gain of feedlot cattle
Authors: Bingham Howard R. , Morley Paul S. , Wittum Thomas E. , Bray Tammy M. , Ellis John A. , Queen W. Greg , Shulaw William P.
Published: December 2005

Objective—To determine whether immunity against bovine respiratory syncytial virus (BRSV) mitigates the effects of 3-methylindole (3MI) on occurrence of bovine respiratory tract disease (BRD) and rate of gain in feedlot cattle.

Animals—254 mixed-breed beef cattle.

Procedure—Cattle were randomly assigned to 1 of 3 groups at the time of arrival at the feedlot. One group was vaccinated with an inactivated BRSV vaccine, another was vaccinated with a modified-live BRSV vaccine, and the third was maintained as unvaccinated control cattle. On days 0 and 28, serum BRSV antibody concentrations were measured, using serum neutralizing and ELISA techniques. Serum 3MI concentrations were measured at feedlot arrival and 3 days later. Cattle were monitored for development of BRD. At slaughter, lungs were evaluated grossly for chronic lesions.

Results—Higher serum 3MI concentrations early in the feeding period were associated with lower mean daily gain. Control cattle were more likely to be treated for BRD after day 3, compared with cattle vaccinated with the modified-live BRSV vaccine. Humoral immunity against BRSV did not appear to modify the effect of 3MI on development of BRD or mean daily gain.

Conclusions and Clinical Relevance—Results suggest that abrogating the effects of 3MI and BRSV infection may improve the health and growth performance of feedlot cattle. However, in this study, immunity against BRSV did not appear to protect against the potential synergism between 3MI and BRSV infection, possibly because of the slow rates of gain of cattle included in the study or timing of sample collection. (Am J Vet Res2000;61:1309–1314)
Activities of NADPH-dependent reductases and sorbitol dehydrogenase in canine and feline lenses
Authors: Salgado Diego , Forrer Rhea S. , Spiess Bernhard M.
Published: December 2005

Objective—To measure activities of NADPH-dependent
reductases and sorbitol dehydrogenase in lenses
from healthy dogs and cats.

Sample Population—Lenses from 37 dogs and 23
cats. All animals were healthy and had serum glucose
concentrations within reference limits.

Procedure—Lenses were homogenized, and activities
of NADPH-dependent reductases and sorbitol
dehydrogenase were measured spectrophotometrically.

Results—Activities of NADPH-dependent reductases
and sorbitol dehydrogenase were significantly lower
in lenses from cats than in lenses from dogs.
However, the ratio of NADPH-dependent reductases
activity-to-sorbitol dehydrogenase activity was significantly
higher in lenses from cats than in lenses from
dogs.

Conclusions and Clinical Relevance—Results indicate
that during periods of hyperglycemia, sorbitol
would accumulate at a faster rate in the lenses of cats
than in the lenses of dogs. Thus, the higher incidence
of diabetic cataracts in dogs, compared with cats, is
likely not attributable to a difference in the ratio of
NADPH-dependent reductases activity-to-sorbitol
dehydrogenase activity. (Am J Vet Res 2000;61:
1322–1324)
Reliability of two 2,400-m time-trial protocols for assessing performance of Standardbred racehorses
Authors: Shearman Jeremy P. , Hopkins Will G.
Published: December 2005

Objective—To evaluate the reliability of 2 time-trial protocols, 1 that involved use of a pacemaker and 1 that did not, for assessing performance of Standardbred racehorses.

Animals—3- to 7-year-old Standardbred maiden pacers.

Procedure—11 Standardbred pacers were used to determine the reliability of a time-trial protocol that involved use of a galloping pacemaker. All tests were performed by a single driver. Horses were paced for an initial 1,600 m then raced and timed for the final 800 m. They were retested 9 days later. Twenty-two horses were used to determine the reliability of a time-trial protocol that did not involve use of a pacemaker. All tests were performed by a second driver. Horses were paced for the first 1,200 m then raced and timed for the final 1,200 m. They were retested 3 and 8 days later.

Results—Reliability of performance time, expressed as the coefficient of variation (ie, the typical percentage variation in a horse's time between trials), was similar for the 2 protocols (1.0% and 1.3%, respectively).

