bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of the bacterial flora of the proximal part of the small intestine in healthy cats, and the effect of sample collection method
Authors: Papasouliotis K. , Sparkes A. H. , Werrett G. , Egan K. , Gruffydd-Jones E. A. , Gruffydd-Jones T. J.
Published: January 2024

Objective

To investigate the bacterial flora of the proximal part of the small intestine of healthy cats and determine the effect of sample collection method on results of bacteriologic culture.

Animals

25 healthy barrier-maintained specific-pathogen-free-derived cats.

Procedure

Aspirated, undiluted samples of proximal small intestinal juice were obtained via oral endoscopy (UEA), and a second sample was collected after instillation of 1 ml of sterile saline solution (diluted, DEA). Undiluted juice also was obtained by direct needle aspiration (NA) from the intestinal lumen. Samples for quantitative and semiqualitative bacteriologic examination were grown aerobically and anaerobically.

Results

Mean (range) log10 colony-forming units of total bacteria/ml were 6.2 (2.0 to 8.3) for NA, 6.0 (2.0 to 7.9) for UEA, and 4.9 (2.0 to 7.5) for DEA samples. One cat had no growth (≤ 2.0 colony-forming units/ml) for samples obtained using all 3 methods, and another cat had no growth for the DEA sample only. Mean total aerobic, anaerobic, and bacterial counts were not significantly different between NA and UEA methods, but these techniques yielded significantly higher mean counts than did DEA samples (P ≤ 0.002, ANOVA). As a percentage of the total bacteria isolated, anaerobes constituted a median 35, 32, and 50% of the NA, UEA, and DEA samples, respectively. Good correlation was found between the NA and UEA samples for total bacteria, aerobes, and anaerobes (r ≥ 0.830).

Conclusions

Compared with human beings, healthy cats carry high numbers of bacteria in the proximal part of the small intestine. By comparison with NA samples, UEA samples accurately reflected bacterial populations in the small intestine, whereas DEA samples significantly underestimated these populations. (Am J Vet Res 1998;59:48–51)
Efficacy of eprinomectin against Hypoderma spp in cattle
Authors: Holste J. E. , Colwell D. D. , Kumar R. , Lloyd J. E. , Pinkall N. P. M. , Sierra M. A. , Waggoner J. W. , Langholff W. K. , Barrick R. A. , Eagleson J. S.
Published: January 2024

Objective

To determine the efficacy of a topical formulation of eprinomectin against natural infestations of first (L1)-stage, and second and third (L2/L3)-stage larvae of Hypoderma spp.

Animals

140 approximately 6- to 18-month-old cattle of various breeds.

Procedure

Cattle, selected from herds with high prevalence of Hypoderma infestation, were treated in 4 experiments: within each replicate, 1 animal received eprinomectin at a dosage of 500 μg/kg of body weight against first-stage larvae (L1). The second animal received the same treatment against second or third-stage larvae (L2/L3). The third animal served as an untreated control. In a fifth experiment, visible warbles were treated on half of the cattle. Remaining cattle served as vehicle-treated controls. In 1 experiment, warbles were examined from time of treatment until all lesions were resolved. In 4 experiments, emerging Hypoderma larvae were recovered, speciated, and enumerated, and viability was determined.

Results

Eprinomectin (500 μg/kg) efficacy was complete against L1. Hypoderma L2/L3 eradication approached 100% efficacy (1 live larva was recorded). Warbles in treated cattle resolved in a significantly shorter time than did those in controls. Adverse reactions related to treatment were not observed in any of the trials.

Conclusions

Eprinomectin (500 μg/kg) applied topically was safe and highly efficacious for treatment of all larval stages of Hypoderma spp in these trials.

Clinical Relevance

Attributes of eprinomectin besides antiparasite efficacy allow treatment of all classes of cattle with no need for meat or milk withdrawal. (Am J Vet Res 1998;59:56–58)
Respiratory depression and apnea induced by propofol in dogs
Authors: Muir W. W. , Gadawski J. E.
Published: January 2024

Objective

To determine the maximal IV administered dose of propofol that would not induce a serious adverse event in nonsedated dogs.

Animals

6 clinically normal dogs (3 males and 3 females) between 8 and 12 months old and weighing between 8.8 and 11.3 kg.

Procedure

Propofol was administered IV at an initial dosage of 6.5 mg/kg of body weight at a rate of 20 mg/10 s. Subsequent doses were incrementally increased by 2.5 mg/kg (eg, second dose: 9 mg/kg) and separated by a minimum of 3 days. This procedure was repeated until a dose that induced a serious respiratory, cardiovascular, or neurologic adverse effect was determined.

Results

Apnea was determined to be the serious adverse effect for all dogs. Duration of apnea varied between dogs, but increased in a dose-dependent manner at dosages > 14 mg/kg.

Conclusions

Respiratory depression and apnea are the most likely adverse effects induced by IV administration of propofol to dogs. Propofol administered IV at a rate of 20 mg/kg/10 s induces minimal cardiovascular depression at dosages in excess of the apneic dosage.

Clinical Relevance

Respiratory depression and apnea should be expected as potential adverse effects after IV administration of propofol to dogs, particularly when administered at rapid rates of infusion. (Am J Vet Res 1998:59:157–161)
Influence of inert ingredients in pesticide formulations on dermal absorption of carbaryl
Authors: Baynes Ronald E. , Riviere Jim E.
Published: January 2024

Objectives

To assess the influence of solvent plus various mixtures on percutaneous absorption and disposition of the carbamate insecticide, carbaryl (CA).

