bluuebunny/crossref_metadata_2025 huggingface dataset:
Polyethylene glycol-6000 as a clearing agent for lipemic serum samples from dogs and the effects on 13 serum assays
Authors: Thompson Morrow B. , Kunze Dolores J.
Published: February 2025

Polyethylene glycol-6000 (peg) was evaluated as a clearing agent for lipemic serum from dogs. Effects of peg-treatment in lipemic and nonlipemic samples were determined for 13 chemical and enzymatic assays (glucose, bun, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, amylase, total protein, albumin, sodium, potassium, chloride, phosphorus, and calcium). Control samples for lipemic sera were prepared by ultracentrifugation. Treatment with peg cleared all lipemic samples. Regression lines for all lipemic samples were highly significant (P < 0.0001) and the sd of the control values around the regression lines were small compared with the mean value for an assay. The technique was simple, quick, and inexpensive. With proper validation, reliable predictions of true serum values could be calculated for lipemic serum samples for all assays studied.
Radiologic and anatomic observations of plantar sesamoid bones at the tarsometatarsal articulations of Greyhounds
Authors: Wood A. K. W. , McCarthy P. H.
Published: February 2025

In Greyhounds, 2 plantar sesamoid bones were identified in radiographs taken of the intact tarsus and also of the tarsometatarsal fibrocartilage, that had been dissected free from the joints. Anatomic dissections defined the precise position of each sesamoid. A prominent sesamoid was present on the lateral side of the tarsometatarsal articulation in 50% of the tarsi; it is proposed that this bone be named the lateral plantar tarsometatarsal sesamoid bone. A smaller bone was detected on the medial side of the tarsometatarsal articulation in 27% of the tarsi; it is proposed that this bone be named the intra-articular tarsometatarsal sesamoid bone.
Hereditary anomaly of neutrophil granulation in Birman cats
Authors: Hirsch V. M. , Cunningham T. A.
Published: February 2025

A hereditary anomaly of neutrophil granulation in purebred Birman cats was described with respect to genetic, electron microscopic, histochemical, and functional characters. The trait was inherited in an autosomal recessive manner and was prevalent in the population studied. Affected cats had fine eosinophilic granules in the cytoplasm of neutrophils. The granules had normal morphology as determined by electron microscopy and did not stain for acid mucopolysaccharide. Bactericidal activity, phagocytosis, and oxidative function of affected neutrophils were not different from those of unaffected neutrophils. The anomaly was concluded to be an alteration in the content of lysosomal granules with increased affinity for acidic dyes.
Tracheal lesions in young turkeys infected with Bordetella avium
Authors: Arp L. H. , Cheville N. F.
Published: February 2025

Forty-six turkeys were inoculated intranasally with Bordetella avium at 3 days of age. Inoculated and noninoculated turkeys (n = 72) were necropsied sequentially from postexposure days (ped) 3 to 53. Tracheal lesions were studied histologically. Mild fibrinopurulent tracheitis, associated with bacterial colonization of ciliated epithelium, was seen at ped 7 to 10. At ped 14 and 21, there were numerous bacterial colonies, loss of ciliated cells, epithelial hyperplasia, depletion of mucus, and diffuse infiltration of lymphocytes and macrophages. At ped 28, the mucosa and tracheal rings were severely distorted. The mucosal epithelium, composed of immature epithelial cells and nononuclear leukocytes, had formed prominent longitudinal folds. Mucous glands were cystic and lined by low cuboidal epithelium. At ped 42 and 53, tracheas appeared normal, except for residual distortion of tracheal rings and shortened luminal epithelium.
Effect of dihydrostreptomycin or oxytetracycline on reproductive capacity of bulls
Authors: Abbitt Bruce , Berndtson William E. , Seidel George E.
Published: February 2025

Young beef bulls (n = 27) were used in a trial to study the effect of dihydrostreptomycin sulfate (dhs) or oxytetracycline (otc) hydrochloride on spermatogenesis, epididymal sperm maturation, and freezability of sperm. Nine of the bulls were given a 22 mg/kg dose of dhs twice, 12 hours between doses. Nine other bulls were treated with otc—1 dose of 26.4 mg/kg of body weight, and then 6 more doses each of 17.6 mg/kg, ca 12 hours between doses. The remaining 9 bulls were nontreated controls. The treatment regimens with the 2 antibiotics were without effect on spermatogenesis. These treatments also were without effect on seminal pH, ejaculate volume, percentage of motile spermatozoa, rate of spermatozoal motility, or concentration of spermatozoa in ejaculates harvested on day 3 or 7 of the study (day 0 = 1st day of treatment). There was a treatment-by-day effect on spermatozoal concentration; the number of sperm per milliliter was markedly increased on day 3 for otc-treated bulls. The increased spermatozoal concentration in the otc-treated group was associated with an influence of the antibiotic on ejaculation. All bulls given this antibiotic ejaculated without palpable penile engorgement or erection on day 3. On day 7 the rate of spermatozoal motility was increased in the 2 treatment groups compared with the rate in the control bulls. Also on day 7, the percentage of motile spermatozoa was greater in the otc-treated bulls than in the control or OHS-treated bulls. It was concluded that otc at 3× the recommended dosage produced transient adverse effects on the bulls’ response to electroejaculation, but that otherwise these antibiotic treatments did not affect reproductive function of young beef bulls.
Experimental cantharidiasis in the horse
Authors: Shawley Richard V. , Rolf Lester L.
Published: February 2025