Conclusions—The small variations in performance times for the 2 time-trial protocols were similar to those of the best comparable laboratory and field tests of human and equine performance. Both protocols would be suitable for investigating factors affecting performance of Standardbred racehorses. (Am J Vet Res2000;61:1339–1342)
Immediate urodynamic and anatomic response to colposuspension in female Beagles
Authors: Rawlings Clarence A. , Mahaffey Mary B. , Chernosky Adriene , Huzella Louis
Published: December 2005

Objective—To characterize urodynamic function and anatomy before and after colposuspension in anesthetized female Beagles.

Animals—12 adult female Beagles.

Procedure—During general anesthesia (thiopental sodium induction and halothane maintenance), urethral pressure profiles, leak point pressure measurements with a 50-ml bladder volume, positive contrast cystograms, and retrograde vaginourethrocystograms were performed. A caudal midline laparotomy was used to perform colposuspension. Urodynamic and radiographic studies were repeated after surgery.

Results—Leak point pressures were increased (120 to 168.9 cm H2O), and maximum urethral closure pressures decreased (43.7 to 19.3 cm H2O ) after colposuspension. The urethra and bladder were moved cranially; the external urethral orifice was positioned closer to the pelvic cavity, and the neck of the bladder was positioned more cranially into the abdomen. Length of the urethra, as measured by use of vaginourethrocystograms, was increased by 3%. As measured by use of urethral pressure profiles, total profile length was increased by 19.9%, and functional profile length was increased by 19.2%.

Conclusions and Clinical Relevance—Increased leak-point pressure correlated with the expected clinical improvement attributable to colposuspension. Increased exposure of the urethra to abdominal and pelvic cavity pressures may be the mechanism by which incontinent dogs become continent after colposuspension. Results of the leak-point pressure test may correlate with clinical behavior before and after colposuspension for treatment of incontinence. (Am J Vet Res2000;61:1353–1357)
Interleukin-8 concentration and neutrophil chemotactic activity in bronchoalveolar lavage fluid of horses with chronic obstructive pulmonary disease following exposure to hay
Authors: Franchini Marco , Gill Urs , Fellenberg Roland von , Bracher Verena D.
Published: December 2005

Objective—To analyze effects of hay dust exposure on interleukin-8 (IL-8) concentration, percentage of neutrophils, and neutrophil chemotactic activity in bronchoalveolar lavage fluid (BALF) of horses with chronic obstructive pulmonary disease (COPD).

Animals—16 healthy horses and 29 horses with COPD.

Procedure—IL-8 concentration, percentage of neutrophils, and neutrophil chemotactic activity in BALF were measured. Values were analyzed with respect to hay dust exposure. These variables were also measured in 5 asymptomatic horses with COPD after the induction of clinical signs by changing feed from silage to hay.

Results—IL-8 concentrations and chemotactic activity in BALF were greater in horses with COPD, compared with healthy horses, and greater in horses with COPD exposed to hay dust, compared with nonexposed affected horses. An increase in IL-8 concentration accompanied by an increase in percentage of neutrophils in BALF and development of clinical signs of COPD were induced in asymptomatic horses with COPD by changing feed from silage to hay.

Conclusions and Clinical Relevance—Exposure of horses with COPD to hay dust components resulted in an increase in IL-8 secretion at the bronchoalveolar surface. This chemokine may play a role in the pathogenesis of COPD, because it causes neutrophil accumulation in the bronchoalveolar space. Our results underscore the importance of eliminating dust sources for the treatment and prevention of COPD in horses. (Am J Vet Res2000;61:1369–1374)
Tyrosine hydroxylase- and neuropeptides-immunoreactive nerves in canine trachea
Authors: Yamamoto Yoshio , Ootsuka Tatsuya , Atoji Yasuro , Suzuki Yoshitaka
Published: December 2005

Objective—To determine distribution of catecholaminergic
and peptidergic nerve fibers in canine
tracheas by use of immunohistochemistry.

Sample Population—10 tracheas collected from
healthy adult dogs after euthanasia.

Procedure—Structure of the nerve network and distribution
of tyrosine hydroxylase (TH)- and 6 types of
neuropeptide-containing nerves in canine tracheas
were immunohistochemically studied, using neurochemical
markers.

