bluuebunny/crossref_metadata_2025 huggingface dataset:
Serum immunoglobulin concentrations after feeding maternal colostrum or maternal colostrum plus colostral supplement to dairy calves
Authors: Francisco S. F. Abel , Quigley J. D.
Published: January 2024

Maternal colostrum or maternal colostrum plus colostral supplement, composed of a blend of lyophilized colostrum and dried whey, was fed to 32 Holstein calves as soon as possible after birth (mean ± sem = 2.0 ± 0.2 hours) and, again, 12 hours later. Mean immunoglobulin concentration in colostrum was 59.2 mg/ml; mean immunoglobulin fraction in supplement was 11.4%. Serum immunoglobulin concentrations were measured at 0, 12, 24, 48, and 72 hours, and at 28 and 56 days. Hour/treatment interactions were significant for total immunoglobulin, IgG1, and IgM concentrations. Immunoglobulin concentrations were highest at 12 hours (total immunoglobulin, IgG1, IgM) or 24 hours (IgG2) in calves fed colostrum plus supplement, whereas all immunoglobulin concentrations were highest at 24 hours in calves fed maternal colostrum only. Peak mean immunoglobulin concentrations did not differ between treatments. Supplementation of colostrum did not increase peak mean serum immunoglobulin concentration, but did alter the serum concentration-time profile from 12 to 72 hours after birth.
Effect of homologous fibrin adhesive on callus formation and extracortical bone bridging around a porous-coated segmental endoprosthesis in dogs
Authors: Roy Robert G. , Markel Mark D. , Lipowitz Alan J. , Gottsauner-Wolf Florian , Taswell Howard F. , Chao Edmund Y.S.
Published: January 2024

Modular, porous-coated, titanium segmental endoprostheses were implanted bilaterally in the femoral diaphysis of 7 adult mixed-breed dogs. Autogenous bone graft in particle form was placed around the implant and bone. In 1 limb, homologous fibrin adhesive was mixed with the graft in situ before soft tissue closure. The contralateral limb was grafted in identical manner, but without fibrin adhesive, and served as a control. Radiography was performed immediately after surgery and 1, 2, 3, 4, 6, 8, 10, and 12 weeks later to assess callus area and bone remodeling. At 12 weeks, dogs were euthanatized and bone/implant fixation strength was tested under torsion and compared with values for 6 in vitro controls. Histomorphometric and microradiographic analyses of transverse sections of the distal portion of the implanted femurs were performed. Radiographic callus area was significantly (P < 0.05) smaller in the femurs grafted with fibrin adhesive, compared with the contralateral control. New bone formation (21.4 ± 1.8% vs 19.2 ± 2.4%), unlabeled bone (64.8 ± 3.0% vs 67.9 ± 4.2%), porosity (13.9 ± 0.7% vs 12.9 ± 0.8%), and bone ingrowth into the porous coating (10.3 ± 0.9% vs 10.0 ± 1.2%) were not significantly different between fibrin- and nonfibrin-grafted implants, respectively. There were no significant differences in torsional strength of implant fixation between the fibrin- and nonfibrin-grafted femurs or between the in vivo implanted femurs and the in vitro controls. These data indicate that fibrin adhesive may have been advantageous in maintaining apposition of bone graft adjacent to the endoprosthesis, but it probably did not have an enhancing effect on extracortical bone bridging or ingrowth over a porous-coated segmental bone replacement endoprosthesis.
Evaluation of agar gel immunodiffusion and indirect fluorescent antibody assays as supplemental tests for dourine in equids
Authors: Hagebock Joyce M. , Chieves Lucious , Frerichs Wayne M. , Miller Charles D.
Published: January 2024

The agar gel immunodiffusion (agid) and indirect fluorescent antibody (ifa) assays were evaluated as supplemental tests to the complement-fixation (cf) test, the official US importation certification test for dourine in equids. The American stabilate (n = 10 animals) or the Canadian stabilate (n = 6 animals) of Trypanosoma equiperdum cultured in rat blood was administered by catheterization and infusion in the urogenital tract of 16 equids. To assess parasitemia and serologic responses by use of the cf, agid, and ifa tests, a total of 787 serum and blood samples were obtained from equids before exposure and 3 times a week after exposure to T equiperdum. Results of the ifa and agid tests were compared with the cf test results. The disease was diagnosed earlier by the ifa test than by the agid test, regardless of antigen preparation or exposure group. The mean number of days between exposure and positive result by the cf and ifa tests was the same when either homologous or heterologous antigen was used in the ifa test.

In general, the ifa test was more sensitive than the agid test in diagnosing dourine, regardless of the antigen preparation used in the test or exposure group. Differences in test specificity were observed among both groups of exposed equids when either antigen was used (P < 0.05). The agid test, using the American antigen, was more specific than the ifa test for sera from both groups of equids. When the Canadian antigen was used, the ifa test was a more specific test than the agid test (P < 0.01).

