bluuebunny/crossref_metadata_2025 huggingface dataset:
Serologic responses of dogs given a commercial vaccine against Leptospira interrogans serovar pomona and Leptospira kirschneri serovar grippotyphosa
Authors: Barr Stephen C. , McDonough Patrick L. , Scipioni-Ball Roberta L. , Starr Jennifer K.
Published: December 2005

Objective—To evaluate serum titers obtained by use of the microscopic agglutination test (ie, MAT titers) toLeptospira interrogansserovar pomona and autumnalis andLeptospira kirschneriserovar grippotyphosa in dogs given a commercial vaccine against serovars pomona and grippotyphosa.

Animals—Forty 12-week-old puppies and 20 mature Beagles.

Procedure—Puppies received a commercial vaccine against serovars pomona and grippotyphosa at 12 weeks of age, then received a booster vaccine and 3 weeks later; mature dogs received the vaccine once. Serum MAT titers to serovars pomona, autumnalis, and grippotyphosa were measured before vaccination and at 2, 4, 6, 10, and 16 weeks after the first or only vaccination.

Results—Of the 40 puppies vaccinated, 40, 0, and 40 developed MAT titers of > 100 after vaccination to serovars pomona, grippotyphosa, and autumnalis, respectively. Microscopic agglutination test titers to serovar autumnalis were higher than MAT titers to serovars pomona and grippotyphosa and persisted in some dogs for 16 weeks (6 weeks longer than for titers to serovar pomona). Of the 20 mature dogs, 13, 5, and 20 developed MAT titers of > 100 at 2 weeks to serovars pomona, grippotyphosa, and autumnalis, respectively. Titers to serovar pomona were higher and persisted in some dogs beyond 16 weeks after vaccination, compared with titers to serovars pomona and grippotyphosa, which persisted for 10 and 6 weeks, respectively.

Conclusions and Clinical Relevance—Subunit vaccines against serovars pomona and grippotyphosa induce MAT titers not only to homologous antigens but also to serovar autumnalis, which could lead to a misdiagnosis of leptospirosis caused by serovar autumnalis. (Am J Vet Res2005;66:1780–1784)
Temporality of early-term abortions associated with mare reproductive loss syndrome in horses
Authors: Cohen Noah D. , Carey Vincent J. , Donahue James G. , Seahorn Janyce L. , Brown II Stuart E. , Riddle Thomas W.
Published: December 2005

Objective—To characterize the temporality of dates
of breeding and abortion classified as mare reproductive
loss syndrome (MRLS) among mares with abortions
during early gestation.

Animals—2,314 mares confirmed pregnant at
approximately 28 days after breeding from 36 farms in
central Kentucky, including 515 mares that had earlyterm
abortions.

Procedure—Farm veterinarians and managers were
interviewed to obtain data for each mare that was
known to be pregnant to determine pregnancy status,
breeding date, last date known to be pregnant, and
date of abortion.

Results—Mares bred prior to April 1, 2001,
appeared to be at greatest risk of early-term abortion,
both among and within individual farms.
Mares bred in mid-February appeared to be at
greatest risk of abortion, with an estimated weekly
incidence rate of abortion of 66% (95% CI, 52% to
80%).

Conclusions and Clinical Relevance—Mares in
central Kentucky bred between mid-February and
early March were observed to be at greatest risk of
early-term abortion, and risk gradually decreased to
a background incidence of abortion of approximately
11%. Mares bred after April 1, 2001, appeared to
be at markedly less risk, indicating that exposure to
the cause of MRLS likely occurred prior to this
date. (Am J Vet Res 2005;66:1792–1797)
Assessment of the dark-adaptation time required for recovery of electroretinographic responses in dogs after fundus photography and indirect ophthalmoscopy
Authors: Tuntivanich Nalinee , Mentzer A. Lexi , Eifler Danielle M. , Montiani-Ferreira Fabiano , Forcier Janice Q. , Johnson Cheri A. , Petersen-Jones Simon M.
Published: December 2005

Objective—To investigate the duration of dark-adaptation time required for recovery of electroretinographic responses after fundus photography or indirect ophthalmoscopy in dogs.

Animals—6 dogs.

Procedure—Initially, scotopic-intensity series of electroretinograms (ERGs) were recorded after 20 minutes of dark adaptation. The fundus of the left eye of each dog was photographed (n = 10) or examined via indirect ophthalmoscopy for 5 minutes with moderate- (117 candela [cd]/m2) or bright-intensity (1,693 cd/m2) light; ERGs were repeated after a further 20 or 60 minutes of dark adaptation (6 procedures/dog).

Results—Following 20 minutes of dark adaptation after fundus photography, the b- and a-wave amplitudes were reduced in response to brighter stimuli, compared with pretest ERGs; after 60 minutes of dark adaptation, ERG amplitudes had recovered. Following 20 minutes of dark adaptation after indirect ophthalmoscopy (moderate-intensity light), significantly lower b-wave amplitudes were recorded in response to 2 of the brighter flash stimuli, compared with pretest ERGs; after 60 minutes of dark adaptation, ERG amplitudes had recovered. Following 20 minutes of dark adaptation after indirect ophthalmoscopy (bright-intensity light), all ERG amplitudes were significantly decreased and implicit times were significantly decreased at several flash intensities, compared with pretest ERGs; after 60 minutes of dark adaptation, ERG amplitudes and implicit times had returned to initial values, except for b-wave amplitudes recorded in response to dimmer stimuli.

Conclusions and Clinical Relevance—Results suggest that at least 60 minutes of dark adaptation should be allowed before ERGs are performed in dogs after fundus photography or indirect ophthalmoscopy. (Am J Vet Res2005;66:1798–1804)
Association between subjective lameness grade and kinetic gait parameters in horses with experimentally induced forelimb lameness
Authors: Ishihara Akikazu , Bertone Alicia L. , Rajala-Schultz Päivi J.
Published: December 2005

Objective—To evaluate the association between subjective lameness grades and kinetic gait parameters and assess the variability in kinetic parameters in horses with experimentally induced forelimb lameness.

