bluuebunny/crossref_metadata_2025 huggingface dataset:
Validation of several types of noxious stimuli for use in determining the minimum alveolar concentration for inhalation anesthetics in dogs and rabbits
Authors: Valverde Alexander , Morey Timothy E. , Hernández Jorge , Davies Wendy
Published: December 2005

Objective—To compare 3 types of noxious stimuli applied to various anatomic areas of anesthetized dogs and rabbits for determination of the minimum alveolar concentration (MAC).

Animals—10 dogs and 10 rabbits.

Procedure—Dogs were anesthetized with isoflurane and halothane in a randomized order. Rabbits were anesthetized with isoflurane. The MAC was determined by skin incision on the lateral aspect of the chest; clamping of the tail, paw of the forelimb, and paw of the hind limb; and application of electrical current to the oral mucosa (dogs only), forelimb, and hind limb. The MAC was the end-tidal concentration midway between the value permitting and preventing purposeful movement in response to noxious stimuli.

Results—In dogs, mean ± SEM MAC for isoflurane was 1.27 ± 0.05% for clamping stimuli, 1.36 ± 0.04% for oral electrical stimulation, 1.35 ± 0.04% for electrical stimulation to the limbs, and 1.01 ± 0.07% for surgical incision. The MAC for halothane was 0.97 ± 0.03% for tail clamping, 0.96 ± 0.03% for clamping of the limbs, 1.04 ± 0.03% for electrical stimulation, and 0.75 ± 0.06% for surgical incision. In rabbits, MAC for isoflurane was 2.08 ± 0.02% for clamping stimuli, 2.04 ± 0.02% for electrical stimulation, and 0.90 ± 0.02% for surgical incision. The MAC for surgical incision was significantly lower than values for the other methods in both species.

Conclusions and Clinical Relevance—Use of electrical current and clamping techniques resulted in similar MAC values. Surgical incision underestimated MAC values in dogs and rabbits. (Am J Vet Res2003;64:957–962)
Characterization of the bacterial population of the genital tract of adult cats
Authors: Holst Bodil Ström , Bergström Annika , Lagerstedt Anne-Sofie , Karlstam Erika , Englund Lena , Båverud Viveca
Published: December 2005

Objective—To characterize the bacteria of the genital tract in adult cats; assess the effect of estrus, mating, and administration of progestins on those microorganisms in females; and evaluate whether results of bacteriologic culture of vaginal swabs are affected by cleansing of the vulva prior to sampling or by repeated sampling.

Animals—66 female and 29 male cats undergoing routine ovariohysterectomy or castration.

Procedure—Specimens were obtained from vaginal and uterine or preputial mucosae with swabs moistened with sterile saline (0.9% NaCl) solution. In 9 cats, vaginal specimens were obtained before and after cleansing of the vulva with ethanol; in 7 female cats, 2 vaginal specimens were obtained in immediate succession.

Results—Aerobic bacteria were most commonly isolated from cats' vaginas and prepuces; anaerobic bacteria were isolated frequently from males (41%) but rarely from females (5%). Generally, culture results were not affected by cleansing of the vulva or repeated vaginal sampling. The bacterial population of the vaginas of cats was influenced by stage of the estrous cycle but not by mating or administration of progestins. Bacteria were not isolated from the uterus of any cat.

Conclusions and Clinical Relevance—In cats, bacteria of the genital tract in females are predominantly aerobic; in males, aerobic and anaerobic bacteria are found. The bacterial population of the vagina is affected by stage of the estrous cycle. Pure growth of bacteria in culture of genital tract specimens is a normal finding; antimicrobials should only be administered if clinical signs of genital infection are present. (Am J Vet Res2003;64:963–968)
Evaluation of a technique of inducing hypertensive renal insufficiency in cats
Authors: Mathur Sheerin , Brown Cathy A. , Dietrich Ursula M. , Munday John S. , Newell Melvin A. , Sheldon Suzanne E. , Cartier Leslie M. , Brown Scott A.
Published: December 2005

Objective—To compare 2 techniques of inducing combined renal insufficiency and systemic hypertension in cats.

Animals—22 cats 6 to 12 months of age.

Procedure—Cats were randomly assigned to 1 of 3 groups. Control (C) group cats had 2 intact kidneys, remnant kidney (RK) group cats underwent unilateral partial renal infarction and contralateral nephrectomy, and remnant-wrap (W) group cats underwent unilateral partial renal infarction and partial abtation and wrapping of the contralateral kidney. Systemic arterial blood pressure (BP) was measured continuously by use of implanted radiotelemetric devices. Renal function was assessed via determination of glomerular filtration rate, measurement of serum creatinine and BUN concentrations, and determination of urine protein-to-creatinine ratio (UP/C). Serum aldosterone concentration and plasma renin activity were measured on day 75.

Results—Systolic BP was significantly higher in groups RK and W than in group C, and systolic BP was significantly higher in group W than in group RK. Serum aldosterone concentration and plasma renin activity were significantly higher in group W, compared with groups C and RK. Glomerular filtration rate was significantly lower in groups RK and W, compared with group C. Histologic indices of renal injury and UP/C were significantly higher in group W, compared with groups C and RK.

Conclusions and Clinical Relevance—Hypertensive renal insufficiency in group W was characterized by marked sustained systemic hypertension, decreased renal function, proteinuria, activation of the reninangiotensin-aldosterone axis, and renal structural injury. Results support the hypothesis that marked systemic hypertension, activation of the reninangiotensin- aldosterone axis, and proteinuria may damage the kidney of cats with preexisting renal insufficiency. (Am J Vet Res2004;65:1006–1013)
Estimation of heritability of atopic dermatitis in Labrador and Golden Retrievers
Authors: Shaw Stephen C. , Wood James L. N. , Freeman Julia , Littlewood Janet D. , Hannant Duncan
Published: December 2005

Objective—To estimate the heritability of atopic dermatitis
in Golden and Labrador Retrievers.