Although differences in the positive predictive value and negative predictive value of the ifa and agid tests were significant (P < 0.01) for both groups of equids, the values were not entirely conclusive in determining which of the 2 assays was better as a supplemental test. It is recommended that the more sensitive ifa test be used for screening the few equids with anticomplementary cf test results for dourine. The agid test can be used to verify positive ifa results for dourine.
Hemostasis in cows with endotoxin-induced mastitis
Authors: Welles Elizabeth G. , Williams Mary A. , Tyler Jeffrey W. , Lin Hui Chu
Published: January 2024

Hemostasis was evaluated in cows with experimentally induced endotoxemia and mastitis, caused by intramammary infusion of endotoxin (1 mg) derived from Escherichia coli. Hemostatic tests included prothrombin time; activated partial thromboplastin time; thrombin time; fibrinogen, fibrin(ogen) degradation products, and platelet concentrations; and antithrombin-III and plasminogen activities. Significant alterations were observed in the mean values of most analytes (prothrombin time was increased; thrombin time was increased with subsequent decrease; activated partial thromboplastin time, fibrinogen concentration, plasminogen activity, and platelet concentration were decreased; and antithrombin-III activity and fibrin(ogen) degradation products concentration were unchanged) at 1 or more postchallenge sample collection times (3, 12, or 24 hours) after endotoxin administration, compared with mean values obtained from samples prior to endotoxin administration. These data indicated activation of hemostatic mechanisms, initiated either directly by endotoxin or by inflammatory mediators released or produced in response to endotoxin infusion.
Adherence of Mycoplasma hyopneumoniae to porcine ciliated respiratory tract cells
Authors: Zielinski Gustavo C. , Ross Richard F.
Published: January 2024

Adherence of Mycoplasma hyopneumoniae to the mucosa of the distal portion of the respiratory tract of swine is an important initial event in development of mycoplasmal pneumonia. A suitable in vitro model of adherence would be useful for investigation of mycoplasmal and host cell factors involved in this process. We have developed an adherence assay, using suspensions of porcine respiratory tract ciliated epithelial cells and M hyopneumoniae. Tracheal epithelial cells, collected by use of cytologic brushes, were mixed with broth cultures of M hyopneumoniae and the mixtures were incubated, diluted, vortexed, and sedimented. Pellets were spread on glass slides, stained with a fluorescent antibody against M hyopneumoniae, and evaluated by fluorescent microscopy. Fluorescence was observed principally among cilia on the ciliated tufts of epithelial cells. Only a few organisms were observed adhering on the nonciliated parts of ciliated cells or on other cell types. When mycoplasmas were preincubated with low dilutions of serum from swine convalescing from M hyopneumoniae disease, attachment was partially inhibited (P < 0.05). Significant inhibition of attachment was not observed when organisms were preincubated with higher dilutions of convalescent serum, with purified IgG from hyperimmune serum against M hyopneumoniae, or with low dilutions of lung lavage fluids (from convalescent swine) that contained specific IgA antibodies against M hyopneumoniae. Preincubation of the organisms with periodate and trypsin abolished attachment and formaldehyde decreased it (P < 0.05), whereas a variety of carbohydrates had no effect on attachment. Preincubation with dextran sulfate, ammonium sulfate, magnesium sulfate, and methionine reduced attachment (P < 0.05). Treatment of cell-Mycoplasma mixtures with the hydrophobic bond-breaking agent tetramethylurea, or incubation in absence of salt, or at low temperature also reduced attachment (P < 0.05). Attachment was not observed when ovine, rabbit, or guinea pig ciliated respiratory tract cells were mixed with M hyopneumoniae. Attachment of M dispar to porcine ciliated cells could not be detected, whereas M hyorhinis attached nonspecifically to all cell types in suspensions of porcine tracheal mucosa. These results indicate that adherence of M hyopneumoniae may be a host-specific event that is mediated by proteins and carbohydrates on the surface of the organism and by sulfur-containing molecules in the host cell membrane. The highly polarized location of the mycoplasmas on the cilia of epithelial cells indicates possible existence of stereospecific interactions between mycoplasmal adhesin(s) and receptor(s) on host cells. However, decreased adherence obtained by incubating Mycoplasma-ciliated cell mixtures with tetramethyl-urea, by incubating mixtures in absence of salt or at low temperature, indicates that nonspecific hydrophobic interactions might have a role in the attachment process.
Effects of triamcinolone acetonide on pulmonary function and bronchoalveolar lavage cytologic features in horses with chronic obstructive pulmonary disease
Authors: Lapointe Jean-Martin , Lavoie Jean-Pierre , Vrins André A.
Published: January 2024

Effects of triamcinolone acetonide (ta) on pulmonary function, bronchoalveolar lavage cytologic features and serum cortisol concentration, were studied in 5 control horses and 5 horses with chronic obstructive pulmonary disease (copd). In experiment 1, horses were brought in from pasture 3 weeks before administration of 1 injection of ta (0.09 mg/kg of body weight, im), and were stabled in dusty conditions throughout the experimental period. Measurements of respiratory rate (f), tidal volume, minute ventilation, expiratory-to-inspiratory time ratio, maximal change in transpulmonary pressure (ΔPL), pulmonary resistance (RL), and dynamic compliance (Cdyn) were obtained during quiet breathing, immediately before (baseline) and 1, 2, 3, 5, and 9 weeks after administration of ta. Pulmonary airway cells were collected by bronchoalveolar lavage while horses were at pasture, at baseline, and 2, 5, and 9 weeks after ta administration. Serum cortisol concentration was measured before and after adrenocortical stimulation with 100 IU of adrenocorticotropic hormone, 1 week prior to ta administration, and 4 and 8 weeks thereafter. In experiment 2, 4 months after ta injection, pulmonary function measurements were repeated in all horses immediately before and 30 minutes after administration of atropine (0.015 mg/kg, iv), to evaluate the reversibility of airway obstruction.