SUMMARY AND CONCLUSIONS

Crystalline cantharidin in an alfalfa cake or in aqueous suspension was given to 8 horses at a dosage level of 450 to 489 μg/kg of body weight (group 1) and 2 horses at a dosage level of 720 μg/kg (group 2) via nasogastric tube. Both group 2 horses and 1 group 1 horse died. Horses were evaluated at 6-hour intervals for 36 hours and then again at postcantharidin hours 48. Data evaluation consisted of a comparison of the nonsurvival and survival data to one another and their respective base-line values at each sampling period, irrespective of the route of administration and dosage level. Consistent findings in both groups included significant (P ≤ 0.05) increases in cardiac rate, respiratory rate, and rectal temperature and decreases in total serum Ca, serum Mg, and K concentrations during at least one 6-hour period. Calcium and Mg concentrations were still significantly (P ≤ 0.05) depressed at postcantharidin hours 48, although other electrolytes and physiologic values had returned to base line. Arterial oxygen tension, total protein, serum creatine kinase, arterial CO2, and plasma bicarbonate were depressed in surviving horses during 1 or more periods. The most consistent clinical signs were anorexia and depression; severe gingival and oral mucosal erosions; washing of the muzzle in water; stiff, short-strided gait; and synchronous diaphragmatic flutter. One group 2 horse that died had microscopic histopathologic features compatible with blister beetle intoxication.

The data indicated that the only clinical measurement that might differentiate blister beetle disease from other acute abdominal crises including monensin toxicosis, beside finding the beetles in digesta and contaminated hay, was the profound and stable hypocalcemia and hypomagnesemia. In terms of prognosis, only a continuum of tachycardia, tachypnea, and increasing creatine kinase activity were associated with nonsurviving horses.
Antagonism of pancuronium neuromuscular blockade in halothane-anesthetized ponies using neostigmine and edrophonium
Authors: Hildebrand S. V. , Howitt G. A.
Published: February 2025

Efficacy of neostigmine (0.04 mg/kg of body weight) and edrophonium (1 mg/kg), as antagonists for pancuronium neuromuscular blockade in halothane-anesthetized ponies, was evaluated. Neostigmine and edrophonium were satisfactory antagonists, with edrophonium having a significantly (P < 0.01) more rapid onset of action than did neostigmine.

Muscarinic activity of neostigmine and edrophonium was also evaluated. Neither antagonist was administered with atropine. Gastrointestinal effects, increased salivation, and increased airway secretions were minimal with edrophonium, but were marked after neostigmine. Blood pressure increased within 1 to 2 minutes of antagonist administration. Heart rate decreased after edrophonium injection, but this occurred after blood pressure increase. Heart rate increased or did not change after neostigmine administration.
Effects of an anabolic steroid on acute uremia in the dog
Authors: Finco Delmar R. , Barsanti Jeanne A. , Adams D. Daryl
Published: February 2025

Four groups of dogs made acutely uremic were treated with placebo, 0.5 mg/kg, 1.0 mg/kg, and 1.5 mg/kg of an anabolic steroid (3-oxo-Δ1,4 androstadiene-17β-ol-undecylenate). Pretreatment and posttreatment measurements of food intake, body weight, pcv, serum creatinine concentration, plasma albumin concentration, nitrogen balance, lean body mass, and limb circumference did not indicate any beneficial effect of this drug in this model of acute uremia.
Diagnosis of canine Cushing's syndrome based on multiple steroid analysis and dexamethasone turnover kinetics
Authors: Lothrop Clinton D. , Oliver Jack W.
Published: February 2025

A comparison of cortisol concentrations, determined by high-performance liquid chromatography (hplc) and radioimmunoassay, was made in healthy, mixed-breed dogs and in dogs with clinical signs of Cushing's syndrome. Absolute concentration of cortisol was less in resting, dexamethasone-suppressed, and ACTH-stimulated plasma samples, when measured by hplc relative to cortisol concentrations determined by radioimmunoassay. Diagnosis of Cushing's syndrome could be made using either method. Plasma concentrations of cortisone and corticosterone were determined by hplc. Cortisone and corticosterone concentrations alone were not diagnostic of Cushing's syndrome; but when used in conjunction with cortisol determinations, they provided additional criteria for laboratory confirmation of the clinical diagnosis of Cushing's syndrome. The clearance of exogenous dexamethasone used in the dexamethasone-suppression test was examined in the normal and cushingoid dogs. Plasma concentrations of exogenous dexamethasone were constant during the 3-hour test in the normal dogs. However, in 75% of the dogs with Cushing's syndrome, exogenous dexamethasone was cleared completely in the 3-hour test. Thus, dexamethasone clearance rates were excessively fast in most dogs with Cushing's syndrome.
Canine and feline thyroid function assessment with the thyrotropin-releasing hormone response test
Authors: Lothrop Clinton D. , Tamas Paul M. , Fadok Valerie A.
Published: February 2025

A canine and feline pituitary-thyroid function test based on thyrotropin-releasing hormone (trh) stimulation of endogenous thyrotropin is described. Serum thyroxine is measured before and after stimulation with trh. A positive response to trh indicated a functionally intact pituitary-thyroid axis. At trh doses of 0.002 to 10.0 mg/kg of body weight, dose response of serum thyroxine to trh stimulation was determined. Increasing the dose of trh increased the duration, but not the magnitude, of thyroxine stimulation. At trh doses > 0.1 mg/kg, drug side effects were salivation, defecation, urination, vomition, miosis, tachycardia, and tachypnea. A useful procedure for pituitary-thyroid function testing was serum thyroxine measurement before and 6 hours after trh (0.1 mg/kg) stimulation.
Familial reflex myoclonus in Labrador Retrievers
Authors: Fox J. G. , Averill D. R. , Hallett M. , Schunk K.
Published: February 2025

