bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of optimal immobilizing doses of a medetomidine hydrochloride and ketamine hydrochloride combination in captive reindeer
Authors: Ryeng Kathrine A. , Arnemo Jon M. , Larsen Stig
Published: December 2005

Objective—To establish optimal immobilizing doses of medetomidine hydrochloride (MED) with ketamine hydrochloride (KET) for hand- and dart-administered injections in captive reindeer.

Animals—12 healthy 6- to 9-month-old reindeer (Rangifer tarandus tarandus).

Procedure—An optimal dose was defined as a dose resulting in an induction time of 150 to 210 seconds, measured from the time of IM injection until recumbency. Initially, each stalled reindeer was immobilized by hand-administered injection. If the induction time was > 210 seconds, the dose was doubled for the next immobilization procedure. If it was < 150 seconds, the dose was halved for the next immobilization procedure. This iteration procedure was continued for each reindeer until an optimal dose was found. Later the reindeer was placed in a paddock and darted with its optimal dose as determined by hand-administered injection. Adjusting to a linear relationship between dose and induction time, optimal darting doses for each reindeer were predicted and later verified.

Results—The established mean optimal hand- and dart-administered doses were 0.10 mg of MED/kg of body mass with 0.50 mg of KET/kg, and 0.15 mg of MED/kg with 0.75 mg of KET/kg, producing mean induction times of 171 seconds and 215 seconds, respectively. The mean induction time after darting was 5 seconds greater than the upper limit of the predefined time interval.

Conclusions and Clinical Relevance—The higher dose requirement of MED-KET administration outdoors, compared with indoors, was explained by factors inherent in the darting technique and the different confinements. The iteration and the prediction methods seem applicable for determination of optimal doses of MED-KET in reindeer. The iteration and the prediction procedures may be used to reduce the number of experimental animals in dose-response studies in other species. (Am J Vet Res2001;62:119–126)
Cloning and characterization of a Moraxella bovis cytotoxin gene
Authors: Angelos John A. , Hess John F. , George Lisle W.
Published: December 2005

Objective—To identify theMoraxella boviscytotoxin gene.

Procedure—Hemolytic and nonhemolytic strains ofM boviswere compared by use of western blotting to identify proteins unique to hemolytic strains. Oligonucleotide primers, designed on the basis of amino acid sequences of 2 tryptic peptides derived from 1 such protein and conserved regions of theCandBgenes from members of the repeats in the structural toxin (RTX) family of bacterial toxins, were used to amplify cytotoxin-specific genes fromM bovisgenomic DNA. Recombinant proteins were expressed, and antisera against these proteins were produced in rabbits.

Results—Several proteins ranging in molecular mass from 55 to 75 kd were unique to the hemolytic strain. An open reading frame encoding a 927-amino acid protein with a predicted molecular mass of 98.8 kd was amplified fromM bovisgenomic DNA. The deduced amino acid sequence encoded by this open reading frame was homologous to RTX toxins. Antisera against the recombinant carboxy terminus encoded by this open reading frame neutralized hemolytic and cytolytic activities of nativeM boviscytotoxin.

Conclusions and Clinical Relevance—A gene was identified inM bovisthat encodes a protein with sequence homology to other RTX toxins. Results of cytotoxin neutralization assays support the hypothesis thatM boviscytotoxin is encoded by this gene and belongs in the RTX family of bacterial exoproteins. Identification of this gene and expression of recombinant cytotoxin could facilitate the development of improved vaccines against infectious bovine keratoconjunctivitis. (Am J Vet Res2001;62:1222–1228)
Assessment of lithium dilution cardiac output as a technique for measurement of cardiac output in dogs
Authors: Mason Douglas J. , O'Grady Micheal , Woods J. Paul , McDonell Wayne
Published: December 2005

Objectives—To determine agreement of cardiac output
measured by use of lithium dilution cardiac output
(LiDCO) and thermodilution cardiac output (TDCO)
techniques in dogs and to determine agreement of
low- and high-dose LiDCO with TDCO.

Animals—10 dogs (7 males, 3 females).

Procedure—Cardiac output was measured in anesthetized
dogs by use of LiDCO and TDCO techniques.
Four rates of cardiac output were induced by occlusion
of the caudal vena cava, changes in depth of
anesthesia, or administration of dobutamine. Lithium
dilution cardiac output was performed, using 2 doses
of lithium chloride (low and high dose). Each rate of
cardiac output allowed 4 comparisons between
LiDCO and TDCO.

Results—160 comparisons were determined of
which 68 were excluded. The remaining 92 comparisons
had values ranging from 1.10 to 12.80 L/min.
Intraclass correlation coefficient (ICC) between lowdose
LiDCO and TDCO was 0.9898 and between
high-dose LiDCO and TDCO was 0.9896. When all
LiDCO determinations were pooled, ICC was 0.9894.
For determinations of cardiac output < 5.0 L/min, ICC
was 0.9730. Mean ± SD of the differences of TDCO
minus LiDCO for all measurements was -0.084 ±
0.465 L/min, and mean of TDCO minus LiDCO for cardiac
outputs < 5.0 L/min was -0.002 ± 0.245 L/min.

Conclusions and Clinical Relevance—The LiDCO
technique is a suitable substitute for TDCO to measure
cardiac output in dogs. Use of LiDCO eliminates
the need for catheterization of a pulmonary artery and
could increase use of cardiac output monitoring,
which may improve management of cardiovascularly
unstable animals. (Am J Vet Res 2001;62:1255–1261)
Characteristics and management practices associated with milk production in dairy herds in Ohio enrolled in official Dairy Herd Improvement Association programs
Authors: Khaitsa Margaret L. , Wittum Thomas E. , Smith Kenneth L. , Henderson Janet L. , Hoblet Kent H.
Published: December 2005

Objective—To determine herd characteristics and management practices associated with milk production in dairy herds enrolled in official Dairy Herd Improvement Association (DHIA) programs in Ohio. Sample Population—186 dairy farms in Ohio.

