bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of bilateral blockade of the pharyngeal branch of the vagus nerve on soft palate function in horses
Authors: Holcombe Susan J. , Derksen Frederik J. , Stick John A. , Robinson N. Edward
Published: January 2024

Objective

To determine the effect of bilateral blockade of the pharyngeal branch of the vagus nerve on soft palate function in horses.

Animals

5 Standardbreds.

Procedure

Peak tracheal inspiratory and expiratory pressures and airflow were measured while horses exercised at the speeds corresponding to 75 and 100% of the speed that resulted in maximal heart rate, with and without pharyngeal branch of the vagus nerve blockade. Respiratory frequency-to-stride frequency coupling ratio was measured by correlating foot fall measurements with respiratory frequency. The pharyngeal branch of the vagus nerve was blocked bilaterally as the nerve coursed through the auditory tube diverticulum (guttural pouch) across the longus capitus muscle.

Results

Persistent, reversible dorsal displacement of the soft palate (DDSP) occurred in all horses after nerve blockade, and lasted from 1 to 3 hours; normal nasopharyngeal function returned within 3 hours. Compared with control values, peak expiratory tracheal pressure increased (P = 0.001), expiratory impedance increased (P = 0.007), and minute ventilation decreased (P = 0.04). Respiratory frequency-to-stride frequency coupling ratio decreased (P = 0.009) so that horses took 1 breath/stride without the nerve block and, approximately, 1 breath/2 strides with the block.

Conclusion

DDSP creates flow-limiting expiratory obstruction and may be caused by neuromuscular dysfunction involving the pharyngeal branch of the vagus nerve. It may alter performance by causing expiratory obstruction and by altering breathing strategy in horses.

Clinical Relevance

A repeatable, reversible model of DDSP exists that allows further study of the disease. Dysfunction of the neuromuscular group, pharyngeal branch of the vagus nerve and palatinus and palatopharyngeus muscles, may be implicated in the pathogenesis of clinical DDSP. (Am J Vet Res 1998;59:504–508)
Supplemental dietary biotin for prevention of lesions associated with aseptic subclinical laminitis (pododermatitis aseptica diffusa) in primiparous cows
Authors: Midla Lowell T. , Hoblet Kent H. , Weiss William P. , Moeschberger Melvin L.
Published: January 2024

Objective

To evaluate, in primiparous cows, the effect of dietary biotin supplementation on severity of lesions of aseptic subclinical laminitis.

Animals

100 primiparous cows in a 800-cow commercial dairy herd.

Procedure

Cows were assigned after calving to a biotin-supplemented (20 mg/head/d) or control group on an alternating basis. Digits 3 and 4 of the left forelimb and right hind limb were examined at a mean of 25, 108, and 293 days after parturition. Toe length, hoof angle, and heel depth were measured, and hooves were examined for solear hemorrhage, yellow solear discoloration, separation of the white line, and heel erosion. Serum and milk biotin concentrations were also measured.

Results

Serum biotin concentrations were significantly higher for supplemented than for control cows. During the second examination, prevalence of separation of the white line of digits 3 and 4 of the hind limb and digit 4 of the forelimb was lower for supplemented than for control cows. Mean decrease in heel depth between the first and third examinations was approximately twice as great for digit 4 of the forelimb and 4 times as great for digit 3 of the forelimb in supplemented, versus control, cows. Other differences were not found.

Conclusions and Clinical Relevance

Results suggest that supplemental dietary biotin may have a beneficial effect on hoof health in intensively managed primiparous dairy cows. (Am J Vet Res 1998;59:733-738)
Comparison of amikacin dosing regimens in neutropenic guinea pigs with Escherichia coli infection
Authors: McClure J. T. , Rosin Eberhard
Published: January 2024

Objective

To derive pharmacokinetic data for 3 amikacin dosing regimens in guinea pigs and to determine whether the antibacterial activity of 15 mg/kg of body weight given twice daily is equivalent to administering the drug more frequently.

Animals

10 guinea pigs in pharmacokinetic trials, and 10 guinea pigs in pretreatment, control, and amikacin treatment groups.

Procedure

Amikacin pharmacokinetic data were determined in guinea pigs after single IM administration of 3.75, 7.5, and 15 mg/kg. Guinea pigs had been made neutropenic by treatment with cyclophosphamide. All guinea pigs were inoculated with 2.8 × 108 colony-forming units (CFU) of Escherichia coli in the thigh muscle, then were allotted to 5 groups: pretreatment (euthanatized 4 hours after inoculation), control, and 3 amikacin treatment groups (3.75 mg/kg, q 3 h; 7.5 mg/kg, q 6 h; and 15 mg/kg, q 12 h). Amikacin administration was begun 4 hours after E coli inoculation and was continued for 72 hours. Numbers of E coli CFU in infected thigh muscle were determined for each guinea pig.

Results

Difference in survival between control and the amikacin-treated groups was significant. The E coli infection concentration (log10 CFU) increased significantly in the control, compared with the pretreatment, group. Infection concentration decreased significantly in all treatment groups, compared with the pretreatment group. There was no significant difference in bacterial killing among the 3 treatment groups.

Conclusion

Amikacin had a significant effect on survival of neutropenic guinea pigs with E coli infection. Antibacterial activity did not differ among 3 doses of amikacin administered at different intervals.

Clinical Relevance

Aminoglycoside dosing regimen with high peak concentration and long drug-free interval is as efficacious as divided dose regimens. (Am J Vet Res 1998;59:750-755)
Effect of finasteride on serum concentrations of dihydrotestosterone and testosterone in three clinically normal sexually intact adult male dogs
Authors: Kamolpatana Kaitkanoke , Johnston Shirley D. , Hardy Sharon K. , Castner Susan
Published: January 2024

Objective

To determine the effect of finasteride at dosages of 0.10, 0.25, and 0.50 mg/kg of body weight, PO, q 24 h, on serum concentrations of dihydrotestosterone (DHT) and testosterone (T) in clinically normal sexually intact adult male dogs.