Animals—32 horses.

Procedures—Forelimb lameness was induced in each horse via injection of lipopolysaccharide into 1 metacarpophalangeal joint (40 experimental trials). Subjective lameness grading and 13 kinetic gait parameters (force plate analysis) were assessed before (baseline) and at 12, 18, and 24 hours after lipopolysaccharide injection. While horses were trotting, kinetic gait analysis was performed for 8 valid repetitions at each time point. Repeated-measures analyses were performed with 8 repetitions for each kinetic parameter as the outcome, and lameness grades, time points after lipopolysaccharide injection, and repetition order as explanatory variables. Sensitivity and specificity of kinetic parameters for classification of horses as sound or lame (in relation to subjective lameness scores) were calculated. Between- and within-horse variabilities of the 13 kinetic parameters were assessed by calculation of coefficients of variation.

Results—Subjective lameness grades were significantly associated with most of the kinetic parameters. Vertical force peak and impulse had the lowest between- and within-horse coefficients of variation and the highest correlations with subjective lameness grade. Vertical force peak had the highest sensitivity and specificity for lameness classification. Vertical force peak and impulse were significantly decreased even in horses with mild or unobservable lameness.

Conclusions and Clinical Relevance—Among the kinetic gait parameters, vertical force peak and impulse had the best potential to reflect lameness severity and identify subclinical forelimb gait abnormalities. (Am J Vet Res2005;66:1805–1815)
Evaluation of subchondral bone mineral density associated with articular cartilage structure and integrity in healthy equine joints with different functional demands
Authors: Lewis Chad W. , Williamson Amanda K. , Chen Albert C. , Bae Won C. , Temple Michele M. , Wong Van W. , Nugent Gayle E. , James Susan P. , Wheeler Donna L. , Sah Robert L. , Kawcak Chris E.
Published: December 2005

Objective—To determine and correlate subchondral
bone mineral density and overlying cartilage structure
and tensile integrity in mature healthy equine stifle
(low magnitude loading) and metacarpophalangeal
(high magnitude loading) joints.

Animals—8 healthy horses, 2 to 3 years of age.

Procedure—Osteochondral samples were acquired
from the medial femoral condyle (FC) and medial
trochlear ridge (TR) of the stifle joint and from the
dorsal (MC3D) and palmar (MC3P) aspects of the distal
medial third metacarpal condyles of the
metacarpophalangeal joint. Articular cartilage surface
fibrillation (evaluated via India ink staining) and tensile
biomechanical properties were determined. The
volumetric bone mineral density (vBMD) of the
underlying subchondral plate was assessed via dualenergy
x-ray absorptiometry.

Results—Cartilage staining (fibrillation), tensile moduli,
tensile strength, and vBMD were greater in the
MC3D and MC3P locations, compared with the FC
and TR locations, whereas tensile strain at failure was
less in MC3D and MC3P locations than FC and TR
locations. Cartilage tensile moduli correlated positively
with vBMD, whereas cartilage staining and tensile
strain at failure correlated negatively with vBMD.

Conclusions and Clinical Relevance—In areas of
high joint loading, the subchondral bone had high
vBMD and the articular cartilage surface layer had
high tensile stiffness but signs of structural wear (fibrillation
and low failure strain). The site-dependent
variations and relationships in this study support the
concept that articular cartilage and subchondral bone
normally adapt to physiologic loading in a coordinated
way. (Am J Vet Res 2005;66:1823–1829)
Measurement of plasma chromogranin A concentrations for assessment of stress responses in dogs with insulin-induced hypoglycemia
Authors: Akiyoshi Hideo , Aoki Mica , Shimada Terumasa , Noda Katsura , Kumagai Daijiro , Saleh Nahed , Sugii Shunji , Ohashi Fumihito
Published: December 2005

Objective—To determine whether cross-reactivity exists between canine chromogranin A (CgA) and anti-human CgA antibody and investigate the usefulness of plasma CgA concentration measurements as an index of acute stress responses in dogs.

Animals—12 healthy Beagles.

Procedure—Canine CgA was extracted and purified from canine adrenal glands of cadaver dogs for studying cross-reactivity with anti-human CgA antibody. Western blotting with anti-human CgA antibody was performed. Blood samples were collected from dogs at 0, 10, 20, 30, 40, 60, 120, and 180 minutes after IV administration of saline (0.9% NaCl) solution or insulin. Canine plasma CgA concentrations were determined by use of a CgA ELISA kit with rabbit antiserum against the carboxy-terminal fragment of human CgA. Plasma cortisol and catecholamine (ie, norepinephrine and epinephrine) concentrations were measured by use of an ELISA and a high-performance liquid chromatography method, respectively.

Results—Purified canine CgA was specifically detected by use of western blot analysis and an ELISA with anti-human CgA antibody. An increase in plasma CgA concentrations was observed in insulin-induced hypoglycemic dogs. Changes in plasma CgA concentration were correlated with changes in plasma cortisol or catecholamine concentrations of hypoglycemic dogs.

Conclusions and Clinical Relevance—Use of the CgA ELISA kit for determination of human plasma CgA concentrations is applicable to the measurement of canine plasma CgA concentrations. Canine plasma CgA concentrations, along with measurements of plasma cortisol and catecholamine concentrations, correctly reflect insulin-induced hypoglycemic stressed conditions in dogs. Measurement of canine plasma CgA concentrations may provide a useful index for evaluation of an acute stress response. (Am J Vet Res2005;66:1830–1835)
Effects of the ingestion of whole colostrum or cell-free colostrum on the capacity of leukocytes in newborn calves to stimulate or respond in one-way mixed leukocyte cultures
Authors: Reber Adrian J. , Hippen Arnold R. , Hurley David J.
Published: December 2005

Objective—To evaluate effects of colostral cells on the ability of neonatal leukocytes to respond in a mixed leukocyte response (MLR) as a means of evaluating specific immune responsiveness.

