bluuebunny/crossref_metadata_2025 huggingface dataset:
Gelatinolytic matrix metalloproteinases-2 and -9 in tracheobronchial lavage fluid obtained from calves with concurrent infections of Pasteurella multocida and Mycoplasma bovirhinis
Authors: Simonen-Jokinen Terhi L. M. , Eskelinen Ulla M. , Härtel Heidi M. , Nikunen Sanna K. , Saloniemi Hannu S. , Maisi Päivi S.
Published: December 2005

Objective—To study gelatinolytic matrix metalloproteinases (MMPs) in tracheobronchial lavage fluid (TBLF) obtained from clinically normal calves and calves withPasteurella multocidainfection.

Sample Population—Samples of TBLF obtained from 11 calves with clinical signs of respiratory tract disease and growth ofP multocidaandMycoplasmaspp during culture of TBLF and samples of TBLF from 6 clinically normal calves with no bacterial growth during culture of TBLF.

Procedure—MMPs in TBLF were analyzed by use of gelatin zymography. Gelatinases were identified on the basis of molecular weights and inhibition by EDTA.

Results—The main gelatinolytic MMPs detected were the proform (90 to 110 kd) and active form (75 to 85 kd) of MMP-9 (gelatinase B) and the proform (67 to 75 kd) and active form (< 65 kd) of MMP-2 (gelatinase A). Increased amounts of active MMP-2 and MMP-9 were detected in TBLF of calves with respiratory tract disease, compared with amounts of active MMP-2 and MMP-9 in TBLF of clinically normal calves. Concurrent infection withMycoplasma bovirhinisin calves with pneumonia attributable toP multocidawas associated with higher concentrations of MMP-9.

Conclusions and Clinical Relevance—The host response toP multocidaincludes increases in MMP-2 and MMP-9 concentrations in TBLF. Greater amounts of MMPs detected in calves with concurrentM bovirhinisandP multocidainfection indicates synergism between these organisms. (Am J Vet Res2005;66:2101–2106)
Evaluation of safety and pharmacokinetics of vancomycin after intravenous regional limb perfusion in horses
Authors: Rubio-Martínez Luis M. , López-Sanromán Javier , Cruz Antonio M. , Santos Martín , Andrés Manuel San , Román Fidel San
Published: December 2005

Objective—To evaluate clinical variables, regional concentrations, and pharmacokinetics of vancomycin in the synovial fluid of distal forelimb joints of horses after IV regional limb perfusion.

Animals—6 horses.

Procedure—Vancomycin was administered via IV regional limb perfusion to the distal portion of the forelimbs of anesthetized horses. Drug (300 mg of vancomycin hydrochloride in 60 mL of saline [0.9% NaCl] solution) was infused into 1 forelimb, whereas the contralateral limb served as a control and was perfused with 60 mL of saline solution. Solutions were injected into the lateral digital vein after digital exsanguination. Synovial fluid from the metacarpophalangeal (MTCP) and distal interphalangeal (DIP) joints and systemic blood were collected prior to perfusion and 15, 30, 45, 65, and 90 minutes after initiation of the infusion. Synovial fluid from the MTCP joint and blood were also obtained at 4, 8, 12, and 24 hours after infusion. Plasma urea and creatinine concentrations, degree of lameness, and certain clinical variables involving the MTCP joint and infusion site were assessed for 7 days. Results were compared between the vancomycin treatment and control groups.

Results—No complications or significant differences in renal function, lameness, or clinical variables were observed between groups. Vancomycin concentrations exceeded 4 µg/mL in MTCP joints for approximately 20 hours. Higher concentrations were reached in DIP joints than in MTCP joints.

Conclusions and Clinical Relevance—IV regional limb perfusion with 300 mg of vancomycin as a 0.5% solution was safe and may be useful in horses as treatment for distal limb infections. (Am J Vet Res2005;66:2107–2113)
Cardiovascular and respiratory effects of ketamine infusions in isoflurane-anesthetized dogs before and during noxious stimulation
Authors: Boscan Pedro , Pypendop Bruno H. , Solano Adrian M. , Ilkiw Jan E.
Published: December 2005

Objective—To characterize the effects of ketamine administration on the cardiovascular and respiratory systems and on acid-base balance and to record adverse effects of ketamine in isoflurane-anesthetized dogs.

Animals—6 healthy adult mongrel dogs.

Procedure—Dogs were anesthetized with isoflurane (1.25 times the individual minimum alveolar concentration) in oxygen, and ketamine was administered IV to target pseudo–steady-state plasma concentrations of 0, 0.5, 1, 2, 5, 8, and 11 µg/mL. Isoflurane concentration was reduced to an equipotent concentration. Cardiovascular, respiratory, and acid-base variables; body temperature; urine production; and adverse effects were recorded before and during noxious stimulation. Cardiac index, stroke index, rate-pressure product, systemic vascular resistance index, pulmonary vascular resistance index, left ventricular stroke work index, right ventricular stroke work index, arterial oxygen concentration, mixed-venous oxygen concentration, oxygen delivery, oxygen consumption, oxygen extraction ratio, alveolar-arterial oxygen partial pressure gradient, and venous admixture were calculated. Plasma ketamine and norketamine concentrations were measured.

Results—Overall, ketamine administration improved ventilation, oxygenation, hemodynamics, and oxygen delivery in isoflurane-anesthetized dogs in a dosedependent manner. With the addition of ketamine, core body temperature was maintained or increased and urine production was maintained at an acceptable amount. However, at the higher plasma ketamine concentrations, adverse effects such as spontaneous movement and profuse salivation were observed. Myoclonus and dysphoria were observed during recovery in most dogs.