Animals

Skin was obtained from the dorsum of 14 female weanling specific-pathogen-free Yorkshire pigs.

Procedure

In this 8-hour in vitro flow-through diffusion study, porcine skin sections were dosed with 40 μg of CA/cm2 of surface area, different amounts of solvents (40 or 80% acetone or dimethyl sulfoxide [DMSO]), different amounts of a surfactant (0, 1, or 5% sodium lauryl sulfate [SLS]), an insect repellent (0 or 15% diethyl-m-toluamide [DEET]), an insecticide synergist (0 or 2% piperonyl butoxide [PB]), and a CA metabolite (40 μg/cm2 1-naphthol (1-NA]).

Results

In general, CA absorption was greater from acetone than from DMSO mixtures, and CA penetration into skin and stratum corneum was greater from DMSO at 8 hours. This is consistent with the flux-time profiles, which depicted initial peak flux within 2 to 3 hours for most acetone mixtures, but a slow increase in flux for DMSO mixtures. Irrespective of the solvent, increasing water content in pesticide dosing mixtures significantly increased CA absorption from SLS mixtures only. The SLS also enhanced CA absorption, especially at low solvent concentrations. The DEET significantly reduced CA absorption from acetone, but not from DMSO mixtures, and 1-NA enhanced CA absorption from acetone, but not from DMSO mixtures. Piperonyl butoxide significantly enhanced CA absorption from acetone and DMSO mixtures. However, addition of PB or PB plus SLS did not significantly increase CA flux above that observed from solvent plus surfactant mixtures.

Conclusions

Inert ingredients can modulate percutaneous absorption of toxicologically important pesticides and their effect or activity on CA disposition is dependent on solvent specificity and solvent concentration. Whereas SLS, PB, and 1-NA can enhance pesticide absorption, DEET can reduce absorption. (Am J Vet Res 1998;59:168–175)
Study of spinal cord evoked injury potential by use of computer modeling and in dogs with naturally acquired thoracolumbar spinal cord compression
Authors: Poncelet L. , Michaux C. , Balligand M.
Published: January 2024

Objective

To add objective measurements of the characteristics of evoked injury potentials (EIP) and their relations to clinical severity in dogs with thoracolumbar spinal cord damage.

Animals

25 dogs with naturally acquired spinal cord compression attributable to disk extrusion or vertebral fracture at the level of the thoracolumbar junction and with various degrees of paresis/paralysis.

Procedure

Spinal cord potentials evoked by tibial nerve stimulation were recorded every 5 to 10 mm at the lamina level in the vicinity of the cord compression. This allowed an EIP to be recorded even in the least handicapped dogs. A computer model yielded information about the waveform changes of the EIP in the vicinity of conduction blocks.

Results

The EIP waveform changed from biphasic to monophasic a short distance caudad to the location of spinal cord compression. Location of a maximal conduction block was measured in relation to position of the electrodes recording this waveform change. The distance between the assumed conduction block and the actual spinal cord compression was larger in the most affected dogs. The amplitude of the EIP was not related to severity of the clinical picture; however, the proximity of the recording electrode to the spine influenced the amplitude and the waveform of the EIP.

Conclusion and Clinical Relevance

Change in the EIP waveform from biphasic to monophasic makes it possible to estimate the conduction block location along the spinal cord. A large distance between the assumed conduction block and site of actual cord compression could be an objective argument to confirm severity of a lesion. (Am J Vet Res 1998;59:300–306)
Effect of ischemia and reperfusion on oxidative processes in the large colon and jejunum of horses
Authors: Kooreman Karin , Babbs Charles , Fessler John
Published: January 2024

Objective

To evaluate and compare oxidative processes during ischemia and reperfusion of the equine large colon and jejunum.

Animals

2 groups of 6 anesthetized horses undergoing a terminal procedure.

Procedure

Isolated loops of large colon and jejunum were subjected to 2 hours of ischemia, followed by 2 hours of reperfusion. Tissue specimens were taken after 105 minutes of ischemia and 10, 30, 60, and 120 minutes of reperfusion. Mesenteric arterial and venous blood samples were collected for blood gas analysis at the same times to evaluate ischemia and reoxygenation. Oxidative processes in tissues were evaluated by use of biochemical assays for malondialdehyde and conjugated dienes and by use of the manganese-diaminobenzidine histochemical technique for localized superoxide generation.

Results

Significant quantities of malondialdehyde and conjugated dienes were detected in the jejunum after 60 and 120 minutes of reperfusion together with histochemical evidence of superoxide generation in jejunal endothelial cells and in submucosal neutrophils and eosinophils.

Conclusions

Oxidative processes do not appear to have an appreciable role in inducing damage in the equine large colon during reperfusion after 2 hours of ischemia. In contrast to the jejunum, reactive oxygen species are not generated in measurable quantities in the large colon subsequent to ischemia and reperfusion.

Clinical Relevance

Free radical scavengers are not likely to be effective in prevention of equine colonic mucosal deterioration after ischemia. (Am J Vet Res 1998;59:340–346)
Characterization of plasma immunoglobulin G concentrations of llamas
Authors: Hutchison Jennifer Μ. , Salman Mowafak D. , Garry Franklyn B. , Johnson LaRue W. , Keefe Thomas J.
Published: January 2024

Objective

To develop appropriate reference ranges for plasma IgG concentrations of llamas.

Animals

643 llamas on 5 farms.

Procedure

Plasma IgG concentration was measured by using a single radial immunodiffusion assay kit. Farm of origin, age, body condition score, and sex were recorded for each llama. The effect of each factor on plasma IgG concentration was evaluated separately, using ANOVA; the association between age and IgG concentration was evaluated, using linear regression. Multivariable regression models were developed to examine concurrent effects of age, sex, body condition score, farm, and various interactions on IgG concentration.