Animals—429 dogs related to 13 dogs with atopic
dermatitis.

Procedure—Atopic dermatitis was defined on the
basis of the type and frequency of clinical signs
recorded in the clinical records, and each dog was
classified with atopic dermatitis or probable atopic
dermatitis or as nonatopic. By use of data from atopic
and nonatopic dogs, regression analyses of parental
status on offspring status were performed to estimate
heritability.

Results—There was no difference in the frequency
of atopic dermatitis between sexes or between
breeds. There was a marked association between
the atopic status of the parent and that of the offspring,
particularly for sires. By use of data from 32
litters in which the status of both parents was
known and considering only those dogs classified
with atopic dermatitis or as nonatopic, the heritability
(± SE) of atopic dermatitis was estimated to be
0.47 (± 0.17).

Conclusions and Clinical Relevance—Atopic dermatitis
has a strong genetic component, and breeding
of dogs with clinical signs of atopic dermatitis
should be discouraged. ( Am J Vet Res 2004;
65:1014–1020)
Evaluation of forelimb horseshoe characteristics of Thoroughbreds racing on dirt surfaces
Authors: Gross Diane K. , Stover Susan M. , Hill Ashley E. , Gardner Ian A.
Published: December 2005

Objective—To describe forelimb horseshoe characteristics of horses racing on dirt surfaces and determine whether these characteristics vary with region of California, season, horse characteristics, and race-related factors.

Animals—5,730 Thoroughbred racehorses.

Procedure—From June 17, 2000, to June 16, 2001, the characteristics of 1 forelimb horseshoe of horses that raced on dirt surfaces at 5 major racetracks in California were recorded. These characteristics included shoe type; toe grab height; and presence of a rim, pad, and heel traction devices (jar caulks, heel stickers, heel blocks, and special nails). Horse and race information was obtained from commercial records. One race/horse was randomly selected.

Results—99% of forelimb horseshoes were aluminum racing plates, 35% had a pad, 23% had a rim, and 8% had a heel traction device. A toe grab was observed on 75% of forelimb horseshoes (14% very low [≤ 2 mm], 30% low [> 2 and ≤ 4 mm], 30% regular [> 4 and ≤ 6 mm], and 1% high [> 6 and ≤ 8 mm]). Forelimb horseshoe characteristics varied with region of California, season, age and sex of the horse, race purse and distance, and track surface condition. Loglinear modeling revealed that all of these factors were significantly interrelated.

Conclusions and Clinical Relevance—Complex interrelationships among forelimb horseshoe characteristics and region, season, age and sex of the horse, and race-related factors need to be considered when evaluating the relationships between injury and horseshoe characteristics in Thoroughbred racehorses. (Am J Vet Res2004;65:1021–1030)
Effect of omeprazole paste on intragastric pH in clinically normal neonatal foals
Authors: Sanchez L. Chris , Murray Michael J. , Merritt Alfred M.
Published: December 2005

Objective—To evaluate the efficacy of omeprazole paste, a commonly used antiulcer drug, on intragastric pH in clinically normal neonatal foals.

Animals—6 clinically normal foals between 5 and 14 days of age.

Procedure—Intragastric pH was recorded in each foal by use of a disposable antimony pH electrode with internal reference. Values for intragastric pH were recorded every 4 seconds by use of an ambulatory pH monitor. There were two 24-hour recordings of intragastric pH for each foal, with 24 hours between recordings. Foals were not administered any drugs during the first recording. Foals were administered omeprazole paste (4 mg/kg, PO) 1 hour after the start of the second recording. Mean pH was calculated for each hour of each 24-hour recording session. Hourly mean values were compared between the first and second 24-hour recordings.

Results—Complete data were obtained from 4 of 6 foals during the first 24-hour recording and 6 of 6 foals during the second 24-hour recording. Foals had significantly higher mean hourly intragastric pH for hours 2 to 22 following omeprazole administration, compared with corresponding hourly pH values in foals during the first recording.

Conclusions and Clinical Relevance—Omeprazole paste can effectively increase intragastric pH in clinically normal neonatal foals within 2 hours after oral administration of the first dose and can be administered to neonatal foals at the rate of 4 mg/kg, PO, every 24 hours. (Am J Vet Res2004;65:1039–1041).
Plasma mineral and energy metabolite concentrations in dairy cows fed an anionic prepartum diet that did or did not have retained fetal membranes after parturition
Authors: Melendez Pedro , Donovan G. Arthur , Risco Carlos A. , Goff Jesse P.
Published: December 2005

Objective—To compare plasma total calcium, phosphorus,
magnesium, nonesterified fatty acids (NEFA),
beta hydroxy butyrate (BHB), and glucose concentrations
in parturient dairy cows that were fed an anionic
prepartum diet between those with and without
retained fetal membranes (RFM) at 24 hours after parturition.

Animals—152 Holstein cows that calved during
October through December of 1997.

Procedure—All cows were fed an anionic prepartum
diet. Blood sample was taken within 6 hours after parturition
from randomly selected cows. Thirty-nine
cows had a diagnosis of RFM at 24 hours after parturition;
113 were not affected with RFM. At calving,
body condition score (BCS; 1 [thin] to 5 [obese]), parity,
and calving difficulty score were recorded. Plasma
calcium, phosphorus, magnesium, NEFA, BHB, and
glucose concentrations were compared between
cows with or without RFM.