Animals

3 intact adult male dogs less than 5 years old.

Procedure

Concentrations of DHT and T were measured by radioimmunoassay of serum from dogs randomly assigned to 1 of 3 treatment groups (0.10, 0.25, or 0.50 mg of finasteride/kg, PO, q 24 h, for 7 days) in a Latin square design with repeated measures. Blood was obtained before and on days 1, 2, 4, and 7 of treatment; 3 blood samples were obtained at 20 minute intervals to detect pulsatile secretion of DHT and T. Dogs were untreated at least 2 weeks between treatments.

Results

Finasteride at all doses was associated with a mean decrease in concentration of DHT of 55% (range, 155 ± 32.3 pg/ml to 70 ± 15 pg/ml), but had no effect on concentration of T (before treatment, 2.6 ± 0.38 ng/ml; after treatment, 2.2 ± 0.63 ng/ml).

Conclusions

Finasteride at these doses significantly decreased serum concentration of DHT in sexually intact adult male dogs. Concentrations of DHT and T before and 7 days after treatment did not differ by dosage of finasteride administered.

Clinical Relevance

Finasteride (5 mg; 1 tablet) may be a drug of choice for treatment of benign prostatic hypertrophy in 10- to 50-kg dogs. (Am J Vet Res 1998;59:762-764)
Morphologic changes and xanthine oxidase activity in the equine jejunum during low flow ischemia and reperfusion
Authors: Vatistas Nicholas J. , Snyder Jack R. , Nieto Jorge , Hildebrand Susan V. , Woliner Michael J. , Harmon Faye A. , Barry Sean J. , Drake Christiana
Published: January 2024

Objective

To determine whether xanthine oxidase and dehydrogenase activities are altered during low flow ischemia and reperfusion of the small intestine of horses.

Animals

5 clinically normal horses without histories of abdominal problems.

Procedure

With the horse under general anesthesia, a laparotomy was performed and blood flow to a segment of the distal jejunum was reduced to 20% of baseline for 120 minutes and was then reperfused for 120 minutes. Biopsy specimens were obtained before, during, and after ischemia for determination of xanthine oxidase and dehydrogenase activities, and for histologic and morphometric analyses.

Results

Percentage of xanthine oxidase activity (as a percentage of xanthine oxidase and dehydrogenase activity) was not altered during ischemia and reperfusion. An inflammatory response developed and progressed during ischemia and reperfusion. Mucosal lesions increased in severity after ischemia and reperfusion. Mucosal surface area and volume decreased during ischemia and continued to decrease during reperfusion. Submucosal volume increased slightly during ischemia, and continued to increase during reperfusion.

Conclusions and Clinical Relevance

Evidence for conversion of xanthine dehydrogenase to xanthine oxidase during ischemia was not found. Factors other than production of reactive oxygen metabolites may be responsible for progressive epithelial loss, decrease in mucosal surface area and volume, and increase in submucosal volume observed in this study. Other methods of determining xanthine oxidase activity that detect the enzyme in sloughed epithelial cells should be used to better define the importance of this pathway in jejunal reperfusion injury in horses. (Am J Vet Res 1998;59:772-776)
Effect of tumor necrosis factor antibody given to horses during early experimentally induced endotoxemia
Authors: Barton Michelle H. , Bruce Elizabeth H. , Moore James N. , Norton Natalie , Anders Brendan , Morris Debra D.
Published: January 2024

Objective

To test efficacy of murine monoclonal, rabbit polyclonal recombinant equine or human tumor necrosis factor-α (rETNF or rHTNF, respectively) antibodies to inhibit native equine tumor necrosis factor (TNF) activity.

Animals

8 and 18 healthy adult horses for parts 1 and 2 of the study, respectively.

Procedures

In part 1, supernates from endotoxin-activated peritoneal macrophages were incubated with various dilutions of each rETNF antibody and subsequently tested for TNF activity. Serum was also obtained from a horse 1 hour after infusion with 20 ng of endotoxin/kg of body weight and was incubated with various dilutions of rabbit polyclonal rHTNF antibody. In part 2, 20 ng of endotoxin/kg was infused in horses during a 30-minute period. Fifteen minutes after the endotoxin infusion was initiated, 1 of 3 preparations was infused: 0.1 mg of rabbit polyclonal rHTNF antibody/kg, 0.1 mg of human IgG/kg, or 500 ml of 5% dextrose. Clinical and hematologic data were collected for 24 hours.

Results

Compared with the monoclonal antibody, the rabbit polyclonal rETNF antibody was more effective in inhibiting TNF activity. The 50% effective doses of the murine monoclonal rETNF, rabbit polyclonal rETNF, and rabbit rHTNF antibodies were 1.8, 0.8, and 0.6 μg of antibody/ml, respectively. In part 2, endotoxin infusion resulted in significant alternations in all variables; however, differences among treatment groups were not significant.

Conclusions and Clinical Relevance

Although murine monoclonal and rabbit polyclonal rETNF or rHTNF antibodies are capable of inhibiting native equine TNF activity in vitro, when given after initiation of endotoxemia, administration of 0.1 mg of rabbit polyclonal rHTNF/kg does not alter the response to infusion of endotoxin. (Am J Vet Res 1998;59:792-797)
Hyperglobulinemia and lymphocyte subset changes in naturally infected, inapparent carriers of equine infectious anemia virus
Authors: Russell Karen E. , Walker Kathy M. , Miller Richard T. , Sellon Debra C.
Published: January 2024

Objective

To determine blood protein concentration, immunoglobulin concentration, and lymphocyte profiles in equine infectious anemia virus (EIAV) seropositive, naturally infected horses without clinical signs of disease.