Three 6-week-old male purebred yellow Labrador Retrievers were presented with intermittent stimulus-sensitive contractions of the appendicular and axial muscles. Five littermates were normal, although the grandsire of the affected litter had sired 2 previous litters containing similarly affected pup. Although alert and responsive, the affected dogs appeared decerebrate with extensor rigidity and opisthotonus during handling. During severe episodes, respiratory distress was observed. Generalized contractions were initiated by voluntary movements, but at rest the muscles relaxed. Neurologic deficits were not detected, although efforts to elicit segmental reflexes, assess muscle tone, or assist walking resulted in generalized stiffness.

Electromyograms from the semitendinous muscles (musculi semitendinosus) had increased motor unit amplitude (up to 5,000 μV) with polyphasic action potentials. There were no myotonic discharges. A reduced interference pattern was seen. A single tactile stimuli of the distal limb resulted in 3 responses, each lasting ≤ 10 ms at latencies of 0 to 12 ms, 20 to 30 ms, and 35 to 40 ms, characteristic for reflex myoclonus. The motor nerve conduction velocities were normal for age (32 to 35 ms). Age-matched control dogs had motor unit action potentials of 100 to 200 μV and single compound motor unit discharges to single tactile stimuli.

Therapeutic trials with diazepam and clonazepam produced minimal effects on the muscle contractions. Values of urinalyses, complete blood cell counts, and serum chemistries were within normal limits. Frozen muscle section biopsy findings, including enzyme histochemical assessment of muscle fiber types, were normal. Examination at necropsy revealed mild precordial esophageal dilation in 2 dogs, but no lesions in skeletal muscle or nervous tissues.

The term familial reflex myoclonic disorder is suggested; lack of reflex inhibition or abnormal suprasegmental discharges resulting from tactile stimuli was speculated as the basic mechanism for the disorder.
Effects of local anesthetics on healing of abdominal wounds in rabbits
Authors: Vasseur Philip B. , Paul Howard A. , Dybdal Noel , Crumley Linda
Published: February 2025

The influence of lidocaine and bupivacaine on the breaking strength and histopathologic appearance of wounds in the ventral abdominal midline (linea alba) of rabbits was studied. In control rabbits, group 1 (n = 24), skin and subcutaneous tissues were incised, permitting direct infiltration of the linea alba with normal saline solution. The linea alba was then incised, and wound margins were apposed in layers, using absorbable suture material. Group 2 rabbits (n = 24) were given 0.5% lidocaine, group 3 rabbits (n = 24) were given 2% lidocaine, and group 4 rabbits (n = 24) were given 0.5% bupivacaine, rather than saline solution.

Eight rabbits from each group were killed 6, 12, and 18 days after wounding. Eight 1.0-cm wide transverse strips were removed from the abdominal wall of each rabbit. Two strips were used for histopathologic evaluation and 6 were tested for failure, using a mechanical testing device. Breaking strengths in group 1 averaged 0.66 kg, 1.35 kg, and 1.57 kg at 6, 12, and 18 days, respectively. None of the test groups had significantly different (P > 0.05) breaking strength results as compared with that in controls. The histopathologic appearance of tissues infiltrated with local anesthetics did not vary consistently from that of tissues infiltrated with normal saline solution. Local infiltration of lidocaine and bupivacaine does not alter substantially the healing of midline abdominal incisions in rabbits.
Characterization of dermonecrotic toxin produced by serotype D strains of Pasteurella multocida
Authors: Nakai Toyotsugu , Sawata Akira , Tsuji Masayoshi , Kume Katsumi
Published: February 2025

Dermonecrotic toxin (dnt) produced by serotype D strains of Pasteurella multocida, isolated from pigs, was characterized and compared with dnt produced by Bordetella bronchiseptica. The dnt prepared by sonication from P multocida or B bronchiseptica had dermonecrotic activity and lethal toxicity for guinea pigs and mice, and also induced marked atrophy of spleens in the mice. Toxicity of P multocida or B bronchiseptica dnt was completely inactivated by heating at 70 C for 30 minutes, and was reduced by treatment with trypsin, formalin, or glutaraldehyde, indicating that the dnt may be a protein. Although biologic and toxic properties of P multocida dnt were similar to those of B bronchiseptica dnt, cross-neutralization tests between P multocida and B bronchiseptica indicated that dnt from the 2 bacterial species were serologically distinct.
Renal clearance and fractional excretion of electrolytes Over a 24-hour period in horses
Authors: Morris Debra Deem , Divers Thomas J. , Whitlock Robert H.
Published: February 2025

Four consecutive 6-hour urine collections were obtained from 10 healthy adult horses given free access to a complete pelleted ration and water. Samples of blood were collected from the jugular vein at the start of the test period and then every 6 hours for 4 consecutive samples.

Mean renal clearance of creatinine (CCr) varied significantly during the four, 6-hour collections, ranging from 1.474 in period II to 2.702 ml/min/kg of body weight during period III (P < 0.05). The CCr in period III was significantly different from the 24-hour mean value of 1.877 ml/min/kg (P < 0.05). The mean 6-hour clearances of potassium (CK), chloride (CCl), and calcium (CCa) also varied significantly during the 4 collections (P < 0.05). The 24-hour mean CK and CCl were different from the mean during period III (P < 0.05) There was significant correlation between mean 24-hour CCr and CK (P < 0.01); CCr and CCl(P < 0.05); CNa and CK(P < 0.01); CNa and CCl(P < 0.01); and CK and CCl (P < 0.001).