Results—Intraepithelial free nerve endings with
immunoreactivity for calcitonin gene-related peptide
(CGRP) and substance P (SP) were observed. Tyrosine
hydroxylase-, SP-, vasoactive intestinal peptide (VIP)-,
and galanin (GAL)-immunoreactive nerve fibers were
observed within and around the submucosal seromucous
gland. In the smooth muscle layer, numerous
TH- and GAL-immunoreactive nerve fibers, a moderate
number of VIP- and neuropeptide Y (NPY)-
immunoreactive nerve fibers, and a few SP- and
methionine enkephalin (ENK)-immunoreactive nerve
fibers were observed. Numerous nerve cell bodies
with VIP and GAL immunoreactivity and a few with
SP, ENK, and NPY immunoreactivity were observed.
Many TH-immunoreactive fibers were arranged in a
meshwork around blood vessels. Nerves with CGRP-,
SP-, VIP-, GAL-, ENK-, and NPY-immunoreactivity were
also observed around blood vessels.

Conclusions—Complex innervation, including catecholamine-
and neuropeptide-containing nerves,
which may be related to regulation of muscle contraction
and glandular secretion, are found in canine
tracheas. (Am J Vet Res 2000;61:1380–1383)
Evaluation of toxicokinetic variables and histologic appearance of arthropathic changes in juvenile rabbits after oral administration of an investigational fluoroquinolone, PD 117596
Authors: Johnson Ron J. , Black William D. , Sigler Robert E. , Baragi Vijaykumar M. , Gough Alec W.
Published: December 2005

Objective—To compare toxicokinetic variables and
associated tissue drug concentrations with severity of
articular lesions in weight-bearing joints of juvenile
rabbits after oral administration of a fluoroquinolone.

Animals—Ten 6- to 7-week-old, 800- to 1,200-g, New
Zealand White rabbits.

Procedures—Rabbits were gavaged daily with the
fluoroquinolone PD 117596 at 500 mg/kg of body
weight for 5 days. Blood samples were collected on
day 4 at preestablished times, up to 24 hours after
drug administration. On day 5 gross lesion severity
and prevalence were evaluated in the major weight-bearing
joints, and tissue specimens were collected
(60 minutes after drug administration). Serum and tissue
drug concentrations were determined by microbiologic
plate assay.

Results—Macroscopically, treatment rabbits had a
high prevalence of arthropathy with the distal portion
of the femur having the highest prevalence and severity
of lesions. Grossly, alterations to articular cartilage
included 1 to 4 mm in diameter vesicles or erosions.
Histologically, vesicles were identified in the midzone
or close to the zone of calcified cartilage of treatment
rabbits. Chondrocyte cellularity was reduced in affected
areas, and perivesicular regions had reduced staining
with Safranin O. Correlation analysis of area under
the curve values with total scores for lesion severity
had a significant positive relationship.

Conclusions—Our findings support the use of juvenile
rabbits as a model for arthropathic changes
induced by fluoroquinolone administration. (Am J Vet
Res 2000;61:1396–1402)
Improved culture methods for isolation of Salmonella organisms from swine feces
Authors: Hoorfar J. , Mortensen A.Visby
Published: December 2005

Objective—To compare 3 alternative culture techniques
for the detection of Salmonella organisms in
swine feces with a modification of the International
Standard Organization (ISO) 6579 standard protocol.

Sample Population—Fecal samples from swine
herds suspected of having Salmonella infections.

Procedure—4 experiments were performed to evaluate
the following: 1) diagnostic sensitivity of the
selective preenrichment and rapid isolation novel
technology (SPRINT) protocol, compared with that of
the modified ISO protocol; 2) detection limit of the
SPRINT protocol for Salmonella organisms; 3) use of
tetrathionate-novobiocin (TTN) broth, compared with
selenite cysteine (SC) broth for selective enrichment;
and 4) use of universal preenrichment (UPE) broth,
compared with buffered peptone water (BPW) for
preenrichment of samples prior to the use of modified
semisolid Rappaport-Vassiliadis (MSRV) plates.

