bluuebunny/crossref_metadata_2025 huggingface dataset:
Cardiopulmonary effects of fentanyl in conscious dogs and dogs sedated with a continuous rate infusion of medetomidine
Authors: Grimm Kurt A. , Tranquilli William J. , Gross David R. , Sisson David D. , Bulmer Barret J. , Benson G. John , Greene Stephen A. , Martin-Jimenez Tomas
Published: December 2005

Objective—To determine the hemodynamic consequences
of the coadministration of a continuous rate
infusion (CRI) of medetomidine with a fentanyl bolus
in dogs.

Animals—12 healthy sexually intact male dogs
weighing 30.3 ± 4.2 kg (mean ± SD).

Procedure—Dogs received either fentanyl alone (15.0
µg/kg, IV bolus) or the same dose of fentanyl during an
11-hour CRI of medetomidine (1.5 µg/kg/h, IV). Prior to
drug administration, dogs were instrumented for measurement
of cardiac output, left atrial pressure, and
systemic arterial blood pressures. Additionally, blood
samples were collected from the pulmonary artery
and left atrium for blood gas analysis.

Results—Medetomidine infusion reduced the cardiac
index, heart rate, and O2 delivery while increasing left
atrial pressure. Subsequent fentanyl administration
further decreased the cardiac index. The PaO2 was not
significantly different between the 2 treatment
groups; however, fentanyl transiently decreased PaO2
from baseline values in dogs receiving a CRI of
medetomidine.

Conclusions and Clinical Relevance—Because of
the prolonged hemodynamic changes associated
with the CRI of medetomidine, its safety should be
further evaluated before being clinically implemented
in dogs. (Am J Vet Res 2005;66:1222–1226)
Evaluation of induction by use of a combination of oxymorphone and diazepam or hydromorphone and diazepam and maintenance of anesthesia by use of isoflurane in dogs with experimentally induced hypovolemia
Authors: Machado Carmen G. , Dyson Doris H. , Mathews Karol A.
Published: December 2005

Objective—To compare induction with hydromorphone and diazepam (HydroD) or oxymorphone and diazepam (OxyD) followed by maintenance with isoflurane in dogs with induced hypovolemia.

Animals—6 healthy mixed-breed dogs.

Procedure—The study used a crossover design. Measurements were obtained in normovolemic dogs during isoflurane. Hypovolemia was induced (blood loss of 30 mL/kg) and measurements repeated following recovery from anesthesia, after HydroD (hydromorphone, 0.1 mg/kg; diazepam, 0.2 mg/kg; IV) or OxyD (oxymorphone, 0.05 mg/kg; diazepam, 0.2 mg/kg; IV), after another dose of the same opioid, during administration of isoflurane (end-tidal concentration, 0.9%), and after glycopyrrolate (0.01 mg/kg, IV). Significant changes were identified.

Results—Induction effect was evident within 1 minute. All dogs were intubated after the second dose of opioid. No significant differences were found between inductions. The HydroD decreased heart rate (mean ± SEM, –41 ± 9.8 beats/min), whereas both inductions increased stroke index (0.4 ± 0.09 mL/kg/beat) and caused moderate respiratory depression. Cardiac index was decreased (±30.2 ± 6.04 mL/kg/min) and there was minor metabolic acidosis during isoflurane following HydroD, compared with values for anesthetized normovolemic dogs. Glycopyrrolate increased heart rate (50 ± 8.6 beats/min) and decreased systolic blood pressure (–23.2 ± 4.87 mm Hg) in dogs induced with HydroD and decreased stroke index (–0.3 ± 0.08 mL/kg/beat) for both inductions.

Conclusions and Clinical Relevance—Similar effects were detected after administration of HydroD or OxyD in hypovolemic dogs. Either combination should be safe for use in hypovolemic dogs. Administration of glycopyrrolate was not beneficial. (Am J Vet Res2005;66:1227–1237)
Biochemical analysis of the articular cartilage and subchondral and trabecular bone of the metacarpophalangeal joint of horses with early osteoarthritis
Authors: Harst Mark R. van der , DeGroot Jeroen , Kiers Geesje H. , Brama Pieter A. J. , Lest Chris H. A. van de , Weeren P. René van
Published: December 2005

Objective—To assess whether site-related changes
in biochemical composition are present in the cartilage
and subchondral and trabecular bone of the
metacarpophalangeal joint of horses with early
osteoarthritis.

Sample Population—Right metacarpophalangeal
joints from 59 mature warmblood horses.

Procedure—Biochemical data (cross-link, amino acid,
DNA, and ash contents; denatured collagen and glycosaminoglycan
[GAG] concentrations; bone mineral
density; and mineral composition) were obtained
from 2 differently loaded sites of phalanx I cartilage
and subchondral and trabecular bone samples; data
were compared with previously published values
from nonosteoarthritic equine joints.

Results—Compared with findings in nonosteoarthritic
joints, GAG concentration was lower in cartilage from
osteoarthritic joints and there was a loss of site differences
in cellularity and lysylpyridinoline (LP) cross-link
content. In subchondral bone, LP cross-link content was
decreased overall and there was a loss of site differences
in osteoarthritic joints; ash content was higher in
the osteoarthritic joints. Hydroxyproline content in trabecular
bone from osteoarthritic joints was greater than
that in nonosteoarthritic trabecular bone. In all 3 layers
and at both sites, the linear increase of the pentosidine
cross-link content with age had diminished or was not
apparent in the horses with osteoarthritic joints.

