bluuebunny/crossref_metadata_2025 huggingface dataset:
Doppler ultrasonographic features of thoracic limb arteries in clinically normal horses
Authors: Cochard Thierry , Toal Robert L. , Saxton A. M.
Published: December 2005

Objectives—To determine blood flow velocities and indices from spectral waveforms obtained by use of Doppler ultrasonography of thoracic limb arteries of horses and to assess interobserver and patient variability associated with the technique.

Animals—9 clinically normal adult horses.

Procedure—Left thoracic limb arteries of 8 nonsedated horses were examined at 5 sites by use of pulsed-wave Doppler ultrasonography to determine a range of values for peak systolic, end diastolic, and mean velocities and resistive and pulsatility indices. Interobserver and patient variabilities were determined by 2 operators repeating similar measurements on 1 horse 8 times at weekly intervals.

Results—A range of values for each variable measured at the 5 selected sites was obtained. For each variable, strong positive correlations (R ≥ 0.7) were detected for > 70% of the site-to-site comparisons made (excluding the coronary band). Among horses, resistive index varied least, whereas over time, mean velocity varied least. Waveform characteristics were consistent with resistive (n = 5) or nonresistive (4) patterns. In the single-horse experiment, waveform characteristics were consistent throughout the 8 weeks, and operator effects were not detected.

Conclusions and Clinical Relevance—Doppler ultrasonography of no one site resulted in more reliable measurements of blood flow characteristics in thoracic limb arteries of horses. Mean velocity and resistive index were the least variable measurements made. Pulsed-wave Doppler ultrasonography may be a useful technique for evaluating diseases that alter normal thoracic limb arterial blood flow in horses. (Am J Vet Res2000;61:183–)
Limb loading activity of adult horses confined to box stalls in an equine hospital barn
Authors: McDuffee Laurie A. , Stover Susan M. , Coleman Kim
Published: December 2005

Objective—To determine a range of limb loading
activity for healthy adult horses confined to box stalls
in an equine veterinary teaching hospital and determine
the effects of hospital environmental factors on
load rates and daily limb loading patterns.

Animals—6 mature healthy horses of various ages,
breeds, and sexes, and 1 horse with a repaired
metatarsal fracture.

Procedure—Step monitors were placed on 2 limbs of
adult horses confined to box stalls. Relocation steps
and weight shifts were recorded, as loading events,
for 24 hours. Influence of forelimb versus hind limb
and environmental factors on load rate (loading
events per hour) were assessed with repeated-measures
ANOVA.

Results—Loading activity was greater for the forelimb
than the hind limb and was greater during the
day than the night. Loading activity differences were
not associated with daytime environmental factors.

Conclusions and Clinical Relevance—Horses with
normal locomotor activity appear to have higher load
rates for forelimbs compared with hind limbs and
higher load rates during the day compared with night.
Knowledge of influence of environmental factors and
mechanical restraint on limb loading activity may be
useful in management of horses with musculoskeletal
disorders. This information may also be used for in
vitro simulation of in vivo loading of limbs during
cyclic biomechanical investigations.(Am J Vet Res
2000;61:234–237)
Expression of cyclooxygenase-2 in transitional cell carcinoma of the urinary bladder in dogs
Authors: Khan K. Nasir M. , Knapp Deborah W. , Denicola Dennis B. , Harris R. Keith
Published: December 2005

Objective—To evaluate expression of cyclooxygenase
(COX)-1 and COX-2 in the urinary bladder epithelium of
clinically normal dogs and in transitional cell carcinoma
cells of dogs.

Animals—21 dogs with transitional cell carcinoma of
the urinary bladder and 8 dogs with clinically normal
urinary bladders.

Procedure—COX-1 and COX-2 were evaluated by
use of isoform-specific antibodies with standard
immunohistochemical methods.

Results—COX-1, but not COX-2, was constitutively
expressed in normal urinary bladder epithelium; however,
COX-2 was expressed in neoplastic epithelium
in primary tumors and in metastatic lesions of all 21
dogs and in new proliferating blood vessels in 3 dogs.
Also, COX-1 was expressed in the neoplastic cells.

Conclusions and Clinical Relevance—Lack of
expression of COX-2 in normal bladder epithelium and
its substantial expression in transitional cell carcinoma
cells suggest that this isoform may be involved in
tumor cell growth. Inhibition of COX-2 is a likely
mechanism of the antineoplastic effects of non
steroidal antiinflammatory drugs. (Am J Vet Res
2000;61:478–481)
Safety of moxidectin in avermectin-sensitive Collies
Authors: Paul Allan J. , Tranquilli William J. , Hutchens Douglas E.
Published: December 2005

Objective—To evaluate the safety of moxidectin administration at doses of 30, 60, and 90 µg/kg of body weight (10, 20, and 30 times the manufacturer's recommended dose) in avermectin-sensitive Collies.

Animals—24 Collies.

Procedure—Collies with mild to severe reactions to ivermectin challenge (120 mg/kg; 20 times the recommended dose for heartworm prevention) were used. Six replicates of 4 dogs each were formed on the basis of body weight and severity of reaction to ivermectin test dose. Within replicates, each dog was randomly allocated to treatment with oral administration of 30, 60, or 90 µg of moxidectin/kg or was given a comparable volume of placebo tablet formulation. Dogs were observed hourly for the first 8 hours and twice daily thereafter for 1 month for signs of toxicosis.

Results—Signs of toxicosis were not observed in any control group dog throughout the treatment observation period. Likewise, signs of toxicosis were not observed in any dog receiving moxidectin at 30, 60, or 90 µg/kg.