Results—Comparing the Salmonella culture results
of 183 swine fecal samples, the diagnostic sensitivity
of the SPRINT protocol (0.86) was not significantly different
than the diagnostic sensitivity of the modified
ISO protocol (0.80), although it was 24 hours faster.
The SPRINT protocol could detect 5 of the 6 investigated
Salmonella serotypes at inoculation concentrations
of < 10 colony-forming units (CFU)/25 g of
uncontaminated feces. The TTN broth performed significantly
better than the SC broth for selective enrichment
of Salmonella organisms. There was no significant
difference in results of preenrichment of samples
between the use of UPE broth or BPW.

Conclusions and Clinical Relevance—The SPRINT
protocol may provide a faster alternative for isolation
of Salmonella organisms from swine fecal samples.
Furthermore, the use of TTN broth instead of SC broth
may increase the sensitivity of the modified ISO 6579
protocol. (Am J Vet Res 2000;61:1426–1429)
Effect of dietary supplements containing antioxidants on attenuation of muscle damage in exercising sled dogs
Authors: Piercy Richard J. , Hinchcliff Kenneth W. , DiSilvestro Robert A. , Reinhart Gregory A. , Baskin Carole R. , Hayek Michael G. , Burr John R. , Swenson Richard A.
Published: December 2005

Objective—To determine whether dietary antioxidants would attenuate exercise-induced increases in plasma creatine kinase (CK) activity in sled dogs.

Animals—41 trained adult sled dogs.

Procedure—Dogs, randomly assigned to 2 groups, received the same base diet throughout the study. After 8 weeks on that diet, 1 group (21 dogs) received a daily supplement containing vitamins E (457 U) and C (706 mg) and β-carotene (5.1 mg), and a control group (20 dogs) received a supplement containing minimal amounts of antioxidants. After 3 weeks, both groups performed identical endurance exercise on each of 3 days. Blood samples were collected before and 3 weeks after addition of supplements and after each day of exercise. Plasma was analyzed for vitamins E and C, retinol, uric acid, triglyceride, and cholesterol concentrations, total antioxidant status (TAS), and CK activity.

Results—Feeding supplements containing antioxidants caused a significant increase in vitamin E concentration but did not change retinol or vitamin C concentrations or TAS. Exercise caused significantly higher CK activity, but did not cause a significant difference in CK activity between groups. Exercise was associated with significantly lower vitamin E, retinol, and cholesterol concentrations and TAS but significantly higher vitamin C, triglyceride, and uric acid concentrations in both groups.

Conclusions and Clinical Relevance—Use of supplements containing the doses of antioxidants used here failed to attenuate exercise-induced increases in CK activity. Muscle damage in sled dogs, as measured by plasma CK activity, may be caused by a mechanism other than oxidant stress. (Am J Vet Res2000;61:1438–1445)
Effects of tilmicosin phosphate, administered prior to transport or at time of arrival, and feeding of chlortetracycline, after arrival in a feedlot, on Mannheimia haemolytica in nasal secretions of transported steers
Authors: Frank Glynn H. , Duff Glenn C.
Published: December 2005

Objective—To determine effects of time of administration of tilmicosin and feeding of chlortetracycline on colonization of the nasopharynx of transported cattle byMannheimia haemolytica(MH).

Animals—454 steers (body weight, 200 kg).

Procedure—3 studies included 4 truckloads of steers assembled and processed in the southeastern United States. For each truckload of steers, a third received tilmicosin before transportation (PRIOR), then all were transported to a feedlot in New Mexico (23 hours). At arrival (day 0), another third received tilmicosin (ARR). The remaining third did not receive tilmicosin (control steers [CTR]). Steers in studies 1 and 2 were housed in a feedlot, and steers in study 3 were housed on wheat pasture. One half of the steers from each group in studies 2 and 3 were fed chlortetracycline on days 5 to 9. Steer with signs of respiratory tract disease were treated. Nasal swab specimens were examined for MH to determine colonization.

Results—PRIOR and ARR steers had a lower incidence of respiratory tract disease and MH colonization than CTR steers, but PRIOR and ARR steers did not differ. Feeding chlortetracycline did not have an effect.