Procedure—All herds in official DHIA programs in 9 counties were invited to participate. Information regarding herd characteristics and management practices was obtained, using a standardized questionnaire. Bulk-tank milk samples were obtained for bacteriologic culture. Official DHIA test-day records were obtained, and associations were identified, using multivariable ANOVA procedures.

Results—Of 479 eligible producers, 186 (39%) participated, and consecutive bulk-tank milk samples were available for culture from 172 (36%).Streptococcus agalactiae and Mycoplasmaspp were not recovered from bulk-tank milk samples, but Staphylococcus aureuswas recovered from 64 (37%) herds. Mean (± SD) number of lactating cows in participating herds was 97 ± 66, with 123 (66%) herds milking < 100 cows. The RHA was significantly associated with number of cows in milk, estimated percentage of herd detected in estrus, reported annual percentage of heifer calves born alive that died before 8 weeks old, percentage days in milk, use of bovine somatotropin during the preceding 2 years, and sex of the person completing the questionnaire.

Conclusions and Clinical Relevance—In this study, the strongest indicator of milk production was number of cows in milk. However, merely adding cows to a herd should not be considered to guarantee increased milk production, because other management traits could be confounded with increased number of cows in a herd. (Am J Vet Res2001;62:1262–1266)
Use of monoclonal antibodies to refine flow cytometric differential cell counting of canine bone marrow cells
Authors: Weiss Douglas J.
Published: December 2005

Objectives—To evaluate use of monoclonal antibodies
to increase accuracy of flow cytometric differential
cell counting of canine bone marrow cells.

Sample Population—Bone marrow specimens from
15 dogs.

Procedures—Specimens were labeled with monoclonal
antibodies that detected CD18, major histocompatability
antigen class-II (MHC class-II), CD14,
and Thy-1. Location of fluorescent and nonfluorescent
cells within gates of a template developed for canine
bone marrow differential cell counting was determined,
the template was revised, and 10 specimens
were analyzed by use of the old and revised templates
and by labeling cells with anti-MHC class-II and
anti-CD14.

Results—Data confirmed the presumptive location of
marrow subpopulations in scatter plots, permitted
detection of lymphocytes and monocytemacrophages,
and was used to revise the analysis
template used for differential cell counting. When differential
cells counts determined by the original and
revised templates were compared with results of
manual differential cell counts, the revised template
had higher correlation coefficients and more similar
mean values. Labeling cells with anti-MHC class-II
and anti-CD14 permitted identification of lymphoid
and monocyte-macrophages cells in bone marrow
specimens.

Conclusions and Clinical Relevance—Use of the
revised flow cytometric analysis template combined
with anti-CD14 and anti-MHC class-II antibody labeling
provides reliable differential cell counts for clinical
bone marrow specimens in dogs. These techniques
have potential applications to clinical bone marrow
examination and preclinical toxicity studies. (Am J Vet
Res 2001;62:1273–1278)
Use of dual energy x-ray absorptiometry for noninvasive body composition measurements in clinically normal dogs
Authors: Lauten Susan D. , Cox Nancy R. , Brawner William R. , Baker Henry J.
Published: December 2005

Objective—To determine quantitative values for components of body composition in clinically normal dogs of various breeds by use of dual energy x-ray absorptiometry (DEXA) and validate the precision and accuracy of DEXA technology in dogs.

Animals—103 clinically normal sexually intact adult dogs.

Procedure—In a cross-sectional study, Beagles, Pembroke Welsh Corgis, Golden Retrievers, Great Danes, Pointers, Rottweilers, and nonpurebred dogs received total body DEXA scans. For the validation portion of the study, the results of DEXA scans of 6 dogs were compared with values obtained by chemical analyses of tissues from euthanatized dogs to determine the accuracy of this modality in dogs.

Results—Results (coefficient of variation) of the precision tests ranged from 0.10% for lean tissue to 5.19% for fat tissue, whereas accuracy tests revealed a difference between percentage bone mineral content and ash values. Body composition differed by sex, such as higher lean tissue and bone mineral content in males within some breeds, and among breeds. Regardless of body size or weight, the percentage of body weight that was bone mineral ranged from 3 to 4.0%.

Conclusions and Clinical Relevance—Results of this cross-sectional study provide valuable body composition data for clinically normal adult dogs, which may have research and clinical applications. (Am J Vet Res2001;62:1295–1301)
Polymerase chain reaction analysis for viruses in paraffin-embedded myocardium from dogs with dilated cardiomyopathy or myocarditis
Authors: Maxson Tracy R. , Meurs Kathryn M. , Lehmkuhl Linda B. , Magnon Alex L. , Weisbrode Steven E. , Atkins Clarke E.
Published: December 2005

Objective—To perform polymerase chain reaction (PCR) analysis on paraffin-embedded myocardium from dogs with dilated cardiomyopathy (DCM) and dogs with myocarditis to screen for canine parvovirus, adenovirus types 1 and 2, and herpesvirus.

Sample Population—Myocardial specimens from 18 dogs with an antemortem diagnosis of DCM and 9 dogs with a histopathologic diagnosis of myocarditis were evaluated.