Conclusions and Clinical Relevance—The moxidectin formulation used in the study reported here appears to have a wider margin of safety than ivermectin or milbemycin in avermectin-sensitive Collies. (Am J Vet Res2000;61:482–483)
Effects of polysulfated glycosaminoglycan and hyaluronan on prostaglandin E2 production by cultured equine synoviocytes
Authors: Frean Stephen P. , Lees Peter
Published: December 2005

Objective—To investigate effects of the anti-arthritic agents hyaluronan and polysulfated glycosaminoglycan (PSGAG) on inflammatory metabolism in cultured equine synoviocytes.

Sample Population—Synoviocytes cultured from samples obtained from the metacarpophalangeal joints of 4 horses.

Procedure—Equine synoviocytes were grown in monolayer culture. Synoviocytes were stimulated with lipopolysaccharide (LPS) and simultaneously treated with various concentrations of hyaluronan or PSGAG for 48 hours. Three hyaluronan preparations were compared. Prostaglandin E2(PGE2) concentrations in culture medium were measured, using radioimmunoassay.

Results—The highest concentrations of hyaluronan and PSGAG tested inhibited PGE2production.

Conclusions and Clinical Relevance—Clinically achievable concentrations of hyaluronan and PSGAG inhibited PGE2synthesis by cultured equine synoviocytes. This anti-inflammatory action may be a mechanism through which these agents exert anti-arthritic effects. The effect was obtained at concentrations that can be achieved by use of intra-articular, but not systemic, administration of hyaluronan or PSGAG. (Am J Vet Res2000;61:499–505)
Heart rate variability in Doberman Pinschers with and without echocardiographic evidence of dilated cardiomyopathy
Authors: Calvert Clay A. , Jacobs Gilbert J.
Published: December 2005

Objective—To characterize the salient variables of the time-domain analysis of heart rate variability (HRV) in clinically normal Doberman Pinschers and to compare those variables with those of Doberman Pinschers with cardiomyopathy and mild to moderate myocardial failure.

Animals—46 Doberman Pinschers.

Procedure—HRV was analyzed in the time-domain from 24-hour Holter recordings obtained from 28 Doberman Pinschers with normal echocardiograms and 18 Doberman Pinschers with echocardiograms consistent with mild to moderate myocardial failure.

Results—Significant differences in HRV variables between the 2 groups of dogs were not detected. The HRV was greater during the nighttime (12 AM to 6 AM), compared with the 24-hour day and an 18-hour (6 AM to 12 AM) period.

Conclusions and Clinical Relevance—HRV of dogs with mild to moderate myocardial failure was not different from that of clinically normal dogs, because there were no disturbances of autonomic balance, baroreceptor function, and other factors that influence HRV in the dogs with cardiomyopathy, or the sensitivity of time-domain analysis was overwhelmed by normal sinus arrhythmia. The techniques now used to study HRV have important limitations, especially in dogs, and better noninvasive tests of autonomic function are needed. (Am J Vet Res2000;61: 506–511)
Comparison of plasma benzodiazepine concentrations following intranasal and intravenous administration of diazepam to dogs
Authors: Platt Simon R. , Randell Susan C. , Scott Karen C. , Chrisman Cheryl L. , Hill Richard C. , Gronwall Ronald R.
Published: December 2005

Objective—To determine whether plasma concentrations of benzodiazepines (BDZ) in dogs following intranasal (IN) administration of diazepam are comparable to concentrations following IV administration.

Animals—6 (4 male, 2 female) healthy adult Greyhounds.

Procedure—Dogs were randomly assigned to 2 groups of 3 dogs in a crossover design. Diazepam (0.5 mg/kg of body weight) was administered intravenously to dogs in group 1 and intranasally to dogs in group 2. Blood was collected from the jugular vein of each dog into tubes containing lithium heparin before and 3, 6, 9, 12, 15, 20, 30, 60, 120, 240, and 480 minutes following diazepam administration. After a 4-day washout period, dogs in group 1 received diazepam intranasally, dogs in group 2 received diazepam intravenously, and blood was again collected. Plasma concentration of BDZ was determined by use of a fluorescence polarization immunoassay.

Results—Mean (± SD) peak plasma concentration of BDZ following IV administration (1316 ± 216 µg/L) was greater than that following IN administration (448 ± 41 µg/L). Time to peak concentration was ≤ 3 minutes following IV administration and 4.5 ± 1.5 minutes following IN administration. Mean bioavailability of BDZ following IN administration was 80 ± 9%.

Conclusions and Clinical Relevance—Diazepam is rapidly and efficiently absorbed following IN administration of the parenteral formulation. Plasma concentrations match or exceed the suggested therapeutic concentration (300 µg/L). Intranasal administration of diazepam may be useful for treatment of seizures in dogs by owners or when intravenous access is not readily available. (Am J Vet Res2000;61:651–654)
Development of a method for determination of cyanide concentrations in serum and rumen fluid of cattle
Authors: Meiser Heribert , Hagedorn Heinz-Werner , Schulz Rüdiger
Published: December 2005

Objectives—To develop a reliable method for measurement
of cyanide concentrations in cattle, using
gas chromatography-mass spectrometry (GC-MS),
and establish reference ranges of cyanide concentrations
in cattle.

Animals—52 Fleckvieh cattle.

Procedure—Cattle were allocated to 3 groups; 12
were fed leguminous grass and hay, 36 were fed
whole-maize and corn-cob silages, and 4 were fed
other feedstuffs. Samples of blood, rumen fluid, and
liver were collected at time of slaughter. Serum,
rumen fluid, and liver homogenate were assayed for
cyanide content, using a derivatization procedure. A
technique for analysis by GC-MS that used selected
ion monitoring was developed.