The 95% confidence interval for 6-hour mean values of fractional excretion of Na (FENa) was 0.032% to 0.522%; FEK was 23.345% to 48.074%; FECl was 0.588% to 1.861%; and FECa was −0.158% to 6.723%. Although FENa, FECl and FECa were highly variable within and between individual horses, mean values for periods I to IV did not differ significantly over time or from 24-hour mean values The FEK varied less throughout the 24-hour test period.

Mean urine volume, urine concentrations of Cr and K, urine osmolality, urine-to-plasma osmolality, urine-to-plasma urea nitrogen, and plasma urea nitrogen varied significantly through time periods I to IV (P < 0.05); however, means for time periods I to IV were not different from 24-hour means.
Immunologic responses of calves to aerosolized antigen: Humoral response to ovalbumin
Authors: Gershwin Laurel J. , Olsen Craig L.
Published: February 2025

The humoral response of cattle to ovalbumin (oa), a nonenvironmental well-defined antigen, was studied. During 9 weeks of aerosolization, weekly serum and nasal secretion concentrations of immunoglobulin (Ig)G1, IgG2, IgM, IgA, and IgE were determined by enzyme-linked immunosorbent assay (elisa) for oa specific antibody. Data from 3 calves given aerosol oa were compared and contrasted with data from 3 calves given aerosol saline solution and 1 calf given parenteral oa. The presence of cytotropic (skin sensitizing) antibody was evaluated during weeks 6 and 9 by direct skin testing with oa.

A humoral response was induced in all 3 calves given aerosol oa. Serum IgG1 and lgG2 titers reached a maximum of 64,000 and 2,000, respectively, in calves given aerosol oa compared with 521,000 and 16,000, respectively, in the calf given parenteral oa. The elisa did not detect an oa-specific IgM response. In contrast, all 3 calves given aerosol oa had serum IgA concentrations that increased to a peak by week 9. The mean IgA absorbance value for the 3 calves given aerosol oa was slightly greater than 5 times that of the calf given parenteral oa. Similarly, nasal secretions from calves given aerosolized oa had absorbance values that were 15-fold greater than that from the calf given parenteral oa.

Calves given aerosol oa had antigen-specific IgE responses during weeks 6 to 8. The elisa results were compared with results of passive cutaneous anaphylaxis tests. The presence of skin-sensitizing antibody was indicated by positive skin tests in the calves given aerosol oa and the calf given parenteral oa by week 9.
Bovine pneumonic pasteurellosis: Model for Pasteurella haemolytica- and Pasteurella multocida-induced pneumonia in cattle
Authors: Panciera R. J. , Corstvet R. E.
Published: February 2025

Pneumonic lesions in calves were induced with Pasteurella haemolytica or P multocida. The inoculum, consisting of a suspension of either organism, was administered by transthoracic intrapulmonic injection to 23 calves. Three died of septicemia; the 20 remaining, killed 96 hours after inoculation, had an expanding unifocal pneumonia qualitatively comparable with that of acute pneumonic pasteurellosis (shipping fever). The concentration of bacteria that consistently produced a lesion was a 5-ml volume containing 109 colony-forming units of bacteria; a concentration of 106 colony-forming units inconsistently produced lesions. Bacteria, except in calves that developed septicemia and died, remained localized at the injection site. The inflammatory process spread within the lungs, not only through airways, but through the interlobular and interalveolar septa as well.
Influence of Escherichia coli endotoxin-induced fever on pharmacokinetics of imidocarb in dogs and goats
Authors: Abdullah A. Salam , Baggot J. Desmond
Published: February 2025

The pharmacokinetics of imidocarb, administered as an iv bolus dose (4 mg/kg), was studied in normal and Escherichia coli endotoxin-induced febrile dogs and goats. In the febrile group, the drug was administered 1 hour after injection of the endotoxin. The plasma and urine concentrations of imidocarb were measured by spectrophotometry. The decline in plasma drug concentrations in both species was analyzed, using a 2-compartment open model. With the exception of the coefficient A and the volume of central compartment, E coli endotoxin-induced fever produced the same changes in kinetic determinants in both species. Fever significantly decreased the distribution rate constant in both dogs (P < 0.05) and goats (P < 0.01). The elimination rate constant and, in turn, the half-life were not altered by the endotoxin-induced fever in either species. The volume of distribution at steady-state was significantly lower (P < 0.01) in the febrile dogs and goats. The body clearance of imidocarb was also significantly lower in the febrile dogs (P < 0.05) and goats (P < 0.01). The decreased apparent volume of distribution and lower body clearance of imidocarb could explain the higher plasma values of the drug in the febrile, compared with normal, animals.
Intra-articular tissue response to analytical grade metrizamide in dogs
Authors: Atilola Matthew A. O. , Lumsden John H. , Hulland Tom J. , Pennock Paul W.
Published: February 2025