Conclusions and Clinical Relevance—Tilmicosin can inhibit MH from colonizing the nasopharynx of cattle. Because tilmicosin inhibits the growth of MH in the respiratory tract, medication with tilmicosin prior to transport should reduce the incidence of acute respiratory tract disease during the first week at the feedlot when calves are most susceptible to infectious organisms. (Am J Vet Res2000;61: 1479–1483)
Evaluation of a method using Proteus mirabilis and Pseudomonas aeruginosa to experimentally induce dual infection of the urinary bladder in dogs
Authors: Bowles Mary H. , Welsh Ronald D. , Hoffman Jay , Turnwald Grant H.
Published: December 2005

Objective—To evaluate a method using Proteus
mirabilis and Pseudomonas aeruginosa to experimentally
induce dual infection of the urinary bladder in
dogs.

Animals—6 healthy mixed-breed dogs.

Procedure—Dogs were anesthetized, and cystitis
was induced by infusing a solution of salicylic acid in
ethanol into the bladder, followed by an inoculum containing
field isolates of P mirabilis and P aeruginosa.
Dogs were examined daily for 21 days after induction
of cystitis. On day 21, dogs were euthanatized, and
urinary bladder, renal pelvis, and prostate specimens
were submitted for bacterial culture.

Results—After induction of cystitis, all dogs had evidence
of thickening of the bladder wall, dysuria,
tenesmus, and hematuria. Urinalysis revealed proteinuria,
hematuria, and pyuria. All urine samples obtained
on day 21 yielded growth of P mirabilis, but P aeruginosa
was not cultured from any of these samples.
Proteus mirabilis was isolated from bladder, renal
pelvis, or prostate specimens from 4 dogs; P aeruginosa
was not isolated from any of the tissue specimens.

Conclusion—Results suggest that the method used
in the present study fails to induce dual infection of
the urinary bladder with P mirabilis and P aeruginosa.
The inability to establish a persistent dual infection
with this method may have been a result of insufficient
pathogenicity of the Pseudomonas isolate or an
inadequacy of the experimental design. (Am J Vet Res
2000;61:1484–1486)
Expression of inflammatory cytokine mRNA in lymphoid tissue from swine experimentally infected with Mycobacterium avium serovar 2
Authors: Hines II Murray E. , Frazier Kendall S.
Published: December 2005

Objective—To evaluate in situ expression of inflammatory cytokine mRNA in lymphoid tissue of swine experimentally infected withMycobacterium aviumserovar 2.

Animals—7 noninfected pigs and 7 pigs infected withM aviumserovar 2.

Procedure—Expression of mRNA of inflammatory cytokines such as tumor necrosis factor α (TNFα), interleukin (IL)-1β, IL-6, and IL-8 in formalin-fixed paraffin- embedded blocks of lymphoid tissue (lymph nodes and tonsil) of swine experimentally infected withM aviumserovar 2 was compared with that of noninfected pigs. Tissues were evaluated by use of morphologic localization of cytokine mRNA, using in situ hybridization at 160 days after inoculation.

Results—A noticeable increase in mRNA expression for TNFα and mild increases in mRNA expression of IL-8 and IL-1β were detected in mandibular lymph nodes from infected swine, compared with noninfected swine. Mild increase in mRNA expression for IL-6 also was observed in tonsils from infected swine. Cytokine mRNA was detected in macrophages and lymphocytes, primarily within cortical follicles and adjacent mantle zones.

Conclusions and Clinical Relevance—Expression of mRNA for inflammatory cytokines was increased in lymphoid tissue of infected swine, possibly resulting from local factors on, or secreted by,M avium. These results suggest that alterations in cytokine mRNA expression are important in the pathogenesis and clinical course of mycobacteriosis in swine. Modulation of the immune response by vaccines that selectively target cytokine expression and secretion in response to mycobacterial challenge may be effective in prevention of mycobacteriosis in swine. (Am J Vet Res2000;61:1487–1491)
Cyclooxygenase expression in canine platelets and Madin-Darby canine kidney cells
Authors: Kay-Mugford Patricia A. , Benn Sally J. , LaMarre Jonathan , Conlon Peter D.
Published: December 2005

Objective—To examine cyclooxygenase (COX) expression in canine platelets and Madin-Darby canine kidney (MDCK) cells in culture.

Sample Population—Canine platelets and MDCK cells.