Results—Compared with a spectrophotometric
method, detection of cyanide in serum and rumen
fluid by use of GC-MS was selective and sensitive,
with a limit of detection of 0.7 µM. Spectrophotometric
analysis yielded false-negative and
false-positive results. Thus, the GC-MS method was
used for subsequent analysis. In all cattle except 1,
cyanide concentration ranged from < 0.7 to 35 µM in
serum and from < 0.7 to 28 µM in rumen fluid;
cyanide concentration in that 1 animal was 206 µM.
Cattle fed clover, grass, grass hay, and clover hay had
8.3- to 8.6-fold higher mean cyanide concentrations
in rumen fluid and serum than cattle fed whole-maize
and corn-cob silages.

Conclusions and Clinical Relevance—Results of
this study suggest a reference range that should be
useful for aiding in the diagnosis of cyanide poisoning.
Also, cattle can apparently accommodate a
serum cyanide concentration of 206 µM without
adverse effects. (Am J Vet Res 2000;61:658–664)
Comparison of two heavy metal chelators for treatment of lead toxicosis in cockatiels
Authors: Denver Mary C. , Tell Lisa A. , Galey Francis D. , Trupkiewicz John G. , Kass Philip H.
Published: December 2005

Objective—To compare efficacy and safety of meso- 2,3-dimercaptosuccinic acid (DMSA) and Ca EDTA for treatment of experimentally induced lead toxicosis in cockatiels ( Nymphicus hollandicus).

Animals—137 (69 females, 68 males) healthy cockatiels between 6 months and 8 years old.

Procedure—Lead toxicosis was induced by placing lead shot in the gastrointestinal tract. Treatment with Ca EDTA (40 mg/kg of body weight, IM, q 12 h), DMSA (40 or 80 mg/kg, PO, q 12 h), and sodium sulfate salts (SSS; 0.5 mg/kg, PO, q 48 h) was initiated 4 days after induction of lead toxicosis. Blood lead concentrations were determined, using atomic absorption spectrophotometry. Number of birds surviving and blood lead concentrations were compared among groups.

Results—In Phase II of the study, administration of DMSA and Ca EDTA significantly decreased blood lead concentrations when used alone or in combination in birds with lead toxicosis. Addition of SSS did not result in further decreases in lead concentrations. Eight of 12 (66.7%) birds without lead toxicosis given 80 mg of DMSA/kg did not survive to the end of the study . Lesions related to treatment with chelating agents were not detected during necropsy.

Conclusions and Clinical Relevance—DMSA and Ca EDTA are effective chelating agents in cockatiels. Because DMSA is administered orally, it may be easier than other chelating agents for bird owners to administer at home. However, the narrow margin of safety of DMSA indicates that this agent should be used with caution. (Am J Vet Res2000;61:935–940)
Analysis of aqueous humor obtained from normal eyes of llamas and alpacas
Authors: Aubin Marcia L. , Gionfriddo Juliet R. , Mama Khursheed R. , Powell Cynthia C.
Published: December 2005

Objective—To evaluate composition of aqueous humor obtained from normal eyes of llamas (Lama glama) and alpacas (Lama pacos).

Sample Population—Aqueous humor obtained from 10 male llamas and 10 male alpacas.

Procedure—All animals had normal eyes, as determined by ocular examination. Aqueous humor samples were obtained via paracentesis of the anterior chamber of animals that were heavily sedated. Chemical analysis included measurement of concentrations of sodium, potassium, magnesium, chloride, bicarbonate, phosphorus, and glucose as well as osmolality and pH.

Results—With the exception of potassium concentrations, values for aqueous humor composition did not differ significantly between llamas and alpacas. Mean ± SD values for llamas and alpacas, respectively, were: sodium, 154.7 ± 2.1 and 152.7 ± 2.1 mEq/L; potassium, 5.3 ± 0.4 and 4.6 ± 0.4 mEq/L; magnesium, 1.8 ± 0.1 and 1.7 ± 0.1 mg/dl; chloride, 130.0 ± 1.6 and 127.0 ± 3.3 mEq/L; bicarbonate, 19.2 ± 1.5 and 20.2 ± 2.3 mEq/L; phosphorous, 2.7 ± 0.3 and 2.5 ± 0.4 mg/dl; glucose, 80.3 ± 3.9 and 80.8 ± 7.3 mg/dl; total protein, 29.0 ± 8.6 and 31.5 ± 10.1 mg/dl; and osmolality, 305.8 ± 11.8 and 306.2 ± 4.9 mOsm. The pH ranged from 7.5 to 8.0 for both species. Potassium concentrations were significantly higher in llamas than alpacas.

Conclusions and Clinical Relevance—Except for potassium, composition of aqueous humor did not differ significantly between llamas and alpacas. Aqueous humor composition of llamas and alpacas is similar to that of other species that have been examined. (Am J Vet Res2001;62:1060–1062)
Changes in protein and nutrient composition of milk throughout lactation in dogs
Authors: Adkins Yuriko , Lepine Allan J. , Lönnerdal Bo
Published: December 2005

Objective—To evaluate changes in protein and nutrient composition of milk throughout lactation in dogs.

Sample Population—Milk samples collected from 10 lactating Beagles.

Procedure—Milk samples were collected on days 1, 3, 7, 14, 21, 28, 35, and 42 after parturition and analyzed to determine concentrations of nitrogen, nonprotein nitrogen, casein, whey proteins, amino acids, lipids, lactose, citrate, minerals, and trace elements. Optimum conditions for separating casein from whey proteins and distribution of milk proteins throughout lactation were assessed by use of polyacrylamide gel electrophoresis.