Results—Cows with RFM had significantly lower
plasma calcium concentration soon after calving,
compared with cows without RFM. Cows with a parity
of ≥ 3 had significantly lower plasma concentrations
of calcium and higher concentrations of magnesium,
compared with cows with a parity of 1 or 2.
Cows with a BCS of ≥ 3.25 at calving had significantly
higher plasma concentrations of BHB than cows
with a BCS of 2.75 to 3.0. Cows with dystocia had
significantly higher plasma concentrations of glucose,
compared with cows without dystocia.

Conclusions and Clinical Relevance—In parturient
cows fed a prepartum anionic diet, those with RFM
have lower plasma calcium concentrations than cows
without RFM, although this association does not
prove a cause-effect relationship. (Am J Vet Res
2004;65:1071–1076)
Inhibitory and excitatory neurotransmitters in the cerebrospinal fluid of epileptic dogs
Authors: Ellenberger Claudia , Mevissen Meike , Doherr Marcus , Scholtysik Günter , Jaggy André
Published: December 2005

Objective—To determine concentrations of excitatory and inhibitory amino acids in CSF of a large number of dogs with idiopathic epilepsy or genetic epilepsy and to evaluate changes in CSF amino acid concentration with regard to drug treatment and sex.

Animals—35 Labrador Retrievers with genetic epilepsy (20 male and 15 female), 94 non-Labrador Retrievers with idiopathic epilepsy (71 male and 23 female), and 20 control dogs (10 male and 10 female).

Procedure—Collection of CSF was performed > 72 hours after the occurrence of seizures. Cerebrospinal fluid concentrations of γ-aminobutyric acid (GABA), glutamate (GLU), aspartate (ASP), serine, and glycine were determined by use of high performance liquid chromatography with electrochemical detection.

Results—CSF concentrations of GABA and GLU were significantly lower in Labrador Retrievers with genetic epilepsy (LR-group dogs) than in control-group dogs or in non-Labrador Retrievers with idiopathic epilepsy (non–LR-group dogs). The GLU-to-GABA ratio was significantly higher in LR-group dogs than in non–LR-group dogs. CSF concentrations of GLU and ASP were significantly lower when all dogs with epilepsy (non–LR- and LR-group dogs combined) were compared with control-group dogs.

Conclusions and Clinical Relevance—A decrease in CSF concentrations of GABA appears to play a role in the pathogenesis of genetically determined epilepsy in Labrador Retrievers. However, this decrease in CSF concentrations of GABA may also be a consequence of seizure activity. The GLU-to-GABA ratio may prove to be a useful indicator of genetic epilepsy in Labrador Retrievers. (Am J Vet Res2004;65:1108–1113)
Investigation of the effect of acepromazine on intravenous glucose tolerance tests in dogs
Authors: Ionut Viorica , Kirkman Erlinda L. , Bergman Richard N.
Published: December 2005

Objective—To investigate the effects of administration
of acepromazine on IV glucose tolerance tests
(IVGTTs) in dogs.

Animals—8 male mixed-breed dogs.

Procedure—With a 1-week interval between tests,
each dog underwent (in random order) an IVGTT with
or without pretest administration of acepromazine
maleate (0.1 mg/kg, SC, 30 minutes prior to the start
of the IVGTT). Food was withheld from the dogs for
14 hours prior to each test. Blood samples were
obtained at 20, 10, and 1 minute prior to and at 2, 3,
4, 5, 6, 8, 10, 12, 14, 16, 19, 22, 25, 30, 40, 50, 60, 70,
80, 90, 100, 120, 140, 160, and 180 minutes after
administration of glucose.

Results—There were no significant differences in the
baseline (ie, after food was withheld) plasma glucose,
lactate, and insulin concentrations between dogs
undergoing the IVGTT and acepromazine-IVGTT; however,
lower baseline free fatty acid concentration was
observed in acepromazine-treated dogs. Analysis of
data via the application of Bergman's minimal model of
glucose kinetics revealed no differences in insulin sensitivity,
acute insulin response to glucose, disposition
index, or glucose effectiveness between dogs treated
or not treated with acepromazine before testing.

Conclusions and Clinical Relevance—Results indicated
that in dogs undergoing IV glucose tolerance
testing, pretest administration of small doses of acepromazine
can be used as a means of chemical
restraint without interfering with results of the glucose
metabolism assessment. (Am J Vet Res
2004;65:1124–1127)
Distribution of mRNA that codes for 5-hydroxytryptamine receptor subtypes in the gastrointestinal tract of dairy cows
Authors: Meylan Mireille , Georgieva Teodora M. , Reist Martin , Blum Jürg W. , Martig Johannes , Georgiev Ivan P. , Steiner Adrian
Published: December 2005

Objective—To describe the distribution of mRNA that codes for 8 subtypes of 5-hydroxytryptamine receptors (5-HTRs) in the digestive tract of dairy cows.

Sample Population—Fresh full-thickness wall specimens from the abomasum (fundus, corpus, and antrum), ileum, cecum, proximal loop of ascending colon, and 4 locations of the spiral colon collected from 10 healthy cows at slaughter.

Procedure—Concentrations of mRNA that code for 5-HTR subtypes (5-HTR1A, 5-HTR1B, 5-HTR1D, 5-HTR1F, 5-HTR2A, 5-HTR2B, 5-HTR2C, and 5-HTR4) in the bovine digestive tract were measured by use of a quantitative real-time reverse transcription-polymerase chain reaction assay. Results were reported in relation to mRNA expression of the housekeeping gene glyceraldehyde phosphate dehydrogenase (GAPDH).