Results

The IgG concentrations were between 127 and 3,969 mg/dl. In llamas < 12 months old, farm of origin accounted for 29% of variability for IgG concentration. Reference range for plasma IgG concentrations in llamas < 12 months old was 391 to 2,357 mg/dl; for llamas > 12 but < 28 months old was 771 to 2,796 mg/dl; and for llamas > 28 months old was 570 to 3,264 mg/dl. These ranges were applicable only for the kit used in this study.

Conclusions

Healthy llamas have a wide range of IgG concentrations. Determinants of IgG concentration are multifactorial, and their importance varies with age of the llamas.

Clinical Implications

The wide range of IgG concentrations observed in healthy llamas and the influence that age and farm may have on IgG concentrations indicate that a result for one specific llama should be interpreted in relation to those of its herdmates. (Am J Vet Res 1998;59:406–409)
Disparate chondrocyte metabolism in three-dimensional fibrin cultures derived from autogenous or commercially manufactured fibrinogen
Authors: Fortier Lisa A. , Brofman Peter J. , Nixon Alan J. , Mohammed Hussni O.
Published: January 2024

Objective

To compare chondrocyte proliferation and metabolism in three-dimensional fibrin cultures formed from polymerized autogenous fibrinogen with that of commercially manufactured fractionated fibrinogen.

Animals

Fibrinogen and chondrocytes for in vitro experimentation derived from 2 horses, ages 12 and 14 months, donated for reasons unrelated to skeletal or hematologic abnormalities.

Procedure

Fibrinogen was isolated from whole blood, using plasma cryoprecipitation and centrifugation, and fractionated fibrinogen was purchased. Each was mixed with 10 × 106 chondrocytes/0.5 ml of fibrinogen, and was polymerized by addition of 0.5 ml of calcium-activated thrombin. Thirty 1-ml fibrin-chondrocyte disks were formed from each fibrinogen source and cultured for 0 (n = 6), 7 (n = 12), or 14 (n = 12) days. Chondrocyte metabolism and cell proliferation in each fibrin type were objectively assessed by assays for total proteoglycan content, [35S]proteoglycan accumulation, proteoglycan monomer size, and total DNA. Cell morphology and cartilage-specific cell function was evaluated by routine histologic, alcian blue histochemical, type-II collagen immunohistochemical, and type-II collagen in situ hybridization methods.

Results

Histologic examination indicated better retention of chondrocyte morphology in autogenous composites. Autogenous fibrinogen also stimulated greater chondrocyte proliferation (DNA content increased 1.4-fold on day 14) and supported higher proteoglycan accumulation (increased 1.4-fold on day 14), compared with commercial, fractionated fibrinogen. Abundant intracellular type-II procollagen mRNA was detected in autogenous fibrin cultures by in situ hybridization, and translation was confirmed by extensive pericellular type-II collagen accumulation.

Conclusions

Autogenous fibrinogen has an inherent capacity to maintain chondrocyte phenotypic metabolism that is reduced or absent in commercially prepared fibrinogen. Enhanced, differentiated cell function may be useful for in vivo applications, but represents an added variable that may confound in vitro experiments, and should be considered when designing studies of chondrocyte function. (Am J Vet Res 1998;59:514–520)
Skeletal muscle glycolytic capacity and phosphofructokinase regulation in horses with polysaccharide storage myopathy
Authors: Valberg Stephanie J. , Townsend DeWayne , Mickelson James R.
Published: January 2024

Objective

To determine whether polysaccharide storage myopathy (PSSM) in Quarter Horses is attributable to a defect in glycolysis or in the allosteric regulation of phosphofructokinase (PFK) enzyme.

Animals

Muscle biopsy specimens were obtained from 6 Quarter Horses with PSSM and 8 Quarter Horse or Thoroughbred control horses.

Procedures

Maximal activity of glycogenolytic and glycolytic enzymes was determined spectrophotometrically. Maximal activity of PFK was determined for each horse at pH 8.0, and at pH 7.0 when variable concentrations of the activators, fructose 6 phosphate, fructose 2,6 bisphosphate, and adenosine monophosphate or inhibitors adenosine triphosphate and citrate were added to the reaction mixture. Relative activity was calculated as activity at pH 7/maximal PFK activity.

Results

Deficiencies in glycogenolytic or glycolytic enzyme activities were not evident in horses with PSSM. Differences between horses with PSSM and control horses in relative activity of PFK were not apparent for any of the activators or inhibitors used in the study.

Conclusions

In a group of horses with PSSM, we were unable to detect a glycogenolytic or glycolytic enzyme deficiency or abnormality in the allosteric regulation of PFK.

Clinical Relevance

Although PSSM is clinically and histologically similar to glycogenolytic/glycolytic enzyme deficiencies in human beings and other animal species, abnormalities in this metabolic pathway are not present in horses with PSSM. (Am J Vet Res 1998;59:782-785)
Cytologic evaluation of bronchoalveolar lavage fluid from horses with recurrent airway obstruction after aerosol and parenteral administration of beclomethasone dipropionate and dexamethasone, respectively
Authors: Rush Bonnie R. , Flaminio M. Julia B. F. , Matson Charles J. , Hakala Joyce E. , Shuman Wilma
Published: January 2024

Objective

To determine cytologic changes in horses with recurrent airway obstruction (heaves) after administration of aerosolized beclomethasone dipropionate and dexamethasone parenterally.