Results—Protein concentration was high in samples collected on day 1 (143 g/L), decreased through day 21 (68.4 g/L), and increased thereafter. Concentration of nonprotein nitrogen did not change throughout lactation (5.7 to 9.9% of total nitrogen content). Casein-towhey ratio was approximately 70:30 and remained constant throughout lactation. Lactose concentration increased from 16.6 g/L on day 1 to 34.0 to 40.2 g/L on days 7 to 42. Lipid concentration ranged from 112.5 to 137.2 g/L. Citrate concentration increased from day 1 (4.8 mM) to day 7 (6.6 mM), then gradually decreased until day 42 (3.9 mM). Iron, zinc, copper, and magnesium concentrations decreased during lactation, whereas calcium and phosphorus concentrations increased. Calcium-to-phosphorus ratio remained constant throughout lactation (approx 1.6:1). Energy content of milk ranged from 1,444 to 1,831 kcal/L.

Conclusions and Clinical Relevance—Protein and nutrient composition of milk changes throughout lactation in dogs. These data can provide valuable information for use in establishing nutrient requirements of puppies during the suckling period. (Am J Vet Res2001;62:1266–1272)
Attenuation of a Brucella abortus mutant lacking a major 25 kDa outer membrane protein in cattle
Authors: Edmonds Matthew D. , Cloeckaert Axel , Booth Natha J. , Fulton W. Todd , Hagius Sue D. , Walker Joel V. , Elzer Philip H.
Published: December 2005

Objective—To determine the virulence of aBrucella abortusmutant, BA25, lacking a major 25 kd outer membrane protein (Omp25) in cattle.

Animals—20 mixed-breed heifers in late gestation.

Procedure—10 heifers were inoculated with 1 × 107colony-forming units of theOmp25mutant via the conjunctival sac, and an equal number were infected with the virulent parental strainB abortus2308. The delivery status of the dams was recorded, and colonization was assessed following necropsy. The ability of BA25 to replicate inside bovine phagocytes and chorionic trophoblasts was also evaluated in vitro because of the propensity of virulent brucellae to replicate inside these cells in vivo.

Results—The parental strain induced abortions in 5 of 10 inoculated cattle, whereas only 1 of 10 dams exposed to BA25 aborted.Brucella abortusstrain 2308 colonized all of the cow-calf pairs and inducedBrucella-specific antibodies in 100% of the dams. In contrast, BA25 was isolated by bacteriologic cultural technique from 30% of the calves and 50% of the inoculated dams (n = 10). Of the 10 heifers inoculated with BA25, 4 did not developBrucella-specific antibodies nor were they colonized by the mutant strain. In bovine macrophages and chorionic trophoblasts, BA25 replicated in significantly lower numbers than the virulent parental strain (n = 3).

Conclusions and Clinical Relevance—The 25 kd outer membrane protein may be an important virulence factor forB abortusin cattle. The attenuation of theOmp25mutant in cattle may involve the inability of BA25 to replicate efficiently in bovine phagocytes and chorionic trophoblasts.(Am J Vet Res2001;62:1461–1466)
Effects of nitrous oxide on mask induction of anesthesia with sevoflurane or isoflurane in dogs
Authors: Mutoh Tatsushi , Nishimura Ryohei , Sasaki Nobuo
Published: December 2005

Objective—To determine the effects of nitrous oxide (N2O) on the speed and quality of mask induction with sevoflurane or isoflurane in dogs.

Animals—7 healthy Beagles.

Procedure—Anesthesia was induced with sevoflurane or isoflurane delivered in 100% oxygen or in a 2:1 mixture of N2O and oxygen via a face mask. Each dog received all treatments with at least 1 week between treatments. Initial vaporizer settings were 0.8% for sevoflurane and 0.5% for isoflurane (0.4 times the minimum alveolar concentration [MAC]). Vaporizer settings were increased by 0.4 MAC at 15-second intervals until settings were 4.8% for sevoflurane and 3.0% for isoflurane (2.4 MAC). Times to onset and cessation of involuntary movements, loss of the palpebral reflex, negative response to tail-clamp stimulation, and endotracheal intubation were recorded, and cardiopulmonary variables were measured.

Results—Administration of sevoflurane resulted in a more rapid induction, compared with isoflurane. However, N2O had no effect on induction time for either agent. Heart rate, mean arterial blood pressure, cardiac output, and respiratory rate significantly increased and tidal volume significantly decreased from baseline values immediately after onset of induction in all groups. Again, concomitant administration of N2O had no effect on cardiopulmonary variables.

Conclusions and Clinical Relevance—Administration of N2O did not improve the rate or quality of mask induction with sevoflurane or isoflurane. The benefits provided by N2O attributable to concentrating and second gas effects appear minimal in healthy dogs when low solubility inhalation agents such as isoflurane and sevoflurane are used for mask induction. (Am J Vet Res2001;62:1727–1733).
Flow cytometric analysis of intracellular complexity and CD45 expression for use in rapid differentiation of leukocytes in bovine blood samples
Authors: Pelan-Mattocks Lisa S. , Pesch Bruce A. , Kehrli Marcus E.
Published: December 2005

Objective—To develop an efficient and reliable method that accurately differentiates bovine lymphocytes from monocytes in leukograms.

Sample Population—Blood samples from 30 healthy cows and 1 calf with bovine leukocyte adhesion deficiency.

Procedure—Flow cytometric analysis of intracellular complexity and CD45 expression on bovine leukocytes was compared with results for conventional light microscopy methods. Verification of leukocyte subpopulations determined by intracellular complexity and CD45 expression was conducted, using 2-color phenotypic analysis with selected monoclonal antibodies.

Results—The CD45 and side-scatter properties of bovine leukocytes clearly differentiated cell types, including neutrophils, eosinophils, monocytes, and lymphocytes.