Procedure—Paraffin-embedded myocardial specimens were screened for viral genome by PCR analysis. Positive-control specimens were developed from cell cultures as well as paraffin-embedded tissue specimens from dogs with clinical and histopathologic diagnoses of viral infection with canine parvovirus, adenovirus types 1 and 2, and herpesvirus. The histologic characteristics of all myocardial specimens were classified regarding extent, location, and type of inflammation and fibrosis.

Results—Canine adenovirus type 1 was amplified from 1 specimen from a dog with DCM. Canine parvovirus, adenovirus type 2, and herpesvirus were not amplified from any myocardial specimens. Histologic analysis of specimens from dogs with DCM revealed variable amounts of fibrosis; myocardial inflammation was observed in 1 affected dog. Histopathologic analysis of specimens from dogs with myocarditis disclosed variable degrees of inflammation and fibrosis.

Conclusions and Clinical Relevance—Viral agents canine parvovirus, adenovirus types 1 and 2, and herpesvirus are not commonly associated with DCM or active myocarditis in dogs. Additional studies evaluating for nucleic acid from viruses that less commonly affect dogs or different types of infectious agents may be warranted to gain insight into the cause of DCM and myocarditis in dogs. (Am J Vet Res2001;62: 130–135)
Evaluation of equine immunoglobulin specific for Rhodococcus equi virulence-associated proteins A and C for use in protecting foals against Rhodococcus equi-induced pneumonia
Authors: Hooper-McGrevy Kathleen E. , Giguere Steve , Wilkie Bruce N. , Prescott John F.
Published: December 2005

Objective—To determine whether purified equine immunoglobulin specific forRhodococcus equivirulence- associated proteins A and C (VapA and VapC) can confer passive protection againstR equi-induced pneumonia in foals.

Animals—Twenty-eight 3-week-old mixed-breed pony foals.

Procedure—7 foals received IV injections of equine hyperimmune plasma (HIP) against whole-cellR equi, and 7 received purified equine immunoglobulin specific for VapA and VapC 1 day prior to intrabronchial infection withR equistrain 103+. Eleven foals were not treated prior to infection, and 3 control foals were neither treated nor infected. Heart rate, respiratory rate, and rectal temperature were recorded twice daily, and serum fibrinogen concentration and WBC count were determined every other day following infection. Foals were euthanatized 14 days following infection, and lung lesions and concentration ofR equiinlungs were assessed.

Results—The onset of clinical signs of pneumonia was significantly delayed in the HIP- and immunoglobulin-treated groups, compared with the untreated infected group. Moreover, pulmonary lesions were less severe in the treated groups, and significantly fewerR equiorganisms were cultured from the lungs of treated foals.

Conclusions and Clinical Relevance—Degree of protection againstR equi-induced pneumonia provided by purified immunoglobulin specific for VapA and VapC was similar to that provided by commercially available HIP. Results not only suggest that immunoglobulin is the primary component of HIP that confers protection againstR equi-induced pneumonia in foals but also indicate that antibodies againstR equiVapA and VapC are protective. (Am J Vet Res2001;62:1307–1313)
Characterization of house dust mite and scabiesmite allergens by use of canine serum antibodies
Authors: Schumann R. Jeffrey , Morgan Marjorie S. , Glass Robert , Arlian Larry G.
Published: December 2005

Objective—To identify the major allergenic proteins from the 3 main species of dust mites to which dogs react (Dermatophagoides farinae, D pteronyssinus,andEuroglyphus maynei) and evaluate the potential crossreactivity of dust mite allergens with antigens from the ectoparasitic miteSarcoptes scabieivarcanis.

Sample Population—Sera from 83 dogs with atopic dermatitis.

Procedure—Sodium dodecylsulfate-polyacrylamide gel electrophoresis and immunoblotting using serum from atopic dogs was used to identify IgE-binding proteins in extracts of the 4 mite species.

Results—Sera of atopic dogs contained IgE against 23, 17, 25, and 17 allergens fromD farinae, D pteronyssinus, E maynei,andS scabiei,respectively. Unlike the situation for humans, the major allergens for dogs are mostly proteins that are larger than 90 kd molecular weight.Dermatophagoides farinaeandE mayneiappear to be more allergenic for dogs than isD pteronyssinus. Some dogs with serum IgE against dust mites also had IgE against antigens ofS scabieivarcanis.

Conclusions and Clinical Relevance—Multiple dust mite allergens induce an IgE response in dogs. These allergens are mostly greater than 90 kd molecular weight. (Am J Vet Res2001;62:1344–1348)
Estimation of the probability for exceeding thresholds of urine specific gravity and plasma concentration of furosemide at various intervals after intravenous administration of furosemide in horses
Authors: Chu Karin K. , Cohen Noah D. , Stanley Scott D. , Wang Naisyin
Published: December 2005

Objective—To estimate the probability of concurrently exceeding thresholds for plasma concentration of furosemide and urine specific gravity after IV administration of furosemide in horses.

Animals—12 mature healthy Thoroughbred (n = 6) or Quarter Horse (6) mares.

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 Res2001;62:1349–1353)
Use of plasma creatine kinase pharmacokinetics to estimate the amount of exercise-induced muscle damage in Beagles
Authors: Chanoit Guillaume P. , Lefebvre Hervé P. , Orcel Karine , Laroute Valérie , Toutain Pierre-Louis , Braun Jean-Pierre
Published: December 2005

Objective—To assess the effects of moderate exercise on plasma creatine kinase (CK) pharmacokinetics and to estimate exercise-induced muscle damage in dogs.

Animals—6 untrained adult Beagles.