Conclusions and Clinical Relevance—In equine
metacarpophalangeal joints with early osteoarthritis,
distinct biochemical changes were detected in the
cartilage and subchondral and trabecular bone. The
dissimilarity in response of the different tissues and
differences between the sites that are affected may
be related to differences in biomechanical loading and
transmission and dissipation of force. (Am J Vet Res
2005;66:1238–1246)
Effects of training on potassium homeostasis during exercise and skeletal muscle Na+,K+-ATPase concentration in young adult and middle-aged Dutch Warmblood horses
Authors: Suwannachot Pisit , Joosten Brian J. L. J. , Klarenbeek Andries , Hofma Jos , Enzerink Edwin , Weeren P. René van , Everts Maria E.
Published: December 2005

Objective—To investigate the effects of moderate short-term training on K+regulation in plasma and erythrocytes during exercise and on skeletal muscle Na+,K+-ATPase concentration in young adult and middle-aged horses.

Animals—Four 4- to 6-year-old and four 10- to 16-yearold Dutch Warmblood horses.

Procedure—The horses underwent a 6-minute exercise trial before and after 12 days of training. Skeletal muscle Na+,K+-ATPase concentration was analyzed in gluteus medius and semitendinosus muscle specimens before and after the 12-day training period. Blood samples were collected before and immediately after the trials and at 3, 5, 7, and 10 minutes after cessation of exercise for assessment of several hematologic variables and analysis of plasma and whole-blood K+concentrations.

Results—After training, Na+,K+-ATPase concentration in the gluteus medius, but not semitendinosus, muscle of middle-aged horses increased (32%), compared with pretraining values; this did not affect the degree of hyperkalemia that developed during exercise. The development of hyperkalemia during exercise in young adult horses was blunted (albeit not significantly) without any change in the concentration of Na+,K+-ATPase in either of the muscles. After training, the erythrocyte K+concentration increased (7% to 10%) significantly in both groups of horses but did not change during the exercise trials.

Conclusions and Clinical Relevance—In horses, the activation of skeletal muscle Na+,K+-ATPase during exercise is likely to decrease with age. Training appears to result in an increase in Na+,K+-ATPase activity in skeletal muscle with subsequent upregulation of Na+,K+-ATPase concentration if the existing Na+,K+-ATPase capacity cannot meet requirements. (Am J Vet Res2005;66:1252–1258)
Effects of continuous low-dose infusion of lipopolysaccharide on expression of E-selectin and intercellular adhesion molecule-1 messenger RNA and neutrophil accumulation in specific organs in dogs
Authors: Sakaue Yoko , Nezu Yoshinori , Yanagisawa Satomi , Komori Shinobu , Hara Yasushi , Takahashi Kimimasa , Tagawa Masahiro , Ogawa Ryo
Published: December 2005

Objective—To determine the effects of continuous low-dose infusion of lipopolysaccharide (LPS) on the expression of E-selectin and intercellular adhesion molecule-1 (ICAM-1) mRNA and neutrophil accumulation in the lungs, liver, spleen, small intestine, and pancreas in dogs.

Animals—11 healthy adult Beagles.

Procedure—Dogs received a continuous infusion of a low dose (10 µg/kg/h, IV) of LPS ( Escherichia coli055:B5) or saline (0.9% NaCl) solution (20 mL/kg/h, IV) for 8 hours. Activity levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) and the number of WBCs in circulation were examined before and 1, 2, 4, and 8 hours after the onset of LPS infusion. Expression of E-selectin and ICAM-1 mRNA and the number of neutrophils in each tissue were examined.

Results—After the onset of LPS infusion, serum TNF-α and IL-1β activities transiently increased. Thereafter, IL-6 activity increased, and high IL-6 activity was maintained throughout the experiment. In dogs in the LPS group, expression of E-selectin mRNA increased only in the lungs, and expression of ICAM-1 mRNA increased in the lungs and liver; the number of neutrophils in the tissue increased in the lungs and liver.

Conclusions and Clinical Relevance—Results suggested that expression of E-selectin and ICAM-1 mRNA increased during sepsis, particularly in the lungs and liver, and that this increase was associated with neutrophil accumulation. Hence, inhibiting the activation of endothelial cells in the lung and liver may decrease organ damage caused by accumulated neutrophils and help regulate multiple-organ dysfunction. (Am J Vet Res2005;66:1259–1266)
Comparison of intraosseous and intravenous infusion of technetium Tc 99m pertechnate in the distal portion of forelimbs in standing horses by use of scintigraphic imaging
Authors: Mattson Shawn E. , Pearce Simon G. , Bouré Ludovic P. , Dobson Howard , Hurtig Mark B. , Black William D.
Published: December 2005

Objective—To describe and compare the distribution
of technetium Tc 99m (99mTc) pertechnate following
intraosseous or IV injection (with or without use of a
tourniquet) in the distal portion of the forelimb in
standing horses.

Animals—4 horses.

Procedure—Each horse received 4 forelimb treatments
in random sequence: intraosseous infusion
with tourniquet application (IOT), intraosseous infusion
without tourniquet application, IV infusion with
tourniquet application (IVT), and IV infusion without
tourniquet application. Dynamic nuclear scintigraphic
imaging of the third metacarpal bone, proximal and
middle phalanges, and distal phalanx was performed
from the start of each treatment until 1 hour after infusion
was completed. Radionuclide activity was compared
within and between treatment groups.

Results—Tourniquet application was necessary to
maintain high levels of radionuclide activity in the distal
portion of the forelimb after intraosseous or IV
infusion with 99mTc pertechnate; IVT and IOT treatments
resulted in similar radionuclide activity in the
proximal and middle phalanges and distal phalanx. Of
the 4 treatments, there was significantly higher
radionuclide activity in the distal aspect of the third
metacarpal bone after the IOT treatment.

Conclusions and Clinical Relevance—By use of a
tourniquet, radionuclide administration via the
intraosseous or IV routes resulted in effective perfusion
of the distal portion of the forelimb and similar
distribution of the agent in the phalanges of horses.
Further studies are required to ascertain whether
these findings apply to delivery of therapeutic agents
in infected tissues via IOT or IVT. (Am J Vet Res
2005;66:1267–1272)
In vitro effects and in vivo efficacy of a novel cyclooxygenase-2 inhibitor in cats with lipopolysaccharide-induced pyrexia
Authors: McCann Margaret E. , Rickes Eric L. , Hora Donald F. , Cunningham Paul K. , Zhang Donghui , Brideau Christine , Black W. Cameron , Hickey Gerard J.
Published: December 2005

Objective—To determine cyclooxygenase (COX)-2 selectivity, pharmacokinetic properties, and in vivo efficacy of firocoxib (ML-1,785,713) in cats.