Conclusions and Clinical Relevance—Infusion of ketamine appears to be a suitable technique for balanced anesthesia with isoflurane in dogs. Plasma ketamine concentrations between 2 to 3 µg/mL elicited the most benefits with minimal adverse effects. (Am J Vet Res2005;66:2122–2129)
Association between the existence of calves persistently infected with bovine viral diarrhea virus and commingling on pen morbidity in feedlot cattle
Authors: O'Connor Annette M. , Sorden Steven D. , Apley Michael D.
Published: December 2005

Objective—To determine the association between the existence of a calf persistently infected (PI) with bovine viral diarrhea virus (BVDV) and pen morbidity.

Animals—5,041 calves in 50 pens at a feedlot in Iowa.

Procedure—In a longitudinal study, ear notches were collected from cattle and tested for BVDV antigen. Characteristics of each pen (owner, sex, disease rate, number of groups, and source) were recorded. The association between the existence of a BVDV–PI calf and morbidity in each pen was examined.

Results—Commingling was associated with an increase in respiratory tract disease (odds ratio [OR], 3; 95% confidence interval [CI], 2.5 to 3.6). Ten BVDV–PI calves (10/5,041 [0.2%]) were identified in 8 of 50 pens. A BVDV–PI calf was associated with reduced pen-level respiratory tract disease (OR, 0.7; 95% CI, 0.5 to 0.9). Disease prevalence (mean ± SD morbidity, 7.9 ± 3.1%) was lowest in pens containing single-source cattle and a BVDV–PI calf (4 pens containing 302 cattle), compared with single-source cattle with no BVDV–PI calf (mean morbidity, 11.89 ± 9.7%; 31 pens containing 3,093 cattle), commingled cattle with no BVDV–PI calf (mean morbidity, 29.3 ± 16.22%; 11 pens containing 1,127 cattle), and commingled cattle with a BVDV–PI calf (mean morbidity, 28.6 ± 10.1%; 4 pens containing 519 cattle).

Conclusions and Clinical Relevance—Commingling was the greatest risk factor associated with morbidity in each pen. A BVDV–PI calf in a pen was not associated with increased disease prevalence in commingled groups. (Am J Vet Res2005;66:2130–2134)
Evaluation of surveillance and sample collection methods to document freedom from infectious bovine rhinotracheitis in cattle populations
Authors: Chriel Mariann , Salman M. D. , Wagner Bruce A.
Published: December 2005

Objectives—To assess the sensitivity of the current
surveillance program used in Denmark for detecting
outbreaks of infectious bovine rhinotracheitis (IBR) at
the herd level and to evaluate the impact of alternative
sample collection strategies on the sensitivity of
the system in an acceptable time frame.

Sample Population—Data from the Danish Central
Husbandry Register on cattle of 24,355 and 25,233
beef herds and on 13,034 and 12,003 dairy herds in
the years 2000 and 2001, respectively.

Procedures—Surveillance programs were evaluated
under current sample collection conditions and under
3 alternative scenarios by use of simulation modeling.
Data from the current detection component of the
surveillance system were used as input, taking into
consideration the sensitivity and specificity of bulktank
milk and serologic testing.

Results—The current system identifies infected dairy
herds within a 3-month period with desired accuracy
largely because of the test characteristics and number
of bulk-tank milk samples. The system is less likely
to detect infected beef herds in a timely manner
because surveillance in beef herds depends solely on
serologic testing at the time of slaughter. The efficiency
of surveillance in dairy cattle herds was not
decreased substantially when the slaughter-surveillance
component was omitted.

Conclusions and Clinical Relevance—Geographically
targeted sample collection during the high-risk
season (winter) was predicted to increase the probability
of rapid detection of IBR infection in cattle. This
approach can be used for assessing other surveillance
systems to determine the best strategies for detection
of infected herds. (Am J Vet Res 2005;66:2149–2153)
Application of a scaling model to establish and validate an interval level pain scale for assessment of acute pain in dogs
Authors: Morton Carolyn M. , Reid Jacky , Scott E. Marion , Holton Lynne L. , Nolan Andrea M.
Published: December 2005

Objective—To establish interval level measurement in a prototype composite measure pain scale (CMPS) for assessment of acute pain in dogs and to investigate the scale's validity.

Animals—20 clinically normal dogs, 20 dogs with medical conditions, and 117 dogs undergoing surgery.

Procedure—First, a scaling model was applied to the CMPS descriptors to establish weights for each and create a continuous scale. Subsequently, 5 observers independently used the scale to score signs of pain in 4 groups of dogs (control dogs, dogs with medical conditions, and 40 dogs undergoing soft tissue or orthopedic surgery). Scores from each group and from groups of conditions perceived to cause no, mild, moderate, and severe pain were compared. In addition, the scale was applied to 77 dogs undergoing orthopedic or soft tissue surgery and scores were compared with simultaneously derived numeric rating scale (NRS) scores; comparisons were made between surgical groups and with time after surgery.

Results—Calculated scale descriptor weights ranged from –2.0 to 2.0 and were transformed to create a continuous scale from 0 to 10. Median CMPS scores differed significantly among the 4 study groups and among pain severity groups and were typically greater with increasing perceived pain severity. Agreement was determined between CMPS and NRS scores, and there was a significant and expected time effect and difference between the CMPS scores of dogs undergoing orthopedic and soft tissue surgery.

Conclusions and Clinical Relevance—Results indicate that this interval level measurement scale is a valid measure of acute pain in dogs. (Am J Vet Res2005;66:2154–2166)
Ex vivo investigation of the use of hydrothermal energy to induce chondrocyte necrosis in articular cartilage of the metacarpophalangeal and metatarsophalangeal joints of horses
Authors: Jenner Florien , Edwards III Ryland B. , Voss Jessica R. , Southwood Louise , Markel Mark D. , Richardson Dean W.
Published: December 2005

Objective—To evaluate the use of hydrothermal ablation
of articular cartilage for arthrodesis in horses
through investigation of the effects of joint lavage
with physiologic saline (0.9% NaCl) solution (80°C) for
various treatment times on chondrocyte viability in
the articular cartilage of the metacarpophalangeal and
metatarsophalangeal joints of cadaveric horse limbs.