Procedure—The study was divided into 3 phases. In phase 1, dogs ran for 1 hour at a speed of 9 km/h, and samples were used to determine the area under the plasma CK activity versus time curve (AUC) induced by exercise. In phases 2 and 3, pharmacokinetics of CK were calculated in dogs during exercise and at rest, respectively. Values for AUC and plasma clearance (Cl) were used to estimate muscle damage.

Results—At rest, values for Cl, steady-state volume of distribution (Vdss), and mean retention time (MRT) were 0.32 ± 0.02 ml/kg of body weight/min, 57 ± 17.3 ml/kg, and 3.0 ± 0.57 h, respectively. During exercise, Cl decreased significantly (0.26 ± 0.03 ml/kg/min), MRT increased significantly, (4.4 ± 0.97 h), and Vdss remained unchanged. Peak of plasma CK activity (151 ± 58.8 U/L) was observed 3 hours after completion of exercise. Estimated equivalent amount of muscle corresponding to the quantity of CK released was 41 ± 29.3 mg/kg.

Conclusion and Clinical Relevance—These results revealed that exercise had a minor effect on CK disposition and that the equivalent amount of muscle damaged by moderate exercise was negligible. This study illustrates the relevance for use of the minimally invasive and quantitative pharmacokinetic approach when estimating muscle damage. (Am J Vet Res2001;62:1375–1380)
Age-related quantitative alterations in lymphocyte subsets and immunoglobulin isotypes in healthy horses
Authors: McFarlane Dianne , Sellon Debra C. , Gibbs Scott A.
Published: December 2005

Objective—To characterize age-associated changes in lymphocyte population subsets and immunoglobulin isotypes.

Animals—30 healthy young light-breed horses (5 to 12 years old) and 30 healthy aged light-breed horses (> 20 years old).

Procedure—Lymphocyte subset populations were identified, using monoclonal antibodies to cell surface markers CD5, CD4, CD8, and IgG. Subset populations were quantitated by use of flow cytometric analysis of antibody-stained cells. Serum immunoglobulin concentration was determined using single radial immunodiffusion.

Results—Absolute cell counts of total lymphocytes, T cells, CD4+and CD8+T cells, and B cells were decreased in aged horses, compared with young horses. There was a significant decrease in the percentage of CD8+cells and an increase in the CD4+-to- CD8+cell ratio in the aged population, compared with young horses. However, serum concentration of IgG, IgG(T), IgM, or IgA did not differ with age.

Conclusions and Clinical Relevance—In horses, total lymphocyte count and lymphocyte subset cell counts decrease with age. Age-matched control values are necessary for optimal evaluation of hematologic variables in aged horses. The decrease in lymphocyte subset cell counts in healthy aged horses mimics that seen in other species and may contribute to an age-associated decrease in immunocompetency. (Am J Vet Res2001;62:1413–1417)
Effect of chronic exposure to excess dietary copper and dietary selenium supplementation on liver specimens from rats
Authors: Aburto Enrique M. , Cribb Alastair E. , Fuentealba I. Carmen
Published: December 2005

Objective—To determine the effects of chronic exposure to excess dietary copper (Cu) on liver specimens from rats and the effects of dietary selenium (Se) supplementation in experimental Cu toxicosis.

Animals—60 weanling male Fischer 344 rats.

Procedure—Rats were randomly assigned to 4 groups of 15 rats each and fed 1 of the following 4 diets: high Cu (500 μg/g)/adequate Se (0.2 μg/g); high Cu (500 μg/g)/supplemented Se (2 μg/g); adequate Cu (18 μg/g)/adequate Se (0.2 μg/g); or, adequate Cu (18 μg/g)/supplemented Se (2 μg/g). Five rats per group were euthanatized after 3, 6, and 12 months, and liver specimens were obtained for histologic examination, histochemistry, metal analysis by atomic absorption spectrophotometry, measurement of glutathione peroxidase activity, and assessment of lipid peroxidation, using quantification of malondialdehyde (MDA) by the thiobarbituric acid reaction.

Results—Hepatic Cu concentration was significantly higher in rats fed high Cu diets (range, 9 to 18 μg/g of tissue [wet weight]), compared with rats receiving adequate Cu diets (4.0 to 5.7 μg/g of tissue). Rats fed high-Cu diets for 3, 6, and 12 months had mild multifocal hepatitis often surrounding necrotic foci. However, an increase in hepatic MDA content, indicative of lipid peroxidation, was not detected in these rats. Development of morphologic changes was not prevented by use of dietary Se supplementation.

Conclusion and Clinical Relevance—Long-term exposure to excess dietary Cu caused mild hepatic lesions in Fischer 344 rats. Dietary Se supplementation did not prevent hepatic damage in rats with Cu toxicosis. (Am J Vet Res2001;62:1423–1427)
Pathogenicity of four strains of entomopathogenic fungi against the bovine tick Boophilus microplus
Authors: Onofre Sideney B. , Miniuk Cindia M. , de Barros Neiva M. , Azevedo João L.
Published: December 2005

Objective—To evaluate the pathogenicity of 4 strains
of the entomopathogenic fungi Metarhizium flavoviride
var flavoviride and Metarhizium anisopliae var
anisopliae in vitro against the bovine tick Boophilus
microplus.

Sample Population—300 B microplus females were
used for each series of 5 conidial suspensions of the
4 fungal strains; a control group of 60 females was
treated with sterilized water.