Animals—5 healthy male and 14 healthy female domestic shorthair cats.

Procedure—Selectivity of firocoxib for inhibiting COX-2 was determined by comparing the potency for inhibiting COX-1 with that of COX-2 in feline blood. Pharmacokinetic properties were determined after IV (2 mg/kg) and oral (3 mg/kg) administration in male cats. In vivo efficacy was evaluated in female cats with lipopolysaccharide (LPS)-induced pyrexia with administration of firocoxib 1 or 14 hours before LPS challenge.

Results—Blood concentrations resulting in 50% inhibition of COX-1 and COX-2 activity in vitro were 7.5 ± 2µM and 0.13 ± 0.03µM, respectively, and selectivity for inhibiting COX-2 relative to COX-1 was 58. Firocoxib had moderate to high oral bioavailability (54% to 70%), low plasma clearance (4.7 to 5.8 mL/min/kg), and an elimination half-life of 8.7 to 12.2 hours. Firocoxib at doses from 0.75 to 3 mg/kg was efficacious in attenuating fever when administered to cats 1 or 14 hours before LPS challenge.

Conclusions and Clinical Relevance—Firocoxib is a potent COX-2 inhibitor and is the only selective COX-2 inhibitor described for use in cats to date. It is effective in attenuating febrile responses in cats when administered 14 hours before LPS challenge, suggesting it would be suitable for once-a-day dosing. Because selective COX-2 inhibitors have an improved therapeutic index relative to nonselective nonsteroidal antiinflammatory drugs in humans, firocoxib has the potential to be a safe, effective anti-inflammatory agent for cats. (Am J Vet Res2005;66:1278–1284)
Use of simulation modeling to estimate herd-level sensitivity, specificity, and predictive values of diagnostic tests for detection of tuberculosis in cattle
Authors: Norby Bo , Bartlett Paul C. , Grooms Daniel L. , Kaneene John B. , Bruning-Fann Colleen S.
Published: December 2005

Objective—To estimate herd-level sensitivity (HSe), specificity (HSp), and predictive values for a positive (HPVP) and negative (HPVN) test result for several testing scenarios for detection of tuberculosis in cattle by use of simulation modeling.

Sample Population—Empirical distributions of all herds (15,468) and herds in a 10-county area (1,016) in Michigan.

Procedures—5 test scenarios were simulated: scenario 1, serial interpretation of the caudal fold tuberculin (CFT) test and comparative cervical test (CCT); scenario 2, serial interpretation of the CFT test and CCT, microbial culture for mycobacteria, and polymerase chain reaction assay; scenario 3, same as scenario 2 but specificity was fixed at 1.0; and scenario 4, sensitivity was 0.9 (scenario 4a) or 0.95 (scenario 4b), and specificity was fixed at 1.0.

Results—Estimates for HSe were reasonably high, ranging between 0.712 and 0.840. Estimates for HSp were low when specificity was not fixed at 1.0. Estimates of HPVP were low for scenarios 1 and 2 (0.042 and 0.143, respectively) but increased to 1.0 when specificity was fixed at 1.0. The HPVN remained high for all 5 scenarios, ranging between 0.995 and 0.997. As herd size increased, HSe increased and HSp and HPVP decreased. However, fixing specificity at 1.0 had only minor effects on HSp and HPVN, but HSe was low when the herd size was small.

Conclusions and Clinical Relevance—Tests used for detecting cattle herds infected with tuberculosis work well on a herd basis. Herds with < approximately 100 cattle should be tested more frequently or for a longer duration than larger herds to ensure that these small herds are free of tuberculosis. (Am J Vet Res2005;66:1285–1291)
Assessment of the genetic risk and impact of lateral transmission in a valine-associated scrapie outbreak in sheep
Authors: Evoniuk Jessica M. , Stoltenow Charles L. , O'Rourke Katherine I. , Moore Bert L. , Redmer Dale A.
Published: December 2005

Objective—To characterize an outbreak of valineassociated
scrapie, assess the relative risk of scrapie
infection in relation to allele frequency at codon 136,
and investigate lateral transmission of infection in a
sheep flock within the United States.

Animals—1,006 sheep.

Procedure—To determine genotypes, blood or
semen samples were assessed via commercial testing;
in 190 slaughtered sheep, scrapie status was
determined via immunohistochemical evaluation of
tissues. Scrapie-positive sheep born to scrapie-negative
dams and sheep infected after 1 year of age were
identified to assess lateral transmission.

Results—Genotypes were determined for codon 171
(164 sheep) or codons 136 and 171 (842 sheep).
Forty-four of 160 slaughtered sheep of known genotype
were scrapie positive. In these sheep, the presence
of at least 1 valine allele at codon 136 (V136) was
highly correlated with scrapie-positive status. Lateral
transmission was the probable source of infection for
4 scrapie-positive sheep born to scrapie-negative
dams and for 11 sheep in which scrapie was diagnosed
at > 50 months of age.