In experiment 1 at baseline, COPD-affected horses had significantly (P < 0.05) higher values than did controls for f, ΔPL, RL, and percentage of neutrophils, and had lower values for Cdyn and percentage of lymphocytes and macrophages. There were significant reductions in ΔPL and RL, and increase in macrophage percentage after ta administration in copd-affected horses only. The degree and duration of these changes varied among individual copd-affected horses, but ΔPL, and RL, values had returned to or were above baseline in all horses 5 weeks after treatment. Baseline cortisol concentration was decreased 4 weeks after ta administration, but the mean increase in cortisol values after adrenocorticotropic hormone stimulation was similar to that observed prior to treatment.

In experiment 2, values of ΔPL, RL, and Cdyn, after atropine administration were similar to those of controls in the 2 copd-affected horses that had improved most after ta, but were only partially improved in the 3 other horses, indicating possible irreversible lesions in the latter.
Benzocaine-induced methemoglobinemia attributed to topical application of the anesthetic in several laboratory animal species
Authors: Davis Judith Anne , Greenfield Randall Elwin , Brewer Thomas George
Published: January 2024

In a screening study, a common benzocaine-containing anesthetic was topically applied to the following species: dogs (n = 11), domestic shorthair cats (n = 38), Long-Evans rats (n = 22), Sprague-Dawley rats (n = 11), ferrets (n = 6), rhesus monkeys (n = 10), cynomolgus monkeys (n = 10), owl monkeys (n = 10), New Zealand White rabbits (n = 18), miniature pigs (n = 9), ICR mice (n = 4), C3H mice (n = 4), and C57BL/10SnJ mice (n = 24). All animals, except mice and rats, received a 2-second spray to the mucous membranes of the nasopharynx for an estimated dose of 56 mg. A 2-second spray to rodents' oral mucous membranes deliverd too great a volume of fluid for these animals; therefore, an equivalent dose was applied to the oral mucosa membranes by use of a 23-gauge needle and syringe. Initial (baseline) blood samples, as well as 4 blood samples taken every 15 minutes after drug application, were analyzed for methemoglobin (MHb), using an oximeter. Positive MHb response (> 3 sd above baseline) was seen in individuals of all groups. The study was repeated in dogs several months later to confirm low response. Response to benzocaine spray was observed in most animals tested, with response peaking between 15 and 30 minutes after dosing. Positive MHb response ranged from 3.5 to 38%, was detected in > 95% of individual animals, and ranged from 15 to 60 minutes after drug administration. Responses were variable because of the screening nature of the study and the topical route of drug administration, but the highest responses were observed in rabbits and cats, and the lowest were seen in mice and dogs. Methemoglobin could be a confounding variable for several types of studies; investigators should consider this toxicity of benzocaine-containing topical anesthetics and use appropriate alternative methods or drugs (ie, lidocaine).
Influence of labor and neonatal hypoxia on sympathoadrenal activation and methionine enkephalin release in calves
Authors: Aurich Jörg E. , Dobrinski Ina , Petersen Annette , Grunert Eberhard , Rausch Wolf-Dieter , Chan Wing W.
Published: January 2024

Labor and delivery stimulate increased release of catecholamines and endogenous opioid peptides in neonates. Catecholamines promote adaptation to the extrauterine environment after birth. Enkephalins are stored together with catecholamines in the adrenal medulla and have an inhibitory effect on catecholamine release. We investigated the influence of labor and neonatal hypoxia on epinephrine, norepinephrine, and met-enkephalin release in calves. Blood samples were taken from the umbilical artery before rupture of the umbilical cord and from the jugular vein repeatedly after birth. Highest plasma norepinephrine concentration was found in calves delivered at the end of gestation (term calves) before umbilical cord rupture. In calves delivered before the physiologic end of gestation (preterm calves), norepinephrine values increased after cord rupture, but remained lower than values in term calves. Epinephrine release followed a similar pattern, but norepinephrine was clearly predominant. In term calves, met-enkephalin values were significantly higher than values in preterm calves. In calves of both groups, met-enkephalin release increased after cord rupture. During birth, the increase in catecholamine release seems to take place earlier than that of enkephalins. Norepinephrine-dominated stimulation during expulsion of the calf might be followed by increasing enkephalinergic inhibition after cord rupture and onset of respiration. Reduced release of catecholamines and enkephalins in preterm calves may be connected with delayed adaptation to the extrauterine environment.
Prevalence of bluetongue virus expression in leukocytes from experimentally infected ruminants
Authors: Ellis John A. , Coen Michael L. , MacLachlan N. James , Wilson William C. , Williams Elizabeth S. , Leudke Albert J.
Published: January 2024

Replication of bluetongue virus (btv) in leukocytes from the blood of sheep, cattle, elk, and mule deer inoculated with btv serotype 10 or 17 was assessed by immunocytochemical staining and dot blot northern hybridization to determine if differences in the prevalence of infection in this blood fraction might account for the differences in clinical disease among these species. Viremia was confirmed by virus isolation in all inoculated animals. Analysis of leukocytes with monoclonal antibodies specific for btv proteins revealed low numbers of infected leukocytes in only 2 sheep 8 days after inoculation with btv serotype 10. Most of the cells expressing btv were identified morphologically as monocytes; approximately 10% of infected cells were lymphocytes. Bluetongue virus was not detected by use of dot-blot hybridization on samples of blood. Our results suggest that differential infection of leukocytes does not account for the pronounced differences in clinical signs and pathologic changes among ruminants.
In situ hybridization of virulent canine distemper virus in brain tissue, using digoxigenin-labeled probes
Authors: Zurbriggen Andreas , Müller Cornelia , Vandevelde Marc
Published: January 2024