Procedure—Total RNA was recovered from isolated canine platelets and MDCK cells. Northern blot analysis and reverse transcription-polymerase chain reaction (RTPCR), using complementary DNA probes and primers designed from the human COX sequences, were used to determine COX-1 and -2 (cyclooxygenase isoforms 1 and 2) messenger RNA (mRNA) expression.

Results—Following northern blot analysis, canine platelets were found to express only the 2.8-kb COX- 1 transcript; COX-2 was not detected. Canine MDCK cells expressed the 4.5-kb COX-2 transcript, in addition to the 2.8-kb COX-1 transcript. A single DNA band of 270 base pairs was identified following gel electrophoresis of the product obtained from RT-PCR of mRNA from canine platelets. Sequencing revealed that this PCR product was 90% homologous to a portion of the human COX-1 gene (Genbank M59979).

Conclusions and Clinical Relevance—Detection of COX-1 by RT-PCR of RNA obtained from canine platelets is a novel finding. The 90% homology of the PCR product with the human sequence suggests strong conservation between the canine and human COX-1 gene. Cloning and sequencing of the canine gene will be required to fully characterize homologous regions. Because of the importance of COX in the inflammatory process and as a potential target of currently available nonsteroidal anti-inflammatory drugs (NSAID), a better understanding of canine COX may improve our ability to use NSAID appropriately, achieve efficacy, and avoid potential adverse drug effects in dogs. (Am J Vet Res2000;61:1512–1516)
Morphologic alterations in the anterior lens capsule of canine eyes with cataracts
Authors: Bernays Michael E. , Peiffer Robert L.
Published: December 2005

Objective—To examine the morphologic changes in
the anterior lens capsule and lens epithelium of
canine eyes with cataracts.

Sample Population—Anterior lens capsules from
the eyes of 25 dogs with cataracts and from an additional
10 canine globes with lenses subjectively
assessed to be normal.

Procedure—Thickness of each anterior lens capsule
was measured by use of a digital microscopic camera
and imaging software. All 25 capsules from eyes with
cataracts were submitted for light microscopy; 4 were
also submitted for electron microscopy.

Results—Thickness of the anterior lens capsule
increased with age for the normal lenses and the
lenses with cataracts; the change with age was similar
for both groups. Light microscopy revealed fibrous
metaplasia of lens epithelial cells in 7 of 25 anterior
lens capsules with focal thickenings of the posterior
aspect of the capsule. Electron microscopy revealed
deposition of collagen and basement membrane-like
material by fibroblast-like cells.

Conclusions—Results indicate that thickness of the
anterior lens capsule in dogs increases with age and
that this increase in thickness is not significantly different
between normal lenses and lenses with
cataracts. In addition, epithelial cells from lenses
with cataracts may undergo metaplasia to form
plaques composed of fibrous tissue and ectopic basement
membrane produced by epithelial cells. (Am J
Vet Res 2000;61:1517–1519)
Use of canine red blood cell with high concentrations of potassium, reduced glutathione, and free amino acid as host cells for in vitro cultivation of Babesia gibsoni
Authors: Yamasaki Masahiro , Asano Hiroyuki , Otsuka Yayoi , Yamato Osamu , Tajima Motoshi , Maede Yoshimitsu
Published: December 2005

Objective—To determine the usefulness of canine RBC with high concentrations of potassium, reduced glutathione (GSH), and amino acid(ie, HK cells) for in vitro cultivation ofBabesia gibsoni.

Animals—RBC were obtained from 3 dogs that had inherited HK cells and from 3 genetically unaffected dogs that, therefore, had RBC with lower potassium (LK) concentrations (ie, LK cells).

Procedures—First,B gibsoniwere cultivated using HK or LK cells in alpha-modification of Eagle medium, consisting of Earle salts with glutamine and without ribosides, deoxyribosides, and sodium bicarbonate under a humidified atmosphere containing 5% CO2at 37 C. Second, parasites were cultivated with LK- or HK-cell lysates. Finally, HK cells were separated into 3 fractions (bottom, middle, top layers) by density gradient centrifugation, andB gibsoniwere cultivated with each of the HK-cell fractions. In addition, the concentrations of free amino acids and reduced glutathione (GSH) in each HK-cell fraction were measured.