Animals—10 Holstein calves, their respective dams, and 10 unrelated adult Holstein cows.

Procedure—Soon after birth, their calves were fed maternal whole colostrum or colostrum after cells were removed by centrifugation. Responses for leukocytes obtained from calves during the first 5 weeks after birth, their dams, and unrelated cows were measured by use of 1-way MLR as an indicator of immune development. An internal control treatment, proliferation of lymphocytes stimulated withStaphylococcusenterotoxin B (SEB), was also measured.

Results—Transfer of colostral leukocytes had a significant effect on the MLR and SEB-induced response in calves. Calves receiving whole colostrum had enhanced responses to maternal and unrelated leukocytes 24 hours after ingestion of colostrum. These responses decreased quickly, indicating direct modulation of the neonatal immune response. Calves receiving whole colostrum effectively stimulated the MLR by 24 hours after ingestion of colostrum. In contrast, calves receiving acellular colostrum did not effectively stimulate the MLR until 2 to 3 weeks after birth.

Conclusions and Clinical Relevance—Ingestion of maternal colostral leukocytes immediately after birth stimulates development of the neonatal immune system. These maternal leukocytes enhance development of antigen-presenting capacity as indicated by their ability to stimulate the MLR and SEB response. The influence of ingested maternal cells on neonatal immunity was also indicated by a reduction in reactivity of neonatal cells to maternal alloantigens. (Am J Vet Res2005;66:1854–1860)
Effect of glucosamine and chondroitin sulfate on regulation of gene expression of proteolytic enzymes and their inhibitors in interleukin-1–challenged bovine articular cartilage explants
Authors: Chan Pooi-See , Caron John P. , Orth Michael W.
Published: December 2005

Objective—To determine the effects of glucosamine (GLN) and chondroitin sulfate (CS), at concentrations attainable in vivo, on expression of genes encoding proteolytic enzymes, enzyme inhibitors, and macromolecules of articular cartilage in interleukin-1(IL- 1)–challenged bovine cartilage explants.

Sample Population—Articular cartilage explants harvested from 9 steers.

Procedures—Cartilage explants were exposed to media containing 10% fetal bovine serum (FBS) only, IL- 1 (50 ng/mL), IL-1 with GLN (5 µg/mL), IL-1 with CS (20 µg/mL), or IL-1 with GLN and CS for 24 and 48 hours. Cartilage was frozen, and RNA was extracted. Gene expression of matrix metalloproteinases (MMPs)-2, -3, -9, -13, and -14; aggrecanases (Aggs)-1 and -2; tissue inhibitors of metalloproteinases (TIMPs)-1, -2, and -3; and type II collagen and aggrecan were assessed with quantitative real-time polymerase chain reaction.

Results—Upregulated MMP-3, MMP-13, and Agg-1 transcripts at 24 hours were repressed by the GLN and CS combination by at least approximately 6-fold. Glucosamine was effective in suppressing IL-1–induced mRNA expression of MMP-13, Agg-1, and Agg-2, whereas CS was effective in decreasing IL-1–induced MMP-13 transcript at 24 hours. At 48 hours, GLN and CS added separately and in combination significantly abrogated Agg-1 and Agg-2 gene induction. The combination also decreased IL-1–stimulated MMP-13 transcript.

Conclusions and Clinical Relevance—GLN and CS, at concentrations that are within the range measured in synovial fluid and blood after oral administration, may regulate expression of matrix degrading enzymes and their inhibitors at the transcriptional level, providing a plausible mechanism for their purported chondroprotective properties. (Am J Vet Res2005;66:1870–1876)
Effects of induction of capacitative calcium entry on equine laminar microvessels
Authors: Robertson Tom P. , Peroni John F. , Lewis Stephen J. , Moore James N.
Published: December 2005

Objective—To determine the effects of induction of capacitative Ca2+entry on tone in equine laminar arteries and veins.

Sample Population—Laminar arteries and veins from 6 adult mixed-breed horses.

Procedure—Arteries and veins were isolated and mounted on small vessel myographs for the measurement of isometric tension. Capacitative Ca2+entry was induced by incubating the vessels with the specific Ca2+-ATPase inhibitor thapsigargin (100nM) in a Ca2+- free physiologic salt solution. Capacitative Ca2+entry–associated contractile responses were determined by the subsequent addition of 2mM Ca2+to the solution bathing the vessels; in some experiments, either the voltage-gated Ca2+blocker diltiazem (10µM) or the putative capacitative Ca2+entry inhibitor trifluoromethylphenylimidazole (300µM) was added to the bathing solution 15 minutes prior to a second 2mM Ca2+exposure. The Sr2+permeability of the capacitative Ca2+entry pathway in laminar vessels was assessed by exposing the vessels to 4mM Sr2+after induction of capacitative Ca2+entry with thapsigargin.

Results—Induction of capacitative Ca2+entry elicited robust contractile responses in laminar veins but did not increase tone in laminar arteries. In laminar veins, capacitative Ca2+entry–induced contractile responses were unaffected by preincubation with diltiazem, attenuated by trifluoromethylphenylimidazole, and were impermeable to Sr2+.

Conclusions and Clinical Relevance—Results indicated that induction of capacitative Ca2+entry elicits vasoconstriction in equine laminar veins but not in laminar arteries and should therefore be considered a potential mechanism by which selective venoconstriction occurs in horses during the development of acute laminitis. (Am J Vet Res2005;66:1877–1880)
Comparison of proteoglycan and collagen in articular cartilage of horses with naturally developing osteochondrosis and healing osteochondral fragments of experimentally induced fractures
Authors: Bertone Alicia L. , Bramlage Lawrence R. , McIlwraith C. Wayne , Malemud Charles L.
Published: December 2005

Objective—To compare articular cartilage from horses with naturally developing osteochondrosis (OC) with normal articular cartilage and healing cartilage obtained from horses with experimentally induced osteochondral fractures.