Only a few hybridization experiments have been performed for detection of canine distemper virus (cdv) nucleic acid sequences in tissue cultures and in various tissues. Those published studies used probes derived from tissue culture-adapted cdv, and hybridization signals were not obtained in the CNS tissue, although infective cdv and viral antigen were detectable in this tissue. We developed probes complementary to virulent cdv and were able to detect viral RNA not only in primary brain cell cultures, but also in brain tissues, by use of in situ hybridization. Sensitivity of the test at least equaled that of immunohistochemistry. We applied digoxigenin-labeled, strand-specific RNA probes complementary to the nucleoprotein-coding viral nucleic acid sequence. Our results indicate that to detect cdv nucleic acid sequences in brain tissues, it is essential to use probes derived from the virulent virus.
Effect of furosemide and weight carriage on energetic responses of horses to incremental exertion
Authors: Hinchcliff K. W. , McKeever K. H. , Muir W. W. , Sams R.
Published: January 2024

The effect of furosemide-induced weight loss on the energetic responses of horses to running was examined in a 3-way crossover study. Eight 2- to 3-year-old Standardbred mares received, in random order, 10 ml of saline solution 4 hours before running on a treadmill (control trial, C); or, during 2 trials, 1 mg of furosemide/kg of body weight, iv, 4 hours before running. During one of the trials when the horses received furosemide, they carried weight equal to that lost over the 3.75 hours after furosemide administration while running (furosemide-loaded, fl), and during the other trial they did not carry weight equal to that lost after furosemide administration (furosemide-unloaded, fu). Horses performed an incremental exercise test on a treadmill during which rates of oxygen consumption (Vco2) and carbon dioxide production (Vco2) were measured, respiratory exchange ratio was calculated, and blood samples were collected for determination of mixed venous plasma lactate concentration and arterial and mixed venous oxygen saturation. Furosemide treatment caused significantly (P < 0.001) greater weight loss than did saline administration; mean ± sem weight loss (exclusive of fecal loss) was 1.6, 8.8, and 10.2 kg (sem = 2.0) for C, fl, and fu trials, respectively. The speed at which peak Vo2 was achieved was 9.31, 9.56, and 9.50 (sem = 0.16) m/s, respectively, time to fatigue was 547, 544, and 553 (sem = 26) seconds, respectively, and the highest speed attained was 10.3, 10.2, and 10.2 (sem = 0.2) m/s, respectively. Mean peak rate of oxygen consumption was 130.7, 129.6, and 129.6 (sem = 1.9) ml/min/kg, respectively. There was a significant (P = 0.070) group × speed interaction for Vco2; during trial fu, horses had significantly (P < 0.05) lower rate of CO2 production at speed of 9 m/s and at the speed that caused peak Vo2, than during trial C. The respiratory exchange ratio during the fu trial was significantly (P < 0.05) less than that during the C trial at the speed that caused peak Vo2. Plasma lactate concentration at speed of 9 m/s for C, fl, and fu trials was 15.4, 16.5, and 13.3 (sem = 0.8) mmol/L, respectively; values for the fl and C trials were not significantly different, whereas the mean value for the fu trial was significantly (P < 0.05) less than that for the C trial. Thus, administration of furosemide to horses altered the energetic response to exertion. Replacement of the furosemide-induced weight loss resulted in Vco2, plasma lactate, and respiratory exchange values indistinguishable from those during the control trial.
Computer-assisted three-dimensional gait analysis of amphotericin-induced carpal lameness in horses
Authors: Peloso J. G. , Stick J. A. , Soutas-Little R. W. , Caron J. C. , DeCamp C. E. , Leach D. H.
Published: January 2024

Motion of 6 clinically sound horses trotting at a speed of 4 m/s on a treadmill was captured by video cameras before and 9, 16, and 23 days after amphotericin-induced lameness to determine the quantitative variables of three-dimensional computer-assisted image analysis that objectively describe carpal lameness. Amphotericin-B was used to induce lameness, and phenylbutazone (2.2 mg/kg of body weight, PO, once) and butorphanol tartrate (0.1 mg/kg im, q 6 h, to effect) were used to control discomfort. Four 60Hz cameras were symmetrically placed around the treadmill to capture 6 seconds of images from retro-reflective spheres taped to the trotting horses. Images were transferred to a video-based digitizer and a computer work station, where 4 files of two-dimensional data were reduced to 1 file of three-dimensional data. The effect of lameness on motion analyzed was assessed by use of two-way ANOVA. Differences between means were assessed, using the Student-Newman-Keul’s test (P ≤ 0.05).

Head and withers excursions, (dorsal vertical displacement of head and withers targets, respectively) during the sound forelimb support phase were increased significantly during all lameness measurement periods. Head excursion, but not withers excursion, during the lame forelimb support phase, was decreased significantly during all lameness measurement periods. Computer determinations of stride length swing phase, stance phase, forelimb abduction, and carpal and fetlock ranges of motion did not consistently characterize the lameness. It was concluded that three-dimensional computer-assisted image analysis could be used for objective lameness evaluation in horses and that head and withers excursions were the most consistent variables for assessing equine carpal lameness.
Evaluation of the microcirculation of the equine small intestine after intraluminal distention and subsequent decompression
Authors: Dabareiner Robin M. , Sullins Kenneth E. , Snyder Jack R. , White Nathaniel A. , Gardner Ian A.
Published: January 2024