Sample Population—7 pairs of metacarpophalangeal
and 8 pairs of metatarsophalangeal joints
from 8 Thoroughbreds.

Procedure—The horses were euthanatized for reasons
unrelated to musculoskeletal disease. On a random
basis, 1 joint of each pair underwent intra-articular
lavage for 5, 10, or 15 minutes with heated saline
solution (80°C); the other joint underwent sham treatment
of similar duration with saline solution at 22°C
(control). Cartilage samples from the distal articular
surface of metacarpus III (or metatarsus III), the proximal
surface of the proximal phalanx, and the lateral
and medial proximal sesamoid bones were assessed
for chondrocyte viability via confocal microscopy and
viability staining following enzymatic digestion.

Results—Compared with the control joints, findings
of both viability assays indicated that the percentage
of sites containing viable chondrocytes in heat-treated
joints was decreased. Treatment hazard ratios of 0.048
(confocal microscopy) and 0.2 (digestion assay) were
estimated. Histologically, periarticular soft tissues had
minimal detrimental effects after heat treatment.

Conclusions and Clinical Relevance—Ex vivo intraarticular
lavage with saline solution at 80°C resulted in
the death of almost all articular chondrocytes in the
joint. This technique may be a satisfactory method for
extensive cartilage ablation when performing
arthrodesis by minimally invasive techniques. (Am J Vet Res 2005;66:36–42)
Effects of preanesthetic administration of morphine on gastroesophageal reflux and regurgitation during anesthesia in dogs
Authors: Wilson Deborah V. , Evans A. Tom , Miller RoseAnn
Published: December 2005

Objective—To determine the effect of morphine
administered prior to anesthesia on the incidence of
gastroesophageal reflux (GER) in dogs during the subsequent
anesthetic episode.

Animals—90 dogs (30 dogs/group).

Procedure—The randomized prospective clinical
study included healthy dogs with no history of vomiting.
Dogs were scheduled to undergo elective orthopedic
surgery. Food was withheld for (mean ± SD)
17.8 ± 4.1 hours prior to induction of anesthesia. The
anesthetic protocol included acepromazine maleate,
thiopental, and isoflurane. Dogs were randomly
selected to receive morphine at various dosages (0,
0.22, or 1.10 mg/kg, IM) concurrent with acepromazine
administration prior to induction of anesthesia.
A sensor-tipped catheter was used to measure
esophageal pH, and GER was defined as a decrease
in pH to < 4 or an increase to > 7.5.

Results—40 dogs had acidic reflux, and 1 had biliary
reflux. Proportions of dogs with GER were 8 of 30
(27%), 15 of 30 (50%), and 18 of 30 (60%) for morphine
dosages of 0, 0.22, and 1.10 mg/kg, respectively.
Mean duration of GER was 91.4 ± 56.8 minutes.
There was no significant association between GER
and age, weight, vomiting after preanesthetic medication,
administration of antimicrobials, or start of
surgery.

Conclusions and Clinical Relevance—Most healthy
dogs vomit after a large dose of morphine, but vomiting
does not increase the likelihood of GER during the
subsequent anesthetic episode. Administration of
morphine prior to anesthesia substantially increases
the incidence of GER during the subsequent anesthetic
episode. (Am J Vet Res 2005;66:386–390)
Influence of medetomidine on stress-related neurohormonal and metabolic effects caused by butorphanol, fentanyl, and ketamine administration in dogs
Authors: Ambrisko Tamas D. , Hikasa Yoshiaki , Sato Kota
Published: December 2005

Objective—To examine stress-related neurohormonal
and metabolic effects of butorphanol, fentanyl, and
ketamine administration alone and in combination
with medetomidine in dogs.

Animals—10 Beagles.

Procedure—5 dogs received either butorphanol (0.1
mg/kg), fentanyl (0.01 mg/kg), or ketamine (10 mg/kg)
IM in a crossover design. Another 5 dogs received
either medetomidine (0.02 mg/kg) and butorphanol
(0.1 mg/kg), medetomidine and fentanyl (0.01 mg/kg),
medetomidine and ketamine (10 mg/kg), or medetomidine
and saline (0.9% NaCl) solution (0.1 mL/kg) in
a similar design. Blood samples were obtained for 6
hours following the treatments. Norepinephrine, epinephrine,
cortisol, glucose, insulin, and nonesterified
fatty acid concentrations were determined in plasma.

Results—Administration of butorphanol, fentanyl, and
ketamine caused neurohormonal and metabolic
changes similar to stress, including increased plasma
epinephrine, cortisol, and glucose concentrations. The
hyperglycemic effect of butorphanol was not significant.
Ketamine caused increased norepinephrine concentration.
Epinephrine concentration was correlated
with glucose concentration in the butorphanol and fentanyl
groups but not in the ketamine groups, suggesting
an important difference between the mechanisms
of the hyperglycemic effects of these drugs.
Medetomidine prevented most of these effects
except for hyperglycemia. Plasma glucose concentrations
were lower in the combined sedation groups
than in the medetomidine-saline solution group.