Conclusions and Clinical Relevance—Results suggest
that the outbreak of scrapie was associated with
a relatively high frequency of V136 in the flock, introduction
of a valine-dependent scrapie strain, and the
occurrence of lateral transmission. Genotyping of
sheep may assist management decisions following
diagnosis of scrapie in a sheep with at least 1 V136. It
may be prudent to remove sheep of the diploid genotype
AVQR (at codons 136 and 171) from infected
flocks. (Am J Vet Res 2005;66:1302–1307)
Effects of cholecystokinin-receptor antagonists on Fos-like immunoreactivity stimulated by sulfated cholecystokinin-8 in neurons of the myenteric plexus and hindbrain of rats
Authors: Webb Tennille , Gulley Stephen , Esdaile Alton R. , Pruitt Fleurette , Sharma Sanjay K. , Williams Carol S. , Sayegh Ayman I.
Published: December 2005

Objective—To evaluate the role of cholecystokinin (CCK)-receptor antagonists in the activation of enteric and hindbrain neurons by sulfated CCK-8.

Animals—81 male Sprague-Dawley rats.

Procedure—Rats were allocated to 10 groups (5 to 22 rats/group). Each rat received 2 IP injections (15 minutes between injections). The first injection consisted of a specific CCK2-receptor (CCK2R) antagonist (L365,260; 150, 500, or 1,000 µg/kg), a specific CCK1-receptor (CCK1R) antagonist (devazepide; 150 µg/kg), or 1% dimethyl sulfoxide (DMSO [ie, vehicle]), and the second injection consisted of sulfated CCK-8 (10 µg/kg) or saline (0.9% NaCl) solution. Rats were anesthetized and perfused with 500 mL of Krebs saline solution, and the myenteric plexuses of the duodenum and jejunum were collected. Rats were then perfused with 500 mL of phosphate-buffered 4% formaldehyde solution; rats were then euthanatized, and the hindbrain of each was harvested. Tissues were stained by use of a diaminobenzidine reaction enhanced with nickel to reveal Fos-like immunoreactivity (Fos-LI), a marker of neuronal activation, in the aforementioned neurons.

Results—Sulfated CCK-8 significantly increased Fos- LI in the myenteric and hindbrain neurons, compared with values for the DMSO injections. All dosages of L365,260 failed to attenuate this increase; however, injection of devazepide attenuated the increase in Fos-LI.

Conclusions and Clinical Relevance—Analysis of the results of this study reveals that sulfated CCK-8 activates myenteric and hindbrain neurons of rats primarily through CCK1R. It provides evidence that CCK2R are lacking or not functional in the gastrointestinal tract of rats. (Am J Vet Res2005;66:1308–1313)
Effects of mosapride, a 5-hydroxytryptamine 4 receptor agonist, on electrical activity of the small intestine and cecum in horses
Authors: Sasaki Naoki , Okamura Kouichi , Yamada Haruo
Published: December 2005

Objective—To examine the effects of various doses
of mosapride, a 5-hydroxytryptamine 4 receptor agonist,
on motility of the small intestine and cecum in
horses by use of electrical activity and to determine
the dose that provides the optimal response.

Animals—6 healthy adult Thoroughbreds.

Procedure—Electrical activity of the small intestine
and cecum was recorded before and after mosapride
administration by use of an electrogastrograph.
Mosapride (0.5, 1, 1.5, and 2 mg/kg) was dissolved in
200 mL of water and administered orally to horses
through a nasogastric tube. Three hours after drug
administration, mean amplitude of electrical activity
calculated for a period of 30 minutes was expressed
as the percentage of the mean amplitude of electrical
activity for a period of 30 minutes before drug
administration.

Results—Mosapride administered orally increased
the percentage of the mean amplitude of electrical
activity in the small intestine and cecum in a dosedependent
manner. Mean ± SD values differed significantly
for 1, 1.5, and 2 mg/kg (127.0 ± 12.5%, 137.7 ±
22.2%, and 151.1 ± 24.0%, respectively) in the small
intestine and for 1.5 and 2 mg/kg (130.1 ± 34.5% and
151.6 ± 45.2%, respectively) in the cecum.

Conclusions and Clinical Relevance—Analysis of
results of this study clearly documents that
mosapride promotes motility in the small intestine
and cecum of horses and that the optimal orally
administered dosage is 1.5 to 2 mg/kg. Therefore,
mosapride may be useful for treatment of horses
with gastrointestinal tract dysfunction. (Am J Vet Res 2005;66:1321–1323)
Epidural migration of new methylene blue in 0.9% sodium chloride solution or 2% mepivacaine solution following injection into the first intercoccygeal space in foal cadavers and anesthetized foals undergoing laparoscopy
Authors: Lansdowne Jennifer L. , Kerr Carolyn L. , Bouré Ludovic P. , Pearce Simon G.
Published: December 2005

Objective—To determine the relationship between epidural cranial migration and injectate volume of an isotonic solution containing dye in laterally recumbent foal cadavers and evaluate the cranial migration and dermatome analgesia of an epidural dye solution during conditions of laparoscopy in foals.

Animals—19 foal cadavers and 8 pony foals.

Procedure—Foal cadavers received an epidural injection of dye solution (0.05, 0.1, 0.15, or 0.2 mL/kg) containing 1.2 mg of new methylene blue (NMB)/mL of saline (0.9% NaCl) solution. Length of the dye column and number of intervertebral spaces cranial and caudal to the injection site were measured. Anesthetized foals received an epidural injection of dye solution (0.2 mL/kg) containing saline solution or 2% mepivacaine. Foals were placed in a 10o headdown position, and pneumoperitoneum was induced. Dermatome analgesia was determined by use of a described electrical stimulus technique. Foals were euthanatized, and length of the dye column was measured.

Results—Epidural cranial migration of dye solution in foal cadavers increased with increasing volume injected. No significant difference was found in epidural cranial migration of a dye solution (0.2 mL/kg) between anesthetized foals undergoing conditions of laparoscopy and foal cadavers in lateral recumbency. Further craniad migration of the dye column occurred than indicated by dermatome analgesia.