Results—B gibsonipreferentially multiplied in HK-cell cultures rather than in LK-cell cultures. Furthermore, the addition of HK-cell lysate to the culture medium resulted in enhanced multiplication of the parasites. Higher multiplication of the parasites was observed in HK cells from the top layer, compared with HK cells from the middle and bottom layers. The HK cells from the top layer had higher concentrations of glutamate, aspartate, and GSH, compared with HK cells from the middle and bottom layer.

Conclusions—Canine HK cells are useful host cells for in vitro cultivation ofB gibsoni, and the high concentrations of glutamate, aspartate, and GSH may result in enhancement of multiplication of the parasites in HK cells. (Am J Vet Res2000;61:1520–1524)
Evaluation of intraocular pressure in eyes of clinically normal llamas and alpacas
Authors: Willis A. Michelle , Anderson David E. , Gemensky Anne J. , Wilkie David A. , Silveira Fernando
Published: December 2005

Objective—To estimate intraocular pressure (IOP) in eyes of healthy camelids, using applanation tonometry.

Animals—The eyes of 34 camelids (16 llamas [Lama glama] and 18 alpacas [L pacos]) that did not have major abnormalities of the ocular surface or intraocular abnormalities.

Procedure—Tonometry measurements were obtained from each eye 3 times during a 24-hour period. Each measurement was the mean of several corneal applanations obtained by use of an applanation tonometer. Data were analyzed, using an ANOVA for a repeated-measures design.

Results—Mean (± SEM) IOP of llamas and alpacas was 13.10 ± 0.35 and 14.85 ± 0.45 mm Hg, respectively. Range of IOP was 7 to 18 mm Hg for llamas and 11 to 21 mm Hg for alpacas. Mean IOP of llamas was significantly less than the mean IOP of alpacas. Significant differences in IOP were not detected between the right and left eye of animals. Significant differences in IOP were not attributed to sex, age, or time of measurement within llamas or alpacas.

Conclusions and Clinical Relevance—Establishing the mean and range of IOP of clinically normal llamas and alpacas provides a frame of reference that is important for use in a complete ophthalmic examination of camelids, which can assist clinicians in the diagnosis of glaucoma and uveitis. Reasons for the difference in mean IOP between llamas and alpacas are unknown. Although the difference may be unimportant clinically, this finding reiterates the fact that caution must be used when extrapolating IOP among species. (Am J Vet Res 2000;61:1542–1544)
Maintenance energy requirements and the effect of diet on performance of racing Greyhounds
Authors: Hill Richard C. , Bloomberg Mark S. , Legrand-Defretin Veronique , Burger Ivan H. , Hillock Sean M. , Sundstrom Deborah A. , Jones Galin L.
Published: December 2005

Objectives—To determine maintenance energy
requirements and effect of diet on performance of
racing Greyhounds.

Animals—7 adult racing Greyhounds.

Procedure—Dogs were fed a higher fat and protein
(HFP) or a lower fat and protein (LFP) diet for 8 weeks
in a crossover design. Dogs were exercised for 15
minutes twice daily in a paddock and raced 500 m
twice weekly. Blood gas, hematologic, and serum biochemical
analyses were performed before and after
racing, and race times were compared at the end of
each diet period.

Results—Mean race time was significantly shorter
(32.81± 0.65 seconds vs 33.05 ± 0.71 seconds), and
mean racing speed over 500 m was significantly
faster (15.25 ± 0.30 vs 15.13 ± 0.30 m·s–1) when dogs
were fed the HFP diet than when they were fed the
LFP diet. Diet had little or no effect on results of blood
gas, hematologic, and serum biochemical analyses,
except that Hct was 4% greater before and after racing
when the HFP diet was fed than when the LFP
diet was fed. Mean SD metabolizable energy intake
from weeks 1 through 16 was 155 ± 9 kcal·kg–0.75·d–1.

Conclusions and Clinical Relevance—Racing
Greyhounds ran faster when fed a diet containing
higher fat and protein and lower carbohydrate contents.
Their maintenance metabolizable energy
requirement was slightly higher than that of moderately
active dogs. (Am J Vet Res 2000;61:1566–1573)