Sample Population—109 specimens of articular cartilage from 78 horses.

Procedure—Morphologic characteristics, proteoglycan (PG), and type II collagen were analyzed in articular cartilage of OC specimens (group 1), matched healing cartilage obtained 40 days after experimentally induced osteochondral fractures (group 2), and matched normal cartilage from the same sites (group 3).

Results—79 specimens of OC cartilage were obtained from horses. Ex vivo PG synthesis was significantly greater in the femoral cartilage, compared with synthesis in the tibial cartilage, and significantly greater for groups 1 and 2, compared with group 3. For groups 1 and 2, femoral fragments had significantly greater PG content, compared with PG content in tibial fragments. Keratan sulfate content was significantly less in group 3, compared with groups 1 and 2. Cartilage from the OC specimens had loss of structural architecture. The OC tissue bed stained positive for chondroitin sulfate and type II collagen, but the fracture bed did not.

Conclusions and Clinical Relevance—Our analyses could not distinguish articular cartilage from horses with OC and a healing fracture. Both resembled an anabolic, reparative process. Immunohistochemical analysis suggested a chondromyxoid tissue in the OC bed that was morphologically similar to fibrous tissue but phenotypically resembled hyaline cartilage. Thus, tissue in the OC bed may be degenerative cartilage, whereas tissue in the fracture bed may be reparative fibrous callus. (Am J Vet Res2005;66:1881–1890)
Comparison of myocardial contrast enhancement via cardiac magnetic resonance imaging in healthy cats and cats with hypertrophic cardiomyopathy
Authors: MacDonald Kristin A. , Wisner Erik R. , Larson Richard F. , Klose Tyler , Kass Philip H. , Kittleson Mark D.
Published: December 2005

Objective—To quantify myocardial contrast enhancement (MCE) of the left ventricle (LV) by use of cardiac magnetic resonance imaging (CMRI) in healthy cats and cats with hypertrophic cardiomyopathy (HCM) and to compare MCE between the 2 groups.

Animals—10 healthy cats and 26 Maine Coon cats with moderate to severe HCM but without clinical evidence of congestive heart failure.

Procedure—Anesthetized cats underwent gradient echo CMRI examination. Short-axis images of the LV were acquired before and 7 minutes after IV administration of gadolinium dimeglumine. Regions of interest were manually traced in the quadrants of 5 mid-LV slices acquired at end systole, and the MCE percentage was calculated from summed weight-averaged data from all slices. Doppler tissue imaging echocardiography was performed to measure the early diastolic myocardial velocity (Em) as an index of diastolic function. Three-way repeated-measures ANOVA was used to determine differences in MCE between cats with HCM and healthy cats. Simple linear regression was used to assess whether MCE was correlated with LV mass, LV mass index (LVMI), or Em. A Student t test was used to compare the SDs of the postcontrast myocardial signal intensity between the 2 groups.

Results—There was no difference in MCE between cats with HCM and healthy cats. There was no correlation of MCE with LV mass, LVMI, or Em. There was no difference in heterogeneity of signal intensities of LV myocardium between the 2 groups.

Conclusions and Clinical Relevance—Contrastenhancement CMRI was not useful in detecting diffuse myocardial fibrosis in cats with HCM. (Am J Vet Res2005;66:1891–1894)
Seroprevalence of antibodies against Borrelia burgdorferi and Anaplasma phagocytophilum in cats
Authors: Magnarelli Louis A. , Bushmich Sandra L. , IJdo Jacob W. , Fikrig Erol
Published: December 2005

Objective—To determine whether cats in the northeastern United States develop serum antibodies against antigens ofBorrelia burgdorferiandAnaplasma phagocytophilumand whether coinfection with the 2 organisms occurs.

Sample Population—Serum samples from 84 healthy cats and 9 cats with lameness, fever, anorexia, or fatigue.

Procedure—Serum antibodies againstB burgdorferiandA phagocytophilumwere measured with an ELISA incorporating a whole-cell preparation or purified recombinant antigens, by means of western blot analysis, or indirect fluorescent antibody (IFA) staining.

Results—ELISA results indicated that 44 of 93 (47%) sera contained antibodies against ≥ 3B burgdorferiantigens, whereas 43 (46%) were reactive to wholecellB burgdorferi. Serum reactivity to protein 35, VlsE, and outer surface proteins A and F was most common. Seropositivity to ≥ 3 antigens occurred at the same rate (5/9) in the 9 ill cats as in the 84 healthy cats (46% [39/84]). Of 13 sera reactive to recombinant antigens, 9 were seropositive as measured by western blot testing with whole-cell antigen. Seropositivity rates of 30% and 38% were detected for antibodies againstA phagocytophilumvia IFA and ELISA testing, respectively. Fifteen (16%) sera had antibodies against both pathogens.

Conclusions and Clinical Relevance—Cats living in areas infested byIxodes scapularisticks are exposed toB burgdorferiandA phagocytophilumand, in some instances, may be coinfected. Most cats appeared healthy. An ELISA incorporating specific recombinant antigens may be used adjunctively with western blot and other assays to confirmB burgdorferiandA phagocytophiluminfection in cats. (Am J Vet Res2005;66:1895–1899)
Identification of microsatellite markers linked to progressive retinal atrophy in American Eskimo Dogs
Authors: Moody Jessica A. , Famula Thomas R. , Sampson Ruth C. , Murphy Keith E.
Published: December 2005

Objective—To identify microsatellite markers linked
to progressive retinal atrophy (PRA) in American
Eskimo Dogs.