Effects of intraluminal distention (25 cm of H2O, 120 minutes) and subsequent decompression (60 minutes) on intramural vascular patterns of the small intestine was evaluated in 7 anesthetized horses. Intraluminal distention (25 cm of H2O, 120 mintutes) was created in 2 jejunal segments in each horse. Experimental and control segments were removed either immediately after the experimental period or after 60 minutes of decompression. The vascular system of experimental and control jejunal segments was lavaged with NaCl, then was injected with a blue-colored radiopaque medium for microangiography or with a diluted methyl methacrylate for scanning electron microscopy of microcorrosion vascular casts. After angiographic evaluation, tissue sections were prepared for light microscopic evaluation to assess vascular filling and tissue morphology. The distended segments had short villi, which were separated by expanded crypts, and had mesothelial cell loss, neutrophil infiltration, and edema in the seromuscular layer. The number of perfused vessels was significantly (P < 0.05) decreased in the seromuscular layer and, to a lesser extent, in the mucosal layer of the distended segments, compared with controls. After decompression, the morphologic lesions progressed in mucosal and serosal layers and the number of observed vessels increased in all intramural layers; however, vascular density did not return to the predistention state. These results identify altered intramural vascular patterns in the equine jejunum during luminal distention and subsequent decompression.
Biomechanical comparison of 1-screw and 2-divergent pin internal fixations for treatment of slipped capital femoral epiphysis, using specimens obtained from immature dogs
Authors: Belkoff Stephen M. , Millis Darryl L. , Probst Curtis W.
Published: January 2024

Biomechanical strength and stiffness of 2 fixation treatments used to repair acute slipped capital femoral epiphysis were evaluated in bone specimens from immature dogs. A servohydraulic testing machine was used to create slipped capital femoral epiphysis in 7 pairs of femurs by shearing the capital femoral epiphysis along the physis in a craniocaudal direction. The slip was reduced and repaired with one 3.5-mm-diameter screw placed in lag fashion or 2 double-pointed, 1.6-mm (0.062 inch)-diameter smooth pins and retested. Strength and stiffness of each intact femur (which served as the control) and repaired femur were compared. Results of the study indicated that the failure strength of 2-pin fixation was significantly (P < 0.05) weaker than its control and the 1-screw fixation. There was no significant difference between failure strength of the 1-screw fixation and its control. The stiffness of 1-screw and 2-pin fixations was not significantly different, compared with each other, but was significantly (P < 0.05) less, compared with their respective controls.
Radiographic assessment of gastric mucosal fold thickness in dogs
Authors: Jakovljevic Samuel , Gibbs Christine
Published: January 2024

One hundred two dogs without known gastric lesions were evaluated to establish a reference range of gastric rugal fold thickness (millimeters). Mucosal folds were measureable for 63 examinations, and the length of the second lumbar vertebra was measured for 61 of the 63 (centimeters). Body weight was available in the case records of 29 dogs. Measurements of the mucosal folds were related to body weight (n = 29) and length of the second lumbar vertebra (n = 61) by use of linear regression analysis. Reference range of normal gastric mucosal fold thickness, 1 to 8 mm, was defined by this study for dogs of any breed weighing between 2 and 50 kg.
Effects of sex, age, puncture site, and blood contamination on the clinical chemistry of cerebrospinal fluid in rhesus macaques (Macaco mulatto)
Authors: Smith M. O. , Lackner A. A.
Published: January 2024

Paired csf and serum samples were obtained from 109 rhesus macaques aged 1 to 18 years. The csf and serum IgG and albumin concentrations were determined, using radial immunodiffusion; csf total protein and glucose were determined, using colorimetric methods; and Na, K, and Cl concentrations were determined, using ion-specific electrodes. The csf protein values were lower than those reported for non-human primates, and this finding was confirmed by results of agar gel electrophoresis. Animal age and sex had no significant effects on csf composition, but serum IgG concentration increased with age. Concentrations of total protein, albumin, and IgG were greater, and concentrations of glucose and potassium were lower in csf obtained from the lumbar rather than the cisternal site. Composition of csf was not significantly altered by contamination with blood at values up to 10,000 RBC/μl. The csf albumin quotient, IgG quotient, and IgG index were determined and differed markedly from values reported for human beings, indicating that the properties and specificity of the blood-brain barrier may be species-specific.
Association of Mycobacterium paratuberculosis infection with reduced mastitis, but with decreased milk production and increased cull rate in clinically normal dairy cows
Authors: Wilson David J. , Rossiter Christine , Han Hong R. , Sears Philip M.
Published: January 2024

Approximately 45 Holstein cows that were Mycobacterium paratuberculosis-positive on the basis of fecal culture results were maintained at any one time in a 210-cow dairy herd. Farm management participated in the New York State Paratuberculosis Eradication Program. Paratuberculosis-positive cows were grouped separately from paratuberculosis-negative cows, but they were otherwise managed identically. During a 1-year study, 180 paratuberculosisnegative cows and 113 clinically normal paratuberculosis-positive cows were identified. Quarter milk samples (n = 6,100) were aseptically collected for microbiologie culture of mastitis pathogens from paratuberculosis-negative cows, and 3,129 quarter samples were obtained from paratuberculosis-positive cows. Dairy Herd Improvement Association (dhia) records were used to monitor milk somatic cell count linear scores, mature equivalent milk production, new mastitis infections, and chronic mastitis infections. For second-lactation cows greater than 100 days in milk production, and increasing with age beyond that point, paratuberculosis-positive cows had lower mature equivalent milk production than did negative herdmates. Rates of new and chronic mastitis infections, as measured by dhia linear scores were significantly (P < 0.05, P = 0.05, respectively) lower in cows with nonclinical paratuberculosis. Infected cows were culled from the herd at a faster rate than were paratuberculosis-negative herdmates. Therefore, paratuberculosis was associated with financial loss attributable to reduced milk production and increased culling of infected cows.
Repeatability of energy expenditure measurements in clinically normal dogs by use of indirect calorimetry
Authors: Walters Lisa M. , Ogilvie Gregory K. , Salman Mowafak D. , Joy Linda , Fettman Martin J. , Hand Michael S. , Wheeler Steven L.
Published: January 2024