Conclusions and Clinical Relevance—This is a rapid assay that is simple to use. More importantly, it is more accurate than the conventional method that involves the use of blood slides and light microscopy, because of the ability of the assay to readily distinguish bovine monocytes and lymphocytes. Rapid preparation of samples and short analysis times allow for efficient and reliable examination of a large number of samples, and the task of viewing slides by light microscopy is eliminated. The labor-savings benefit of this procedure is most apparent in research environments that require frequent processing of batches of blood samples. (Am J Vet Res2001;62:1740–1744)
Effects of aerosolized albuterol on physiologic responses to exercise in Standardbreds
Authors: Mazan Melissa R. , Hoffman Andrew M.
Published: December 2005

Objective—To examine the effects of an aerosolized β2-adrenoreceptor agonist, albuterol, on performance during a standardized incremental exercise test in clinically normal horses.

Animals—8 Standardbred pacing mares.

Procedure—Clinically normal horses, as judged by use of physical examination, hematologic findings, serum biochemical analysis, and airway endoscopy, were randomly assigned to 2 groups and were given 900 µg of albuterol via a metered-dose inhaler 30 minutes before beginning a standardized incremental exercise test in a crossover design with a 7-day minimum washout. Further examination included measurement of baseline lung mechanics, response to histamine bronchoprovocation, and bronchoalveolar lavage.

Results—No significant differences (albuterol vs placebo) were seen for any incremental exercise test variables (ie, maximum oxygen consumption, maximum carbon dioxide consumption, respiratory quotient, treadmill speed at heart rate of 200 beats/min, or number of steps completed during an incremental exercise protocol). Mast cell percentage was significantly (r= –0.84) associated with the concentration of aerosolized histamine that evoked a 100% increase in total respiratory system resistance. No other direct correlations between bronchoalveolar lavage fluid cell types and any indices of exercise capacity or airway reactivity were found.

Conclusions and Clinical Relevance—Although no horse had exercise intolerance, 4 horses had airway hyperreactivity with bronchoalveolar lavage fluid mastocytosis; these horses may have been subclinically affected with inflammatory airway disease. In our study, albuterol did not enhance performance in 8 clinically normal racing-fit Standardbreds. (Am J Vet Res2001;62:1812–1817)
Computed tomographic study of the effect of a tongue-tie on hyoid apparatus position and nasopharyngeal dimensions in anesthetized horses
Authors: Cornelisse Cornelis J. , Rosenstein Diana S. , Derksen Frederik J. , Holcombe Susan J.
Published: December 2005

Objective—To determine the effect of manual
tongue protrusion on the dimensions of the hyoid
apparatus, nasopharynx, and oropharynx in anesthetized
horses.

Animals—5 adult horses.

Procedure—Horses were anesthetized and positioned
in sternal recumbency for 2 sequential computed
tomographic (CT) scans. Images were acquired
with the tongue in a natural position inside the mouth.
Then, the tongue was pulled rostrally and secured,
and a second CT scan was performed. Dorsoventral
length of the hyoid apparatus and angles of the
basisphenoid, basihyoid, and ceratohyoid were measured
on 3-dimensional reconstructed CT images.
Cross-sectional diameters and areas of the nasopharynx
and oropharynx were determined on reformatted
images in the transverse and longitudinal planes,
using osseous landmarks for consistency. Results
were tested between the 2 groups to determine significant
differences.

Results—We were unable to detect a significant
difference between any of the lengths or angles of
the hyoid apparatus measured with or without rostral
protrusion of the tongue. Similarly, nasopharyngeal
and oropharyngeal diameters and cross-sectional
areas were not significantly different with or
without rostral protrusion of the tongue.

Conclusions and Clinical Relevance—Tying the
tongue rostrally out of a horse's mouth did not influence
the position of the hyoid apparatus or dimensions
of the nasopharynx or oropharynx in anesthetized
horses. Currently, no data suggest that application
of a tongue-tie is effective for maintaining stability
and patency of the nasopharyngeal or orolaryngeal
airways in horses during races. (Am J Vet Res
2001;62:1865–1869)
Evaluation of an autogenous Salmonella bacterin and a modified live Salmonella serotype Choleraesuis vaccine on a commercial dairy farm
Authors: House John K. , Ontiveros Monica M. , Blackmer Nicole M. , Dueger Erica L. , Fitchhorn Jennifer B. , McArthur Gary R. , Smith Bradford P.
Published: December 2005

Objective—To compare the efficacy of aSalmonellabacterin and a modified liveSalmonellaser. Choleraesuis vaccine on a commercial dairy.

Animals—450 cows in late gestation and 80 calves.

Procedure—Group-1 cows (n = 150) were vaccinated once with a modified liveSCholeraesuis (serogroup C1) strain 54 (SC54) vaccine, group-2 cows (150) were vaccinated on enrollment and 30 days later with aSalmonellaser. Montevideo (serogroup C1) bacterin, and group-3 cows (150) served as unvaccinated controls. One gallon of colostrum harvested from the first 80 cows to calve was fed to each calf. Outcome assessments included fecal shedding ofSalmonellaspp for the first 10 days after parturition (cows) or birth (calves), milk production, involuntary culling rate, mastitis incidence, antimicrobial use, and mortality rate.

Results—Salmonellae were isolated from 306 of 309 (99%) cows and 64 of 74 (86.5%) calves. Shedding frequency was less in SC54-vaccinated cows and calves that received colostrum from those cows, compared with the other groups, and vaccination was specifically associated with less shedding of serogroup C1 salmonellae. Production data were similar among groups.

Conclusions and Clinical Relevance—Vaccination of pregnant cows with an autogenousSalmonellabacterin had no effect on fecal shedding of salmonellae, whereas vaccination with a modified liveSCholeraesuis vaccine reduced the frequency of fecal shedding of serogroup C1 salmonellae during the peripartum period. A commercialSCholeraesuis vaccine licensed for use in swine may be more efficacious than autogenousSalmonellabacterins on dairies infected with serogroup C1 salmonellae. (Am J Vet Res2001;62:1897–1902)
Cardiopulmonary function in horses during anesthetic recovery in a hydropool
Authors: Richter Marina C. , Bayly Warwick M. , Keegan Robert D. , Schneider Robert K. , Weil Ann B. , Ragle Claude A.
Published: December 2005

Objective—To determine the cardiovascular and respiratory effects of water immersion in horses recovering from general anesthesia.