Animals

26 clinically normal seropositive horses, 6 febrile ponies with experimentally induced EIA, and 52 clinically normal seronegative horses and ponies.

Procedure

Serum and EDTA-anticoagulated blood were obtained from all horses and ponies, and total serum protein and albumin concentrations, immunoglobulin concentrations, and blood lymphocyte subset counts were determined.

Results

Compared with seronegative horses, EIAV seropositive inapparent carrier horses had no significant difference in serum reverse transcriptase activity, PCV, or platelet count. Inapparent carrier horses had increased plasma total solids and serum globulin concentrations and decreased serum albumin concentration and albumin-to-globulin ratio. Total serum immunoglobulin and serum IgM concentrations were increased. In-apparent carrier horses had significantly decreased percentages of CD5+ and CD4+ blood lymphocytes.

Conclusions

Serum protein and lymphocyte subset changes in EIAV-infected inapparent carrier horses are consistent with immune activation or chronic inflammation, both of which may, in part, be the result of virus-induced polyclonal B-cell activation.

Clinical Relevance

EIAV seropositive horses have immune-related abnormalities consistent with ongoing viral activity regardless of the duration they have been infected, even when the usual signs of disease (anemia, fever, weight loss) are not apparent. (Am J Vet Res 1998;59:1009–1015)
Pulmonary function in horses with recurrent airway obstruction after aerosol and parenteral administration of beclomethasone dipropionate and dexamethasone, respectively
Authors: Rush Bonnie R. , Raub Elizabeth S. , Rhoads William S. , Flaminio M. Julia B. F. , Matson Charles J. , Hakala Joyce E. , Gillespie Jerry R.
Published: January 2024

Objective

To determine changes in clinical signs of disease and response to pulmonary function testing in horses with recurrent airway obstruction (heaves) after aerosol and parenteral administration of beclomethasone dipropionate and dexamethasone, respectively.

Animals

6 horses with inducible and reversible heaves.

Procedure

Episodes of heaves were induced by exposure (challenge) to moldy hay and straw for 7 days. Horses were assigned to treatment groups (aerosolized beclomethasone dipropionate, parenterally administered dexamethasone, aerosolized propellant [control]), and respiratory frequency and subjective assessment of respiratory effort were determined twice daily. Maximal change in pleural pressure (ΔPplmax), pulmonary resistance (RL), and dynamic compliance (Cdyn) was determined on days 0, 7, 10, 14, and 21.

Results

The RL and ΔPplmax were increased, and Cdyn was decreased in all horses in response to natural challenge. Beclomethasone reduced RL on day 10, reduced ΔPplmax on days 14 and 21 and increased Cdyn on day 14. Dexamethasone reduced RL and ΔPplmax on days 10, 14, and 21 and increased Cdyn on days 10 and 14. Respiratory effort (subjective assessment) improved after 2 and 3 days of beclomethasone and dexamethasone administration but rebounded to pretreatment values 1 and 3 days after discontinuation of drugs.

Conclusions

Pulmonary function testing responses and clinical signs of airway obstruction were improved by administration of beclomethasone. The magnitude of response to aerosolized beclomethasone generally was less marked than the response to parenterally administered dexamethasone. Higher or more frequent dosing of aerosolized beclomethasone may be necessary to achieve the anti-inflammatory response to parenterally administered dexamethasone. (Am J Vet Res 1998;59:1039–1043)
Determination of age in dogs and cats by use of changes in lens reflections and transparency
Authors: Tobias Gerald , Tobias Todd A. , Abood Sarah K. , Hamor Ralph E. , Ballam Joan M.
Published: January 2024

Objective

To develop and test a noninvasive technique for determining age in dogs and cats on the basis of changes in lens reflections and transparency.

Animals

85 dogs representing 5 breeds and 73 domestic shorthair cats.

Procedure

While examining dilated eyes in a darkened room, using a penlight, 2 experienced examiners who were blinded to actual age of animals individually measured the diameter of reflections from the anterior (La) and posterior (Lb) surfaces of the lens and scored lens transparency (Ltr) from 1 (clear) to 5 (severe opacity). Models were developed to predict age on the basis of these measurements.

Results

Aging models developed for dogs and cats were as follows: Agedogs = 2.197 − 0.070 × (La) + 1.361 × (Lb) + 1.193 × (Ltr) and Agecats = 1.988 + 1.024 × (La) + 2.220 × (Lb) + 1.019 × (Ltr), where age was expressed in years, and La and Lb were in millimeters. All variables, except La in dogs, contributed significantly to accuracy of the models. Correlation between predicted and actual ages, as measured by Pearson's product-moment correlation coefficient, was significant in both species (P < 0.0001). Significant differences were not found between examiners or between the first and second evaluations by the same examiner.

Conclusions and Clinical Relevance

A noninvasive technique based on evaluation of lens reflections and transparency can provide clinically useful predictions of age in mature dogs and cats. This technique could be an important tool for veterinarians or humane shelters in determining differential diagnoses and assessing longevity and adoptability of mature animals of unknown age. (Am J Vet Res 1998;59:945–950)
Further validation of antibody-capture and antigen-capture enzyme-linked immunosorbent assays for determining exposure of cattle to bovine coronavirus
Authors: Smith David R. , Nielsen Paul R. , Gadfield Kathy L. , Saif Linda J.
Published: January 2024

Objective

To further validate an antibody-capture ELISA for measuring bovine coronavirus (BCV) exposure (antibody seroresponse) in cattle and to explain the apparent loss of sensitivity of a BCV antigen-capture ELISA when testing feces from adult versus neonatal cattle.