Procedure—For each fungal strain, sporulating cultures
were used to produce conidial suspensions
containing 104, 105, 106, 107, and 108 conidia/ml. A
bioassay was performed by immersing B microplus
females in conidial suspensions; the procedure was
repeated with a new group of 60 females for each
dilution (a total of 300). A control group was
immersed in the same volume of sterilized distilled
water. Ticks were maintained at 27 C and 80% relative
humidity for 7 days, and the following variables
were evaluated: weight before egging, egging
weight, percentage eclosion, reproductive efficiency,
and percentage control.

Results—A low index of eclosion was found in the
treated groups, with a progressive decrease in percentage
eclosion (control = 100%) with increased
conidial concentration. The highest level of effectiveness
of biocontrol was detected in groups treated
with concentrations of 107 and 108 conidia/ml.

Conclusions and Clinical Relevance—Strains of the
entomopathogenic fungi M anisopliae var anisopliae
and M flavoviride var flavoviride were effective as biological
control agents against B microplus, with M
flavoviridestrain CG-291 being the most effective. The
pathogenicity of these strains and the development
of an application method for this fungus for control of
ticks may result in improved animal productivity and a
reduction in environmental pollution through the use
of fewer chemical insecticides. (Am J Vet Res
2001;62:1478–1480)
Correlation of QT dispersion with indices used to evaluate the severity of familial ventricular arrhythmias in Boxers
Authors: Spier Alan W. , Meurs Kathryn M. , Muir William W. , Lehmkuhl Linda B. , Hamlin Robert L.
Published: December 2005

Objective—To measure QT interval duration and QT
dispersion in Boxers and to determine whether QT
variables correlate with indices of disease severity in
Boxers with familial ventricular arrhythmias, including
the number of ventricular premature complexes per
day, arrhythmia grade, and fractional shortening.

Animals—25 Boxers were evaluated by ECG and
echocardiography.

Procedure—The QT interval duration was measured
from 12-lead ECG and corrected for heart rate (QTc),
using Fridericia's formula. The QT and QTc were calculated
for each lead, from which QT and QTc dispersion
were determined. Echocardiography and 24-hour
ambulatory ECG were performed to evaluate for
familial ventricular arrhythmias. Total number of ventricular
premature complexes, arrhythmia grade, and
fractional shortening were determined and used as
indices of disease severity.

Results—There was no correlation between any QT
variable and total number of ventricular premature
complexes, arrhythmia grade, or fractional shortening.
No difference between QT dispersion and QTc
dispersion was identified, and correction for heart rate
did not affect the results.

Conclusions and Clinical Relevance—QT interval
duration and dispersion did not correlate with indices
of disease severity for familial ventricular arrhythmias.
Heart rate correction of the QT interval did not appear
to be necessary for QT dispersion calculation in this
group of dogs. QT dispersion does not appear to be a
useful noninvasive diagnostic tool in the evaluation of
familial ventricular arrhythmias of Boxers.
Identification of affected individuals at risk for sudden
death remains a challenge in the management of this
disease. (Am J Vet Res 2001;62:1481–1485)
Effects of the synthetic selectin inhibitor TBC1269 on tissue damage during acute Mannheimia haemolytica-induced pneumonia in neonatal calves
Authors: Radi Zaher A. , Caverly Jessica M. , Dixon Richard A. , Brogden Kim A. , Ackermann Mark R.
Published: December 2005

Objective—To determine effects of the selectin inhibitor TBC1269 on neutrophil-mediated pulmonary damage during acuteMannheimia haemolytica-inducedpneumonia in newborn calves.

Animals—Eighteen 1- to 3-day-old colostrumdeprived calves.

Procedure—Mannheimia haemolyticaor saline (0.9% NaCl) solution was inoculated in both cranial lung lobes of 12 and 6 calves, respectively. Calves were euthanatized 2 (saline, n = 3;M haemolytica, n = 4) or 6 hours (saline, n = 3;M haemolytica, n = 8) after inoculation. FourM haemolytica-inoculated calves euthanatized at 6 hours also received TBC1269 (25 mg/kg, IV) 30 minutes before and 2 hours after inoculation. Conjugated diene (CD) concentrations, inducible nitric oxide synthase (iNOS) expression, and apoptotic cell counts were determined in lung specimens collected during necropsy.

Results—Conjugated diene concentrations were significantly increased in allM haemolytica-inoculated groups, compared with saline-inoculated groups. Calves treated with TBC1269 had decreased concentrations of CD, compared with untreated calves, although the difference was not significant. Number of apoptotic neutrophils and macrophages increased significantly in TBC1269-treated calves, compared with untreated calves. Inducible nitric oxide synthase was expressed by epithelial cells and leukocytes. However, iNOS was less abundant in airway epithelial cells associated with inflammatory exudates. Degree of iNOS expression was similar between TBC1269-treated and untreated calves.

Conclusions—Mannheimia haemolyticainfection in neonatal calves resulted in pulmonary tissue damage and decreased epithelial cell iNOS expression. The selectin inhibitor TCB1269 altered, but did not completely inhibit, neutrophil-mediated pulmonary damage. (Am J Vet Res2001;62:17–22)
Reliability of three bulk-tank antimicrobial residue detection assays used to test individual milk samples from cows with mild clinical mastitis
Authors: Gibbons-Burgener Suzanne N. , Kaneene John B. , Lloyd James W. , Leykam Joseph F. , Erskine Ronald J.
Published: December 2005

Objective—To determine the likelihood of false-positive results when testing milk samples from individual cows by use of 3 commercially available assays (Penzyme Milk Test and the SNAP β-lactamand Delvo- SP assays) labeled for use with commingled milk.

Sample Population—Milk samples from 111 cows with mild clinical mastitis.