Sample Population—Blood samples or buccal
epithelial cells from 66 American Eskimo Dogs,
including 53 PRA-unaffected and 13 PRA-affected
dogs.

Procedure—The genotypes of unaffected and affected
dogs were determined by use of microsatellite
markers spanning canine chromosome 9 (CFA09).
Homozygosity mapping was used to detect linkage
between markers and the gene locus for PRA.

Results—Significant allelic association between
marker alleles and the gene locus for PRA was
detected for GALK1 and TK1, indicating linkage
between these markers and the causative gene locus
for PRA.

Conclusions and Clinical Relevance—These data
indicate that PRA in American Eskimo Dogs is located
on CFA09 and allow for the development of a
microsatellite-based test to identify carrier (unaffected)
and affected dogs before clinical signs appear.
(Am J Vet Res 2005;66:1900–1902)
Use of vitamin B12 in joint lavage for determination of dilution factors of canine synovial fluid
Authors: Bruin Tanya de , Rooster Hilde de , Bree Henri van , Cox Eric
Published: December 2005

Objective—To test a modified saline (0.9% NaCl) solution joint washing (lavage) technique that includes the use of vitamin B12as an internal marker for the evaluation of synovial fluid dilution in lavage samples from canine joints.

Sample Population—9 plasma samples obtained from blood samples of 9 healthy dogs and 9 synovial fluid samples aspirated from stifle joints of 9 cadaveric dogs.

Procedure—Photometric absorbances of 25% vitamin B12solution, canine synovial fluid, and canine plasma were measured in a spectrophotometer to establish an optimal wavelength for analysis. Canine synovial fluid and plasma samples were mixed with the 25% vitamin B12solution to obtain 1%, 3%, 5%, 10%, 20%, and 50% solutions of synovial fluid or plasma. Diluted synovial fluid and plasma samples were used to simulate joint lavage samples and to examine the possible interference of these substances (synovial fluid or plasma) with the absorbance of the 25% vitamin B12solution in photometric analysis.

Results—The optimal wavelength was found to be at 550 nm. Canine synovial fluid and plasma samples did not interfere with the absorbance measurements of the 25% vitamin B12solution up to a 50% dilution of plasma or synovial fluid.

Conclusions and Clinical Relevance—The modified saline solution joint lavage method with the use of a 25% vitamin B12solution as an internal standard provides an accurate and reliable technique for the evaluation of synovial fluid dilution in lavage samples from canine joints. (Am J Vet Res2005;66:1903–1906)
Electrophysiologic differentiation of homozygous and heterozygous Abyssinian-crossbred cats with late-onset hereditary retinal degeneration
Authors: Hyman Jennifer A. , Vaegan  , Lei Bo , Narfström Kristina L.
Published: December 2005

Objective—To develop a method to electrophysiologically
differentiate heterozygous-carrier Abyssiniancrossbred
cats from homozygous-affected Abyssiniancrossbred
cats before clinical onset of inherited rodcone
retinal degeneration.

Animals—14 back-crossed Abyssinian-crossbred cats
of unknown genotype (homozygous or heterozygous)
for inherited rod-cone retinal degeneration, 24 agematched
mixed-breed control cats, 6 age-matched
heterozygous Abyssinian-crossbred cats, and 6
homozygous Abyssinian cats.

Procedure—Electroretinography (ERG) of heterozygous
and homozygous cats revealed differences,
especially for scotopic recordings. Frequent ophthalmoscopy
and ERG (2 to 5 times; at intervals of 3 to 6
months) of back-crossed cats were performed.
Amplitudes and implicit times were analyzed by use
of a graphic representation of results. Ratios for
amplitudes of the b-waves to amplitudes of the awaves
(b-wave:a-wave) were compared.

Results—8 back-crossed cats had decreased a-wave
amplitudes, increased b-wave implicit times, and
abnormal ERG waveforms. Values for the b-wave:awave
for the highest scotopic light intensity were significantly
higher for those same 8 cats.

Conclusions and Clinical Relevance—The 8
back-crossed Abyssinian-crossbred cats with
abnormal results developed fundus changes over
time consistent with disease. A graphic representation
of ERG results can be used to differentiate
between genotypes prior to funduscopic changes.
Values for the b-wave:a-wave ratio provide confirmation.
These ERG analyses may be applied clinically
in the diagnosis of retinal degenerations in
various species.

Impact for Human Medicine—Cats with hereditary
rod-cone degeneration may be a useful model
for comparative studies in relation to retinitis pigmentosa
in humans. Similar evaluations of ERG
results could possibly be used for humans with
suspected generalized retinal degeneration. (Am J
Vet Res 2005;66:1914–1921)
Reference range values of regional left ventricular myocardial velocities and time intervals assessed by tissue Doppler imaging in young nonsedated Maine Coon cats
Authors: Chetboul Valerie , Sampedrano Carolina Carlos , Tissier Renaud , Gouni Vassiliki , Nicolle Audrey P. , Pouchelon Jean-Louis
Published: December 2005

Objective—To describe and analyze the left ventricular
free wall (LVFW) radial and longitudinal motions in
a population of healthy Maine Coon cats by use of
quantitative 2-dimensional color tissue Doppler imaging
(TDI).

Animals—23 healthy young Maine Coon cats (mean
± SD: age, 2.1 ± 0.9 years; weight, 5.0 ± 1.0 kg).

Procedure—TDI was performed by the same trained
observer (VC) on all cats. Radial LVFW velocities were
recorded in endocardial and epicardial LVFW segments,
and longitudinal velocities were recorded in
the mitral annulus and in basal and apical LVFW segments.
Isovolumic contraction and relaxation times
were calculated in each myocardial segment, and the
coefficients of variation (CVs; %) were determined for
each TDI parameter.