Animals

6 horses with inducible and reversible heaves.

Procedure

Episodes of heaves were induced by exposure to moldy hay and straw for 7 days. Horses were assigned to treatment groups (aerosolized beclomethasone, parenterally administered dexamethasone, aerosolized propellant), and pulmonary inflammation was evaluated by serial cytologic examination of bronchoalveolar lavage (BAL) fluid samples obtained on days 0, 7, 10, 14, and 21. Total and differential cell counting and phenotypic analysis of lymphocyte subpopulations in BAL fluid were performed.

Results

7 days of natural challenge induced neutrophilic inflammation. Neutrophil counts in BAL fluid were reduced in beclomethasone- and dexamethasone-treated horses on days 10 and 14 but rebounded to pretreatment values on day 21. The proportion of proinflammatory lymphocyte subpopulations (CD4+ and B+) and MHC class-II antigen expression were increased on days 14 and 21 in propellant-treated horses, compared with beclomethasone- and dexamethasone-treated horses.

Conclusions

Aerosolized beclomethasone attenuated neutrophilic pulmonary inflammation and prevented alteration in lymphocyte subpopulations in horses with heaves. Results were similar to the response associated with parenterally administered dexamethasone. Short-term administration of aerosolized beclomethasone without minimizing environmental allergen exposure is not expected to provide prolonged anti-inflammatory benefit for horses with heaves. (Am J Vet Res 1998;59:1033–1038)
Experimental model of synovitis/capsulitis in the equine metacarpophalangeal joint
Authors: Cornelissen B. P. M. , Rijkenhuizen A. B. M. , van den Hoogen B. M. , Rutten V. P. M. G. , Barneveld A.
Published: January 2024

Objective

To develop and define a model of acute synovitis/capsulitis in the equine metacarpophalangeal joint (fetlock) to study clinical effects of diagnostic or therapeutic procedures.

Animals

5 adult Standardbreds.

Procedure

Polyvinyl alcohol foam particles were injected into the left front fetlock of horses; the right front fetlock was used as a control. Horses were examined clinically and for lameness on a regular basis. Blood samples were taken to measure routine variables. Synovial fluid samples were collected from both fetlocks, and macroscopic, microscopic, and biochemical variables were measured. The effects of local diagnostic nerve blocks and intra-articular anesthesia of the fetlock on ensuing lameness were determined on days 2 and 3. After macroscopic evaluation at necropsy, histologic examination was performed on the fetlock cartilage and capsule.

Results

Changes in synovial fluid variables included increased TNF-α and matrix metalloproteinases values and in other indicators of acute inflammation. With respect to application of local nerve blocks, lameness decreased most after a combination of metacarpal and palmar nerve blocks, whereas lameness could only partially be blocked by intra-articular anesthesia. At necropsy, mild chronic inflammation of the synovium and deeper layers of the joint capsule was found; polyvinyl alcohol particles had been incorporated into the joint capsule. There was no evidence of articular cartilage damage.

Conclusions

Injection of polyvinyl alcohol foam particles induces transient synovitis/capsulitis in the fetlock, mimicking clinical joint disorders. The model does not seriously affect the horse's long-term well-being. Such model serves well for studying the effect of diagnostic or therapeutic procedures. (Am J Vet Res 1998;59:978–985)
Molecular diagnostic tests for ascertainment of genotype at the mucopolysaccharidosis type VII locus in dogs
Authors: Ray Jharna , Haskins Mark E. , Ray Kunal
Published: January 2024

Objective

To develop a molecular diagnostic test to ascertain genotype of the mucopolysaccharidosis type VII (MPS VII) locus.

Sample Population

Blood samples from 45 mixed-breed (German Shepherd Dog X Beagle) dogs that were phenotypically normal or affected with MPS VII.

Procedure

The canine ß-glucuronidase gene (exon 3) was amplified by polymerase chain reaction (PCR), using 2 pairs of primers to determine the genotype of the MPS VII locus by 2 independent methods. For the first method, PCR products were used for heteroduplex analysis, using conformation-sensitive gel electrophoresis. In the second method, an allele-specific restriction site was created by use of a mismatch primer in PCR. The amplified DNA fragment was digested with a restriction enzyme (Eag I) to enable identification of the wild-type and mutant alleles.

Results

Conformation-sensitive gel electrophoresis resulted in a single DNA band representing homoduplex when the sample contained a wild-type or MPS VII allele, but 2 bands representing hetero- and homoduplexes when both alleles were in the sample. Restriction digestion of the DNA fragment obtained by use of a mismatch primer was cleaved only when the template was a wild-type allele. Thus, samples from phenotypically normal carrier dogs that contained wild-type and MPS VII alleles were partially digested by the enzyme.

Conclusions

The diagnostic test used 2 strategies for independently ascertaining the wild-type or mutant MPS VII alleles in dogs. Thus, test results can distinguish phenotypically normal MPS Vll-carrier dogs from homozygous normal dogs. (Am J Vet Res 1998;59:1092-1095)
Immunophenotypic characterization of lymphomas from the mediastinum of young ferrets
Authors: Coleman Leslie A. , Erdman Susan E. , Schrenzel Mark D. , Fox James G.
Published: January 2024

Objective

To determine the phenotype of naturally developing lymphomas in young ferrets.

Animals

10 ferrets with lymphoma.

Procedure

Neoplastic tissues were graded histologically according to the National Cancer Institute's Working Formulation for non-Hodgkin’s lymphoma and phenotype was determined by means of immunohistochemical staining. A polyclonal anti-human CD3 and a monoclonal anti-human CD79 antibody were used to classify the lymphomas in situ as T-cell or B-cell origin. Specificity of antibodies was determined by evaluating lymphoid tissue from normal ferrets in situ, which was confirmed by western blot analyses.