Procedure—Cows were randomly assigned to the control (no antimicrobials) or intramammary treatment group. Posttreatment milk samples were collected at the first milking after the labeled withholding period or an equivalent time for controls, randomly ordered, and tested twice by use of each assay and once by use of high-performance liquid chromatography. Sensitivity, specificity, and positive and negative predictive values were determined for each assay. Concordance of results for the same sample was assessed for each assay by calculating κ.

Results—Sensitivities of the Delvo-SP and SNAP β-lactam assays were > 90%, whereas the sensitivity of the Penzyme Milk Test was 60%. Positive predictive values (range, 39.29 to 73.68%) were poor for all 3 assays. Concordance of test results was excellent for the SNAP β-lactam and Delvo-SP assays (κ = 0.846 and 0.813, respectively) but was less for the Penzyme Milk Test (κ = 0.545).

Conclusions and Clinical Relevance—Because of the low positive predictive values, these 3 assays may not be useful for detecting violative antimicrobial residues in individual milk samples from cows treated for mild clinical mastitis. However, repeatability of each assay was considered good to excellent. (Am J Vet Res2001;62:1716–1720)
Additive effects of a sodium chloride restricted diet and furosemide administration in healthy dogs
Authors: Lovern Cindy S. , Swecker William S. , Lee John C. , Moon Martha L.
Published: December 2005

Objective—To determine the effects of a low or high
sodium (Na) diet with or without furosemide administration
on plasma electrolyte concentrations and the
renin-angiotensin-aldosterone system in healthy
dogs.

Animals—20 healthy adult dogs.

Procedure—Dogs were randomly allotted to 4 groups
of 5 dogs each as follows: dogs fed a low Na diet
(0.08% Na and 0.8% chloride [Cl] on a dry matter
[DM] basis); dogs fed a low Na diet with added NaCl
(1.0% Na and 2.2% Cl on a DM basis); dogs fed a low
Na diet and treated with furosemide (2 mg/kg of body
weight, PO, q 12 h); and dogs fed a low Na diet with
added NaCl and treated with furosemide. Plasma
electrolyte concentrations were measured on days 0,
21, and 35. Plasma renin activity and aldosterone concentration
were analyzed by use of radioimmunoassays
on days 0, 21, 35, and 53.

Results—Furosemide treatment significantly decreased
plasma Cl concentration and significantly
increased plasma renin activity and aldosterone concentration.
Dogs fed a low Na diet had significantly
higher plasma renin activities and plasma aldosterone
concentrations. A significant interaction between a
low Na diet and furosemide administration resulted in
the lowest plasma Cl concentrations, highest plasma
renin activities, and highest plasma aldosterone concentrations.

Conclusions and Clinical Relevance—In healthy
dogs, feeding a low Na diet and administering
furosemide resulted in an additive effect on plasma Cl
concentration, renin activity, and aldosterone concentration,
which may be an important consideration for
treating dogs with cardiac disease. (Am J Vet Res
2001;62:1793–1796)
Molecular and genetic basis for thrombasthenic thrombopathia in Otterhounds
Authors: Boudreaux Mary K. , Catalfamo James L.
Published: December 2005

Objectives—To determine the molecular and genetic
basis for thrombasthenic thrombopathia in Otterhounds
and establish whether the defect would be
best classified as type-I Glanzmann's thrombasthenia.

Animals—57 dogs, including 13 affected Otterhounds,
23 carrier Otterhounds, 17 unaffected
Otterhounds, and 4 clinically normal unrelated dogs of
other breeds.

Procedure—Functional (platelet aggregation, clot
retraction, buccal mucosa bleeding time) and biochemical
(electrophoresis, flow cytometry, fibrinogen
content) analyses were conducted. In addition, firststrand
cDNA synthesis from platelet total RNA was
performed. Exons of the genes encoding for glycoproteins
(GP) IIb and IIIa were amplified in overlapping
fashion. The resulting products were excised from
agarose gels and sequenced. The sequences
obtained were compared with known cDNA
sequences for canine GPIIb and GPIIIa.

Results—A single nucleotide change at position
G1193 (1100) was detected in exon 12 of the gene
encoding for platelet GPIIb in 2 affected Otterhounds.
Carrier Otterhounds were heterozygous at this position,
and 2 unaffected Otterhounds were unchanged.
This nucleotide change would result in substitution of
histidine for aspartic acid at position 398 (367) within
the third calcium-binding domain of GPIIb.

Conclusions and Clinical Relevance—These studies
suggest that thrombasthenic thrombopathia of
Otterhounds is homologous phenotypically and has a
similar molecular basis to type-I Glanzmann's thrombasthenia
in humans. (Am J Vet Res 2001;62:1797–1804)
Comparison of endogenous feline leukemia virus RNA content in feline vaccine and nonvaccine site-associated sarcomas
Authors: Kidney Beverly A. , Ellis John A. , Haines Deborah M. , Jackson Marion L.
Published: December 2005

Objective—To determine whether feline vaccine siteassociated sarcomas (VSS) contain a higher amount of endogenous FeLV (enFeLV) RNA, compared with feline nonvaccine site-associated sarcomas (non-VSS).

Sample Population—Formalin-fixed paraffin-embedded (FFPE) tissues from 50 VSS and 50 cutaneous non-VSS.

Procedure—RNA was extracted from FFPE sections of each tumor, and regions of the long terminal repeat (LTR) and envelope (env) gene of enFeLV were amplified by use of reverse transcriptase-polymerase chain reaction (RT-PCR). The density of each RT-PCR product band for enFeLV was compared with that of a constitutively expressed gene, glyceraldehyde-3-phosphate dehydrogenase (GAPDH). An integrated density value (IDV) was determined by use of densitometry, and the IDV ratio for enFeLV to GAPDH was calculated for each enFeLV primer set.