Conclusions and Clinical Relevance—Opioids or
ketamine used alone may cause changes in stressrelated
biochemical variables in plasma.
Medetomidine prevented or blunted these changes.
Combined sedation provided better hormonal and
metabolic stability than either component alone. We
recommend using medetomidine-butorphanol or
medetomidine-ketamine combinations for sedation or
anesthesia of systemically healthy dogs. (Am J Vet Res 2005;66:406–412)
Risk of infection with Cryptosporidium parvum and Cryptosporidium hominis in dairy cattle in the New York City watershed
Authors: Nydam Daryl V. , Lindergard Gabbriella , Santucci Fiametta , Schaaf Stephanie L. , Wade Susan E. , Mohammed Hussni O.
Published: December 2005

Objective—To determine the risk posed by
Cryptosporidium parvum and Cryptosporidium
hominis from dairy cattle in the New York City watershed
(NYCW).

Sample Population—Samples from cattle at risk for
shedding Cryptosporidium organisms on randomly
selected dairy farms in the NYCW.

Procedure—Feces were collected for 4 years from
calves at risk for infection on 37 dairies. Oocysts were
detected by use of centrifugation concentration-flotation
microscopy. The DNA was directly isolated from
fecal samples and used to amplify fragments of the
small subunit ribosomal RNA and thrombospondinrelated
adhesion protein C-2 genes by use of nested
polymerase chain reaction assays. Small subunit ribosomal
RNA fragments were restriction digested by
the enzyme VspI and thrombospondin-related adhesion
protein C-2 fragments were digested by Eco91I
to distinguish between C hominis (formerly known as
genotype 1) and C parvum (formerly known as genotype
2).

Results—Of 437 fecal samples examined, 214 contained
oocysts. Amplicons were generated for 200
samples. We can be certain, with 95% confidence,
that cattle in the NYCW did not harbor C hominis.

Conclusions and Clinical Relevance—Cryptosporidium
infections in cattle are under examination
because of the potential contamination of public waters
by manure. Although cattle may be the source of
zoonotic infection via C parvum, they pose little risk for
C hominis (the strain commonly isolated from humans
in waterborne outbreaks of disease). Other sources of
oocysts should be considered when investigating outbreaks
attributable to contaminated urban drinking
water because cattle pose only a small risk via shedding
of C hominis. (Am J Vet Res 2005;66:413–417).
Effect of early training on the jumping technique of horses
Authors: Santamaría Susana , Bobbert Maarten F. , Back Willem , Barneveld Ab , van Weeren P. Rene
Published: December 2005

Objective—To investigate the effects of early training for jumping by comparing the jumping technique of horses that had received early training with that of horses raised conventionally.

Animals—40 Dutch Warmblood horses.

Procedure—The horses were analyzed kinematically during free jumping at 6 months of age. Subsequently, they were allocated into a control group that was raised conventionally and an experimental group that received 30 months of early training starting at 6 months of age. At 4 years of age, after a period of rest in pasture and a short period of training with a rider, both groups were analyzed kinematically during free jumping. Subsequently, both groups started a 1-year intensive training for jumping, and at 5 years of age, they were again analyzed kinematically during free jumping. In addition, the horses competed in a puissance competition to test maximal performance.

Results—Whereas there were no differences in jumping technique between experimental and control horses at 6 months of age, at 4 years, the experimental horses jumped in a more effective manner than the control horses; they raised their center of gravity less yet cleared more fences successfully than the control horses. However, at 5 years of age, these differences were not detected. Furthermore, the experimental horses did not perform better than the control horses in the puissance competition.

Conclusions and Clinical Relevance—Specific training for jumping of horses at an early age is unnecessary because the effects on jumping technique and jumping capacity are not permanent. (Am J Vet Res2005;66:418–424)
Evaluation of the phospholamban gene in purebred large-breed dogs with dilated cardiomyopathy
Authors: Stabej Polona , Leegwater Peter A. , Stokhof Arnold A. , Domanjko-Petrič Aleksandra , van Oost Bernard A.
Published: December 2005

Objective—To evaluate the role of the phospholamban gene in purebred large-breed dogs with dilated cardiomyopathy (DCM).

Animals—6 dogs with DCM, including 2 Doberman Pinschers, 2 Newfoundlands, and 2 Great Danes.

Procedure—All dogs had clinical signs of congestive heart failure, and a diagnosis of DCM was made on the basis of echocardiographic findings. Blood samples were collected from each dog, and genomic DNA was isolated by a salt extraction method. Specific oligonucleotides were designed to amplify the promoter, exon 1, the 5'-part of exon 2 including the complete coding region, and part of intron 1 of the canine phospholamban gene via polymerase chain reaction procedures. These regions were screened for mutations in DNA obtained from the 6 dogs with DCM.

Results—No mutations were identified in the promoter, 5' untranslated region, part of intron 1, part of the 3' untranslated region, and the complete coding region of the phospholamban gene in dogs with DCM .

Conclusions and Clinical Relevance—Results indicate that mutations in the phospholamban gene are not a frequent cause of DCM in Doberman Pinschers, Newfoundlands, and Great Danes. (Am J Vet Res2005;66:432–436)
Inheritance of hereditary equine regional dermal asthenia in Quarter Horses
Authors: Tryon Robert C. , White Stephen D. , Famula Thomas R. , Schultheiss Patricia C. , Hamar Dwayne W. , Bannasch Danika L.
Published: December 2005

Objective—To assess heritability and mode of inheritance
for hereditary equine regional dermal asthenia
(HERDA) in Quarter Horses.

Animals—1,295 horses with Quarter Horse bloodlines,
including 58 horses affected with HERDA.

Procedure—Horses were classified as affected or
unaffected or as undetermined when data were insufficient
to assess phenotype. Pedigree data were analyzed
to determine the probable mode of inheritance.
Heritability was estimated by use of Bayesian statistical
methods.

Results—Heritability (mean ± SD) of HERDA was
estimated to be 0.38 ± 0.13, with both sexes having
an equal probability of being affected. Results for evaluation
of the pedigrees were consistent with a single
Mendelian autosomal recessive mode of inheritance.