Results—Mean relative mRNA concentrations for 5-HTR were low (range, 0% to 1.32% of GAPDH), and mRNA that codes for 5-HTR1Awas not detected. In the abomasum, mRNA expression was highest for 5-HTR1Band 5-HTR2B, followed by subtypes 1F, 2A, 1D, and 4, whereas 5-HTR2Cwas not detected. In intestinal samples, concentrations of subtypes 1B, 2B, and 4 were highest, followed by 1D, 1F, 2A, and 2C. Relative concentrations of mRNA that code for 5-HTR2Awere significantly higher in the abomasum than the intestines, but lower for 5-HTR2B, 5-HTR2C, and 5-HTR4.

Conclusions and Clinical Relevance—Relative concentrations of mRNA that code for 5-HTRs differ among locations in the gastrointestinal tract of cattle. Understanding differences in the distribution of 5- HTRs in healthy cattle and cattle with gastrointestinal tract disease may lead to improved therapeutic approaches for abomasal and cecal motility disorders. (Am J Vet Res2004;65:1151–1158)
Comparison of L-selectin and Mac-1 expression on blood and milk neutrophils during experimental Escherichia coli-induced mastitis in cows
Authors: Diez-Fraille Araceli , Mehrzad Jalil , Meyer Evelyne , Duchateau Luc , Burvenich Christian
Published: December 2005

Objective—To evaluate L-selectin (CD62L) and Mac-1 (CD11b) expression at the surface of blood and milk neutrophils during the early inflammatory response toEscherichia coli-induced mastitis in cows.

Animals—6 healthy Holstein heifers in early lactation.

Procedure—Blood and milk samples were collected before and after intramammary administration of 104CFU's ofE coliin the left mammary gland quarters. Bacterial counts and electrolyte concentrations in milk, rectal temperature, differential blood leukocyte counts, milk somatic cell counts, neutrophil viability, and the expression of CD62L and CD11b on blood and milk neutrophils were determined longitudinally.

Results—Bacteria grew during the first 6 hours after inoculation with a pronounced leukocytic influx. Coincident with neutrophil influx was an increase in CD62L+and CD11b+milk neutrophils, as well as an improved viability of milk neutrophils. The peak of the inflammatory reaction was reached approximately 12 hours afterE coliinoculation. From that time forward, changes in CD62L and CD11b expression were opposed to each other, with a decrease in CD62L expression and an increase in CD11b expression on blood and milk neutrophils; the magnitude of the differences in CD62L and CD11b expression between blood and milk neutrophils decreased. Percentages of CD62L+and CD11b+milk neutrophils increased to percentages that were similar to blood neutrophils (ie, approx 92%).

Conclusions and Clinical Relevance—The presence of adhesion molecules on a large percentage of milk neutrophils during the acute inflammatory response, together with the changes in receptor density, suggest a major role for CD62L and CD11b in neutrophil function during coliform mastitis. (Am J Vet Res2004;65:1164–1171)
Efficacy of a long-acting formulation of ceftiofur crystalline-free acid for the treatment of naturally occurring infectious bovine keratoconjunctivitis
Authors: Dueger Erica L. , George Lisle W. , Angelos John A. , Tankersley Natalie S. , Luiz Kelsie M. , Meyer Jonalee A. , Portis Ellen S. , Lucas Merlyn J.
Published: December 2005

Objective—To evaluate the efficacy of ceftiofur crystalline- free acid (CCFA) administered into the posterior aspect of an ear for treatment of corneal ulceration associated with naturally occurring infectious bovine keratoconjunctivitis (IBK).

Animals—78 beef calves located at Sierra Foothills Field Station (SFS) and 52 calves located at a commercial dairy (CD). All calves were from 3 to 9 months old.

Procedure—At each site, calves were randomly allocated to 1 of 2 treatment groups by use of a block design determined by corneal ulcer size. A single dose of CCFA (6.6 mg of ceftiofur equivalents/kg, SC) was administered into the posterior aspect of a pinna. A second group of calves received a single dose of vehicle (0.03 mL/kg, SC; controls). Corneal ulcers were photographed, and clinical signs were assessed in calves every 3 to 4 days for 21 days.

Results—A positive treatment effect was detected at SFS. Results at the CD were inconclusive because ulcer healing occurred rapidly in control and CCFA-treated calves. At SFS, treatment with CCFA resulted in shorter mean healing times, smaller corneal ulcer surface area measurements, amelioration of ocular discharge and photophobia, and a 50% increase in the percentage of calves healed by day 14. After adjustment for initial corneal ulcer size, treatment with CCFA resulted in a 4-fold increase in the odds of corneal ulcer healing by day 14, compared with controls.

Conclusions and Clinical Relevance—A single dose of CCFA administered into the posterior aspect of a pinna had a positive treatment effect against naturally occurring IBK in calves with corneal ulcerations . (Am J Vet Res2004;65:1185–1188)
Comparison of lactated Ringer's solution and a physiologically balanced 6% hetastarch plasma expander for the treatment of hypotension induced via blood withdrawal in isoflurane-anesthetized dogs
Authors: Muir William W. , Wiese Ashley J.
Published: December 2005

Objective—To compare the effects of lactated Ringer's solution (LRS) with those of a physiologically balanced 6% hetastarch plasma expander administered to isoflurane-anesthetized dogs with hypotension induced by blood withdrawal.

Animals—12 healthy Beagles.