The effect of analytical grade metrizamide (am) injected into the canine stifle, for purposes of arthrography, was studied in 12 adult dogs using saline solution as the control solution injected into the contralateral joints. The am was used at a concentration of 280 mg of iodine/ml and was administered at the dose of 0.3 ml/cm thickness of the stifle joint. For each joint, arthrocentesis was done before and 7 days after injection of either the contrast medium or saline solution. Physical, biochemical, and cytologic examinations were done on the synovial fluid while the synovial membranes and femoral articular cartilages were sectioned, stained, and examined for histopathologic changes. At the 95% confidence level, significant differences in the total and differential mononuclear cell counts were not seen between the am- and saline solution-injected joints. However, some subtle changes in the synovial membranes were observed. Intra-articular injection of am or saline solution initiated a mild inflammatory response, the am causing slightly more response than the saline solution.
Evaluation of cytopathologic changes induced in chicken tracheal epithelium by Mycoplasma gallisepticum in vivo and in vitro
Authors: Dykstra M. J. , Levisohn S. , Fletcher O. J. , Kleven S. H.
Published: February 2025

Changes in tracheal epithelial surfaces induced by Mycoplasma infection in vivo and in vitro included release of mucous granules followed by exfoliation of ciliated and nonciliated epithelial cells. Light microscopy, scanning electron microscopy, and transmission electron microscopy confirmed that the loss of cilia from individual cells was infrequent. Epithelial cells typically lost their intercellular connections, rounded up, exfoliated, and then lysed—giving rise to a population of cellular organelles, such as mitochondria and cilia intermixed with mucus to form the exudate found within the tracheal lumen. Repair of the epithelial surface was effected by basilar epithelial cells differentiating and filling in the spaces formed by exfoliated cells. These cells were hypertrophied, nonciliated at 14 days after infection in vivo, and covered with microvilli. In sectioned material obtained during the infection, there was increasing epithelial thickness due to cellular infiltration and edema. Tracheal rings in vitro showed similar changes to those seen in vivo, except that exfoliation was more severe and occurred earlier. In addition, there were no cellular infiltration due to the lack of a vascular supply and only a small amount of mucus due to the smaller number of mucous cells available to release into the tracheal lumen.
Role of insects in the transmission of bovine leukosis virus: Potential for transmission by stable flies, horn flies, and tabanids
Authors: Buxton B. A. , Hinkle N. C. , Schultz R. D.
Published: February 2025

The ability of stable flies (Stomoxys calcitrans, horn flies (Haematobia irritans), and tabanids (Diptera: Tabanidae) to transmit bovine leukosis virus (blv) was investigated. Stable flies and horn flies were fed on blood collected from an infected cow, and the flies’ mouthparts were immediately removed, placed in RPMI-1640 medium, ground, and inoculated into sheep and calves. Infection of sheep occurred with mouthparts from as few as 25 stable flies or 25 horn flies. However, sheep were not infected when removal of stable fly mouthparts was delayed ≥ 1 hour after blood feeding. Infection of calves occurred after inoculation of mouthparts removed immediately after feeding from as few as 50 stable flies or 100 horn flies.

Infected blood, applied by capillary action to the mouthparts (labella) of 15 deer flies (Chrysops sp) and a single horse fly (Tabanus atratus) caused infection in each of 2 sheep. Infection did not occur in 2 calves inoculated daily for 5 days with mouthparts from 50 horn flies collected after feeding on a blv-infected steer. Four calves receiving bites from 75 stable flies interrupted from feeding on a blv-positive cow also were not infected. Seronegative cattle held for 1 to 4 months in a screened enclosure with positive cattle in the presence of biting flies were not infected with blv. The feeding behavior of each insect is discussed to assess their potential as vectors of blv.
Isolation of bovine eosinophils by density gradient centrifugation
Authors: Chambers W. H. , Washburn S. M. , Campos M. , Klesius P. H.
Published: February 2025

A method for the isolation of an enriched population (> 60%) of bovine eosinophils was developed, using density gradient centrifugation. Eosinophils were isolated from peripheral blood by centrifugation on a density gradient medium of sp gr 1.092. Viability was ≥ 95%, and the isolated eosinophils were found to be functional in chemokinetic and antibody-dependent cellular-cytotoxicity assays. This method represents a simple, rapid method for obtaining bovine eosinophils that can be used in a variety of assays of eosinophil function.
Postmortem magnesium concentration in bovine vitreous humor: Comparison with antemortem serum magnesium concentration
Authors: Lincoln S. D. , Lane V. M.
Published: February 2025

The range for postmortem vitreous humor Mg2+ concentration in 97 healthy cattle was 1.8 mg/dl to 2.72 mg/dl at 23 C for a 48-hour postmortem interval. The postmortem vitreous Mg2+ concentration closely paralleled the antemortem serum Mg2+ concentration at 23 C. Low environmental temperature (4 C) had no effect on postmortem vitreous concentration. However, high environmental temperatures (30 C) significantly (P < 0.05) reduced postmortem vitreous Mg2+ concentration at the 36-hour postmortem interval. It was concluded that postmortem vitreous humor Mg2+ determination could be a useful diagnostic aid in cattle for detecting Mg2+ imbalances for at least 48 hours after death, provided the postmortem environmental temperature did not exceed 23 C after 24 hours.
Efficacy of oral clorsulon in the treatment of Fasciola hepatica infections in calves
Authors: Yazwinski T. A. , Kilgore R. L. , Presson B. L. , Williams M. L. , Fulton R. K. , Pote L. , Greenway T. E.
Published: February 2025

Twenty calves at each of 2 Arkansas locations were inoculated with infective Fasciola hepatica metacercariae. After 56 days, the calves at each site were randomly assigned by weight to 2 treatment groups of 10 calves/group; vehicle control or clorsulon at the rate of 7 mg/kg of body weight. All treatments were given orally as a suspension. Calves were killed 6 weeks after treatment and F hepatica counts were performed for all animals. At the 2 sites, mean levels of efficacy were 96% and 91%. Adverse reactions to clorsulon or the vehicle were not observed in the calves.
Platelet and fibrinogen kinetics in healthy and African swine fever-affected swine: [75Se]Selenomethionine-labeling study
Authors: Edwards J. F. , Dodds W. J.
Published: February 2025