Results—LVFW velocities were significantly higher in
the endocardial layers than in the epicardial layers and
also significantly higher in the basal than in the apical
segments. Annular velocities were significantly higher
than basal myocardial velocities in systole and early
diastole. Coefficient of variation values were lower for
radial velocities, particularly in systole, and were also
lower for time intervals (16% to 22%) than for
myocardial velocities (19% to 62%).

Conclusions and Clinical Relevance—Because
Maine Coon cats are predisposed to an inherited
hypertrophic cardiomyopathy, which is a common
cause of death in this breed, TDI could provide a useful
tool for early detection of the disease. Tissue
Doppler imaging indices may complete the conventional
analysis of the left ventricular function in Maine
Coon cats. However, the usefulness of TDI indices in
the early detection of myocardial dysfunction needs
to be clarified. (Am J Vet Res 2005;66:1936–1942)
Pharmacokinetics of a single dose of enrofloxacin administered orally to captive Asian elephants (Elephas maximus)
Authors: Sanchez Carlos R. , Murray Suzan Z. , Isaza Ramiro , Papich Mark G.
Published: December 2005

Objective—To determine the pharmacokinetics of enrofloxacin after oral administration to captive elephants.

Animals—6 clinically normal adult Asian elephants (Elephas maximus).

Procedure—Each elephant received a single dose of enrofloxacin (2.5 mg/kg, PO). Three elephants received their complete diet (pellets and grain) within 2 hours after enrofloxacin administration, whereas the other 3 elephants received only hay within 6 hours after enrofloxacin administration. Serum concentrations of enrofloxacin and ciprofloxacin were measured by use of high-performance liquid chromatography.

Results—Harmonic mean half-life after oral administration was 18.4 hours for all elephants. Mean ± SD peak serum concentration of enrofloxacin was 1.31 ± 0.40 µg/mL at 5.0 ± 4.2 hours after administration. Mean area under the curve was 20.72 ± 4.25 (µg × h)/mL.

Conclusions and Clinical Relevance—Oral administration of enrofloxacin to Asian elephants has a prolonged elimination half-life, compared with the elimination half-life for adult horses. In addition, potentially therapeutic concentrations in elephants were obtained when enrofloxacin was administered orally at a dosage of 2.5 mg/kg. Analysis of these results suggests that enrofloxacin administered with feed in the manner described in this study could be a potentially useful antimicrobial for use in treatment of captive Asian elephants with infections attributable to organisms, such asBordetellaspp,Escherichia coli,Mycoplasmaspp,Pasteurellaspp,Haemophilusspp,Salmonellaspp, andStaphylococcusspp. (Am J Vet Res2005;66:1948–1953)
Investigation of the effects of deracoxib and piroxicam on the in vitro viability of osteosarcoma cells from dogs
Authors: Royals Stephen R. , Farese James P. , Milner Rowan J. , Lee-Ambrose Linda , Gilder James van
Published: December 2005

Objective—To determine whether exposure of canine osteosarcoma cells to deracoxib or piroxicam results in decreased viability, whether the cytotoxic effects of deracoxib and piroxicam involve induction of apoptosis, and whether deracoxib is a more potent inhibitor of osteosarcoma cell growth than piroxicam.

Sample Population—1 fibroblast and 3 osteosarcoma cell lines.

Procedure—Cell counts and viability assays were performed using osteosarcoma cells (POS, highly metastatic POS, and canine osteosarcoma cell 31) and fibroblasts after 72 hours of incubation with deracoxib at concentrations of 0.5µM to 500µM or piroxicam at concentrations of 1µM to 1,000µM. Percentage viability was determined for each concentration. A DNA fragmentation analysis was performed to assess drug-induced apoptosis.

Results—Concentration of deracoxib required for 50% inhibition of cell viability (IC50) was reached in all 3 osteosarcoma cell lines and ranged from 70 to 150µM, whereas the IC50for piroxicam was only reached in the POS cell line at 500µM. Neither deracoxib nor piroxicam induced sufficient toxicity in fibroblasts to reach an IC50. Exposure of osteosarcoma cells to cytotoxic concentrations of deracoxib and piroxicam did not result in DNA fragmentation.

Conclusions and Clinical Relevance—Intermediate and high concentrations of deracoxib and high concentrations of piroxicam were cytotoxic to osteosarcoma cells; neither drug inhibited cell viability at typical plasma concentrations in dogs. Deracoxib inhibited viability of cells at concentrations that did not affect fibroblast viability. There was no evidence of apoptosis induction for either drug; however, only 1 cell line was evaluated for apoptosis induction and only for a limited selection of drug concentrations. (Am J Vet Res2005;66:1961–1967)
Validation of magnetic resonance imaging for measurement of equine articular cartilage and subchondral bone thickness
Authors: Murray Rachel C. , Branch Marion V. , Tranquille Carolyne , Woods Sarah
Published: December 2005

Objective—To validate use of magnetic resonance images (MRIs) for measurement of equine articular cartilage and subchondral bone thickness by comparison with measurements in histologic specimens.

Sample Population—32 cadaveric carpal joints from 16 horses.

Procedure—Magnetic resonance imaging was performed by use of 3-dimensional fast spoiled gradient echo (SPGR) and T2* 3-dimensional fast gradient echo (GRE) pulse sequences with and without fat saturation. Standard sites on the medial and lateral facets of the intermediate, radial, and third carpal bones were used for subchondral bone and articular cartilage thickness measurements. Digital image analysis software was used for MRI measurements 10 mm from the dorsal extent and perpendicular to the articular surface. Histomorphometric measurements of hyaline, calcified cartilage, and subchondral bone thickness were obtained at selected sites. Comparisons between histomorphometric and MRI measurements and between magnetic resonance pulse sequences were evaluated.

Results—There were significant correlations between GRE and SPGR and SPGR and histologic measurements of articular cartilage, with no significant difference between measurements and good agreement. When calcified cartilage was excluded from the histologic measurement, MRI measurements were significantly greater than histologic measurements. For subchondral bone thickness, there was significant correlation between GRE and SPGR but GRE was significantly greater than SPGR measurements. Histomorphometric and MRI measurements were strongly correlated and not significantly different.