Animals—6 healthy adult horses.

Procedure—Horses were anesthetized 3 times with halothane and recovered from anesthesia while positioned in lateral or sternal recumbency in a padded recovery stall or while immersed in a hydropool. Cardiovascular and pulmonary functions were monitored before and during anesthesia and during recovery until horses were standing. Measurements and calculated variables included carotid and pulmonary arterial blood pressures (ABP and PAP, respectively), cardiac output, heart and respiratory rates, arterial and mixed venous blood gases, minute ventilation, end expiratory transpulmonary pressure (PendXes), maximal change in transpulmonary pressure (ΔPtpmax), total pulmonary resistance (RL), dynamic compliance (Cdyn), and work of breathing ().

Results—Immersion in water during recovery from general anesthesia resulted in values of ABP, PAP, PendXes, ΔPtpmax, RL, andthat were significantly greater and values of Cdynthat were significantly less, compared with values obtained during recovery in a padded stall. Mode of recovery had no significant effect on any other measured or calculated variable.

Conclusions and Clinical Relevance—Differences in pulmonary and cardiovascular function between horses during recovery from anesthesia while immersed in water and in a padded recovery stall were attributed to the increased effort needed to overcome the extrathoracic hydrostatic effects of immersion. The combined effect of increased extrathoracic pressure and PAP may contribute to an increased incidence of pulmonary edema in horses during anesthetic recovery in a hydropool. (Am J Vet Res2001;62:1903–1910)
Effects of vitamin E on urokinase-plasminogen activator receptor expression by bovine neutrophils
Authors: Politis Ioannis , Hidiroglou Nick , Cheli Federica , Baldi Antonella
Published: December 2005

Objective—To determine the effect of vitamin E supplementation on urokinase-plasminogen activator (u-PA) receptor (u-PAR) expression by neutrophils of dairy cows.

Animals—16 healthy Holstein dairy cows.

Procedure—16 cows were assigned to 1 of 2 experimental groups: control (no vitamin E supplementation) and vitamin E supplementation. Supplementation of vitamin E started 4 weeks prior to and continued up to 4 weeks after parturition and included oral administration of vitamin E at 3,000 U/cow per day; these cows also received 1 injection of vitamin E (5,000 units), 1 week prior to the expected date of parturition. Blood samples were collected, and neutrophils were isolated weekly throughout the experimental period. The following variables were measured: u-PA (mRNA), total cell-associated u-PA activity, membrane-bound u-PA activity, and free unoccupied u-PA binding sites on the cell membrane of neutrophils.

Results—Stimulated neutrophils isolated from cows that received vitamin E supplementation had significantly higher u-PA mRNA and total cell-associated and membrane-bound u-PA activity at postpartum week 1, compared with those of stimulated neutrophils isolated from control cows. There were no differences between groups throughout the whole experimental period in u-PA binding sites of neutrophils.

Conclusions and Clinical Relevance—The increased total cell-associated and membrane-bound u-PA activity in neutrophils isolated from cows that received vitamin E may facilitate the ability of neutrophils to extravasate and reach the mammary gland at postpartum week 1. Rapid recruitment of neutrophils is critical for proper defense of the gland.(Am J Vet Res2001;62:1934–1938)
Effects of racing and training on serum thyroid hormone concentrations in racing Greyhounds
Authors: Hill Richard C. , Fox Leslie E. , Lewis Daniel D. , Beale Karin M. , Nachreiner Raymond F. , Scott Karen C. , Sundstrom Deborah A. , Jones Galin L. , Butterwick Richard F.
Published: December 2005

Objectives—To determine the effects of racing and training on serum thyroxine (T4), triiodothyronine (T3), and thyroid stimulating hormone (TSH) concentrations in Greyhounds.

Animals—9 adult racing Greyhounds.

Procedure—Serum thyroid hormone concentrations were measured before and 5 minutes after a race in dogs trained to race 500m twice weekly for 6 months. Resting concentrations were measured again when these dogs had been neutered and had not raced for 3 months. Postrace concentrations were adjusted relative to albumin concentration to allow for effects of hemoconcentration. Thyroid hormone concentrations were then compared with those of clinically normal dogs of non-Greyhound breeds.

Results—When adjusted for hemoconcentration, total T4concentrations increased significantly after racing and TSH concentrations decreased; however, there was no evidence of a change in free T4or total or free T3concentrations. Resting total T4concentrations increased significantly when dogs had been neutered and were not in training. There was no evidence that training and neutering affected resting TSH, total or free T3, or free T4concentrations. Resting concentrations of T3, TSH, and autoantibodies against T4, T3, and thyroglobulin were similar to those found in other breeds; however, resting free and total T4concentrations were lower than those found in other breeds.

Conclusions and Clinical Relevance—Except for total T4, thyroid hormone concentrations in Greyhounds are affected little by sprint racing and training. Greyhounds with low resting total and free T4concentrations may not be hypothyroid. (Am J Vet Res2001;62:1969–1972)
Pharmacokinetics and pharmacodynamics of danofloxacin in serum and tissue fluids of goats following intravenous and intramuscular administration
Authors: Aliabadi Fariborz S. , Lees Peter
Published: December 2005

Objective—To determine the pharmacokinetics and pharmacodynamics of danofloxacin in goats and the concentrations required to induce bacteriostasis, bactericidal activity, and bacterial elimination.

Animals—6 healthy British Saanen goats.