Results

All 10 ferrets had clinically aggressive tumors, irrespective of the phenotype. Nine ferrets had T-cell lymphoma that extensively involved the mediastinum. Remnants of thymic tissue, indicative of thymic origin, were identified in lymphoma of these 9 ferrets. One ferret had a B-cell multicentric lymphoma without involvement of the mediastinum.

Conclusions

The majority of lymphomas in these young ferrets involved the mediastinum and were of T-cell phenotype.

Impact for Human Medicine

There are many similarities between the lymphoma syndrome of ferrets and the condition documented for cats and children with lymphoma of the mediastinal area.

Clinical Relevance

Differential diagnoses for young ferrets with clinical signs of lethargy or respiratory distress should include T-cell lymphoma of the mediastinum. ((Am J Vet Res 1998;59:1281-1286)
Periodontal healing of canine experimental grade-III furcation defects treated with autologous fibrinogen and absorbable barrier membrane
Authors: Bianucci Henri C. , Smith Mark M. , Saunders Geoffrey K. , Reddy Michael S. , Cox Charles F. , Till Linda G. , Feldman Bernard F.
Published: January 2024

Objective

To determine the effects of autologous fibrinogen (AF) and absorbable barrier membrane (ABM) on periodontal healing of canine experimental grade-III furcation defects.

Animals

18 conditioned, laboratory-source, adult Beagles.

Procedure

Defects were developed bilaterally at the second and fourth premolars and maintained for 12 weeks. Defects were treated with AF, ABM, AF and ABM, or debridement. Digital subtraction radiography, histologic evaluation, and histomorphometric analysis of defect healing was done at 1, 3, and 6 months after treatment to determine percentage increases in bone volume, height, area, and length of periodontal regeneration along the perimeter of the defect.

Results

Comparison of defects at post-treatment intervals indicated significantly greater healing of debridement and AF-treated defects, compared with ABM-treated defects at 3 months; however, by 6 months, there were no significant differences in defect healing for all histomorphometric variables. Defects treated with ABM were associated with significantly less root ankylosis than other treatments. Defects treated with debridement had significantly greater increases in bone volume at 6 months after treatment, compared with groups treated with ABM. There was a significant correlation between regenerated bone area, bone volume, and periodontal regeneration for all treatments at 3 and 6 months after treatment.

Conclusion and Clinical Relevance

Use of AF and ABM did not enhance the amount of periodontal healing, compared with debridement only. The ABM-treated defects were essentially devoid of root ankylosis. Grade-III furcation defects may respond equally well to conservative periodontal surgery or guided tissue regenerative techniques. The prevention of root ankylosis is a substantial benefit favoring this latter method of treatment. (Am J Vet Res 1998;59:1329-1338)
Hoof size, shape, and balance as possible risk factors for catastrophic musculoskeletal injury of Thoroughbred racehorses
Authors: Kane Albert J. , Stover Susan M. , Gardner Ian A. , Bock Kirsten B. , Case James T. , Johnson Bill J. , Anderson Mark L. , Barr Bradd C. , Daft Barbara M. , Kinde Hailu , Larochelle Danielle , Moore Janet , Mysore Jagannatha , Stoltz James , Woods Leslie , Read Deryck H. , Ardans Alex A.
Published: January 2024

Objective

To evaluate hoof size, shape, and balance as risk factors for catastrophic musculoskeletal injuries (CMI), including suspensory apparatus failure (SAF) and cannon bone condylar fracture (CDY) in Thoroughbred racehorses.

Animals

95 Thoroughbred racehorses that died between 1994 and 1996.

Procedure

38 quantitative measures of hoof size, shape, and balance were obtained from orthogonal digital images of the hoof and were compared between case horses with forelimb CMI (70), SAF (43), and CDY (10) injuries and control horses whose death was unrelated to the musculoskeletal system (non-CMI, 25). Comparison of group means between cases and controls was done using ANOVA, and multivariable logistic regression was used to estimate odds ratios.

Results

Odds of CMI were 0.62 times lower for a 5- mm increase in ground surface width difference and 0.49 times lower for a 100-mm2 increase in sole area difference. Odds of SAF were 6.75 times greater with a 10° increase in toe-heel angle difference and 0.58 times lower with a 100-mm2 increase in sole area difference. Odds of CDY were 0.26 times lower with a 3° increase in toe angle, 0.15 times lower with a 5- mm increase in lateral ground surface width, and 0.35 times lower with a 100-mm2 increase in sole area difference.

Clinical Relevance

Decreasing the difference between toe and heel angles should decrease risk of SAF for Thoroughbred racehorses and should be considered in addition to increasing toe angle alone to help prevent catastrophic injury. Trimming the hoof to perfect mediolateral symmetry may not be a sound approach to avoiding injury. (Am J Vet Res 1998;59: 1545-1552)
Dynamics of cell-associated viremia and antibody response during the early phase of lentivirus infection in sheep
Authors: Juste R. A. , Kwang J. , de la Concha-Bermejillo A.
Published: January 2024

Objective

To determine patterns of cell-associated viremia and antibody responses during the early phase of ovine lentivirus (OvLV) infection in sheep.

Animals

18 neonatal lambs.