Procedure—Blood was withdrawn from isofluraneanesthetized dogs (volume withdrawn measured) to a systolic arterial blood pressure (SAP) of 80 mm Hg. Six dogs each received either LRS or hetastarch solution (90 mL/kg/h, IV). Hemodynamic variables, pH, blood gas concentrations, PCV, serum electrolyte and total protein concentrations, and colloid osmotic pressure (COP) were determined at baseline, while SAP was 80 mm Hg, and after fluid treatment. The volume of fluid administered and rate of return of SAP to within 10% of baseline values were recorded.

Results—Mean ± SD volume of blood withdrawn to decrease SAP to 80 mm Hg was 173 ± 38 mL. Hemodynamic variables decreased after blood withdrawal but returned to baseline values more rapidly after infusion of a smaller volume of hetastarch solution, compared with the response to LRS infusion. Whereas PCV and serum total protein concentration decreased after administration of either solution, COP decreased only after administration of LRS. The total volume of hetastarch solution and LRS required to restore and maintain SAP to within 10% of baseline values was 1.1 ± 0.9 and 4.4 ± 1.7 times greater than the volume of blood removed, respectively.

Conclusions and Clinical Relevance—Compared with LRS infusion, smaller volumes of hetastarch solution normalized and maintained SAP without lowering COP in isoflurane-anesthetized dogs after blood withdrawal. (Am J Vet Res2004;65:1189–1194)
Effects of a menthol-based analgesic balm on pressor responses evoked from muscle afferents in cats
Authors: Ragan Brian G. , Nelson Amanda J. , Foreman Jonathan H. , Bell Gerald W. , Iwamoto Gary A.
Published: December 2005

Objective—To evaluate changes in heart rate (HR)
and mean arterial pressure (MAP) as indicators of
changes in pressor response for muscle afferents
after topical application of menthol (MEN)-based analgesic
balm.

Animals—11 decerebrate cats.

Procedure—Pressor responses were reflexively
evoked by static contraction of hind limb muscles,
which are caused by group III and IV afferents.
Responses were monitored without interference
from anesthesia or effects of higher brain function by
the use of decerebrate cats. After obtaining baseline
data, MEN analgesic balm (1.9%) was applied to the
skin over contracting muscles of 1 hind limb in 6 cats;
petrolatum was applied to 5 control cats. Muscle contractions
were evoked every 10 minutes, alternating
between hind limbs, for 120 minutes. Peak MAP and
HR were analyzed.

Results—Peak MAP responses evoked by static
muscle contraction for the ipsilateral hind limb were
significantly attenuated 20 minutes after application,
but approached baseline values 40 minutes after
application. The pressor response was significantly
decreased 20 minutes after application during the last
12 seconds of the stimulus, which was attributed to
group IV afferents. There were no significant differences
in HR responses.

Conclusions and Clinical Relevance—Application of
MEN analgesic balm to the skin over contracting muscles
significantly decreased the pressor response to
static muscle contractions. This suggests that topical
application of MEN has effects on responses evoked
from receptors located in muscles. The MEN analgesic
balm appeared to attenuate the pressor
response 20 minutes after application, but it was a
short-term effect. (Am J Vet Res 2004;65:1204–1210)
Influence of weight bearing and hoof position on Doppler evaluation of lateral palmar digital arteries in healthy horses
Authors: Pietra Marco , Guglielmini Carlo , Nardi Stefano , Gandini Gualtiero , Cipone Mario
Published: December 2005

Objective—To describe the pulsed-wave Doppler tracing of the equine lateral palmar digital artery and its modification in relation to standardized changes in posture.

Animals—17 healthy Saddlebred horses.

Procedure—Pulsed-wave Doppler examinations of left and right lateral palmar digital arteries of the horses were performed. The baseline examination was performed on each forelimb while horses were standing squarely with the body weight equally distributed among the 4 limbs (BED position). For each forelimb, the examination was repeated during 3 standardized modifications of the horse's posture (non–weightbearing [NWB] position, full weight-bearing [FWB] position, and a position involving hyperextension of the distal interphalangeal joint [HE position]). In each position, mean values of systolic peak velocity, first and second diastolic peak velocity, end-diastolic velocity, mean velocity, and resistive index were calculated. Data obtained in each different posture were compared statistically.

Results—No significant differences in blood flow variables were detected between the left and right forelimbs. However, significant differences were detected in values of first diastolic velocity, second diastolic velocity, mean velocity, and resistive index between the NWB position and FWB position. Also, end-diastolic velocity in the NWB position was significantly different from that recorded in the HE position.

Conclusions and Clinical Relevance—The pulsedwave Doppler tracing of the equine lateral palmar digital artery was modified considerably with changes in posture. This suggests that the use of a precisely standardized posture for horses is required to obtain repeatable data. (Am J Vet Res2004;65:1211–1215)
Effect of strain and serotype of vesicular stomatitis virus on viral shedding, vesicular lesion development, and contact transmission in pigs
Authors: Stallknecht David E. , Greer Jonathan B. , Murphy Molly D. , Mead Daniel G. , Howerth Elizabeth W.
Published: December 2005

Objective—To determine whether pigs can be infected with strains of vesicular stomatitis virus New Jersey (VSV-NJ) and vesicular stomatitis virus Indiana (VSV-I) isolated during recent vesicular stomatitis outbreaks that primarily involved horses in the western United States and determine the potential for these viruses to be transmitted by contact.

Animals—128 pigs.