Conclusions and Clinical Relevance—HERDA in
Quarter Horses is an inherited disease, and affected
horses are more likely to produce affected offspring.
An autosomal recessive mode of inheritance should be
considered by people making breeding decisions
involving Quarter Horses when a first-degree relative
has been confirmed with HERDA or has produced
affected offspring. In addition, breeders whose horses
have produced affected offspring can reduce the likelihood
of producing affected horses in the future by
avoiding inbreeding. (Am J Vet Res 2005;66:437–442)
Association of maximum voluntary dietary intake of freeze-dried garlic with Heinz body anemia in horses
Authors: Pearson Wendy , Boermans Herman J. , Bettger William J. , McBride Brian W. , Lindinger Michael I.
Published: December 2005

Objective—To characterize hematologic and clinical
consequences of chronic dietary consumption of
freeze-dried garlic at maximum voluntary intake in
horses.

Animals—4 healthy sex- and age-matched horses.

Procedure—An initial garlic dose (0.05 g/kg, twice
daily) was fed to 2 horses in a molasses carrier as
part of their normal ration and was gradually
increased to maximum voluntary intake (0.25 g/kg,
twice daily) over 41 days. Dietary supplementation
then continued for a total of 71 days. Two control
horses were fed molasses with no garlic with their
ration. Blood samples were collected weekly and
analyzed for hematologic and biochemical changes,
including the presence of Heinz bodies. Recovery of
affected blood values was followed for 5 weeks
after termination of dietary supplementation with
garlic.

Results—At a daily dose of > 0.2 g/kg, horses fed garlic
developed hematologic and biochemical indications
of Heinz body anemia, as characterized by
increases in Heinz body score (HBS), mean corpuscular
volume (MCV), mean corpuscular hemoglobin,
platelet count, and serum unconjugated and total
bilirubin concentrations and decreases in RBC count,
blood hemoglobin concentration, mean corpuscular
hemoglobin concentration, and serum haptoglobin
concentration. Recovery from anemia was largely
complete within 5 weeks after termination of dietary
supplementation with garlic. Heinz body score and
MCV remained high at the end of the 5-week recovery
period.

Conclusions and Clinical Relevance—Horses will voluntarily
consume sufficient quantities of garlic to cause
Heinz body anemia. The potential for garlic toxicosis
exists when horses are chronically fed garlic. Further
study is required to determine the safe dietary dose of
garlic in horses. (Am J Vet Res 2005;66:457–465)
Effects of oral potassium supplementation on acid-base status and plasma ion concentrations of horses during endurance exercise
Authors: Hess Tanja M. , Kronfeld David S. , Williams Carey A. , Waldron Jeannie N. , Graham-Thiers Patricia M. , Greiwe-Crandell Kathleen , Lopes Marco A. , Harris Pat A.
Published: December 2005

Objective—To compare effects of oral supplementation with an experimental potassium-free sodiumabundant electrolyte mixture (EM-K) with that of oral supplementation with commercial potassium-rich mixtures (EM+K) on acid-base status and plasma ion concentrations in horses during an 80-km endurance ride.

Animals—46 healthy horses.

Procedure—Blood samples were collected before the ride; at 21-, 37-, 56-, and 80-km inspection points; and during recovery (ie, 30-minute period after the ride). Consumed electrolytes were recorded. Blood was analyzed for pH, PvCO2, and Hct, and plasma was analyzed for Na+, K+, Cl–, Ca2+, Mg2+, lactate, albumin, phosphate, and total protein concentrations. Plasma concentrations of H+and HCO3–, the strong ion difference (SID), and osmolarity were calculated.

Results—34 (17 EM-K and 17 EM+K treated) horses finished the ride. Potassium intake was 33 g less and Na+ intake was 36 g greater for EM-K-treated horses, compared with EM+K-treated horses. With increasing distance, plasma osmolarity; H+, Na+, K+, Mg2+, phosphate, lactate, total protein, and albumin concentrations; and PvCO2and Hct were increased in all horses. Plasma HCO3–, Ca2+, and Cl–concentrations were decreased. Plasma H+concentration was significantly lower in EM-K-treated horses, compared with EM+K-treated horses. Plasma K+concentrations at the 80-km inspection point and during recovery were significantly less in EM-K-treated horses, compared with EM+K-treated horses.

Conclusions and Clinical Relevance—Increases in plasma H+ and K+ concentrations in this endurance ride were moderate and unlikely to contribute to signs of muscle fatigue and hyperexcitability in horses. (Am J Vet Res2005;66:466–473)
Effects of sodium hyaluronate and methylprednisolone acetate on proteoglycan synthesis in equine articular cartilage explants
Authors: Doyle Aimie J. , Stewart Allison A. , Constable Peter D. , Eurell Jo Ann C. , Freeman David E. , Griffon Dominique J.
Published: December 2005

Objective—To determine effects of sodium hyaluronate (HA) on corticosteroid-induced cartilage matrix catabolism in equine articular cartilage explants.

Sample Population—30 articular cartilage explants from fetlock joints of 5 adult horses without joint disease.

Procedure—Articular cartilage explants were treated with control medium or medium containing methylprednisolone acetate (MPA; 0.05, 0.5, or 5.0 mg/mL), HA (0.1, 1.0, or 1.5 mg/mL), or both. Proteoglycan (PG) synthesis was measured by incorporation of sulfur 35-labeled sodium sulphate into PGs, and PG degradation was measured by release of radiolabeled PGs into the medium. Total glycosaminoglycan (GAG) content in media and explants and total explant DNA were determined.