Procedures

12 lambs were inoculated intratracheally with OvLV within 24 hours after birth; 6 lambs were inoculated with noninfected cell culture supernatant. Degree of cell-associated viremia was measured every other week for 16 weeks by use of a limited dilution assay. Antibody responses to OvLV transmembrane (TM) and p25 proteins were determined weekly by use of a recombinant ELISA. Neutralizing antibody responses were measured before and 8 and 16 weeks after inoculation.

Results

Degree of cell-associated viremia peaked between 2 and 6 weeks after inoculation and then decreased. For inoculated lambs, mean anti-p25 titer peaked 5 weeks after inoculation then slowly declined, whereas mean anti-TM and neutralizing antibody titers increased steadily. Over time, mean degree of cell-associated viremia was negatively correlated with mean anti-TM titer. Maximum individual degree of cell-associated viremia was positively correlated with maximum individual anti-TM titer.

Conclusions

Results suggest that after experimental inoculation, OvLV replicates actively for several weeks and that an increase in anti-TM titer coincides with a decrease in degree of cell-associated viremia. Although the role antibodies play in protecting against lentivirus infection remains uncertain, understanding the dynamics of the antibody response may have important implications for diagnosis of OvLV infection, and antibodies may prove to be valuable markers for prediction of infection and disease. (Am J Vet Res 1998;59:563–568)
In vivo effect of Pasteurella haemolytica infection on bovine neutrophil morphology
Authors: Clarke Cyril R. , Confer Anthony W. , Mosier Derek A.
Published: January 2024

Objective

To determine whether characteristic changes in neutrophil morphology caused in vitro by Pasteurella haemolytica leukotoxin (LKT) can be observed in vivo by electron microscopic examination of infected tissue chamber fluids and pneumonic lungs.

Animals

7 mixed-breed beef calves.

Procedure

Tissue chambers were implanted subcutaneously in 3 calves and were inoculated with P haemolytica or phosphate-buffered saline solution. Chamber fluid samples, obtained at 8 and 32 hours after inoculation, were examined, using electron microscopy. Experimental pneumonia was induced in an additional 4 calves by transthoracic inoculation with P haemolytica. These calves were euthanatized at 6, 12, 24, and 36 hours after inoculation and lung sections were examined, using transmission electron microscopy.

Results

On examination, using transmission electron microscopy, neutrophils in lung sections and tissue chamber fluids had cytoplasmic and nuclear changes indicative of irreversible cell injury, including cell swelling, loss of plasma membrane ruffling, mitochondrial swelling, autolytic vacuolation, disruption of plasma membrane, nuclear pyknosis, karyolysis, and karyorrhexis. On examination, using scanning electron microscopy, leukocytes obtained from tissue chambers did not have their typical convoluted surfaces, but appeared rounded and swollen or shrunken with pitted surfaces.

Conclusions

Pasteurella haemolytica-induced changes in neutrophil morphology in vivo were similar to those previously induced by in vitro exposure of neutrophils to LKT. Changes were suggestive of injury initiated by damage to the plasma membrane, which is consistent with the mechanism of action of pore-forming cytolysins.

Clinical Relevance

Pasteurella haemolytica LKT appears to be an important virulence factor in vivo; a fact that should be addressed in the development of vaccines. (Am J Vet Res 1998;59:588–592)
Urolithiasis in dogs I: Mineral prevalence and interrelations of mineral composition, age, and sex
Authors: Ling Gerald V. , Franti Charles E. , Ruby Annette L. , Johnson Deedra L. , Thurmond Mark
Published: January 2024

Objective

To compile and statistically analyze selected data from a large number of canine urinary calculi.

Sample Population

11,000 specimens: 5,781 from female dogs, 5,215 from male dogs, and 4 from dogs of unrecorded sex.

Procedure

Records were used to compile information from all canine calculi analyzed between July 1981 and January 1994. Interrelations of mineral composition, location of specimens within the urinary tract, age and sex of affected dogs, and number of previous episodes of urolithiasis were determined.

Results

Approximately 70% of the specimens were from a first episode of urolithiasis. Calculi were located in the urinary bladder of 93.1% of females and 79.0% of males, and in the upper urinary tract of 4% of females and 2% of males. Calculi were found in multiple sites in 23.1% of males and 5.2% of females. Significantly higher proportions of struvite, apatite, and urate were found in uroliths from females; oxalate, cystine, silica, and brushite were significantly more prevalent in males. Sixty-one percent of specimens from males and 29% from females were composed of a single mineral substance. The most common mineral combination of 2 or more minerals included struvite and apatite. An additional 67 specimens from male dogs and 49 from female dogs contained other mineral combinations. In 48% of specimens from males and nearly 62% of specimens from females, the minerals formed several distinct layers of differing composition.

Conclusions

Male and female dogs form urinary calculi composed of 1 or more of several distinct minerals. Prevalence of canine uroliths differs between ages and between the sexes. Many specimens contain complex layering of minerals; most specimens were found in the urinary bladder.

Clinical Relevance

Sex and age of dogs, mineral types of likely calculi in males versus females, and their anatomic location are important considerations for clinicians when evaluating risk in dogs with urolithiasis. (Am J Vet Res 1998;59:624–629)
Urolithiasis in dogs IV: Survey of interrelations among breed, mineral composition, and anatomic location of calculi, and presence of urinary tract infection
Authors: Ling Gerald V. , Franti Charles E. , Johnson Deedra L. , Ruby Annette L.
Published: January 2024

Objective

To compile and analyze selected data from a large number of canine urinary calculus specimens that were subjected to quantitative, layer-by-layer mineral analysis.

Sample Population

11,000 canine urinary calculus specimens: 5,781 from female dogs, 5,215 from male dogs, and 4 from dogs of unrecorded sex.