Energy expenditure (ee) was determined, using an open-flow indirect calorimetry system in a group of 20 clinically normal, apparently resting, client-owned dogs. Five evaluations were performed over an 8-hour period to determine reliability of the method. The intraclass correlation coefficient was calculated as the ratio of within- and between-subject variances, using repeated-measures anova. When only the middle 3 evaluations were included, the intraclass correlation coefficient was 0.87, indicating good reliability. The first evaluation was higher than the subsequent 4 evaluations for rate of O2 consumption (Vo2/kg and Vo2/kg0.75; (P ≤ 0.01), and ee/kg and ee/kg0.75 (P ≤ 0.005). The respiratory quotients at the first (P = 0.004) and second (P = 0.013) evaluations were different from the respiratory quotient at the fourth evaluation. Therefore, the first evaluation may not be representative of the actual ee. The mean value of at least 3 subsequent evaluations after an adequate adaptation period (5 to 10 minutes) to the equipment will be useful for predicting energy requirements of apparently resting, clinically normal dogs.
Effects of anesthesia induced and maintained by continuous intravenous administration of guaifenesin, ketamine, and xylazine in spontaneously breathing sheep
Authors: Lin Hui-Chu , Tyler Jeff W. , Welles Elizabeth G. , Spano Joseph S. , Thurmon John C. , Wolfe Dwight F.
Published: January 2024

Anesthesia was induced and maintained in 6 Suffolk wethers by continuous iv infusion of guaifenesin (50 mg/ml), ketamine (1 mg/ml), and xylazine (0.1 mg/ml) in 5% dextrose in water (triple drip) to assess the anesthetic and cardiopulmonary effects. All sheep were positioned in right lateral recumbency. Dosages of triple drip used for induction and maintenance of anesthesia were 1.2 ± 0.02 ml/kg and 2.6 ml/kg/h, respectively. Lack of gross purposeful movement of sheep to electrical stimulation indicated that analgesia and muscular relaxation induced by triple trip were adequate for surgical procedures. Heart rates and arterial blood pressure remained unchanged from baseline values during a 1-hour period of anesthesia. Arterial blood pressures were measured indirectly, using an inflation cuff placed over the metatarsal artery at the heart level. Significant decrease in arterial partial pressure of O2 (Pao2), coupled with an increase in arterial partial pressure of CO2 (Paco2), from baseline values was observed throughout the course of the study. Decrease in Pao2 was observed concomitantly with significant (P < 0.05) increase in respiration rate. Changes in arterial blood gas tensions observed in this study were attributed to respiratory depressant effect induced by anesthetic drugs and right-to-left shunting, perfusion/ventilation mismatch, or both caused by right lateral recumbency. Administration of 100% O2 via the endotracheal tube reduced the magnitude of the decrease in Pao2. All sheep recovered smoothly and stood within 96.3 ± 48.9 minutes after termination of triple drip administration
Flow cytometric analysis of neutrophils in cows’ milk
Authors: Miller Robert H. , Paape Max J. , Filep Renee , Link Sarah
Published: January 2024

Procedures were developed to count neutrophils in milk, using a flow cytometer. Milk samples from 2 experiments were counted: 1 with 4 noninfected cows and a second with 5 noninfected cows that were injected with endotoxin in 2 mammary quarters. Thus, the procedures were evaluated on normal milk and on that with high somatic cell count.

Flow cytometric procedures involved fluorescence detection (from the dye carboxydimethylfluorescein diacetate) to distinguish intact and viable from fragmented cells, forward light scatter to detect cell size differences, and right-angle side scatter to detect cellular granularity. High fluorescence, large size, and high degree of granularity identified viable neutrophils. For all samples, neutrophils were also counted manually, using the cytologic centrifugation approach to create the slides; manual counts were used as the standard for comparison.

In experiment 1 (normal milk), mean values for percentage of viable neutrophils estimated by manual and flow cytometry procedures agreed closely (26% vs 25.8% for foremilk and 28.8% vs 26.6% for bucket milk). Sources of variation in manual and flow cytometric estimates of percentage of neutrophils were examined. Cow variation was significant (P < 0.01) for manual and flow cytometric counts, but was larger for flow cytometric counts. Day-to-day variation in counts on milk from the same cow was negligible for manual counts, but was significant (P < 0.01) for flow cytometric counts. Coefficients of variation were considerably larger for manual counts than for flow cytometry.