Results—Methylprednisolone acetate caused a decrease in PG synthesis, whereas HA had no effect. Only the combination of MPA at a concentration of 0.05 mg/mL and HA at a concentration of 1.0 mg/mL increased PG synthesis, compared with control explants. Methylprednisolone acetate increased degradation of newly synthesized PGs into the medium, compared with control explants, and HA alone had no effect. Hyaluronate had no effect on MPAinduced PG degradation and release into media. Neither MPA alone nor HA alone had an effect on total cartilage GAG content. Methylprednisolone acetate caused an increase in release of GAG into the medium at 48 and 72 hours after treatment. In combination, HA had no protective effect on MPA-induced GAG release into the medium. Total cartilage DNA content was not affected by treatments.

Conclusions and Clinical Relevance—Our results indicate that HA addition has little effect on corticosteroid- induced cartilage matrix PG catabolism in articular cartilage explants. (Am J Vet Res2005;66:48–53)
Detection of synovial macrophages in the joint capsule of dogs with naturally occurring rupture of the cranial cruciate ligament
Authors: Klocke Nathan W. , Snyder Paul W. , Widmer William R. , Zhong Wenxuan , McCabe George P. , Breur Gert J.
Published: December 2005

Objective—To test the hypotheses that the densities
of macrophages in the synovial membranes and capsules
of stifle joints in dogs with ruptured cranial cruciate
ligaments are greater than those of normal joints
and that those densities in affected joints are positively
correlated with the chronicity and severity of
the disease.

Animals—17 dogs with naturally occurring rupture of
the cranial cruciate ligament and 5 healthy control
dogs.

Procedure—All dogs underwent orthopedic and radiographic
evaluations. In affected dogs, duration of clinical
signs was used as an indicator of disease chronicity
and the severity of osteoarthritis in the stifle joint
was determined radiographically. Joint capsule specimens
were evaluated histologically; macrophages,
interleukin-6, and tumor necrosis factor-α were identified
by use of immunocytochemical techniques.

Results—Compared with unaffected joints,
macrophage density was increased in all affected
joints. Duration of disease was significantly associated
with radiographic severity of osteoarthritis and
synovial macrophage density. Synovial macrophage
density was significantly associated with severity of
osteoarthritis and with the presence of interleukin-6
and tumor necrosis factor-α.

Conclusions and Clinical Relevance—Results suggest
that synovial macrophages may be involved in the
development of pathologic changes (including osteophyte
formation) in the stifle joints of dogs with
osteoarthritis secondary to rupture of the cranial cruciate
ligament. Determination of the importance of synovial
macrophages in the development of changes in
osteoarthritic joints may result in new treatment strategies
that involve elimination of the deleterious effects
of those cells. (Am J Vet Res 2005;66:493–499)
Investigation of the induction of antibodies against Crandell-Rees feline kidney cell lysates and feline renal cell lysates after parenteral administration of vaccines against feline viral rhinotracheitis, calicivirus, and panleukopenia in cats
Authors: Lappin Michael R. , Jensen Wayne A. , Jensen Tracey D. , Basaraba Randall J. , Brown Cathy A. , Radecki Steven V. , Hawley Jennifer R.
Published: December 2005

Objective—To determine whether administration of Crandell-Rees feline kidney (CRFK) cell lysates or vaccines against feline viral rhinotracheitis, calicivirus, and panleukopenia (FVRCP vaccines) that likely contain CRFK cell proteins induces antibodies against CRFK cell or feline renal cell (FRC) lysates in cats.

Animals—14 eight-week-old cats.

Procedure—Before and after the study, renal biopsy specimens were obtained from each cat for histologic evaluation. Each of 4 FVRCP vaccines was administered to 2 cats at weeks 0, 3, 6, and 50. Between weeks 0 and 50, another 3 pairs of cats received 11 CRFK cell lysate inoculations SC (10, 50, or 50 µg mixed with alum). Clinicopathologic evaluations and ELISAs to detect serum antibodies against CRFK cell or FRC lysates were performed at intervals.

Results—Cats had no antibodies against CRFK cell or FRC lysates initially. All cats administered CRFK cell lysate had detectable antibodies against CRFK cell or FRC lysates on multiple occasions. Of 6 cats vaccinated parenterally, 5 had detectable antibodies against CRFK cell lysate at least once, but all 6 had detectable antibodies against FRC lysate on multiple occasions. Cats administered an intranasal-intraocular vaccine did not develop detectable antibodies against either lysate. Important clinicopathologic or histologic abnormalities were not detected during the study.

Conclusions and Clinical Relevance—Parenteral administration of vaccines containing viruses likely grown on CRFK cells induced antibodies against CRFK cell and FRC lysates in cats. Hypersensitization with CRFK cell proteins did not result in renal disease in cats during the 56-week study. (Am J Vet Res2005;66:506–511)
Computed tomography and cross-sectional anatomy of the thorax in clinically normal dogs
Authors: De Rycke Lieve M. , Gielen Ingrid M. , Simoens Paul J. , van Bree Henri
Published: December 2005

Objective—To provide a detailed anatomic description of the thorax in clinically normal dogs by means of computed tomography.

Animals—4 clinically normal adult German Shepherd Dogs weighing 28 to 37 kg.

Procedure—Dogs were anesthetized and positioned in ventral recumbency for computed tomographic (CT) examination of the thorax. A CT image from the thoracic inlet to the diaphragm was made by use of a third-generation scanner with a slice thickness of 5 mm. Individual images were reviewed by use of soft tissue (window width, 250 Hounsfield units; window level, 35 Hounsfield units) and lung (window width, 1,000 Hounsfield units; window level, –690 Hounsfield units) settings. One dog, weighing 28 kg, was euthanatized, bound on a wooden frame in the same position as used for CT examination, and frozen at –14oC until solid. By use of an electric band saw, the frozen thorax was sectioned at 10-mm-thick intervals. Slab sections were immediately cleaned, photographed, and compared with corresponding CT images.

Results—Anatomic sections were studied, and identified anatomic structures were matched with structures on corresponding CT images. Except for some blood vessels and details of the heart, most of the bony and soft tissue structures of the thorax discerned on anatomic slices could be found on matched CT images.