Procedure

Records of the Urinary Stone Analysis Laboratory, School of Veterinary Medicine, University of California were used to compile information regarding urinary calculus specimens from dogs. Records surveyed were of all canine calculi submitted for analysis between July 1981 and January 1994. Results analyzed included those of a mixed-breed group and 26 common breeds of stone-forming dogs. Interrelations of breed, sex, and age of the affected dogs, mineral composition of the specimens, and associated urinary tract infections were analyzed statistically.

Results

Proportions of culture-positive specimens were significantly correlated between the sexes (r = 0.494, P = 0.008). Staphylococcus intermedius was isolated most often from either sex, ranging from 36.1% (Basset Hounds) to 67.9% (Pekingese) of cultured specimens from females and 8.7% (Chihuahuas) to 71.4% (Scottish Terriers) of specimens from males. The second most frequently isolated bacterial species, Escherichia coli, ranged from 0% in males of 2 breeds and females of 4 breeds to 25% in Cairn Terrier males and 19.4% in Basset Hound females. Streptococcus spp were the third most frequently isolated bacterial species. Significant correlations between the sexes were found for percentages of calculi located in the urinary bladder (r = 0.490, P = 0.008), and for calculi voided in the urine (r = 0.503, P = 0.006).

Conclusions

Breed and sex differences in prevalence of urolithiasis- and mineral-associated bacterial infections are numerous. Staphylococcus intermedius was the most common isolate from specimens from all but 3 of 54 breed/sex groupings. For either sex, streptococcal infections were significantly related to proportions of calculi passed in the urine. (Am J Vet Res 1998;59:650–660)
Purification of two equine pepsinogens by use of high-performance liquid chromatography
Authors: Sayegh Ayman I. , Anderson Neil V. , Harding Joseph W. , Cerpovicz Paul , DeBowes Richard M. , Ritter Robert C. , Baker Gordon J. , Reeck Gerald
Published: January 2024

Objectives

To purify and characterize pepsinogens in equine gastric mucosa.

Sample Population

Stomachs collected from 2 healthy horses at necropsy.

Procedure

After collection, stomachs were placed immediately in ice before storage at −48 C. After slow thawing, the mucosa was scraped off while the tissue was immersed in 0.1 M potassium phosphate (pH 7.4) at 4 C, then was homogenized. The filtered extract was subjected to anion-exchange chromatography. Fractions that were found to contain pepsin or pepsinogen were further chromatographed. Individual fractions were tested for pepsinogen or pepsin content by monitoring proteolytic activity at pH 2 and 3, respectively. Fractions from all columns were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to confirm molecular weight of pepsinogens and pepsin.

Results

Two pepsinogens and at least 1 pepsin were purified from equine gastric mucosa.

Conclusions

On the basis of molecular mass, equine gastric mucosa contains 2 pepsinogens.

Clinical Relevance

Results of this study will enable future development of an ELISA or radioimmunoassay for use in the diagnosis of equine gastric ulceration. (Am J Vet Res 1999;60:114–118)
Effect of various short-term storage methods on viability of cancellous bone fragments
Authors: McAnulty Jonathan F.
Published: January 2024

Objective

To determine effects of various storage methods on ex vivo viability of cancellous bone fragments.

Sample Population

Cancellous bone fragments obtained from 4 New Zealand White rabbits.

Procedure

Cancellous bone fragments were stored for 3 hours on ice in 1 of 5 preservation solutions or in 0.9% NaCI. Fragments were then reperfused (37 C) in oxygenated physiologic buffer solution for 1 hour. Cellular viability in fragments was assessed by ethidium monoazide labeling and fluorescence microscopy.

Results

Viability in fresh cancellous bone ranged from 85 to 100% (mean ± SEM, 88 ± 7%). Storage of fragments significantly reduced viability. Viability in bone fragments stored at 22 C in blood-soaked sponges or 0.9% NaCI solution was 63.8 ± 3 and 65.2 ± 7%, respectively. Use of cold 0.9% NaCI solution reduced viability to 53.6 ± 3%. Viability was significantly better for fragments stored in cold phosphate-buffered sucrose (70.4 ± 2%) and EuroCollins (71.4 ± 3%) solutions. After warm reperfusion, viability was best for fragments stored in cold phosphate-buffered sucrose (70.2 ± 4%), EuroCollins (72.6 ± 3%), or UW lactobionate solutions (69.6 ± 3%), compared with those stored in cold 0.9% NaCI (47.6 ± 3%) or hypertonic citrate (53.0 ± 3%) solutions or blood-soaked sponges (57.2 ± 3%).

Conclusions

Hypothermic storage in solutions designed to prevent temperature-dependent cell injury were best for maintaining cancellous bone fragment viability.

Clinical Relevance

Hypothermia may be advantageous for use in storing cancellous bone fragments during procedures that dictate a prolonged period between harvest and placement of graft fragments. (Am J Vet Res 1999;60:63–67)
Sedative effects of intramuscular administration of a low dose of romifidine in dogs
Authors: Lemke Kip A.
Published: January 2024

Objective

To evaluate sedative effects of IM administration of a low dose of romifidine in dogs.

Animals

13 healthy adult Beagles.

Procedure

Physiologic saline solution (0.2 ml), 0.1% romifidine (10, 20, or 40 µg/kg), or 10% xylazine (1 mg/kg) was given IM in a crossover study design. Heart rate, respiratory rate, rectal temperature, hemoglobin saturation, and scores for sedation, muscle relaxation, posture, auditory response, and positioning response were recorded before and at regular intervals for up to 240 minutes after drug administration.