Platelet and fibrinogen survival times were determined in healthy pigs and in pigs infected with African swine fever (asf) virus. Cohort labeling with [75Se]selenomethionine was performed. The platelet survival time in healthy pigs was 5.3 ± 0.7 days, and the fibrinogen survival time was 6.7 ± 0.8 days. Early deaths and profound thrombocytopenia prevented calculation of accurate platelet and fibrinogen survival times in asf virus-infected animals. The asf virus-infected pigs died of extensive hemorrhage and effusions while thrombocytopenic; however, there was normal thrombocytopoiesis during infection, as measured by incorporation of the radionuclide into platelets. There was a slight decrease in plasma fibrinogen concentration when the platelet count decreased. A dysfunctional fibrinogen was present late in the infection.
Haemonchus contortus and Ostertagia circumcincta: Fenbendazole treatment and abomasal permeability changes in sheep
Authors: Dakkak Allal , Daoudi Ahmed , Ruckebusch Yves
Published: February 2025

Effects of fenbendazole (7.5 mg/kg of body weight infused during 90 minutes) on abomasal transmural potential difference (pd), pH, and ionic concentrations were determined in 8 lambs fitted with permanent abomasal cannulae. Four sheep were treated before inoculation and on day 28 after inoculation, with 200,000 3rd-stage Ostertagia circumcincta larvae and 4 others were similarly inoculated with 15,000 3rd-stage Haemonchus contortus larvae.

In worm-free lambs, the unique effect was an increase in Na+ concentration of the abomasal contents. The O circumcincta or H contortus-inoculated lambs had an increase in pd, pH, and Na+ concentrations. Treatment further increased these concentrations, but the effects on pd occurred and ceased earlier in sheep inoculated with O circumcincta than in those inoculated with H contortus. The results indicated that part of the changes were linked to substances produced by the parasites or by the host. The increase in pd and pH was associated with a decrease in K+ concentration and indicated that these substances stimulated HCO-3 transfer.
Effect of vitamin A deficiency on mammary gland development and susceptibility to mastitis through intramammary infusion with Staphyloccus aureus in mice
Authors: Chew B. P. , Zamora C. S. , Luedecke L. O.
Published: February 2025

Weanling mice were fed 0 or 150 μg retinol equivalent/kg of diet for 5 weeks, were bred, and allowed to complete gestation. On day 3 of lactation, all mice were separated from their litters for 1 hour and were then anesthetized. The 4th right or left mammary gland was inoculated with 0.1 ml of S Aureus (1010 colony-forming units/0.1 ml). Exactly 24 hours after inoculation, the mice were euthanatized and the mammary glands were removed and fixed for histologic evaluations. Vitamin A-deficient dams had smaller litter size and lower liver stores of vitamin A; however, deficiency was not severe enough to produce external signs of vitamin A deficiency in the dams. Morphologic studies showed large areas of adipose tissue, greatly reduced ductal and lobule-alveolar development, and decreased total secretory activity in mammary glands from vitamin A-deficient females. On the other hand, mammary glands from vitamin A-supplemented mice had extensive lobule-alveolar development and highly distended alveoli. Extensive necrosis of alveolar tissue was observed in staphylococcus-infused mammary glands of all mice. Large numbers of leukocytes and cell debris were present in the lumen of alveoli and ducts. However, mammary glands from vitamin A-deficient females had more extensive pathologic damage compared with corresponding glands from vitamin A-supplemented mice. Results indicated that vitamin A-deficient mice had reduced mammary development and increased pathologic damage to the mammary gland after intramammary challenge with staphylococcus.
Effects of cryotherapy on the palmar and plantar digital nerves in the horse
Authors: Schneider Robert K. , Mayhew Ian G. , Clarke Gary L.
Published: February 2025

The duration of anesthetic effect and the histopathologic changes resulting from a controlled freeze of the palmar and plantar digital nerves in the horse were evaluated. Two techniques were compared: (i) nerves were frozen by direct application of the cryoprobe after surgical exposure and (ii) nerves were frozen by percutaneous application of the cryoprobe to the overlying skin.

Return of skin sensation and ability to detect a stimulus were used to determine return of nerve function. The duration of anesthetic effect was significantly (P < 0.005) longer for nerves frozen after surgical exposure than for those frozen by the percutaneous technique (mean 156 days vs 47.5 days).

At the termination of the study, horses were euthanatized and all nerves were examined histologically. Neuromas-in-continuity were observed in 10 of 28 frozen nerves. Classification was based on the involvement of the supporting fibrous connective tissues of the nerve, endoneurium, perineurium, and epineurium. The direct technique of freezing the nerve after surgical exposure was repeatable and could be used to provide temporary neurectomy in the horse. The percutaneous technique caused a temporary loss of pain perception, but could not be relied on to interrupt nerve function for longer than a few weeks.
Effects of gastric distention-volvulus on coronary blood flow and myocardial oxygen consumption in the dog
Authors: Horne W. A. , Gilmore D. R. , Dietze A. E. , Freden G. O. , Short C. E.
Published: February 2025

Gastric distention-volvulus (gdv; at 50 mm of Hg gastric inflation pressure) was experimentally induced in 8 dogs anesthetized using pentobarbital. Hemodynamic indices including heart rate, mean arterial pressure, cardiac output, and coronary blood flow (4 dogs) were measured during a 20-minute period of gdv and for 10 minutes after decompression. Arterial and coronary venous oxygen tensions were also measured for calculation of myocardial oxygen extraction (7 dogs) and myocardial oxygen consumption (4 dogs). Dogs were monitored for 72 hours postoperatively for the occurrence of arrhythmias, then were euthanatized for gross and histologic examination of the heart.