Conclusions and Clinical Relevance—Because CT images provide detailed information on most structures of the canine thorax, results of our study could be used as a guide for evaluation of CT images of the thorax of dogs with thoracic diseases. (Am J Vet Res2005;66:512–524)
Effects of Carolina rinse solution, dimethyl sulfoxide, and the 21-aminosteroid, U-74389G, on microvascular permeability and morphology of the equine jejunum after low-flow ischemia and reperfusion
Authors: Dabareiner Robin M. , White Nathaniel A. , Snyder Jack R. , Feldman Bernard F. , Donaldson Lydia L.
Published: December 2005

Objective—To evaluate effects of Carolina rinse solution, dimethyl sulfoxide (DMSO), and 21-aminosteroid, U-74389G, on microvascular permeability and morphology of the equine jejunum after low-flow ischemia and reperfusion.

Animals—20 healthy adult horses.

Procedure—Under anesthesia, full-thickness biopsy specimens of a distal portion of the jejunum were obtained for baseline measurements. In addition to a control segment, 2 jejunal segments were identified as sham-operated or experimental segments. Experimental segments underwent 60 minutes of low-flow ischemia and 3.5 hours of reperfusion. Treatments were as follows: U-74389G (3 mg/kg, IV; 6 horses), DMSO (20 mg/kg, IV; 6) diluted in 1 L of saline (0.9% NaCl) solution, local perfusion (via jejunal artery) of Carolina rinse solution (0.5 mL/kg; 4), and local perfusion of lactated Ringer's solution (0.5 mL/kg; 4).

Results—Jejunal microvascular permeability was significantly lower after treatment with Carolina rinse solution or DMSO, compared with U-74389G or lactated Ringer's solution treatments. After DMSO treatment, serosal- and submucosal-layer edema was significantly increased in experimental segments, compared with control or sham-operated segments; however, edema increases were significantly less than for lactated Ringer's solution or U-74389G treatments. Significant decreases in intestinal wet weight-to-dry weight ratio were found following Carolina rinse solution or DMSO treatments, compared with lactated Ringer's solution or U-74389G treatments. Edema formation and leukocyte infiltration in jejunal segments of horses treated with lactated Ringer's solution or U-74389G were increased, compared with Carolina rinse solution or DMSO treatments.

Conclusions and Clinical Relevance—Carolina rinse solution and DMSO may be protective against ischemia-reperfusion injury in the equine jejunum. (Am J Vet Res2005;66:525–536)
Analgesic effects of epidurally administered levogyral ketamine alone or in combination with morphine on intraoperative and postoperative pain in dogs undergoing ovariohysterectomy
Authors: Acosta Alinne Dalla-Porta , Gomar Carmen , Correa-Natalini Claudio , Bopp Simone , Polydoro Alexandre , Sala-Blanch Xavier
Published: December 2005

Objective—To evaluate the analgesic and adverse effects of epidurally administered levogyral (S[+]) ketamine alone or in combination with morphine on intraoperative and postoperative pain in dogs undergoing ovariohysterectomy.

Animals—30 dogs scheduled for ovariohysterectomy.

Procedure—Dogs were randomly allocated to 1 of 3 groups. Dogs in group 1 received S(+) ketamine (1 mg/kg), dogs in group 2 received S(+) ketamine (0.5 mg/kg) and morphine (0.05 mg/kg), and dogs in group 3 received S(+) ketamine (1 mg/kg) and morphine (0.025 mg/kg). The skin was incised 15 minutes after epidural administration of analgesics. Heart rate (HR), respiratory rate (RR), systolic blood pressure (SBP), oxygen saturation as measured by pulse oximetry, and arterial blood gases were obtained before anesthesia, 15 minutes after epidural administration of analgesics, 15 and 30 minutes after initiation of surgery, and at the end of surgery. During the intraoperative period, an increase of ≥ 20% in baseline values for HR, RR, and SBP was considered a sign of intraoperative pain. Signs of pain and adverse effects were assessed at 2, 4, and 8 hours postoperatively.

Results—There were no significant differences in intraoperative or postoperative measurements among the 3 groups. No dogs had intraoperative signs of pain. Mean postoperative pain assessment scores were < 3.5 in all 3 groups. Salivation was the most frequent adverse effect in dogs in groups 1 and 3, and sedation occurred more frequently in dogs in groups 2 and 3.

Conclusions and Clinical Relevance—All 3 analgesic regimens provided good respiratory and cardiovascular stability intraoperatively and adequate postoperative analgesia with minimal adverse effects. (Am J Vet Res2005;66:54–61)
Assessment of the effects of erythromycin, neostigmine, and metoclopramide on abomasal motility and emptying rate in calves
Authors: Wittek Thomas , Constable Peter D.
Published: December 2005

Objective—To determine and compare the effects of erythromycin, neostigmine, and metoclopramide on abomasal motility and emptying rate in suckling calves.

Animals—6 male Holstein calves (15 to 40 days of age).

Procedure—Calves were monitored for 1 hour before being fed milk replacer (60 mL/kg; time, 0 minutes) and then were monitored for another 3 hours. Calves received 6 treatments in randomized order: erythromycin (8.8 mg/kg, IM) at –30 minutes; low-dose erythromycin (0.88 mg/kg, IM) at –30 minutes; erythromycin (8.8 mg/kg, IM) at –30 minutes and neostigmine (0.02 mg/kg, SC) at –30 and 90 minutes; neostigmine (0.02 mg/kg, SC) at –30 and 90 minutes; metoclopramide (0.1 mg/kg, IM) at –30 and 90 minutes; and placebo (2 mL of saline [0.9% NaCl] solution, SC) at –30 minutes. Abomasal volume was calculated from ultrasonographic measurements of abomasal width, length, and height. Abomasal motility and emptying rate were assessed by measuring luminal pressure and change in abomasal volume over time.