Animals

98 adult cows from herds with and without winter dysentery; 10 gnotobiotic or colostrum-deprived calves.

Procedures

Results of an antibody-capture ELISA for BCV and a plaque reduction virus neutralization assay performed on paired serum samples from 24 cattle were compared with each other and with results of immunoelectron microscopy (IEM) of feces for BCV. For samples from 98 cattle, results of antibody-capture ELISA were compared with results of IEM. Calves were inoculated with feces ELISA-positive or IEM-positive for BCV and monitored for BCV infection. An ELISA was developed to detect BCV antigen-antibody complexes in feces and results were compared with results of an antigen-capture ELISA and IEM.

Results

Antibody-capture ELISA results correlated with neutralization assay results, but agreed more closely with results of IEM. Calves became infected with BCV following inoculation with either ELISA-positive or ELISA-negative but IEM-positive feces. Results of the antigen-antibody ELISA correlated with results of IEM and the antigen-capture ELISA.

Clinical Implications

In adult cattle, testing of paired serum samples by use of an antibody-capture ELISA may be a better indicator of recent BCV exposure than results of virus neutralization tests. Antigen-antibody binding in feces may interfere with results of antigen-capture ELISA for BCV. (Am J Vet Res 1998;59:956–960)
Molecular basis of variation in protective SzP proteins of Streptococcus zooepidemicus
Authors: Walker John A. , Timoney John F.
Published: January 2024

Objectives

To characterize, on a molecular basis, variable regions of the SzP proteins of the Moore and Bryans serovars of Streptococcus zooepidemicus and specificity of opsonic responses.

Sample Population

14 Moore and Bryans serovars of S zooepidemicus.

Procedure

Using polymerase chain reaction analysis and primers from the 5’ and 3’ sequences of the prototype gene SzPW60, the SzP genes of each Moore and Bryans serovar were sequenced and translated, then the amino acid sequences were compared.

Results

Comparison of the amino acid sequences revealed 2 variations at the N terminus; a hypervariable (HV) region from residue 106 to 166, approximately; and proline-glutamic acid-proline-lysine repeats in the carboxy terminus that ranged in number from 7 to 12. Five distinct motifs, HV 1 to 5, which varied independently of the N termini were found in the internal HV region. All serovars were opsonized by antiserum to the prototype SzPW60 protein, indicating that opsonogenic epitopes are on the conserved regions of the protein.

Conclusion and Clinical Relevance

Variant motifs may be valuable in epizootiologic and pathogenesis studies of S zooepidemicus infections of the respiratory tract of young horses and in determining whether there are populations of S zooepidemicus unique to specific animal hosts. It is also clear from the opsonic responses to SzP that at least a portion of the protective responses are probably not serovar specific. (Am J Vet Res 1998;59:1129-1133)
Synergistic effect of hydrochloric acid and bile acids on the pars esophageal mucosa of the porcine stomach
Authors: Lang Jennifer , Blikslager Anthony , Regina Dan , Eisemann Joan , Argenzio Robert
Published: January 2024

Objectives

To determine effects of finely ground diet and food deprivation on pH and bile acid concentration in the proximal portion of the porcine stomach and effects of bile acids and pH on the pars esophageal mucosa in vitro.

Animals

Sixteen 15- to 30-kg pigs.

Procedures

Gastric content samples obtained from pigs fed a finely ground pelleted or coarsely ground meal diet were assayed for gastric pH and bile acids. Stratified squamous epithelium was studied in an Ussing chamber, and histologically. Electrical conductance and transmucosal mannitol fluxes (as indices of tissue permeability) were determined at pH 4.0, 2.0, and 1.5 and in response to treatment with 0, 1, 2, or 3 mM taurodeoxycholate or glycocholate.

Results

Pigs fed the finely ground feed had significantly (P = 0.01 ) lower proximal stomach pH than did pigs fed the coarse meal. Proximal stomach bile acids concentration was significantly (P = 0.04) higher in pigs fed the finely ground diet. The H+ and bile acids concentration increased with time after feeding. In vitro exposure of the stratified mucosa to high H+ (pH < 4.0) and bile salt concentration (≥ 1.0 mM) resulted in significant (P < 0.05) dose-dependent increase in tissue conductance and mannitol fluxes, whereas low pH or bile acids alone had little effect.

Conclusions

High H+ and bile acids concentration in the stomach of pigs fed finely ground diets or subjected to feed deprivation may contribute to ulceration of the pars esophageal tissue. Bile acids act synergistically and in dose-dependent manner, with low pH causing damage to the stratified squamous epithelium in vitro. (Am J Vet Res 1998;59:1170-1176)
Establishment of a monoclonal antibody (1/14/16H9) for detection of equine keratan sulfate
Authors: Okumura Masahiro , Fujinaga Toru
Published: January 2024

Objectives

To establish a sensitive and specific monoclonal antibody (MAB) against equine keratan sulfate (KS) and to develop an enzyme immunoassay for measurement of the concentration of KS in serum and synovial fluid from horses.

Sample Population

18 synovial fluid and 48 serum samples were obtained from clinically normal horses and horses with arthritis.

Procedure

BALB/c mice were immunized with chondroitinase-ABC-digested proteoglycan monomer from equine joint cartilage, and MAB were raised, using Sp2/O cells as a fusion partner. A competitive ELISA was optimized, using one of the established MAB, and KS concentration in synovial fluid and sera from horses was measured.

Results

The high-titer MAB1/14/16H9, which specifically recognizes the epitope on equine KS, was identified. This antibody had no reactivity with chondroitin sulfate and core protein of proteoglycan monomers, hyaluronan, heparin, dermatan sulfate, and heparan sulfate. A competitive ELISA for determination of KS concentration was optimized, using this antibody. Precision data were obtained for the range of 10 to 160 ng/ml. The within- and between-assay coefficients of variation were 10.0 and 12.7%, respectively.