Procedure—Danofloxacin (1.25 mg/kg of body weight) was administered IV and IM in a cross-over design with 14 days between treatments. A tissue cage was used for evaluation of drug distribution into transudate and exudate. The ex vivo antibacterial activity of danofloxacin in serum, exudate, and transudate against a caprine isolate ofMannheimia haemolyticawas determined. Pharmacokinetic and pharmacodynamic data were integrated to determine the ratio of the area under the concentration versus time curve to the minimum inhibitory concentration of danofloxacin (AUIC).

Results—Elimination half-lives of danofloxacin in serum were 4.67 and 4.41 hours after IV and IM administration, respectively. Volume of distribution was high after administration via either route, and bioavailability was 100% after IM administration. Rate of penetration into exudate and transudate was slow, but elimination half-lives from both fluids were approximately twice that from serum. Drug concentrations in serum, exudate, and transudate for 9 to 12 hours after administration induced marked ex vivo antibacterial activity. For serum, AUIC24hvalues required for bacteriostasis, bactericidal effect, and bacterial elimination were 22.6, 29.6, and 52.4, respectively. Similar values were obtained for exudate and transudate.

Conclusions and Clinical Relevance—Integration of danofloxacin pharmacokinetic and pharmacodynamic data obtained in goats may provide a new approach on which to base recommendations for therapeutic dosages. (Am J Vet Res2001;62:1979–1989)
von Willebrand disease phenotype and von Willebrand factor marker genotype in Doberman Pinschers
Authors: Brooks Marjory B. , Erb Hollis N. , Foureman Polly A. , Ray Kunal
Published: December 2005

Objective—To define the relationship between clinical expression of a type-1 von Willebrand disease phenotype and genotype at 2 von Willebrand factor marker loci in Doberman Pinschers.

Animals—102 client-owned Doberman Pinschers.

Procedures—Dogs were recruited on the basis of plasma von Willebrand factor concentration, clinical history, and pedigree. Blood samples and response to a history questionnaire were obtained for each dog. Plasma von Willebrand factor concentration was measured by use of an ELISA, and genotyping was performed via polymerase chain reaction for 1 intragenic and 1 extragenic von Willebrand factor marker. Amplification product size was determined by use of polyacrylamide gel electrophoresis (intragenic marker) or automated sequence analysis (extragenic marker). Western blots were prepared from a subset of dogs with low plasma von Willebrand factor concentration to evaluate multimer distribution.

Results—Strong associations were detected between plasma von Willebrand factor concentration and von Willebrand factor marker genotype. Twentyfive dogs had substantial reduction in plasma von Willebrand factor concentration and multiple hemorrhagic events. All were homozygous for a 157-basepair intragenic marker allele and homozygous or compound heterozygous for 1 of 4 extragenic marker alleles. These marker genotypes were exclusively detected in dogs with low plasma von Willebrand factor concentration, although some dogs with these genotypes did not have abnormal bleeding.

Conclusions and Clinical Relevance—Type-1 von Willebrand disease in Doberman Pinschers is associated with the von Willebrand factor gene locus; however, the expression pattern in this breed appears more complex than that of a simple recessive trait. (Am J Vet Res2001;62:364–369)
Results of intradermal tests in horses without atopy and horses with chronic obstructive pulmonary disease
Authors: Lorch Gwendolen , Hillier Andrew , Kwochka Kenneth W. , Saville William J. , Kohn Catherine W. , Jose-Cunilleras Eduard
Published: December 2005

Objective—To compare results of intradermal tests (IDT), conducted using environmental allergens, in horses without atopy and horses with chronic obstructive pulmonary disease (COPD).

Animals—38 horses (22 horses without atopy and 16 horses with COPD).

Procedure—All horses were examined (physical examination, hematologic examination, serum biochemical analyses, examination of bronchoalveolar lavage fluid). An IDT was conducted, using a full panel of 73 allergens consisting of grasses, weeds, trees, molds, and insects. Results of the IDT were evaluated 30 minutes and 4, 6, and 24 hours after injection of allergens. Horses without atopy were euthanatized, and gross and histologic changes of lung parenchyma were assessed.

Results—Horses without atopy had a greater number of positive immediate and late-phase reactions than did horses with COPD. Horses with COPD did not have a significantly greater number of positive reactions than horses without atopy at any time period for any allergen group (grasses, weeds, trees, molds, and insects).

Conclusions and Clinical Relevance—Positive results of IDT document allergen-specific hypersensitivity but do not necessarily distinguish clinically relevant reactions from subclinical reactivity in horses with COPD. Interpreting the clinical relevance of results of IDT requires a thorough knowledge of the medical history, physical examination findings, and environment of each animal. (Am J Vet Res2001;62:389–397)
Effect of increased dietary protein and decreased dietary carbohydrate on performance and body composition in racing Greyhounds
Authors: Hill Richard C. , Lewis Daniel D. , Scott Karen C. , Omori Mayuko , Jackson Melissa , Sundstrom Deborah A. , Jones Galin L. , Speakman John R. , Doyle Celeste A. , Butterwick Richard F.
Published: December 2005

Objective—To determine effects of increased dietary
protein and decreased dietary carbohydrate on hematologic
variables, body composition, and racing performance
in Greyhounds.

Animals—8 adult Greyhounds.

Procedure—Dogs were fed a high-protein (HP; 37%
metabolizable-energy [ME] protein, 33% ME fat, 30%
ME carbohydrate) or moderate-protein (MP; 24% ME
protein, 33% ME fat, 43% ME carbohydrate) extruded
diet for 11 weeks. Dogs subsequently were fed
the other diet for 11 weeks (crossover design). Dogs
raced a distance of 500 m twice weekly. Rectal temperature,
hematologic variables before and after racing,
plasma volume, total body water, body weight,
average weekly food intake, and race times were
measured at the end of each diet period.