Conclusions and Clinical Relevance—Epidural cranial migration increases with volume of injectate. On the basis of dermatome analgesia, an epidural injection of 2% mepivacaine (0.2 mL/kg) alone provides analgesia up to at least the caudal thoracic dermatome and could permit caudal laparoscopic surgical procedures in foals. (Am J Vet Res2005; 66:1324–1329)
Prediction of serum ionized calcium concentration by use of serum total calcium concentration in dogs
Authors: Schenck Patricia A. , Chew Dennis J.
Published: December 2005

Objective—To determine whether total serum calcium (tCa) or adjusted tCa concentrations accurately predict ionized calcium (iCa) status in dogs.

Sample Population—1,633 canine serum samples.

Procedure—The tCa concentration was adjusted for total protein (TP) or albumin concentration by use of published equations. Correlations between iCa and tCa or adjusted tCa, tCa and TP, and tCa and albumin were calculated. Diagnostic discordance between tCa or adjusted tCa and iCa was determined. Diagnostic discordance in predicting iCa was also determined for 490 dogs with chronic renal failure (CRF). Sensitivity, specificity, positive and negative predictive values, and positive and negative diagnostic likelihood ratios were calculated for tCa, tCa adjusted for TP, and tCa adjusted for albumin.

Results—Diagnostic discordance was 27% when tCa concentration was used to predict iCa status. Use of adjusted tCa increased diagnostic discordance to approximately 37% for all dogs and 55% for dogs with CRF. Positive predictive value and positive diagnostic likelihood ratios were poor when tCa concentration was used to predict iCa status. The tCa concentration overestimated normocalcemia and underestimated hypocalcemia. Adjusted tCa overestimated hypercalcemia and underestimated hypocalcemia.

Conclusions and Clinical Relevance—Adjusted tCa or tCa concentrations are unacceptable for predicting iCa status in dogs. Use of adjustment equations is not recommended. Direct measurement of iCa concentration is necessary for accurate assessment of calcium status. Use of tCa or adjusted tCa concentrations to predict iCa status in dogs could cause serious mistakes in diagnosis and case management, especially in dogs with CRF. (Am J Vet Res2005;66:1330–1336)
Evaluation of the precision of intradermal injection of control substances for intradermal testing in clinically normal horses
Authors: Wong David M. , Buechner-Maxwell Virginia A. , Manning Thomas O. , Ward Daniel L.
Published: December 2005

Objective—To evaluate the precision of intradermal testing (IDT) in horses.

Animals—12 healthy adult horses.

Procedure—IDT was performed on the neck of each horse by use of 2 positive control substances (histamine and phytohemagglutinin [PHA]) and a negative control substance. An equal volume (0.1 mL) for each injection was prepared to yield a total of 20 syringes ([4 concentrations of each positive control substance plus 1 negative control substance] times 2 positive control substances times 2 duplicative tests) for each side of the neck. Both sides of the neck were used for IDT; therefore, 40 syringes were prepared for each horse. Hair was clipped on both sides of the neck, and ID injections were performed. Diameter of the skin wheals was recorded 0.5, 4, and 24 hours after ID injection.

Results—Intra- and interhorse skin reactions to ID injection of histamine and PHA resulted in wheals of uniform size at 0.5 and 4 hours, respectively. Significant intra- and interhorse variation was detected in wheals caused by PHA at 24 hours.

Conclusions and Clinical Relevance—ID injection of histamine and PHA caused repeatable and precise results at 0.5 and 4 hours, respectively. Concentrations of 0.005 mg of histamine/mL and 0.1 mg of PHA/mL are recommended for use as positive control substances for IDT in horses. This information suggests that consistent wheal size is evident for ID injection of control substances, and variation in wheals in response to ID injection of test antigens results from a horse's immune response to specific antigens. (Am J Vet Res2005;66:1341–1347)
Effects of preoperative administration of carprofen on renal function and hemostasis in dogs undergoing surgery for fracture repair
Authors: Bergmann Hannes M. L. , Nolte Ingo J. A. , Kramer Sabine
Published: December 2005

Objective—To evaluate effects of preoperative administration of carprofen on renal function and hemostasis in dogs undergoing general anesthesia for fracture repair.

Animals—26 client-owned dogs.

Procedure—Anesthesia was induced with levomethadone, diazepam, and propofol and maintained by administration of isoflurane in oxygen-nitrous oxide. Carprofen (4 mg/kg, SC) was administered 1 hour before induction to 13 dogs (group 1) and after extubation to the other 13 dogs (group 2). All dogs also received carprofen (4 mg/kg, SC, q 24 h) for the first 4 days after surgery. Renal function (glomerular filtration rate [GFR], urinary protein-to-urinary creatinine ratio [UP:UC], and results of urinalysis and biochemical analysis of plasma), hemostatic variables (bleeding time, platelet aggregation, prothrombin time [PT], activated partial thromboplastin time [APTT], and platelet count), and Hct were assessed before and at various time points after surgery.

Results—Analysis of results for renal function tests, most of the hemostatic and plasma biochemical variables, and Hct did not reveal significant differences between treatment groups. Values for GFR, UP:UC, PT, APTT, and platelet aggregation were outside reference ranges in many dogs before surgery and during the first 6 hours after surgery. In most dogs, these trauma-induced pathologic changes returned to within reference ranges during the 4-day period after surgery.

Conclusions and Clinical Relevance—Carprofen did not cause clinically relevant adverse effects in dogs anesthetized for fracture repair after 5 days of treatment, even when it was administered before surgery or given to patients with trauma-induced alterations in renal function or hemostasis. (Am J Vet Res2005;66:1356–1363)
Evaluation of expected response to selection for orthopedic health and performance traits in Hanoverian Warmblood horses
Authors: Stock Kathrin F. , Distl Ottmar
Published: December 2005

Objective—To determine whether selection schemes accounting for orthopedic health traits were compatible with breeding progress in performance parameters in Hanoverian Warmblood horses.

Animals—5,928 horses.