Conclusions and Clinical Relevance—Magnetic resonance imaging provides a good representation of cartilage and subchondral bone thickness, supporting its use in the study and clinical diagnosis of osteochondral structure and alteration. (Am J Vet Res2005;66:1999–2005)
Effects of dietary oils on the development of gastric ulcers in mares
Authors: Frank Nicholas , Andrews Frank M. , Elliott Sarah B. , Lew John
Published: December 2005

Objective—To assess antiulcerogenic properties of 3 dietary oils.

Animals—8 healthy adult mares.

Procedure—A protocol to induce gastric ulcers was used and included 240 mL of water plus corn oil, refined rice bran oil, or crude rice bran oil administered each day for 6 weeks according to a 4 × 4 Latin square randomized crossover design with 5-week washout intervals. A 7-day alternating feed deprivation period was included between weeks 5 and 6. Omeprazole was administered daily for the last 14 days of each washout interval. Endoscopic examinations of the stomach were performed at 0, 5, and 6 weeks, and the number (0 to 4 scale) and severity (0 to 5 scale) of ulcers were scored. Gastric fluid was collected at 0 and 5 weeks.

Results—Median body weight significantly increased by 29 kg (range, 10 to 50 kg). Mean ± SE gastric fluid pH significantly decreased from 4.9 ± 0.4 to 3.1 ± 0.3 over 5 weeks, and total volatile fatty acid concentration significantly decreased over time. Mean ± SE severity of nonglandular ulcers significantly increased from 0.4 ± 0.1 to 1.2 ± 0.2 over 5 weeks. Nonglandular ulcers significantly increased in number (mean ± SE, 1.3 ± 0.2 to 3.0 ± 0.2) and severity (mean ± SE, 1.2 ± 0.2 to 2.6 ± 0.2) during the 7-day alternating feed deprivation period. No effects of treatment were detected.

Conclusions and Clinical Relevance—In this model dietary oils did not prevent gastric ulcers from forming in the nonglandular portion of the stomach of horses. (Am J Vet Res2005;66:2006–2011)
Pharmacokinetics of ketamine and its metabolite, norketamine, after intravenous administration of a bolus of ketamine to isoflurane-anesthetized dogs
Authors: Pypendop Bruno H. , Ilkiw Jan E.
Published: December 2005

Objective—To determine the pharmacokinetics of ketamine and norketamine in isoflurane-anesthetized dogs.

Animals—6 dogs.

Procedure—The minimum alveolar concentration (MAC) of isoflurane was determined in each dog. Isoflurane concentration was then set at 0.75 times the individual's MAC, and ketamine (3 mg/kg) was administered IV. Blood samples were collected at various times following ketamine administration. Blood was immediately centrifuged, and the plasma separated and frozen until analyzed. Ketamine and norketamine concentrations were measured in the plasma samples by use of liquid chromatography–mass spectrometry. Ketamine concentration-time data were fitted to compartment models. Norketamine concentration-time data were examined by use of noncompartmental analysis.

Results—The MAC of isoflurane was 1.43 ± 0.18% (mean ± SD). A 2-compartment model best described the disposition of ketamine. The apparent volume of distribution of the central compartment, the apparent volume of distribution at steady state, and the clearance were 371.3 ± 162 mL/kg, 4,060.3 ± 2,405.7 mL/kg, and 58.2 ± 17.3 mL/min/kg, respectively. Norketamine rapidly appeared in plasma following ketamine administration and had a terminal half-life of 63.6 ± 23.9 minutes. A large variability in plasma concentrations, and therefore pharmacokinetic parameters, was observed among dogs for ketamine and norketamine.

Conclusions and Clinical Relevance—In isoflurane-anesthetized dogs, a high variability in the disposition of ketamine appears to exist among individuals. The disposition of ketamine may be difficult to predict in clinical patients. (Am J Vet Res2005;66:2034–2038)
Agreement in histologic assessments of the pituitary pars intermedia in aged horses
Authors: McFarlane Dianne , Miller Lisa M. , Craig Linden E. , Dybdal Noel O. , Habecker Perry L. , Miller Margaret A. , Patterson Jon S. , Cribb Alastair E.
Published: December 2005

Objective—To evaluate concordance among veterinary pathologists in the assessment of histologic findings in the pars intermedia of pituitary gland sections from aged horses with mild signs suggestive of pituitary pars intermedia dysfunction (PPID).

Sample Population—10 pituitary glands from aged horses.

Procedure—7 pathologists were provided with signalment, clinical signs, and a single H&E-stained pituitary gland section from 10 aged horses with mild signs suggestive of PPID. Pathologists described histologic findings for each section and stated whether findings were consistent with PPID. Agreement among pathologists and with antemortem diagnostic test results was calculated.

Results—Overall, only fair agreement was found among the pathologists as to which horses had histologic findings consistent with disease (mean ± SE kappa value, 0.34 ± 0.069). Interpretation of individual sections varied, with minimal agreement (4 or 5/7 pathologists) for 5 of 10 sections evaluated. Postmortem assessment was in agreement with an antemortem endocrine diagnostic test result 79% of the time.

Conclusions and Clinical Relevance—Validation of antemortem diagnostic testing for PPID in horses often relies on the results of postmortem histologic evaluation. The lack of consensus in histologic interpretation of pituitary glands from aged horses with mild clinical signs in our study indicates that postmortem histologic evaluation of pituitary glands is an inappropriate standard in validation of antemortem diagnostic tests for detection of early PPID. Caution should be used when interpreting diagnostic test results in horses in which early PPID is suspected. (Am J Vet Res2005;66:2055–2059)
Inflammatory changes in ruptured canine cranial and human anterior cruciate ligaments
Authors: Barrett Jennifer G. , Hao Zhengling , Graf Benjamin K. , Kaplan Lee D. , Heiner John P. , Muir Peter
Published: December 2005

Objective—To compare expression of tartrate-resistant acid phosphatase (TRAP) and cathepsin K and histologic changes in canine cranial cruciate ligaments (CCLs) and human anterior cruciate ligaments (ACLs).