Conclusions

MAB 1/14/16H9 that specifically recognized equine KS was established and was used to develop an enzyme immunoassay for measurement of the concentration of KS in synovial fluid and sera from horses. It is expected that the assay system using MAB 1/14/16H9 will contribute to evaluation of cartilage metabolic activity in horses. (Am J Vet Res 1998;59:1203-1208)
Computer-assisted image analysis of intratumoral vessel density in mammary tumors from dogs
Authors: Griffey Stephen M. , Verstraete Frank J. M. , Kraegel Susan A. , Lucroy Michael D. , Madewell Bruce R.
Published: January 2024

Objective

To determine whether intratumoral microvessel density can be used to distinguish benign from malignant mammary tumors in dogs and to predict the outcome of surgical treatment for small volume (< 3-cm diameter) tumors.

Sample Population

Tissue sections from 58 mammary tumors (42 malignant and 16 benign) from dogs.

Procedure

Mammary tumors were stained by immunohistochemistry for factor VIII-related antigen. Computer-assisted image analysis was used to determine intratumoral vessel density in immunostained areas. Total vascular density (TVD), calculated from 3 non-overlapping fields, was analyzed for correlation with patient or tumor histomorphologic characteristics, and results obtained by surgical treatment of small volume tumors.

Results

Mean TVD of malignant tumors was significantly greater than that of benign tumors. Total vascular density was not correlated with patient age, sex, reproductive status, clinical tumor stage, or histologic type. For small volume (< 3-cm diameter) malignant tumors, mean TVD was higher in tumors that recurred after surgery than in tumors that did not recur; however, TVD was not predictive of time to recurrence.

Conclusion and Clinical Implications

Immunohistochemistry and computer-assisted image analysis allowed objective quantitation of intratumoral microvessel density in formalin-fixed, paraffin-embedded tissue sections. Tumors with high TVD were more likely to recur after surgical treatment than tumors with low TVD suggesting that TVD measurements can be used by the clinician, in addition to histologic type and clinical stage, to predict prognosis after surgical treatment. These data also provide rationale for use of antiangiogenesis strategies for treatment of malignant mammary tumors in dogs. (Am J Vet Res 1998;59:1238-1242)
Long-term surgical preparation of portal vein-drained viscera for determination of their nutritional requirements in preruminant calves
Authors: Nappert Germain , Naylor Jonathan M. , Semple Hugh A. , Ferguson James
Published: January 2024

Objective

To develop a surgical preparation to study the nutrient concentration difference across the portal vein-drained viscera of preruminant calves over a 2-week period.

Animals

9 healthy preruminant male Holstein calves.

Procedure

A bilateral subcostal approach was used to reach the portal area to provide access for proper placement of an ultrasonic transit time flow probe around the portal vein. The umbilical vein was used as an entry point for the portal vein catheter. The femoral artery was also catheterized. Calves were observed daily, and food intake was recorded. Body weight was recorded weekly. The calves were euthanatized, and necropsy was performed 2 weeks after surgery.

Results

Of the 9 calves, 7 recovered without surgical complications. Within 24 hours of surgery, 1 calf developed an intestinal hernia at the flank incision that was surgically repaired without further complications. One calf was euthanatized a week after surgery because it developed septicemia secondary to catheter-related infection.

Conclusion

The bilateral subcostal approach provided access to the portal area, and the umbilical vein was useful as an entry point. Application of an ultrasonic flow probe provided consistent measurements of blood flow over a 2-week period.

Clinical Relevance

These results may have implications for development of treatment to promote gastrointestinal tract healing in calves with diarrhea. (Am J Vet Res 1998;59:1323-1328)
Use of a [13C]urea breath test for detection of gastric infection with Helicobacter spp in dogs
Authors: Cornetta Angelyn M. , Simpson Kenneth W. , Strauss-Ayali Dalit , McDonough Patrick L. , Gleed Robin D.
Published: January 2024

Objective

To evaluate a [13C]urea breath and blood test (UBBT) for detection of gastric infections with Helicobacter spp in dogs.

Animals

8 Beagles with, and 3 Beagles without, gastric Helicobacter spp infection.

Procedure

The UBBT was evaluated in dogs of known infection status before and after treatment with amoxicillin, metronidazole, and famotidine (AMF). A standard dose of [13C]urea (4 mg/kg of body weight) was given, and breath and blood samples were obtained at 0, 20, 40, and 60 minutes after administration. Effect of AMF treatment on breath and blood 13CO2 values, gastric urease activity (GUA), and gastric spiral organisms (GSO) was evaluated 3 to 4 and 28 to 29 days after 14 days of AMF treatment.

Results

Breath and blood 13CO2 values were higher in infected dogs than uninfected dogs. Endogenous 13CO2 production was minimal. Breath and blood 13CO2 values varied by 10 and 13%, respectively, between test periods. There was a correlation (R2 = 0.985) between breath and blood 13CO2 values. In 6 of 8 infected dogs, these values were decreased 3 days after completion of AMF administration and biopsy specimens lacked GSO and GUA. For these 6 dogs, breath and blood 13CO2 values were variable 28 days after completion of AMF treatment, and were associated with recurrence of GSO in 6 dogs and GUA in 4 dogs.