Results—Administration of erythromycin (8.8 mg/kg) increased the frequency of abomasal luminal pressure waves and the mean abomasal luminal pressure and decreased the half-time of abomasal emptying by 37%. Administration of metoclopramide, neostigmine, and low-dose erythromycin (0.88 mg/kg) did not alter abomasal motility, mean luminal pressure, or emptying rate.

Conclusions and Clinical Relevance—Results indicated that administration of erythromycin at the labeled antimicrobial dose (8.8 mg/kg, IM) exerted an immediate, marked prokinetic effect in healthy suckling calves, whereas administration of metoclopramide or neostigmine did not alter abomasal motility or emptying rate. (Am J Vet Res2005;66:545–552)
Effect of exercise on age-related changes in collagen fibril diameter distributions in the common digital extensor tendons of young horses
Authors: Edwards Lindsey J. , Goodship Allen E. , Birch Helen L. , Patterson-Kane Janet C.
Published: December 2005

Objective—To determine whether specific treadmill exercise regimens would accelerate age-related changes in collagen fibril diameter distributions in the common digital extensor tendon (CDET) of the forelimbs of young Thoroughbreds.

Animals—24 female Thoroughbreds.

Procedure—Horses were trained for 18 weeks (6 horses; short term) or 18 months (5 horses; long term) on a high-speed treadmill; 2 age-matched control groups (6 horses/group) performed walking exercise only. Horses were (mean ± SD) 24 ± 1 months and 39 ± 1 months old at termination of the shortterm and long-term regimens, respectively. Midmetacarpal CDET specimens were obtained and processed for transmission electron microscopy. Diameter and area of at least 1,000 collagen fibrils/specimen were measured by use of computerized image analysis. Mass-average diameter (MAD) of collagen fibrils and collagen fibril index were calculated for each horse.

Results—Collagen fibril MAD for the older horses was significantly less than that for the younger horses. Exercise did not significantly affect fibril diameter or distributions in either age group, and collagen fibril index did not differ significantly between groups.

Conclusions and Clinical Relevance—Age-related reduction in collagen fibril MAD agreed with findings for other tendons and species. Training did not accelerate age-related change in the CDET, in contrast to a reported decrease in collagen fibril MAD in the superficial digital flexor tendon of horses trained long term. Our results support the concept that the functionally distinct nature of the CDET and superficial digital flexor tendon in horses results in fundamentally different responses to high-speed exercise regimens. (Am J Vet Res2005;66:564–568)
Effects of caffeine on exercise performance of physically fit Thoroughbreds
Authors: Savage Kathleen A. , Colahan Patrick T. , Tebbett Ian R. , Rice Brett L. , Freshwater Lester L. , Jackson Christie A.
Published: December 2005

Objective—To determine the effects of a dose of caffeine
(2.5 mg/kg, IV) administered to physically fit
Thoroughbreds during incremental exercise testing to
fatigue on a treadmill.

Animals—10 conditioned Thoroughbreds.

Procedure—Horses were randomly assigned to
receive caffeine or a control solution. Each horse
received both treatments in a crossover design with a
3-week interval between treatments. Each horse was
administered caffeine (2.5 mg/kg) or an equivalent
amount of a control solution IV. One hour after injection,
each horse performed an incremental exercise
test to exhaustion. Hematologic values, heart rate,
oxygen consumption, carbon dioxide production, plasma
lactate concentration, urine and serum concentrations
of caffeine and metabolites, and time until
exhaustion were monitored. Statistical analysis was
performed by use of a mixed-effects linear model.

Results—Significant differences in measured values
when horses were treated with caffeine or the control
solution were not detected.

Conclusions and Clinical Relevance—A dose of caffeine
(2.5 mg/kg, IV) appears to have no effect on any
performance variable of physically fit Thoroughbreds
during incremental exercise testing to fatigue. (Am J Vet Res 2005;66:569–573)
Influence of general anesthesia on pharmacokinetics of intravenous lidocaine infusion in horses
Authors: Feary Darien J. , Mama Khursheed R. , Wagner Ann E. , Thomasy Sara
Published: December 2005

Objective—To compare the disposition of lidocaine administered IV in awake and anesthetized horses.

Animals—16 horses.

Procedure—After instrumentation and collection of baseline data, lidocaine (loading infusion, 1.3 mg/kg administered during 15 minutes (87 µg/kg/min); constant rate infusion, 50 µg/kg/min) was administered IV to awake or anesthetized horses for a total of 105 minutes. Blood samples were collected at fixed times during the loading and maintenance infusion periods and after the infusion period for analysis of serum lidocaine concentrations by use of liquid chromatography with mass spectral detection. Selected cardiopulmonary parameters including heart rate (HR), mean arterial pressure (MAP), arterial pH, PaCO2, and PaO2were also recorded at fixed time points during lidocaine administration. Serum lidocaine concentrations were evaluated by use of standard noncompartmental analysis.

Results—Serum lidocaine concentrations were higher in anesthetized than awake horses at all time points during lidocaine administration. Serum lidocaine concentrations reached peak values during the loading infusion in both groups (1,849 ± 385 ng/mL and 3,348 ± 602 ng/mL in awake and anesthetized horses, respectively). Most lidocaine pharmacokinetic variables also differed between groups. Differences in cardiopulmonary variables were predictable; for example, HR and MAP were lower and PaO2 was higher in anesthetized than awake horses but within reference ranges reported for horses under similar conditions.

Conclusions and Clinical Relevance—Anesthesia has an influence on the disposition of lidocaine in horses, and a change in dosing during anesthesia should be considered. (Am J Vet Res2005;66:574–580)