Results—The median (interquartile range) of the IDV ratio for the enFeLV LTR primer set was 0.52 (0.26 to 1.17) for the VSS group and 0.84 (0.21 to 1.53) for the non-VSS group. The median (interquartile range) of the IDV ratio for the enFeLVenvprimer set was 0.60 (0.37 to 0.91) for the VSS group and 0.59 (0.36 to 1.09) for the non-VSS group.

Conclusions—Because the amount of enFeLV RNA within the LTR andenvgene was not significantly different between the VSS and non-VSS groups, enFeLV replication or expression is unlikely to be involved in VSS development. (Am J Vet Res2001;62:1990–1994)
Evaluation of an in-shoe pressure measurement system in horses
Authors: Judy Carter E. , Galuppo Larry D. , Snyder Jack R. , Willits Neil H.
Published: December 2005

Objective—To develop an objective, accurate method for quantifying forelimb ground reaction forces in horses by adapting a human in-shoe pressure measurement system and determine the reliability of the system for shod and unshod horses.

Animals—6 adult Thoroughbreds.

Procedure—Horses were instrumented with a human in-shoe pressure measurement system and evaluated at a trot (3 m/s) on a motorized treadmill. Maximum force, stance time, and peak contact area were evaluated for shod and unshod horses. Three trials were performed for shod and unshod horses, and differences in the measured values were examined with a mixed model ANOVA for repeated measures. Sensor accuracy was evaluated by correlating measured variables to clinically observed lameness and by a variance component analysis.

Results—4 of 6 horses were determined to be lame in a forelimb on the basis of clinical examination and measured values from the system. No significant differences were observed between shod and unshod horses for maximum force and stance time. A significant decrease in peak contact area was observed for shod and unshod horses at each successive trial. Maximum force measurements provided the highest correlation for detecting lameness (r= 0.91, shod horses;r= 1.0, unshod horses). A variance component analysis revealed that 3 trials provided a variance of 35.35 kg for maximum force (± 5.78% accuracy), 0.007 seconds for stance time (± 2.5% accuracy), and 8.58 cm2 for peak contact area (± 11.95% accuracy).

Conclusions and Clinical Relevance—The in-shoe pressure measurement system provides an accurate, objective, and effective method to evaluate lameness in horses. (Am J Vet Res2001;62:23–28)
Evaluation of a polyvalent enzyme-linked immunosorbent assay incorporating a recombinant p44 antigen for diagnosis of granulocytic ehrlichiosis in dogs and horses
Authors: Magnarelli Louis A. , IJdo Jacob W. , Van Andel Amy E. , Wu Caiyun , Fikrig Erol
Published: December 2005

Objective—To develop and evaluate a polyvalent ELISA incorporating a highly specific recombinant antigen (p44) for diagnosis of granulocytic ehrlichiosis in dogs and horses.

Animals—32 dogs and 43 horses.

Procedure—Results of the ELISA were compared with results of indirect fluorescent antibody (IFA) staining and western immunoblotting incorporating whole-cell antigen.

Results—For the canine and equine samples, percentages of samples with positive IFA staining, western immunoblotting, and ELISA results were similar. For 29 (91%) canine samples and 30 (70%) equine samples, results of IFA staining, western immunoblotting, and the ELISA were in complete agreement. Results of the ELISA for 3 canine serum samples known to contain antibodies toEhrlichia canisand 12 equine serum samples known to contain antibodies toE risticiiwere negative.

Conclusions and Clinical Relevance—Results of the present study suggest that a polyvalent ELISA incorporating a recombinant p44 antigen is suitable for detecting antibodies toE equiin dogs and horses. (Am J Vet Res2001;62:29–32)
Evaluation of the safety of an abbreviated course of injections of allergen extracts (rush immunotherapy) for the treatment of dogs with atopic dermatitis
Authors: Mueller Ralf S. , Bettenay Sonya V.
Published: December 2005

Objective—To evaluate the safety of an abbreviated course of injections of allergen extracts (rush immunotherapy) for the treatment of dogs with atopic dermatitis.

Animals—30 dogs with atopic dermatitis examined at a veterinary dermatology referral practice for treatment with allergen-specific immunotherapy.

Procedure—A catheter was placed in a vein in each dog. Dogs were constantly observed throughout the procedure. Allergen extracts were administered in increasing concentrations every 30 minutes for 6 hours to a maintenance concentration of 20,000 protein nitrogen units/ml. Epinephrine, oxygen, and emergency treatment were available as needed.

Results—In 22 (73%) dogs, rush immunotherapy safely replaced the prolonged induction period (15 weeks) of weekly injections that consists of increasing concentrations of allergen extract. In 7 (23%) dogs, the induction period was abbreviated to 4 weeks. Of the 8 dogs that developed problems during rush immunotherapy, increased pruritus necessitated premature cessation of rush immunotherapy in 7, and 1 developed generalized wheals. Oral administration of prednisolone (1 mg/kg of body weight) resulted in resolution of adverse effects in all 8 dogs.

Conclusion and Clinical Relevance—Rush immunotherapy performed by personnel at a veterinary hospital is a safe method for treatment of dogs with atopic dermatitis. (Am J Vet Res2001;62:307–310)
Screening method for identification of β-lactams in bovine urine by use of liquid chromatography and a microbial inhibition test
Authors: Musser Jeffrey M.B. , Anderson Kevin L. , Moats William A.
Published: December 2005

Objective—To develop a multiple-residue screening
method for the detection of β-lactams in bovine urine.