Procedure—Pigs were challenged with VSV-NJ or VSV-I from the 1995 and 1997 outbreaks of vesicular stomatitis in the western United States, respectively, or with VSV-NJ (OS) associated with vesicular stomatitis in feral pigs on Ossabaw Island, Ga. Pigs (3/group) were inoculated with each virus via 3 routes and evaluated for viral shedding, seroconversion, and the development of vesicular lesions. In another experiment, the potential for contact transmission of each virus from experimentally infected to naïve pigs was evaluated.

Results—Infection of pigs was achieved for all 3 viruses as determined by virus isolation and detection of seroconversion. In inoculated pigs, all 3 viruses were isolated from multiple swab samples at concentrations sufficient to infect other pigs. However, compared with results obtained with the 2 VSV-NJ strains, viral titers associated with VSV-I were low and the duration of virus shedding was reduced. Results from the contact transmission trials were consistent with these results; virus transmission was detected most frequently with the VSV-NJ strains.

Conclusions and Clinical Relevance—Pigs can be infected with VSV-NJ and VSV-I. Differences in the extent of viral shedding and potential for contact transmission were apparent between serotypes but not between the VSV-NJ strains investigated. (Am J Vet Res2004;65:1233–1239)
Correlation of computed tomographic images with anatomic features of the abdomen of ringed seals (Phoca hispida)
Authors: Smodlaka Hrvoje , Henry Robert W. , Daniels Gregory B. , Reed Robert B.
Published: December 2005

Objective—To correlate anatomic features of the abdomen of the ringed seal (Phoca hispida) identified in plastinated cross-sections with images obtained via computed tomography (CT) and thereby establish reference standards for normal abdominal organ size and position in this species.

Sample Population—2 adult male ringed seal cadavers.

Procedure—With the seal in sternal recumbency, CT images of the abdomen were acquired by use of a 4th-generation CT scanner. Image slice thickness was 1 cm, with no interslice gap. After imaging, the abdominal region was sectioned transversely into 4- cm slices, which were plastinated and photographed. Plastinated slices were matched to their corresponding CT images in preparation for anatomic descriptions.

Results—Relevant anatomic features were identified and labeled on both the plastinated tissue slice and corresponding CT image. Normal abdominal organ size and position were assessed, and topographic relationships among organs were ascertained.

Conclusions and Clinical Relevance—The data obtained provide some reference standards for normal abdominal organ size and position in ringed seals. This information may aid researchers of future physiologic and clinical studies in this species. (Am J Vet Res2004;65:1240–1244)
Effect of trilostane on serum concentrations of aldosterone, cortisol, and potassium in dogs with pituitary-dependent hyperadrenocorticism
Authors: Wenger Monique , Sieber-Ruckstuhl Nadja S. , Müller Claudia , Reusch Claudia E.
Published: December 2005

Objective—To evaluate the effect of trilostane on serum concentrations of aldosterone, cortisol, and potassium in dogs with pituitary-dependent hyperadrenocorticism (PDH), compare the degree of reduction of aldosterone with that of cortisol, and compare aldosterone concentrations of healthy dogs with those of dogs with PDH.

Animals—17 dogs with PDH and 12 healthy dogs.

Procedure—For dogs with PDH, the initial dose of trilostane was selected in accordance with body weight. A CBC count, serum biochemical analyses, and ACTH stimulation tests were performed in each dog. Dogs were evaluated 1, 3 to 4, 6 to 8, and 10 to 12 weeks after initiation of treatment. Healthy dogs were evaluated only once.

Results—Serum aldosterone concentrations before ACTH stimulation did not change significantly after initiation of treatment with trilostane. At each evaluation after initiation of treatment, serum aldosterone concentrations after ACTH stimulation were significantly lower than corresponding concentrations before initiation of treatment. The overall effect of trilostane on serum aldosterone concentration was less pronounced than the effect on serum cortisol concentration. Median potassium concentrations increased slightly after initiation of treatment with trilostane. Dogs with PDH had significantly higher serum aldo sterone concentrations before and after ACTH stimulation than healthy dogs.

Conclusions and Clinical Relevance—Treatment with trilostane resulted in a reduction in serum cortisol and aldosterone concentrations in dogs with PDH, although the decrease for serum aldosterone concentration was smaller than that for serum cortisol concentration. There was no correlation between serum concentrations of aldosterone and potassium during treatment. (Am J Vet Res2004;65:1245–1250)
Evaluation of experimental methods to induce congenital hypothyroidism in guinea pigs for use in the study of congenital hypothyroidism in horses
Authors: D'Amours Geneviève H. , Taylor Susan M. , Olfert Ernest D. , Simko Elemir , Allen Andrew L.
Published: December 2005

Objective—To develop a method to reliably induce
congenital hypothyroidism in guinea pigs (Cavia porcellus)
and assess similarities between the resultant
developmental abnormalities and those described in
horses with congenital hypothyroidism.

Animals—35 female guinea pigs and their offspring.

Procedure—Guinea pigs were allocated to control
groups or groups treated with a low-iodine diet
before and throughout gestation; an SC injection of
100 or 200 µCi of radioactive iodine 131 (131I) on day
40 of gestation; or 0.1% propylthiouracil (PTU) continuously
in the drinking water, beginning day 3 or 40
of gestation. In all groups, assessments included
gestation duration, litter size, proportion of stillborn
pups, and laboratory analyses in live pups and dams;
postmortem examinations were performed on all
pups and dams and selected tissues were examined
histologically.

Results—Compared with control animals, pups from
dams receiving a low-iodine diet or 131I SC had mild
changes in their thyroid glands but no grossly or radiographically
detectable lesions of hypothyroidism.
Pups from dams receiving PTU were often stillborn
(24/27 pups) and had enlarged thyroid glands (characterized
by large, variably sized follicles of tall columnar
epithelium and little or no colloid), an incomplete coat,
and radiographically detectable skeletal dysgenesis.