Experimental gdv resulted in significant (P < 0.05) decreases in cardiac output (89%), mean arterial pressure (45%), and coronary blood flow (50%) compared with control values. Myocardial oxygen extraction increased (30%) and overall myocardial oxygen consumption decreased (50%), compared with control values. Evidence of subendocardial necrosis was seen in 6 dogs, 4 of which had developed ventricular arrhythmias 8 to 24 hours postoperatively.
Ultrastructure of normal epiphyseal cartilage of the articular-epiphyseal cartilage complex in growing swine
Authors: Carlson C. S. , Hilley H. D. , Henrikson C. K.
Published: February 2025

Normal epiphyseal cartilage from the articular-epiphyseal cartilage complex (a-e complex) of the distal parts of the femur and humerus of growing commercial crossbred boars was collected, embedded in plastic, and studied by light and electron microscopies. The morphology of this cartilage was determined to provide a basis for comparison with cartilage affected with osteochondrosis, an important clinical disease in swine.

Normal epiphyseal cartilage from the a-e complex in growing swine was divided into 4 major regions of cells; resting, proliferating, hypertrophic, and calcifying regions. Cells in the resting zone contained prominent lipid and densely aggregated glycogen. As the cells proliferated and matured, the lipid and glycogen became less prominent. The lipid droplets became smaller and scarcer, and the glycogen became dispersed in the cytoplasm. Proliferating and hypertrophic cells clustered in roughly egg-shaped groups of 4 to 8 cells/plane of section. In the calcifying region, the interterritorial matrix (between cell clusters) calcified, and the territorial matrix (uniting cells in a cluster) remained uncalcified. Calcified matrix extended the depth of one cell group from the area of capillary penetration, and the capillaries invaded by entering a cluster of cells.

Territorial matrices in all regions of a-e complex epiphyseal cartilage were composed of randomly oriented collagen fibrils with a granular fibrillar proteoglycan network dispersed between the fibrils. Heterogeneity of chondrocytes was characterized by the presence of both light- and dark-staining cells in the proliferating through calcifying regions and by 3 morphologically distinct light cell types in the late hypertrophic and calcifying regions.
Production of superoxide anion by bovine pulmonary macrophages challenged with soluble and particulate stimuli
Authors: Dyer Robert M. , Benson Charles E. , Boy Mary G.
Published: February 2025

The effects of opsonized zymosan, phorbal myristate acetate, and live Pasteurella haemolytica on superoxide anion production by bovine pulmonary macrophages were determined. The anion responses were dose-dependent for all stimuli, except for unopsonized P haemolytica. The effect of viable P haemolytica on macrophage viability was related to bacterial dosage and the presence of opsonizing antibody. Superoxide responses varied directly with the dose of opsonized live P haemolytica, but indirectly with macrophage viability.
Effect of vaccination with live or killed Pasteurella haemolytica on resistance to experimental bovine pneumonic pasteurellosis
Authors: Confer A. W. , Panciera R. J. , Fulton R. W. , Gentry M. J. , Rummage J. A.
Published: February 2025

Using 6- to 8-month-old beef calves, 3 experiments were conducted to compare the effect of vaccination with live or killed Pasteurella haemolytica on resistance to a transthoracic challenge exposure with the organism and to correlate serum antibody response with resistance. In each experiment, calves were vaccinated twice at 1-week intervals and were challenge exposed 21 days after the first inoculation. Lung lesions were evaluated by a system, such that higher scores indicated the more severe lesions. In each experiment, calves immunized with live P haemolytica had lower lesion scores than calves vaccinated with saline solution or bacterin. In 2 of the experiments, the differences were significant (P < 0.05). In all experiments, calves vaccinated parenterally with a commercial P haemolytica/P multocida bacterin or with a formalin-killed P haemolytica bacterin had lesion scores that were not significantly different (P > 0.05) than for control calves vaccinated with saline solution.

Live and killed bacterial preparations induced a significant serum antibody response to P haemolytica as measured by a quantitative fluorometric immunoassay. The antibody response to vaccination was not affected by preexisting titers to P haemolytica. Serum antibody titers were not consistently as high for calves vaccinated with bacterins as for calves vaccinated with live organisms.

Although high antibody titers correlated with low lesion scores when calves vaccinated with saline solution or live organisms were analyzed collectively, there was not a significant correlation between the 2 variables when calves, vaccinated with saline solution or with bacterin, were analyzed collectively. These data indicate that, although bacterins may induce a detectable serum antibody response, they do not induce protection against transthoracic challenge exposure to P haemolytica.
Antagonism of xylazine sedation with yohimbine, 4-aminopyridine, and doxapram in dogs
Authors: Hatch Roger C. , Kitzman Joseph V. , Zahner Joanne M. , Clark J. Derrell
Published: February 2025

Groups of atropinized dogs (6 dogs/group) were sedated with xylazine (2.2 mg/kg of body weight, im). At recumbency, the dogs were given iv saline solution (control groups), yohimbine (0.05, 0.1, and 0.2 mg/kg), 4-aminopyridine (4-ap; 0.3, 0.6, and 0.9 mg/kg), doxapram (0.5, 1.0, 2.0, and 4.0 mg/kg), or the smallest dose of these antagonists in dual combinations or in triple combination. Two additional groups were sedated with an overdose of xylazine (11 mg/kg, im). At recumbency, 1 of these groups was given saline solution iv and the other group was given yohimbine iv (0.4 mg/kg) as the antagonist.