Procedure—Relative breeding values (RBVs) were predicted for osseous fragments in fetlock (metacarpo- and metatarsophalangeal) and tarsal joints, deforming arthropathy in tarsal joints, and pathologic changes in distal sesamoid bones. Selection schemes were developed on the basis of total indices for radiographic findings (TIR), dressage (TID), and jumping (TIJ). Response to selection was traced over 2 generations of horses for dressage and jumping ability and all-purpose breeding. Development of mean RBVs and mean total indices in sires and prevalences of orthopedic health traits in their offspring were used to assess response to selection.

Results—Giving equal weight to TIR and TID, TIJ, or a combined index of 60% TID and 40% TIJ, 43% to 53% of paternal grandsires and 70% to 82% of descending sires passed selection. In each case, RBVs and total indices increased by as much as 9% in selected sires, when compared with all sires, and prevalences of orthopedic health traits in offspring of selected sires decreased relatively by as much as 16%. When selection was exclusively based on TID, TIJ, or TID and TIJ, percentages of selected sires were 44% to 66% in the first and 73% to 84% in the second generation and TID and TIJ increased by 9% to 10% and 19% to 23%, respectively.

Conclusions and Clinical Relevance—Compared with exclusively performance-based selection, percentages of selected sires changed slightly and breeding progress in TID, TIJ, or TID and TIJ was only slightly decreased; however, prevalences of orthopedic health traits decreased in offspring of TIR-selected sires. (Am J Vet Res2005;66:1371–1379)
Evaluation of a multiplex polymerase chain reaction assay for simultaneous detection of Rhodococcus equi and the vapA gene
Authors: Halbert Natalie D. , Reitzel Ruth A. , Martens Ronald J. , Cohen Noah D.
Published: December 2005

Objective—To evaluate sensitivity and specificity of a multiplex polymerase chain reaction (PCR) assay for simultaneous detection ofRhodococcus equiand differentiation of strains that contain the virulence-associated gene (vapA) from strains that do not.

Sample Population—187 isolates ofR equifrom equine and nonequine tissue and environmental specimens and 27 isolates of bacterial species genetically or morphologically similar toR equi.

Procedure—The multiplex PCR assay included 3 gene targets: a universal 311-bp bacterial 16S ribosomal RNA amplicon (positive internal control), a 959-bpR equi-specific target in the cholesterol oxidase gene (choE), and a 564-bp amplicon of the vapA gene. Duplicate multiplex PCR assays for these targets and confirmatory singleplex PCR assays for vapA andchoEwere performed for each R equiisolate. An additional PCR assay was used to examine isolates for thevapBgene.

Results—Results of duplicate multiplex and singleplex PCR assays were correlated in all instances, revealing high specificity and reliability (reproducibility) of thevapAmultiplex assay. Of the pulmonary isolates from horses with suspectedR equipneumonia, 97.4% (76/78) yielded positive results forvapA. Seven of 50 (14%) human isolates ofR equiyielded positive results forvapA. Six humanR equiisolates and 1 porcine isolate yielded positive results forvapB. No isolates withvapAandvapBgenes were detected.

Conclusions and Clinical Relevance—The multiplex PCR assay is a sensitive and specific method for simultaneous confirmation of species identity and detection of the vapA gene. The assay appeared to be a useful tool for microbiologic and epidemiologic diagnosis and research. (Am J Vet Res2005;66:1380–1385)
Comparison of various blood-typing methods for the feline AB blood group system
Authors: Stieger Knut , Palos Hanna , Giger Urs
Published: December 2005

Objective—To compare feline blood-typing results determined by use of the card (CARD), gel (GEL), tube (TUBE), University of Pennsylvania (Penn) tube, and Penn slide tests.

Sample Population—Blood samples from 38 healthy cats.

Procedure—Blood samples, anticoagulated with EDTA, were screened by use of each blood-typing method according to manufacturers' protocols.

Results—On the basis of the standard Penn tube and slide test results, 20, 11, and 7 cats were classified as type A positive, type B positive, and type AB positive, respectively. The same results were obtained with the anti-B and anti-B reagents of the TUBE test. Use of anti-A antibodies of original polyclonal and current monoclonal CARD tests resulted in mostly 2+ to 3+ (scale, 0 to 4+) agglutination reactions with blood samples from type A-positive cats; agglutination reactions with blood samples from type AB-positive cats were weak (1+). The anti-B lectin of the CARD test induced a 2+ to 4+ reaction with blood from all type B- and type AB-positive cats. Use of the GEL test allowed recognition of type A and type B blood samples; following addition of anti-A serum to control columns, type B blood was differentiated from type AB blood.

Conclusions and Clinical Relevance—Use of the inpractice CARD test allows identification of type A and type B-positive cats, but weak reactions of type AB blood with the anti-A monoclonal antibody raise concerns. The modified GEL and TUBE tests appear to be reliable clinical laboratory methods for feline blood typing. (Am J Vet Res2005;66:1393–1399)
Ultrastructural morphologic evaluation of the phenotype of valvular interstitial cells in dogs with myxomatous degeneration of the mitral valve
Authors: Black Alexander , French Anne T. , Dukes-McEwan Joanna , Corcoran Brendan M.
Published: December 2005

Objective—To evaluate morphologic changes in valvular interstitial cells of dogs and to find evidence for disease-associated phenotypic changes in these cells.

Animals—5 clinically normal dogs and 5 dogs with severe mitral valve endocardiosis.

Procedure—Mitral valve leaflets were evaluated by use of transmission electron microscopy. Differences in cell type and cell location were identified.

Results—A change in cell type toward a myofibroblast or smooth muscle cell phenotype was detected, with the smooth muscle cell type being most common. These cells had long amorphous cytoplasmic extensions, fibrillar cytoplasm, incomplete basal lamina, few mitochondria, and eccentrically placed nuclei but lacked smooth endoplasmic reticulum or Golgi complexes. Remaining valvular interstitial cells had heterochromatic nuclei and produced only minimal quantities of collagen. Compared with normal valves, myxomatous valves had many interstitial-like cells located adjacent to the endothelium. Deeper within the abnormal valves, cells with a heterogenous phenotype formed groupings that appeared to be anchored to adjacent collagen.