Conclusions and Clinical Relevance—Many of the
lesions detected in guinea pig pups from the experimentally
treated dams were similar to those
described in foals with congenital hypothyroidism.
Experimental induction of congenital hypothyroidism
in guinea pigs may be useful for the study of naturally
occurring congenital hypothyroidism in horses. (Am
J Vet Res 2004;65:1251–1258)
Correlation of prostaglandin E2 concentrations in synovial fluid with ground reaction forces and clinical variables for pain or inflammation in dogs with osteoarthritis induced by transection of the cranial cruciate ligament
Authors: Trumble Troy N. , Billinghurst R. Clark , McIlwraith C. Wayne
Published: December 2005

Objective—To evaluate the temporal pattern of prostaglandin (PG) E2concentrations in synovial fluid after transection of the cranial cruciate ligament (CCL) in dogs and to correlate PGE2concentrations with ground reaction forces and subjective clinical variables for lameness or pain.

Animals—19 purpose-bred adult male Walker Hounds.

Procedure—Force plate measurements, subjective clinical analysis of pain or lameness, and samples of synovial fluid were obtained before (baseline) and at various time points after arthroscopic transection of the right CCL. Concentrations of PGE2were measured in synovial fluid samples, and the PGE2concentrations were correlated with ground reaction forces and clinical variables.

Results—The PGE2concentration increased significantly above the baseline value throughout the entire study, peaking 14 days after transection. Peak vertical force and vertical impulse significantly decreased by day 14 after transection, followed by an increase over time without returning to baseline values. All clinical variables (eg, lameness, degree of weight bearing, joint extension, cumulative pain score, effusion score, and total protein content of synovial fluid, except for WBC count in synovial fluid) increased significantly above baseline values. Significant negative correlations were detected between PGE2concentrations and peak vertical force (r, –0.5720) and vertical impulse (r, –0.4618), and significant positive correlations were detected between PGE2concentrations and the subjective lameness score (r, 0.5016) and effusion score (r, 0.6817).

Conclusions and Clinical Relevance—Assessment of the acute inflammatory process by measurement of PGE2concentrations in synovial fluid may be correlated with the amount of pain or lameness in dogs. (Am J Vet Res2004;65:1269–1275)
Use of pressure platform gait analysis in cats with and without bilateral onychectomy
Authors: Romans Cory W. , Conzemius Michael G. , Horstman Christopher L. , Gordon Wanda J. , Evans Richard B.
Published: December 2005

Objective—To determine peak vertical force (PVF) and vertical impulse (VI) in cats that had or had not undergone bilateral forelimb onychectomy.

Animals—26 healthy adult cats.

Procedure—Onychectomized cats (n = 13) had undergone surgery more than 6 months prior to the study. The PVF and VI were collected from all limbs of each cat with a 2-m pressure platform walkway. Cats were allowed to walk at a comfortable velocity, and acceleration was restricted to ± 0.5 m/s2. Five valid trials were recorded for each cat with all trials collected in a single 1-hour session. All forces were normalized to and expressed as a percentage of the cat's body weight.

Results—Gait data were successfully collected in all cats. No significant difference was found for PVF or VI between cats that had or had not had onychectomy. Limb loads were greater in forelimbs than hind limbs for all trials. Mean PVF and VI in the forelimbs of cats in the nononychectomy group were 56.41% and 18.85%, respectively. Mean PVF and VI in the hind limbs of cats in the nononychectomy group were 50.22% and 14.56%, respectively.

Conclusions and Clinical Relevance—Gait analysis was successfully performed in cats with a pressure platform walkway. The absence of differences in PVF and VI between the 2 groups of cats suggests that bilateral forelimb onychectomy did not result in altered vertical forces measured more than 6 months after surgery in cats. (Am J Vet Res2004;65:1276–1278)
Assessment of the efficacy of a single dose of a recombinant vaccine against West Nile virus in response to natural challenge with West Nile virus-infected mosquitoes in horses
Authors: Siger Leonardo , Bowen Richard A. , Karaca Kemal , Murray Michael J. , Gordy Paul W. , Loosmore Sheena M. , Audonnet Jean-Christophe F. , Nordgren, Robert M. , Minke Jules M.
Published: December 2005

Objective—To determine the onset of immunity after
IM administration of a single dose of a recombinant
canarypox virus vaccine against West Nile virus
(WNV) in horses in a blind challenge trial.

Animals—20 mixed-breed horses.

Procedure—Horses with no prior exposure to WNV
were randomly assigned to 1 of 2 groups (10 horses/group). In 1 group, a recombinant canarypox
virus vaccine against WNV was administered to
each horse once (day 0). The other 10 control horses
were untreated. On day 26, 9 treated and 10 control
horses were challenged via the bites of mosquitoes
(Aedes albopictus) infected with WNV.
Clinical responses and WNV isolation were monitored
for 14 days after challenge exposure; antibody
responses against WNV after administration of the
vaccine and challenge were also assessed in both
groups.

Results—Following challenge via WNV-infected mosquitoes,
1 of 9 treated horses developed viremia. In
contrast, 8 of 10 control horses developed viremia
after challenge exposure to WNV-infected mosquitoes.
All horses seroconverted after WNV challenge;
compared with control horses, antibody responses in
the horses that received the vaccine were detected
earlier.