In experiment 2 (milk with high cell count, foremilk), agreement between mean values obtained by flow cytometry and by manual counting was somewhat less. However, predicting manual percentage of neutrophils, using the flow cytometric estimate, had R2 of 0.77. Regression of the manual percentage of neutrophils value on the flow cytometric percentage of neutrophil value was close to 1.0, with only a small negative intercept. Some additional refinement of flow cytometric procedures may be required before flow cytometric estimates of percentage of neutrophils can be accepted without simultaneous validation by use of manual counting. In particular, causes of day-today variation in flow cytometric results should be identified and reduced.
Comparison of techniques for diagnosis of proliferative enteritis of swine
Authors: Jones Gary F. , Davies Peter R. , Rose Rebecca , Ward Gilbert E. , Murtaugh Michael P.
Published: January 2024

In an abattoir-based case-control study, histologic, and macroscopic examination of porcine intestines at slaughter and 2 molecular assays were compared for use as diagnostic tests of proliferative enteritis (pe). Fecal samples and intestinal specimens were collected from pigs with grossly thick ileum and from clinically normal pigs at slaughter. Tissue specimens were fixed in neutral buffered 10% formalin, and sectioned. Sections stained with H&E were examined for proliferative lesions by a pathologist unaware of the group to which the pig had been assigned on the basis of results of gross examination. Adjacent tissue sections, stained with Warthin-Starry (silver) stain, were examined for presence of the intracellular bacterium of pe, ileal symbiont (is)-intracellularis, in the enterocytes of the intestinal crypts by the senior author, who was unaware either of the group to which the pig had been assigned or diagnosis by the pathologist. Bacterial DNA was extracted from the fecal samples and assayed by dot-blot hybridization and polymerase chain reaction (pcr) for presence of is-intracellularis dna, without knowledge of results of the other examinations. The pcr assay for is-intracellularis was a specific and sensitive diagnostic test for pe, and dot-blot hybridization was sensitive, but was less specific. Macroscopic examination of intestines at slaughter was a sensitive, but not specific, test.

Association between is-intracellularis and proliferative lesions was statistically examined in the same study. There was a highly significant (P = 0.0078) association between presence of naturally acquired proliferative lesions and intracellular infection induced by is-intracellularis. The odds ratio of ≥ 14 and estimated attributable fraction of ≥ 92% indicate that is-intracellularis may be a necessary cause of pe.
Cardiopulmonary effects of halothane in hypovolemic dogs
Authors: Pascoe Peter J. , Haskins Steve C. , Ilkiw Jan E. , Patz John D.
Published: January 2024

Cardiopulmonary effects of halothane administration were studied in hypovolemic dogs. Baseline cardiopulmonary data were recorded from conscious dogs after instrumentation. Hypovolemia was induced by withdrawal of blood from dogs until mean arterial pressure of 60 mm of Hg was achieved. Blood pressure was maintained at 60 mm of Hg for 1 hour, by further removal or replacement of blood. Halothane was delivered by face mask, dogs were intubated, then halothane end-tidal concentration of 1.13 ± 0.02% was maintained, and cardiopulmonary effects were measured 3, 15, 30, and 60 minutes later. After blood withdrawal and prior to halothane administration, systemic vascular resistance index, oxygen extraction, and base deficit increased. Compared with baseline values, these variables were decreased: mean arterial pressure, mean pulmonary arterial pressure, pulmonary arterial occlusion pressure, cardiac index, oxygen delivery index, oxygen consumption index, mixed venous oxygen tension, mixed venous oxygen content, venous admixture, arterial bicarbonate concentration, and mixed venous pH. At all times after intubation, arterial and venous oxygen tensions and mixed venous carbon dioxide tensions were increased. Three minutes after intubation, base deficit and mixed venous carbon dioxide tension increased, and mean arterial pressure and arterial and venous pH decreased, compared with values measured immediately prior to halothane administration. Fifteen minutes after intubation, systemic vascular resistance index decreased and, at 15 and 30 minutes, mean arterial pressure and arterial and venous pH remained decreased. At 60 minutes, mean pulmonary arterial pressure and pulmonary arterial occlusion pressure were increased and mixed venous pH was decreased, compared with values measured before halothane administration. Results of this study indicated that induction of anesthesia with halothane and maintenance at an end-tidal halothane concentration of 1.13% induced significant changes in blood pressure, with minimal effects on cardiac output and pulmonary function, when administered to hypovolemic dogs.
Evaluation of a dosing method for studying ergonovine effects in cattle
Authors: Oliver J. W. , Linnabary R. D. , Abney L. K. , van Manen K. R. , Knoop R. , Adair H. S.
Published: January 2024

We evaluated the feasibility of using miniosmotic pumps as a way to continuously treat cattle with a singular ergot alkaloid (ergonovine) of known content, thus mimicking the natural fescue toxicosis disease state, but allowing study of specific alkaloid effects. Dosing animals with increasing amounts of ergonovine via miniosmotic pumps, followed by daily acquisition of plasma samples for high-performance liquid chromatographic determination of the alkaloid, resulted in stepwise increases in plasma ergonovine concentration. However, despite the detectable blood concentration of ergonovine, calves did not have typical clinical signs of ergot alkaloid toxicosis. Similarly, serum prolactin concentration was unaffected by ergonovine in these cattle, implicating some other alkaloid of endophyte-infested fescue as causative of the usual prolactin-suppressive response. The results confirm use of this animal dosing method to study biological effects of singular purified alkaloids of known amount, without bioavailability concerns. Thus, this dosing method will facilitate studies to determine the harmful effects of individual alkaloids found in toxic tall fescue, and ultimately, to alleviate their costly effects in cattle, horses, and other species.
Comparison of transducer placement sites for Doppler echocardiography in dogs with subaortic stenosis
Authors: Lehmkuhl Linda B. , Bonagura John D.
Published: January 2024

Effects of transducer placement site and various operators on Doppler echocardiographic measures were evaluated in 12 dogs with subaortic stenosis. Dogs sedated by iv administration of acepromazine and buprenorphine were examined by 2 observers. Maximal aortic velocity and aortic velocity time integral were determined from Doppler aortic velocity spectra recorded, using a 1.9-MHz continuous wave nonimaging transducer placed at 3 echocardiographic sites: left ventricular apex (la), suprasternal notch (ssn), and subcostal (sc). Doppler-estimated left ventricular-to-aortic pressure gradients were calculated from the traced velocity spectra by application of the modified Bernoulli equation.