Conclusions and Clinical Relevance—Myxomatous degeneration of the mitral valve in dogs is associated with phenotypic alteration, changing from an interstitial to a mixed myofibroblast or smooth muscle cell phenotype. A closer association between interstitial cells and the endothelium is evident in diseased valves. In response to the disease process, valvular interstitial cells of dogs appear to change toward a smooth muscle phenotype, possibly in an attempt to maintain valve tone and mechanical function. (Am J Vet Res2005;66:1408–1414)
Determination of glutathione peroxidase and superoxide dismutase-like activities in equine spermatozoa, seminal plasma, and reproductive tissues
Authors: Baumber Julie , Ball Barry A.
Published: December 2005

Objective—To determine glutathione peroxidase (GPX) and superoxide dismutase (SOD)-like activities in spermatozoa, seminal plasma, and reproductive tissues (ie, testis, epididymis, bulbourethral gland, prostate, vesicular gland, and ampulla) in horses.

Sample Population—Seminal plasma from 17 stallions, spermatozoa from 5 stallions, and reproductive tissues from 3 stallions.

Procedure—Activity of GPX was determined by use of assays measuring oxidation of NADPH in the presence of exogenous glutathione, cumene hydroperoxide, and glutathione reductase. Activity of SOD-like enzymes was determined by use of the nitroblue tetrazolium assay.

Results—Mean GPX and SOD-like activities in seminal plasma were 1.3 ± 0.1 nmol of NADPH oxidized/ min/mg of protein and 29.2 ± 6.6 U/mg of protein, respectively. Mean GPX activities in spermatozoa separated from seminal plasma by centrifugation and via Percoll gradient were 2.2 ± 0.3 nmol and 6.1 ± 1.3 nmol of NADPH oxidized/min/mg of protein, respectively. Mean SOD-like activity of spermatozoa separated by centrifugation was 58.6 ± 22.3 U/mg of protein; SOD-like activity was not detected in Percollseparated spermatozoa. Among reproductive tissues, the ampulla and prostate had the highest SOD-like activity, although this was not significantly different from activity in other tissues. Testes and spermatozoa from the cauda epididymis contained significantly more GPX activity than other tissues.

Conclusions and Clinical Relevance—Results suggest that although equine seminal plasma contains high SOD-like enzyme activity, spermatozoa have limited GPX and SOD-like activity. Enzymatic antioxidant activity in equine spermatozoa appears to be predominantly derived from seminal plasma adsorbed onto the plasma membrane. Removal of seminal plasma during semen processing may increase oxidative stress in equine spermatozoa. (Am J Vet Res2005;66:1415–1419)
Assessment of the effects of electromagnetic field modification on egg-laying hens in commercial flocks as indicated by production measures
Authors: Keirs Robert W. , Peebles Edgar D. , Sarjeant Walter J. , Gerard Patrick D. , Terner Jonathan A.
Published: December 2005

Objective—To assess the effects of electromagnetic (EM) field modification by use of Nufield EM field modification (NEFM) units on egg-laying hens in commercial flocks as indicated by production measures, including hen-day mortality rate (HDMR) and eggs per hen housed (EHH).

Animals—16 commercial flocks of egg-laying hens.

Procedure—5 caged commercial table egg layer flocks (Single Comb White Leghorns) successively housed at the same location during a 6-year period were exposed to NEFM. There were 7 hens/cage (317 cm2of floor space/bird). At the same site, 11 concurrent non–NEFM-exposed flocks (4 genetically different strains) were sequentially housed. All 16 flocks underwent the same feed and management practices. For each NEFM- and non–NEFM-exposed flock, HDMR and EHH were compared with their respective national breeder goals (BG), defined as the reasonable genetic potential expressed under optimal management and environmental conditions. Furthermore, the HDMRs and EHHs of the NEFM- and non–NEFM-exposed flocks were compared.

Results—Mean HDMR and EHH of the NEFMexposed flocks was 36.9% less and 4.96% greater than the relevant BG, respectively. Mean HDMR and EHH of the non–NEFM-exposed flocks was 12.6% and 0.49% greater than the relevant BG, respectively. Compared with the 11 non–NEFM-exposed flocks, the NEFM-exposed flocks collectively had a 47.6% decrease in HDMR and 1.33% increase in EHH.

Conclusions and Clinical Relevance—Results strongly suggest that application of NEFM in commercial egg-layer flocks improves production measures, which has important welfare implications as well as gross economic advantage. (Am J Vet Res2005;66:1425–1429)
Comparison of arterial pressure waveform analysis with the lithium dilution technique to monitor cardiac output in anesthetized dogs
Authors: Chen Hui Cheng , Sinclair Melissa D , Dyson Doris H. , McDonell Wayne N. , Sears William C.
Published: December 2005

Objective—To assess agreement between arterial
pressure waveform–derived cardiac output (PCO) and
lithium dilution cardiac output (LiDCO) systems in
measurements of various levels of cardiac output
(CO) induced by changes in anesthetic depth and
administration of inotropic drugs in dogs.

Animals—6 healthy dogs.

Procedure—Dogs were anesthetized on 2 occasions
separated by at least 5 days. Inotropic drug administration
(dopamine or dobutamine) was randomly
assigned in a crossover manner. Following initial calibration
of PCO measurements with a LiDCO measurement,
4 randomly assigned treatments were
administered to vary CO; subsequently, concurrent
pairs of PCO and LiDCO measurements were
obtained. Treatments included a light plane of anesthesia,
deep plane of anesthesia, continuous infusion
of an inotropic drug (rate adjusted to achieve a mean
arterial pressure of 65 to 80 mm Hg), and continuous
infusion of an inotropic drug (7 µg/kg/min).