Conclusions and Clinical Relevance

Results of this study indicate that UBBT may provide a noninvasive procedure for detection of gastric infections with Helicobacter spp in dogs. Treatment with amoxicillin, metronidazole, and famotidine may not be effective in eradicating gastric infections with Helicobacter spp in dogs. (Am J Vet Res 1998;59:1364–1369)
Innervation of the equine mature and immature proximal sesamoid bone by calcitonin gene-related peptide and substance P-containing nerves
Authors: Cornelissen B. P. M. , Buma P. , Rijkenhuizen A. B. M. , Barneveld A.
Published: January 2024

Objective

To localize and determine relative frequency of occurrence of calcitonin gene-related peptide (CGRP) and substance P (SP) fibers in the proximal sesamoid bones (PSB) and adjacent structures in sound horses.

Sample Population

4 foals and 3 adult horses.

Procedure

Medial PSB and adjacent ligaments of both forelimbs were collected, flushed, and fixed in buffered 4% formalin. The left PSB were cut into 5 longitudinal, sagittally oriented slabs, and the right PSB were cut into 5 transverse slabs. After decalcification in EDTA, slices were transferred to a 30% sucrose solution, deep frozen, sectioned (80 μm), and stored in Tris-buffered saline solution for free-floating immunocytochemical processing, staining of which was performed by use of the peroxidase-antiperoxidase method with polyclonal rabbit antibodies against CGRP and SP. Sections were examined by light microscopy.

Results

Calcitonin gene-related peptide and SP fibers were present throughout the PSB; in ligaments, they were concentrated at the attachment sites. Presentation of the fibers, the innervation pattern, and intensity in the bones of horses differed from that in foals, in which the fibers were more delicate and frequency of occurrence was lower. In horses, innervation with CGRP and SP fibers was more dense in the periphery of the bone, whereas in foals, local difference in innervation of the bone was not evident. With the exception of the intersesamoidean ligament, ligaments were more richly innervated than was bone.

Conclusion

Presence of the nociceptive peptides CGRP and SP indicated that the PSB and, more practically, the adjacent ligaments are sensitive structures. (Am J Vet Res 1998;59:1378–1385)
Anatomic site and interanimal variability in morphologic characteristics of bottlenose dolphin (Tursiops truncatus) skin likely to affect dermal absorption studies
Authors: Colbert A. , Stoskopf M. , Brownie C. , Scott G. I. , Levine J.
Published: January 2024

Objective

To investigate anatomic site and interanimal variability in dolphin skin for use in development of models for cutaneous absorption studies.

Sample Population

Skin from 30 healthy free-ranging bottlenose dolphins (17 males and 13 females grouped by age) and 10 captive males between 13 and 19 years old.

Procedure

Biopsy specimens were collected from the 10 male dolphins at 3 anatomic sites and from the 30 dolphins at 1 site; specimens were evaluated by light microscopy. Stratum externum thickness, minimal depth to the vasculature, and maximal epidermal depth were measured at 4 locations on 4 sequential sections. Comparisons of replicate measurements for 3 skin characteristics were made within and among anatomic sites, between dolphins of the same sex and approximate age, and across males and females of various ages.

Results

The stratum externum in male dolphins was thicker. Differences attributable to age and anatomic site were not significant. Variation attributable to differences in stratum externum thickness between dolphins was significant. Differences among body sites within the same dolphin were significant but were not consistent from dolphin to dolphin. Mean stratum externum thickness was not different between males of the 2 cohorts, but mean maximal epidermal depth and mean minimal depth to the vasculature were different. Variances within the 2 male cohorts were not significantly different.

Conclusions

Studies affected by stratum externum thickness should eliminate the effect attributable to sex difference by using dolphins of the same sex or grouping analytical data by sex. Precision could be improved without increasing the total number of dolphins by collecting more than 1 sample/dolphin. (Am J Vet Res 1998;59:1398–1403)
Evaluation of a diagnostic monoclonal antibody-based capture enzyme-linked immunosorbent assay for detection of a 26- to 28-kd Fasciola hepatica coproantigen in cattle
Authors: Abdel-Rahman Salma M. , O'Reilly Kathy L. , Malone John B.
Published: January 2024

Objective

To develop a monoclonal antibody-based capture ELISA for detection of a 26- to 28-kd coproantigen of Fasciola hepatica in the feces of infected cattle.

Animals

27 crossbred yearling calves, 2 New Zealand White rabbits.

Procedure

A capture ELISA that uses a previously described monoclonal antibody (MAB) M2D5/D5F10 was developed. The MAB was used to capture the antigen from the feces, and hyperimmune rabbit serum raised against the purified 26- to 28-kd glycoprotein was used to detect the coproantigen. This test was used for the detection of the antigen in the feces of 27 experimentally infected calves with known numbers of flukes. Fecal specimens obtained before infection from the same calves were used as negative controls.

Results

The assay results identified all calves infected with more than 10 flukes at necropsy, and as little as 300 pg of coproantigen/ml of fecal supernatant was detected. The assay results correlated well with the number of flukes, suggesting that it is possible to estimate fluke burden. Infections as early as 6 weeks’ duration were detected, before flukes mature to adults and start to shed eggs.

Conclusions

In experimentally infected calves, the coproantigen capture ELISA was more sensitive and easier to perform than microscopic examination for the diagnosis of F hepatica infection; moreover, 6-week-old prepatent infections were detectable.

Clinical Relevance

This capture ELISA containing an F hepatica 26- to 28-kd coproantigen is a quantitative assay that is more sensitive than fecal egg counting. In addition, the assay is rapid, easy to perform and lends itself well to large numbers of samples. Because it is antigen based, the ELISA may be useful for diagnosis of F hepatica infection in other species, including human beings. (Am J Vet Res 1998;59:533–537)
Venezuelan field trials of vaccines against brucellosis in swine
Authors: Lord Veronica R. , Cherwonogrodzky John W. , Schurig Gerhardt G. , Lord Rexford D. , Marcano Mabel J. , Meléndez Gerardo E.
Published: January 2024

Objective

To evaluate live attenuated Brucella abortus RB51, killed B suis cells, O-polysaccharide (OPS) from B abortus 1119-3 and OPS from B suis 1330, for protection of swine against B suis challenge exposure under farm conditions.