Results

Scores for sedation, muscle relaxation, posture, auditory response, and positioning response increased in a dose-dependent manner after romifidine administration. Sedation induced by the highest dose of romifidine (40 µg/kg) was comparable to that induced by xylazine (1 mg/kg). Heart rate, respiratory rate, and rectal temperature decreased in a dose-dependent manner after romifidine administration, but hemoglobin saturation did not change.

Conclusions and Clinical Implications

Romifidine (10, 20, or 40 µg/kg, IM) is an effective sedative in dogs, but causes a decrease in heart rate, respiratory rate, and rectal temperature. (Am J Vet Res 1999;60: 162-168)
Breakage and deformation characteristics of hypodermic devices under static and dynamic loading
Authors: Hoff S. J. , Sundberg P.
Published: January 2024

Objective

To characterize the strength and limitations of hypodermic needles to reduce the risk of leaving broken needles in the flesh of animals.

Sample Population

Skin of porcine cadavers.

Procedure

Stainless steel needles of various gauges combined with aluminum and plastic hubs were subjected to standard test-stand conditions to compare strength under various loading regimens. A device that simulated animal motion was constructed to test breakage characteristics during animal movement.

Results

Needles and needle/hub assemblies were resilient to needle breakage, except when bent needles were straightened and a load reapplied. Needle gauge and length drastically affected strength. For 16- and 20-gauge needles, a 1.0-in needle was 1.6 times stronger than a 1.5-in needle. Adding animal movement for 20-gauge, 1.5-in needles resulted in a 40% increase in hub failures for plastic, compared to aluminum hub needles.

Conclusions and Clinical Relevance

Findings of this study are important considerations for meat packers to address in their Hazard Analysis and Critical Control Points plans.(Am J Vet Res 1999;60:292–298)
Measurement of synovial fluid and serum concentrations of the 846 epitope of chondroitin sulfate and of carboxy propeptides of type II procollagen for diagnosis of osteochondral fragmentation in horses
Authors: Frisbie David D. , Ray Christopher S. , Ionescu Mirela , Poole A. Robin , Chapman Phillip L. , McIlwraith C. Wayne
Published: January 2024

Objective

To determine whether serum or synovial fluid concentrations of chondroitin sulfate epitope 846 and carboxy propeptides of type II collagen (CPII) can be used to diagnose osteochondral fragmentation (OC) in horses.

Animals

38 horses with unilateral OC of the radiocarpal (n = 31) or intercarpal (33) joints and 8 clinically and radiographically normal horses.

Procedures

For horses with OC, serum and synovial fluid concentrations of epitope 846, CPII, and keratan sulfate (KS) were determined, along with synovial fluid WBC counts and total protein concentrations. Serum epitope 846, CPII, and KS concentrations were measured in control horses.

Results

Synovial fluid epitope 846 and total protein concentrations were significantly higher in the joints with OC than in unaffected joints, but CPII and KS concentrations and WBC counts were not. Synovial fluid total protein and 846 epitope concentrations were linearly related to grade of OC. Serum epitope 846 and CPII concentrations were significantly higher in horses with OC than in control horses. Discriminant analysis allowed 27 of 34 (79%) horses to be correctly classified as having or not having OC on the basis of serum epitope 846 and CPII concentrations.

Conclusions

Results suggest that serum and synovial fluid concentrations of epitope 846 and CPII are associated with OC. Increases in concentrations of epitope 846 and CPII suggest that increased synthesis of cartilage aggrecan and type II procollagen may be associated with OC.

Clinical Relevance

Measurement of serum epitope 846 and CPII concentrations may be useful in the diagnosis of OC in horses. (Am J Vet Res 1999;60:306–309)
Granuloma development in cattle after intratonsilar inoculation with Mycobacterium bovis
Authors: Palmer Mitchell V. , Whipple Diana L. , Rhyan Jack C. , Bolin Carole A. , Saari Dennis A.
Published: January 2024

Objective

To examine the temporal development of tuberculous lesions in cattle inoculated with Mycobacterium bovis.

Animals

15 mature crossbred cows obtained from a herd with no history of M bovis infection.

Procedure

Inoculation of cattle was done by intratonsilar instillation of 1.48 × 105 to 5.4 × 107 colony-forming units of M bovis strain 2045T. At 3 to 4 hours, 4 weeks, 6 weeks, and 8 weeks after inoculation, tissues were examined for gross and microscopic lesions and processed for isolation of M bovis.

Results

Retropharyngeal lymph nodes from cattle examined 4 weeks after inoculation contained microgranulomas consisting of aggregates of macrophages with few neutrophils. Retropharyngeal lymph nodes from all cattle examined 6 and 8 weeks after inoculation contained multiple, large, coalescing granulomas consisting of central areas of necrosis with mild fibrosis, numerous macrophages, lymphocytes, plasma cells, multinucleated giant cells, and neutrophils. Three of 8 cattle examined 6 or 8 weeks after inoculation had lesions in nonretropharyngeal sites with morphologic characteristics similar to that seen in retropharyngeal lymph node granulomas from cattle examined 4 weeks after inoculation.

Conclusion

Granulomas can develop in draining lymph nodes of cattle in as little as 4 weeks after inoculation via intratonsilar instillation of M bovis. Intralesional morphologic changes between 4 and 6 weeks after inoculation indicate an increase in cellular chemotaxis and differentiation. Dissemination of bacteria to distant sites most likely was by lymphatic and hematogenous routes after establishment of the primary infection in retropharyngeal lymph nodes. (Am J Vet Res 1999;60:310–315)