Conclusions and Clinical Relevance—In horses, a
single dose of the recombinant canarypox virus-WNV
vaccine appears to provide early protection against
development of viremia after challenge with WNVinfected
mosquitoes, even in the absence of measurable
antibody titers in some horses. This vaccine
may provide veterinarians with an important tool in
controlling WNV infection during a natural outbreak or
under conditions in which a rapid onset of protection
is required. (Am J Vet Res 2004;65:1459–1462)
Effects of season and sample handling on measurement of plasma α-melanocyte-stimulating hormone concentrations in horses and ponies
Authors: McFarlane Dianne , Donaldson Mark T. , McDonnell Sue M. , Cribb Alastair E.
Published: December 2005

Objective—To investigate effects of sample handling, storage, and collection time and season on plasma α-melanocyte-stimulating hormone (α-MSH) concentration in healthy equids.

Animals—11 healthy Standardbreds and 13 healthy semiferal ponies.

Procedure—Plasma α-MSH concentration was measured by use of radioimmunoassay. Effects of delayed processing were accessed by comparing α-MSH concentrations in plasma immediately separated with that of plasma obtained from blood samples that were stored at 4oC for 8 or 48 hours before plasma was separated. Effects of suboptimal handling were accessed by comparing α-MSH concentrations in plasma immediately stored at -80°C with plasma that was stored at 25°C for 24 hours, 4oC for 48 hours or 7 days, and –20°C for 30 days prior to freezing at –80°C. Plasma α-MSH concentrations were compared among blood samples collected at 8:00 AM, 12 noon, and 4:00 PM. Plasma α-MSH concentrations were compared among blood samples collected in January, March, April, June, September, and November from horses and in September and May from ponies.

Results—Storage of blood samples at 4°C for 48 hours before plasma was separated and storage of plasma samples at 4°C for 7 days prior to freezing at –80°C resulted in significant decreases in plasma α-MSH concentrations. A significantly greater plasma α-MSH concentration was found in September in ponies (11-fold) and horses (2-fold), compared with plasma α-MSH concentrations in spring.

Conclusions and Clinical Relevance—Handling and storage conditions minimally affected plasma α-MSH concentrations. Seasonal variation in plasma α-MSH concentrations must be considered when evaluating pituitary pars intermedia dysfunction in equids. (Am J Vet Res2004;65:1463–1468)
Pharmacokinetics of R(–) and S(+) carprofen after administration of racemic carprofen in donkeys and horses
Authors: Mealey Katrina L. , Matthews Nora S. , Peck Kenneth E. , Burchfield Melissa L. , Bennett Brad S. , Taylor Tex S.
Published: December 2005

Objective—To compare plasma disposition of the R(–) and S(+) enantiomers of carprofen after IV administration of a bolus dose to donkeys and horses.

Animals—5 clinically normal donkeys and 3 clinically normal horses.

Procedure—Blood samples were collected from all animals at time 0 (before) and at 10, 15, 20, 30, and 45 minutes and 1, 1.5, 2, 2.5, 3, 4, 5, 6, 8, 10, 24, 28, 32, and 48 hours after IV administration of a bolus of carprofen (0.7 mg/kg). Plasma was analyzed in triplicate via high-performance liquid chromatography to determine the concentrations of the carprofen enantiomers. A plasma concentration-time curve for each donkey and horse was analyzed separately to estimate noncompartmental pharmacokinetic variables.

Results—In donkeys and horses, the area under the plasma concentration versus time curve (AUC) was greater for the R(–) carprofen enantiomer than it was for the S(+) carprofen enantiomer. For the R(–) carprofen enantiomer, the AUC and mean residence time (MRT) were significantly less and total body clearance (ClT) was significantly greater in horses, compared with donkeys. For the S(+) carprofen enantiomer, AUC and MRT were significantly less and ClTand apparent volume of distribution at steady state were significantly greater in horses, compared with donkeys.

Conclusions and Clinical Relevance—Results have suggested that the dosing intervals for carprofen that are used in horses may not be appropriate for use in donkeys. (Am J Vet Res2004;65:1479–1482)
Comparison of the cognitive palatability assessment protocol and the two-pan test for use in assessing palatability of two similar foods in dogs
Authors: Araujo Joseph A. , Studzinski Christa M. , Larson Brian T. , Milgram Norton W.
Published: December 2005

Objective—To compare preferences of dogs for 2
similar foods by use of 2 distinct methods (the cognitive
palatability assessment protocol [CPAP] and the
2-pan test).

Animals—13 Beagles.

Procedure—6 dogs were trained in a 3-choice object-discrimination–learning task in which their nonpreferred
objects were associated with a reward of a
lamb-based or chicken-based food. The number of
choices for each object was used to determine food
preferences. Preference of the same foods was also
assessed by use of a 2-pan test in which all 13 dogs
were provided the 2 foods in identical bowls. The
amount of each food consumed in 10 minutes was
used to determine food preference.

Results—All dogs had a noticeable preference for the
chicken-based food during the CPAP. Once established,
preferences remained consistent and were
not affected by satiety. The 2-pan test identified a
preference for the chicken-based food in dogs with
previous exposure to the food but only a weak and
nonsignificant preference for the same food in dogs
without previous exposure. Food preferences in the
2-pan test varied considerably. Total food consumption
and the ability to detect a preference were
reduced when dogs were fed prior to testing.

Conclusions and Clinical Relevance—The CPAP
provides a reliable measure of food preference that
requires few test subjects. The 2-pan test reveals similar
preferences but with variability in data that
requires larger numbers of subjects and is susceptible
to effects from prior exposure and feeding of the
test foods to the subjects. (Am J Vet Res 2004;65:1490–1496)