Each observer recorded high-quality Doppler spectral signals in all dogs from the sc and LA transducer sites and in 83% of dogs from the ssn window. Mean values for maximal aortic velocity and velocity time integral differed among sites (P < 0.05), but not between observers. Maximal velocity and velocity time integral measured from the sc transducer site were higher than those measured from the ssn or la positions. Presumably, sc transducer placement provided the highest aortic velocities because of optimal alignment with aortic outflow. The maximal pressure gradient estimated from sc velocities exceeded ssn values by 27 mm of Hg and LA measurements by 38 mm of Hg. In this study, the optimal site for the Doppler echocardiographic detection of subaortic stenosis and assessment of this lesion's hemodynamic importance in most affected dogs was the sc position.
Modulation of bovine neutrophil functions by monoclonal antibodies
Authors: Salgar Shashikumar K. , Paape Max J. , Alston-Mills Brenda , Peters Robert R.
Published: January 2024

The main objective of the study reported here was to generate a panel of monoclonal antibodies (mab) to bovine neutrophil surface antigens, and to identify mab that modulate neutrophil chemotaxis, respiratory burst, and phagocytosis. A further objective was to study mab reactivity with resting and activated neutrophils, to identify activation antigens and adhesion molecules.

A panel of 14 mab was generated by producing murine hybridomas. Neutrophils incubated with mab at 4 C for 2 hours were used in chemotaxis, respiratory burst, and phagocytosis assays. Chemotaxis was evaluated in Boyden chambers, using Escherichia coli endotoxin-activated fetal bovine serum as the chemoattractant. Respiratory burst was determined by measuring chemoluminescence of neutrophils incubated with 5-amino-2,3-dihydro-l,4-phthalazinedione, and serum opsonized zymosan. Phagocytosis was determined by flow cytometry, using fluorescein-labeled Staphylococcus aureus. The mab S7G8, S5F8G10, S7E10, and S5F8B8 enhanced chemotaxis (to > 125% of control). The mab S7E10 and S8D9 enhanced respiratory burst activity (to > 125% of control), whereas mab S2G8, S4G10, S8G10, and S5F8B8 caused inhibition (to < 75% of control). The mab S2G8, S4G10, S8G10, and S5F8G10 enhanced phagocytosis (to > 125% of control). Chemotaxis, respiratory burst, and phagocytosis values of neutrophils not bound with mab served as controls for comparison.

The mab binding for nonactivated neutrophils (at 4 C) ranged from 9 to 100%, and for activated neutrophils (at 37 C; at 37 C with phorbol myristate acetate) from 90 to 100%. Binding of mab S4F5, S5F8B8, S6C6, S7E10, S8D9, and S5F8G10 increased when neutrophils had been incubated at 37 C. Binding of these mab was further increased after incubation with phorbol myristate acetate (100 ng/ml) at 37 C, indicating recognition of activation antigens by mab. The mab generated in this study appeared to be potential candidates for studying mechanisms of neutrophil function and for enhancing neutrophil function in vitro and in vivo.
Clinical and clinicopathologic changes in cows with endotoxin-induced mastitis treated with small volumes of isotonic or hypertonic sodium chloride administered intravenously
Authors: Tyler Jeff W. , Welles Elizabeth G. , Erskine Ronald J. , Lin Hui-Chu , Williams M. A , Spano Joseph S. , Gaslin J. Todd , McClure Kimberly A.
Published: January 2024

We characterized the clinicopathologic manifestations of experimentally induced endotoxin-induced mastitis. Responses to hypertonic fluid therapy also were assessed. Eight cows received 1 mg of endotoxin by intramammary infusion in the left forequarter. Four hours after endotoxin administration, cows received 0.9% NaCl, 5 ml/kg of body weight (n = 4) or 7.5% NaCl, 5 ml/kg (n = 4) IV. Endotoxin-infused cows had expanded plasma volume, hyponatremia, transient hyperchloremia and hypophosphatemia, increased serum glucose concentration, and decreased serum activities of liver- and muscle-specific enzymes. Calculated plasma volume increased at 6 hours in cows receiving hypertonic NaCl, and at 12, 24, and 48 hours after endotoxin infusion in both groups. Concurrent observations of decreased serum protein concentration, erythrocyte count, and hematocrit supported observations of increased plasma volume. Relative plasma volume was greater in cows receiving hypertonic NaCl (124.3%) than in cows receiving isotonic NaCl (106.6%) at 6 hours after endotoxin infusion. Cattle receiving hypertonic NaCl had increased voluntary water intake after iv fluid administration. Increased water consumption was not accompanied by increased body weight, indicating probable occurence of offsetting body water loss. Serum sodium concentration in cows receiving hypertonic NaCl was increased 2 hours after fluid administration, but the magnitude of the change was minimal (< 4 mmol/L) and transient, indicating rapid equilibration with either interstitial or intracellular spaces. Serum sodium concentration was decreased in cows receiving isotonic NaCl at 12, 24, and 48 hours after endotoxin administration, compared with concentration prior to endotoxin adminstration, indicating selective loss of sodium.