Animals

10 infected boars, 160 unvaccinated control sows and their 1,040 progeny, and 610 vaccinated sows and their 6,600 progeny.

Procedure

Gilts (45 to 65 days or 4 to 6 months old) were vaccinated or not vaccinated. For the latter gilts, additional variables studied were dose, number of doses, and delivery route. Mature gilts were mated with 4 infected boars, then serologic reaction to Brucella spp, results of bacteriologic culture of vaginal secretions, presence of abortion, and litter size were assessed. Various tissues obtained from aborted fetuses were obtained for culture of Brucella spp.

Results

About 40% of unvaccinated control gilts seroconverted to Brucella spp, 27% were positive for OPS precipitation by use of agar gel immunodiffusion, 23% aborted their fetuses, and the remaining gilts had litters of 5 to 8 pigs. Killed B suis cells provided the following protection: 25% of vaccinates were seropositive, 5% had positive results of agar gel immunodiffusion, 5% aborted, and the remaining gilts had litters of 7 to 8 pigs. Gilts that received live RB51 or OPS vaccine were protected. Serologic reactions were always negative, abortion did not occur (ie, 100% were protected), and litter size was 10 to 12 pigs.

Conclusions

Live attenuated B abortus RB51 or purified OPS was effective in protecting gilts against B suis infections. Dose (106 to 109 cells, 100 to 500 μg, respectively), number of doses (1 or 3), or route (IM or PO) made little difference. Further research is required to determine why these 2 vaccine candidates are similar in protection effectiveness and whether they can be used after infection as a treatment. (Am J Vet Res 1998;59:546–551)
Demonstration of a capsule on Mycoplasma ovipneumoniae
Authors: Niang Mamadou , Rosenbusch Ricardo F. , Andrews John J. , Kaeberle Merlin L.
Published: January 2024

Objective

To examine Mycoplasma ovipneumoniae for presence of a capsule and its potential role in adherence.

Sample Population

17 isolates of M ovipneumoniae and 2 isolates of M arginini, recovered from sheep with respiratory tract disease.

Procedure

Mycoplasmas were cultured in modified Friis broth medium, ovine fetal lung cells, or ovine tracheal ring explants. Pelleted mycoplasmas or ring cultures infected with mycoplasmas were treated with ruthenium red or polycationic ferritin and visualized by transmission electron microscopy. Reactivity of several lectins with the mycoplasmas was studied by use of a microtitration plate agglutination test.

Results

Electron microscopy revealed a large number of M ovipneumoniae cells covered with an electron dense-stained amorphous material suggesting that it was a capsule. Multiple passages of the microorganisms in modified Friis broth medium decreased thickness of the capsule, but not percentage of cells encapsulated. Marked differences were observed when M ovipneumoniae isolates grown in modified Friis broth medium or co-cultured with ovine fetal lung cells were compared for capsular thickness or percentage of encapsulation. In thin sections of ruthenium red-stained tracheal ring cultures, the mycoplasmas appeared to be in close contact with cilia through their capsule. All isolates of M ovipneumoniae reacted strongly with wheat germ agglutinin lectin.

Conclusions

Mycoplasma ovipneumoniae produces a polysaccharide capsule with variable thickness that is dependent on culture conditions and strain. Morphologic observations suggest that this capsule facilitates adherence of the organism to ciliated epithelium. (Am J Vet Res 1998;59:557–562)
Diagnostic implications of concurrent inoculation with attenuated and virulent strains of porcine reproductive and respiratory syndrome virus
Authors: Mengeling William L. , Lager Kelly M. , Wesley Ronald D. , Clouser Deborah F. , Vorwald Ann C. , Roof Michael B.
Published: January 2024

Objective

To determine the predominant strain of progeny virus in samples obtained from cell cultures and pigs exposed simultaneously to attenuated and virulent strains of porcine reproductive and respiratory syndrome virus (PRRSV).

Sample population

Cell cultures and twenty 4-week-old pigs.

Procedure

Cell cultures and pigs were simultaneously exposed to various relative concentrations of an attenuated, cell-culture-adapted vaccine strain and a virulent field strain of PRRSV. Progeny virus obtained at selected intervals thereafter was tested to determine strain identity by use of restriction fragment length polymorphism (RFLP) analysis.

Results

Progeny virus from infected cell cultures comprised the attenuated strain, alone or in combination with the virulent strain, except when cultures had been exposed to a large excess (> 100,000-fold) of the virulent strain. Progeny virus from infected pigs comprised only the virulent strain regardless of the relative concentrations of the 2 strains to which the pigs had been exposed.

Conclusions

During concurrent replication in cell cultures, the attenuated strain quickly predominated. Conversely, during concurrent replication in pigs, the virulent strain quickly predominated.

Clinical Relevance

It is unlikely that only an attenuated strain of PRRSV would be identified by RFLP testing of samples obtained from pigs concurrently infected with a virulent strain of PRRSV. Nevertheless, the ability of a cell-culture-adapted attenuated strain of PRRSV to predominate during cell culture passage (the first step in the current RFLP testing procedure) indicated that, if possible, samples should be obtained from pigs that do not have a history of direct or indirect exposure to attenuated-virus vaccine. (Am J Vet Res 1999;60:119–122)
Magnetic resonance arthrography of the cubital joint in dogs affected with fragmented medial coronoid processes
Authors: Snaps F. R. , Park R. D. , Saunders J. H. , Balligand M. H. , Dondelinger R. F.
Published: January 2024

Objective

To evaluate efficacy of intra-articular injection of gadolinium tetra-azacyclododecane tetra-acetic acid (gadolinium-DOTA) for delineating fragmented medial coronoid processes (FMCP) and lesions on the medial aspect of the humeral condyle (MAHC).