Study Population—Sections of cruciate ligaments from 15 dogs with ruptured CCLs, 8 aged dogs with intact CCLs, 14 human beings with ruptured ACLs, and 11 aged human beings with intact ACLs.

Procedure—The CCLs and ACLs were evaluated histologically, and cells containing TRAP and cathepsin K were identified histochemically and immunohistochemically, respectively.

Results—The proportion of ruptured CCLs that contained TRAP+cells was significantly higher than the proportion of intact ACLs that did but similar to proportions of intact CCLs and ruptured ACLs that did. The proportion of ruptured CCLs that contained cathepsin K+cells was significantly increased, compared with all other groups. Numbers of TRAP+and cathepsin K+cells were significantly increased in ruptured CCLs, compared with intact ACLs. The presence of TRAP+cells was correlated with inflammatory changes, which were most prominent in ruptured CCLs.

Conclusion and Clinical Relevance—Results suggest that synovial macrophage-like cells that produce TRAP are an important feature of the inflammation associated with CCL rupture in dogs. Identification of TRAP and cathepsin K in intact CCLs and ACLs from aged dogs suggests that these enzymes have a functional role in cruciate ligament remodeling and repair. We hypothesize that recruitment and activation of TRAP+macrophage-like cells into the stifle joint synovium and CCL epiligament are critical features of the inflammatory arthritis that promotes progressive degradation and eventual rupture of the CCL in dogs. (Am J Vet Res2005;66:2073–2080)
Effects of long-term dietary supplementation with clinoptilolite on incidence of parturient paresis and serum concentrations of total calcium, phosphate, magnesium, potassium, and sodium in dairy cows
Authors: Katsoulos Panagiotis-Dimitrios , Roubies Nikolaos , Panousis Nikolaos , Arsenos Georgios , Christaki Efterpi , Karatzias Harilaos
Published: December 2005

Objective—To determine whether dietary supplementation
with clinoptilolite affects the incidence of
parturient paresis and serum concentrations of total
calcium (tCa), inorganic phosphorus (PO4
2–), magnesium
(Mg2+), potassium (K+), and sodium (Na+) in dairy
cattle.

Animals—52 dairy cows.

Procedure—Cows were placed into 3 groups. The first
2 groups (group A [n = 17] and group B [17]) were
offered a concentrate supplemented with 1.25% and
2.5% clinoptilolite, respectively. The third (group C [n =
18]) served as a control and was offered the concentrate
alone. The experiment started 1 month before
parturition and lasted until the beginning of the next
nonlactating period. Around the time of calving, all
cows were monitored for the development of parturient
paresis. Blood samples were taken at the commencement
of the experiment, on the day of calving,
and thereafter at monthly intervals to measure serum
tCa, PO4
2–, Mg2+, K+, and Na+ concentrations.

Results—The incidence of parturient paresis in group
B cows was significantly lower, compared with group
C cows. However, serum concentrations of tCa,
PO4
2–, Mg2+, K+, and Na+ were not significantly affected
by long-term supplementation with clinoptilolite.

Conclusions and Clinical Relevance—In the context
of this experiment, clinoptilolite supplementation at
2.5% appeared to have reduced the incidence of parturient
paresis in dairy cows, suggesting that its effectiveness
depends on the amount incorporated in the
ration of cows. Addition of clinoptilolite in the concentrate
of dairy cows during the nonlactating period
could be used as a cost-effective preventive treatment
for parturient paresis. (Am J Vet Res
2005;66:2081–2085)
Assessment of plasma brain natriuretic peptide concentration in Boxers with arrhythmogenic right ventricular cardiomyopathy
Authors: Baumwart Ryan D. , Meurs Kathryn M.
Published: December 2005

Objective—To determine whether Boxers with a clinical
diagnosis of arrhythmogenic right ventricular cardiomyopathy
(ARVC) have increased plasma concentrations
of brain natriuretic peptide (BNP), compared
with concentrations in clinically normal dogs.

Animals—13 Boxers with ARVC, 9 clinically normal
Boxers, 10 clinically normal non-Boxer dogs, and 5
hound dogs with systolic dysfunction.

Procedure—All Boxers were evaluated via 24-hour
ambulatory electrocardiography and echocardiography;
the number of ventricular premature contractions
(VPCs) per 24 hours was assessed. Hound
dogs with cardiac pacing-induced systolic dysfunction
(positive control dogs) and clinically normal non-Boxer
dogs (negative control dogs) were evaluated
echocardiographically. Three milliliters of blood was
collected from each dog for measurement of plasma
BNP concentration by use of a radioimmunoassay.

Results—Mean ± SD plasma BNP concentration for
the ARVC-affected Boxers, clinically normal Boxers,
negative control dogs, and positive control dogs was
11.0 ± 4.6 pg/mL, 7.9 ± 3.2 pg/mL, 11.5 ± 4.9 pg/mL,
and 100.8 ± 56.8 pg/mL, respectively. Compared with
findings in the positive control group, plasma BNP
concentration in each of the other 3 groups was significantly
different. There was no significant difference
in BNP concentration between the 2 groups of
Boxers. A significant correlation between plasma BNP
concentration and number of VPCs per 24 hours in
the ARVC-affected Boxers was not identified.

Conclusions and Clinical Relevance—A significant
difference in BNP concentration between Boxers with
ARVC and clinically normal Boxers was not identified.
Results suggest that BNP concentration may not be
an indicator of ARVC in Boxers. (Am J Vet Res
2005;66:2086–2089)