Animals—6 clinically normal Holstein cows and 6
calves.

Procedure—Pooled urine obtained from cows was
used as a negative-control sample or spiked with
varying concentrations of 6 β-lactam antibiotics. Urine
samples were prepared for liquid chromatography by
diluting 1 ml of urine with 9 ml of 0.01M KH2PO4,
0.01M Na2PO4, and filtering. Filtrate (2,000 ml) was
eluted with a mobile phase in a gradient program. A
fraction corresponding to each β-lactam of interest
was collected and evaporated to < 1 ml, and water
then was added to achieve a 1ml volume. The collected
fraction was tested, using a microbial inhibition
test. Then, calves were fed milk spiked with a mixture
of 5 β-lactam antibiotics at a concentration 40X
the FDA tolerance in milk. Three hours following the
feeding, urine samples were obtained from the calves
and tested, as described for the urine samples for the
cows.

Results—The lowest concentrations of amoxicillin,
ampicillin, cephapirin, cloxacillin, desfuroylceftiofurcysteine,
and penicillin G that were consistently
detected in urine were 100, 10, 100, 250, 1,000, and
10 ng/ml, respectively. Amoxicillin, ampicillin,
cephapirin, cloxacillin, desacetylcephapirin, and penicillin
G were detected in urine samples of 6/6, 5/6,
0/6, 6/6, 2/6, and 3/6 calves respectively, fed antibiotic-
spiked milk.

Conclusions and Clinical Relevance—The integrated
method described can be used to detect or identify
β-lactam antibiotics in bovine urine. This method
can be used to test cattle for β-lactam residues. (Am
J Vet Res 2001;62:326–330)
Evaluation of the cardiac actin gene in Doberman Pinschers with dilated cardiomyopathy
Authors: Meurs Kathryn M. , Magnon Alex L. , Spier Alan W. , Miller Mathew W. , Lehmkuhl Linda B. , Towbin Jeffrey A.
Published: December 2005

Objective—To evaluate the coding region of the cardiac
actin gene in Doberman Pinschers with dilated
cardiomyopathy (DCM) for mutations that could be
responsible for the development of the condition

Animals—28 dogs (16 Doberman Pinschers with
DCM and 12 mixed-breed control dogs).

Procedure—Ten milliliters of blood was collected
from each dog for DNA extraction.
Polymerase chain reaction (PCR) primers were
designed to amplify canine exonic regions, using the
sequences of exons 2 to 6 of the cardiac actin gene.
Single-stranded conformational polymorphism analysis
was performed for each exon with all samples.
Autoradiographs were analyzed for banding patterns
specific to affected dogs. The DNA sequencing was
performed on a selected group of affected and control
dogs.

Results—Molecular analysis of exons 2 to 6 of the
cardiac actin gene did not reveal any differences in
base pairs between affected dogs and control dogs
selected for DNA evaluation.

Conclusions—Mutations in exons 5 and 6 of the cardiac
actin gene that have been reported in humans
with familial DCM do not appear to be the cause of
familial DCM in Doberman Pinschers. Additionally,
evaluation of exons 2 to 6 for causative mutations did
not reveal a cause for inherited DCM in these
Doberman Pinschers. Although there is evidence that
DCM in Doberman Pinschers is an inherited problem,
a molecular basis for this condition remains unresolved.
Evaluation of other genes coding for
cytoskeletal proteins is warranted. ( Am J Vet Res
2001;62:33–36)
Comparison of detomidine and romifidine as premedicants before ketamine and halothane anesthesia in horses undergoing elective surgery
Authors: Taylor Polly M. , Bennett Rachel C. , Brearley Jacqueline C. , Luna Stelio P. L. , Johnson Craig B.
Published: December 2005

Objective—To compare detomidine hydrochloride and romifidine as premedicants in horses undergoing elective surgery.

Animals—100 client-owned horses.

Procedure—After administration of acepromazine (0.03 mg/kg, IV), 50 horses received detomidine hydrochloride (0.02 mg/kg of body weight, IV) and 50 received romifidine (0.1 mg/kg, IV) before induction and maintenance of anesthesia with ketamine hydrochloride (2 mg/kg) and halothane, respectively. Arterial blood pressure and blood gases, ECG, and heart and respiratory rates were recorded. Induction and recovery were timed and graded.

Results—Mean (± SD) duration of anesthesia for all horses was 104 ± 28 minutes. Significant differences in induction and recovery times or grades were not detected between groups. Mean arterial blood pressure (MABP) decreased in both groups 30 minutes after induction, compared with values at 10 minutes. From 40 to 70 minutes after induction, MABP was significantly higher in detomidine-treated horses, compared with romifidine-treated horses, although more romifidine-treated horses received dobutamine infusions. In all horses, mean respiratory rate ranged from 9 to 11 breaths/min, PaO2from 200 to 300 mm Hg, PaCO2from 59 to 67 mm Hg, arterial pH from 7.33 to 7.29, and heart rate from 30 to 33 beats/min, with no significant differences between groups.

Conclusions and Clinical Relevance—Detomidine and romifidine were both satisfactory premedicants. Romifidine led to more severe hypotension than detomidine, despite administration of dobutamine to more romifidine-treated horses. Both detomidine and romifidine are acceptable α2-adrenoceptor agonists for use as premedicants before general anesthesia in horses; however, detomidine may be preferable when maintenance of blood pressure is particularly important. (Am J Vet Res2001;62:359–363)