Results—When dogs were fed the MP diet, compared
with the HP diet, values (mean ± SD) differed
significantly for race time (32.43 ± 0.48 vs 32.61 ±
0.50 seconds), body weight (32.8 ± 2.5 vs 32.2 ± 2.9
kg), Hct before (56 ± 4 vs 54 ± 6%) and after (67 ± 3
vs 64 ± 8%) racing, and glucose (131 ± 16 vs 151 ±
27 mg/dl) and triglyceride (128 ± 17 vs 104 ± 28
mg/dl) concentrations after racing.

Conclusions and Clinical Relevance—Greyhounds
were 0.18 seconds slower (equivalent to 0.08 m/s or
2.6 m) over a distance of 500 m when fed a diet with
increased protein and decreased carbohydrate.
Improved performance attributed to feeding meat to
racing Greyhounds apparently is not attributable to
increased dietary protein and decreased dietary carbohydrate.
(Am J Vet Res 2001;62:440–447)
Neodymium:yttrium aluminum garnet laser ventriculocordectomy in standing horses
Authors: Hawkins Jan F. , Andrews-Jones Lydia
Published: December 2005

Objective—To develop a technique for neodymium:yttrium-aluminum-garnet (Nd:YAG) laser ventriculocordectomy in standing horses and document healing in horses undergoing laser ventriculocordectomy.

Animals—6 horses between 2 and 32 years old.

Procedure—Under endoscopic guidance, the left laryngeal ventricle was everted with grasping forceps and excised with an Nd:YAG laser, using 60 watts of power in a noncontact fashion (6,403 to 9,197 Joules). Following removal of the ventricle, the vocal cord was photoablated. Horses were examined endoscopically 2, 7, 14, 21, 30, and 47 days after ventriculocordectomy, and 1 horse was euthanatized on each of these days. At necropsy, the larynx was removed intact and examined grossly. Samples were collected for histologic examination of the ventriculocordectomy site.

Results—Endoscopic examination revealed granulation tissue by day 7, the start of epithelialization by day 21, and healing by day 47. At necropsy, 4 horses were found to have a small amount of ventricular mucosa remaining dorsally and 1 additional horse was found to have a mucocele. Granulation tissue was identified grossly and histologically in the horses euthanatized between 7 and 30 days after surgery. Incipient reepithelialization was evident histologically on day 14, and complete reepithelialization of the surgery site was evident by day 47.

Conclusion and Clinical Relevance—Results suggest that ventriculocordectomy can safely be performed with an Nd:YAG laser in standing horses. (Am J Vet Res2001;62:531–537)
Optimization of coagulometric tests that incorporate human plasma for determination of coagulation factor activities in canine plasma
Authors: Mischke Reinhard
Published: December 2005

Objective—To optimize methods used to measure coagulation factor activities in canine plasma, define reference ranges in dogs, and compare activities between canine and human plasma.

Sample Population—Human plasma samples (n = 5) and plasma from healthy dogs (140) and dogs with low factor V activity (7), high factor V activity (7), and low factor VIII:C activity (6).

Procedure—Coagulometric tests incorporated human plasma deficient in a single coagulation factor (human deficient plasma). Standard curves were generated with pooled plasma from 100 healthy dogs. Effect of sample dilution was evaluated, using plasma from dogs with high or low factor V activity and low factor VIII:C activity. Reference ranges for healthy dogs were established. Activities in human plasma were determined by comparison with standard curves obtained with canine plasma.

Results—Activities of factors V and VIII:C in samples diluted ≤ 1:20 influenced results of tests for other coagulation factors. Activities of factors V and VIII:C in human plasma were significantly less than in canine plasma. For the other coagulation factors, significant differences in human plasma-to-canine plasma activity ratios were detected among different sample dilutions.

Conclusion and Clinical Relevance—Accurate measurement of coagulation factor activities in canine plasma, using human deficient plasma, requires higher sample dilutions (ie, > 1:20) than typically used for human plasma. Differences in activities between human and canine plasma and nonparallelism of the standard curves emphasize the necessity for use of species-specific standard curves for accurate determination of coagulation factor activity. (Am J Vet Res2001;62:625–629)
Inoculation of two genotypes of Hemobartonella felis (California and Ohio variants) to induce infection in cats and the response to treatment with azithromycin
Authors: Westfall Donald S. , Jensen Wayne A. , Reagan William J. , Radecki Steven V. , Lappin Michael R.
Published: December 2005

Objectives—To describe clinical and laboratory findings associated with cats experimentally infected by inoculation with the 2 recognized genotypes ofHemobartonella felis(small variant, Hfsm; large variant, Hflg) and to determine the response of cats to treatment with azithromycin.

Animals—18 young adult domestic shorthair cats of both sexes.

Procedures—Cats were inoculated withH felisand monitored weekly, using CBC counts and a polymerase chain reaction (PCR) designed to detect both genetic variants ofH felis. Beginning 26 days after inoculation, 11 cats were administered azithromycin (15 mg/kg of body weight, PO, q 12 h, for 7 days).

Results—Inoculation resulted in coinfection with Hflg and Hfsm, and both variants were detected by PCR. Clinical abnormalities and anemia were most severe in Hflg- and dual-infected cats. Results of PCR and CBC were positive forH felisin 112/112 (100%) and 42/112 (37.5%), respectively, samples collected after inoculation. Administration of azithromycin had little effect on clinical variables, including anemia. All cats, regardless of treatment with azithromycin, had positive results for the PCR at the end of the study period.

Conclusions and Clinical Relevance—In these cats, Hflg was more pathogenic than Hfsm, and coinfection with both variants was detected. Results of the PCR were superior to results of CBC for detecting infection withH felis. Azithromycin administered at the dose and duration reported here was not efficacious for the treatment of cats with hemobartonellosis. (Am J Vet Res2000;62:687–691)