Sample Population

14 cubital joints in 9 dogs.

Procedure

Magnetic resonance imaging (MRI) was performed with and without intra-articular injection of a solution of 2 mmol of gadolinium-DOTA/L. Arthrographic images obtained after injection of contrast medium were compared with those obtained without contrast medium. Evidence of contrast medium around or in the medial coronoid process and infiltration of contrast medium in subchondral bone lesions was recorded. Twenty-four hours after imaging, arthroscopy was performed, and lesions detected were correlated with results of MRI.

Results

An abnormal coronoid process was diagnosed in 13 of 14 joints. A fragmented process (free) was seen in 7 of 14 joints; nondisplaced mineralized medial (in situ) coronoid processes were evident in 4 joints; and nondisplaced unmineralized medial coronoid processes were evident in 2 joints. Lesions on the MAHC were diagnosed in 4 of 12 joints. In 5 joints, a hyperintense signal resulted from contrast medium that infiltrated between the fragmented process and ulna. In 2 joints, contrast medium did not infiltrate completely around the process and was stopped by an isointense structure (ie, abnormal cartilage). Subchondral bone lesions were enhanced by use of contrast medium.

Conclusion and Clinical Relevance

Use of arthrography enabled us to identify FMCP easily, but did not provide important additional information about changes on the medial coronoid process, compared with MRI performed without contrast medium. (Am J Vet Res 1999;60:190–193)
Cardiovascular effects of epidurally administered oxymorphone and an oxymorphone-bupivacaine combination in halothane-anesthetized dogs
Authors: Torske Kristine E. , Dyson Doris H. , Conlon Peter D.
Published: January 2024

Objective

To evaluate cardiovascular effects of epidurally administered oxymorphone (OXY) and an OXY-bupivacaine combination (O/B) in halothaneanesthetized dogs.

Animals

6 dogs.

Procedure

In a randomized crossover design study, dogs were anesthetized with halothane and given OXY, O/B, and saline solution (SAL). Eucapnia and end-tidal halothane concentration of 1.2% were established. Heart rate (HR), systemic and pulmonary arterial pressures, central venous pressure (CVP), and cardiac output were measured at baseline and 5, 15, 30, 45, 60, and 75 minutes after treatment. At 90 minutes, glycopyrrolate was administered IV, and measurements were repeated at 95 minutes. Cardiac index (CI), stroke volume, stroke index, systemic vascular resistance (SVR), and left ventricular work were calculated. End-tidal halothane concentration was decreased to 0.8% from 17 to 45 minutes and to 0.5% from 47 to 95 minutes for OXY and O/B, where-as for SAL, it was maintained at 1.5 and 1.2%, respectively. Samples were obtained at 0, 2, 5, 15, 30, 45, 60, and 95 minutes for measurement of serum opiate concentration and comparison with values after IM administration of OXY.

Results

HR decreased, but CVP and SVR increased in response to OXY and O/B. These changes were reversed after IV administration of glycopyrrolate, resulting in significant increase in CI, compared with that in response to SAL. Serum opiate concentration increased markedly and peaked within 15 minutes after OXY and O/B administration but did not differ from values after IM administration.

Conclusions

Epidural administration of OXY results in rapid systemic uptake and decreased HR. Glycopyrrolate administration improves HR, resulting in improved CI at equipotent halothane concentrations. (Am J Vet Res 1999;60:194–200)
Evaluation of toxicosis of liposome-encapsulated cis-bis-neodecanoato-trans-R, R-1, 2-diaminocyclohexane platinum (II) in clinically normal cats
Authors: Fox Leslie E. , Toshach Katrina , Calderwood-Mays Maron , Khokhar Abdul R. , Kubilis Paul , Perez-Soler Roman , MacEwen E. Gregory
Published: January 2024

Objective

To determine adverse effects of single and multiple doses of liposome-encapsulated cis-bis-neodecanoato-trans-R, R-1, 2-diaminocyclohexane platinum (II) (L-NDDP) administered IV to healthy adult cats.

Animals

10 healthy adult cats.

Procedure

8 cats were given a single dose of L-NDDP (at rates of 75, 100, 150, or 200 mg/m2), and 2 cats were given liposomal lipid (1,500 mg/m2). Six of the 10 cats were given doses of L-NDDP at the maximum tolerated dosage (100 mg/m2) or a lower dosage (75 mg of L-NDDP/m2) at 21-day intervals, for a total of 4 treatments. Hematologic and serum biochemical analyses, urinalyses, and physical examinations were used to monitor effects of L-NDDP.

Results

All cats had transient pyrexia, lethargy, vomiting (1 to 3 times/24 h), inappetence, and an acute species-specific infusion reaction that was prevented by administration of atropine-diphenhydramine. Dose-limiting toxicosis was evident as a 10- day course of lethargy, intermittent vomiting, and diarrhea. In cats given multiple doses, dose-related thrombocytopenia, cumulative myelosuppression, transient increased hepatic transaminase activity, and mild to moderate hepatic hydropic degeneration and proximal renal tubular lipidosis in excess of lipidosis expected for this species were detected. Bone marrow hypoplasia was detected in some cats that received higher doses (cumulative dosages of 300 or 400 mg of L-NDDP/m2).

Conclusion

Cats can safely be given L-NDDP at potentially therapeutic dosages without inducing renal or pulmonary toxicoses.

Clinical Relevance

Because L-NDDP has better tumoricidal activity than cisplatin (in vivo and in vitro) and is not cross resistant, it may be similarly or more efficacious than cisplatin in humans and dogs. (Am J Vet Res 1999;60:257–263)