Results—Significant differences in PCO and LiDCO
measurements were found during deep planes of
anesthesia and with dopamine infusions but not during
the light plane of anesthesia or with dobutamine
infusions. The PCO system provided higher CO measurements
than the LiDCO system during deep
planes of anesthesia but lower CO measurements
during dopamine infusions.

Conclusions and Clinical Relevance—The PCO system
tracked changes in CO in a similar direction as
the LiDCO system. The PCO system provided better
agreement with LiDCO measurements over time
when hemodynamic conditions were similar to those
during initial calibration. Recalibration of the PCO system
is recommended when hemodynamic conditions
or pressure waveforms are altered appreciably. (Am J Vet Res 2005;66:1430–1436)
Plasma pharmacokinetics and synovial fluid concentrations after oral administration of single and multiple doses of celecoxib in Greyhounds
Authors: Hunter Robert P , Radlinsky MaryAnn , Koch David E , Corse Matthew , Pellerin Marie A. , Halstead Jennifer
Published: December 2005

Objective—To determine the plasma pharmacokinetics and synovial fluid concentrations after oral administration of single and multiple doses of celecoxib in Greyhounds.

Animals—7 adult Greyhounds.

Procedure—Dogs received celecoxib (median dose, 11.8 mg/kg [range, 11.5 to 13.6 mg/kg], PO, q 24 h) for 10 days. Blood samples were collected prior to administration of celecoxib and serially for 24 hours after the 1st and 10th doses were administered. A synovial joint catheter was placed into a stifle joint in each dog for collection of synovial fluid samples. Concentrations of celecoxib in plasma and synovial fluid were quantified by use of a validated liquid chromatography/mass spectrometry method. Identification of hydroxy- and carboxyl-celecoxib in plasma and synovial fluid was also performed. Pharmacokinetic parameters were determined by use of noncompartmental analysis.

Results—Administration of multiple doses of celecoxib resulted in a significant decrease (40%) in median area under the curve (AUC) values and a corresponding decrease in median maximum concentrations (Cmax; 2,620 to 2,032 ng/mL) between the 1st and 10th doses. Synovial fluid concentrations were less than the corresponding plasma concentrations at all times except 24 hours after administration of the 10th dose of celecoxib.

Conclusions and Clinical Relevance—Celecoxib distributes into the synovial fluid of Greyhounds. Although the exact mechanism for the decreases in AUC and Cmaxis not known, results suggested that the plasma pharmacokinetics of celecoxib are different after administration of multiple doses in Greyhounds. These findings warrant further investigation on the absorption, distribution, metabolism, and elimination of celecoxib in Greyhounds and other breeds of dogs. (Am J Vet Res2005;66:1441–1445)
Evaluation of calciotropic hormones in cats with odontoclastic resorptive lesions
Authors: Reiter Alexander M. , Lyon Kenneth F , Nachreiner Raymond F. , Shofer Frances S.
Published: December 2005

Objective—To assess associations between epidemiologic and laboratory variables and calciotropic hormones in cats with odontoclastic resorptive lesions (ORLs).

Animals—182 client-owned cats older than 1 year of age with oral disease.

Procedure—Information on medical history, behavior, living environment, and feeding management was assessed by use of a questionnaire. After induction of general anesthesia, oral examination was performed following standardized protocols and included dental probing and full-mouth radiography. Laboratory analyses included evaluation of FeLV-FIV status, serum biochemical analyses, CBC, urinalysis, and serum concentrations of intact parathyroid hormone (iPTH), parathyroid hormone-related peptide (PTHrP), 25-hydroxyvitamin D (25-OHD), free thyroxine (fT4), and ionized calcium (iCa).

Results—ORLs were identified in 72.5% of cats. Mandibular third premolars were the most commonly affected teeth. Cats with ORLs were significantly older (mean, 9.2 years) than cats without ORLs (mean, 6.6 years). Multivariate logistic regression analysis revealed that 25-OHD, urine specific gravity, jaw-opening reflex on probing, and missing teeth were significant variables, even after accounting for age. Cats with ORLs had significantly higher mean serum concentration of 25-OHD (112.4 nmol/L) and significantly lower mean urine specific gravity (1.0263), compared with cats without ORLs (89.8 nmol/L and 1.0366, respectively).

Conclusions and Clinical Relevance—Results did not indicate associations between iPTH, PTHrP, or fT4and development of ORLs. In affected cats, the importance of high serum 25-OHD and low urine specific gravity has not been determined. (Am J Vet Res2005;66:1446–1452)
Evaluation of a questionnaire regarding nonphysical aspects of quality of life in sick and healthy dogs
Authors: Wojciechowska Janina I. , Hewson Caroline J. , Stryhn Henrik , Guy Norma C. , Patronek Gary J. , Timmons Vianne
Published: December 2005

Objective—To evaluate the ability of a questionnaire regarding the nonphysical aspects of quality of life (QOL) to differentiate sick and healthy dogs.

Animals—120 dogs.

Procedure—The questionnaire was administered by telephone to owners of 120 dogs with appointments at a veterinary teaching hospital. A QOL score was calculated for each dog on the basis of questions relevant to the dog during the 7 days before the interview. Scores were recorded as bar graphs, and linear regression was used to examine the effect of health status and other variables on QOL score. Certain questions were eliminated post hoc, on the basis of defined criteria, and the analyses were repeated.

Results—Scores were similar for sick (range, 67.0% to 93.8%) and healthy (range, 68.0% to 89.8%) dogs. Environment (suburban vs rural) and duration of ownership were significant explanatory variables and accounted for 10.5% of the variation in the QOL score. Eleven questions were eliminated post hoc. The scores derived from the 2 versions of the questionnaire were highly correlated (r= 0.92).

Conclusions and Clinical Relevance—There was no evidence that the QOL questionnaire could differentiate healthy dogs from sick dogs; environmental and owner factors appeared to be more important. (Am J Vet Res2005;66:1461–1467)