With the 2.2 mg/kg dose of xylazine, control mean arousal time (mat) and mean walk time (mwt) were 15.5 minutes and 24.8 minutes, respectively. These values were decreased by the individual antagonists to 0.5 to 2.5 minutes and 0.9 to 7.4 minutes, respectively. Approximate equipotent doses of antagonists (mg/kg) were: yohimbine, 0.2; 4-ap, 0.6; and doxapram, 0.5. Relapses did not occur after yohimbine or 4-ap. With doxapram, muscle tremors and spasms, abnormal postures, or aggressive behavior occurred in several dogs and several dogs had partial or complete relapses. The small doses of individual antagonists were synergistic with regard to mat, mwt, and duration of residual sedation, but the various combinations of antagonists were not more effective in these regards than were larger doses of the single antagonists.

With the overdose of xylazine, control mat and mwt were 41.5 minutes and 144.5 minutes, respectively. Yohimbine decreased these values to 2.2 minutes and 2.5 minutes, respectively, Relapses did not occur.

Of the antagonists tested, yohimbine was most effective, in that it provided the best combination of short mat and mwt, minimal residual sedation and ataxia without relapse, and fewest side effects, Yohimbine was also an excellent antidote for an overdose of xylazine. Combinations of yohimbine, 4-ap, and doxapram did not offer a real advantage over yohimbine alone for antagonism of xylazine sedation in dogs.
Appearance of immunoglobulin classes and complement (C3) during Corynebacterium renale-induced experimental pyelonephritis in the rat
Authors: De Buysscher Edward V. , Appleton Judith A. , Kadis Solomon
Published: February 2025

The local appearance of various immunoglobulin (Ig) isotypes in the urinary tract during ascending pyelonephritis was studied in rats experimentally infected with Corynebacterium renale. The indirect fluorescent antibody assay was used to detect IgG, IgM, IgA, IgE, and C3 on C renale present in the urine of the experimental animals. Corynebacterium renale coated with IgM and IgG antibodies was found beginning on the 4th day after induced infection, with IgG being the more abundant isotype. Coating with IgA occurred as early as the 4th day, but was less dense than coating with IgG. The presence of C3 on C renale was concurrent with IgM and IgG coating. A significant quantity of IgE could not be identified on antibody-coated C renale. Thus, IgG is the major component of the humoral immune response in this model of ascending pyelonephritis. The IgM early during infection and IgA later during infection seem not to be a major component of the immune response in this model.
In vitro cultivation of Babesia bigemina
Authors: Vega C. A. , Buening G. M. , Green T. J. , Carson C. A.
Published: February 2025

A strain of Babesia bigemina was isolated from an infected calf and propagated in vitro. Culture conditions included washing of infected and normal bovine erythrocytes in a special solution, and the use of a 5% to 10% (v/v) erythrocyte suspension in medium 199 (with 20% to 50% fresh normal bovine serum) at a depth of 4 mm in a 5% CO2, 2% O2, 93% N2 atmosphere. After 36 days in vitro and 9 subcultures, the cultured organism was inoculated into a susceptible calf. This calf developed clinical signs of disease and recovered when treated with 1% trypan blue solution. The strain was also reisolated from the second calf. The original isolate had been maintained in continuous in vitro cultivation for more than 99 days.
Effect of verapamil on cardiac chronotropic response to vagal stimulation in neonatal pigs
Authors: Lee John C. , McGrath Charles J. , Kornegay E. T.
Published: February 2025

The effects of verapamil on the chronotropic response to vagal stimulation in young pigs anesthetized with sodium pentobarbital (30 mg/kg of body weight, intraperitoneally) was evaluated. After bilateral vagotomy, the administration of verapamil (loading dose of 100 μg/kg, followed by 2 μg/kg/min infusion) resulted in a significant (P < 0.05) reduction in heart rate (hr) and mean arterial blood pressure. Cardiac frequency responses to vagal stimulation were obtained by stimulating the distal end of the right vagus nerve at selected frequencies (5, 10, 15, and 20 Hz) with supramaximal voltage (10 to 15 V) and constant duration (2 ms). The hr was measured after 15 s at each level of stimulation. The slopes of decrease in hr to the frequency of vagal stimulation were significantly (P < 0.05) reduced after verapamil as compared with its controls. After atropine (0.5 mg/kg), the vagally induced tachycardia was partially attenuated by verapamil, but was completely eliminated by β blockade with propranolol (1 mg/kg). These findings indicated that verapamil may influence the parasympathetic control of the heart in young pigs.
Pharmacokinetics of ticarcillin in the dog
Authors: Tilmant Latayah , Brown Murray P. , Gronwall Ronald R.
Published: February 2025

Five healthy adult dogs were given a single iv dose (40 mg/kg of body weight) of ticarcillin disodium. Serum concentrations were measured serially over a period of 12 hours. Five days later, the drug was administered im to the dogs at the same dose rate, and serum concentrations were measured serially for 12 hours. The mean peak serum concentration after im administration was 120.5 μg/ml at 1.5 hours. Pharmacokinetic values following iv administration were (i) elimination rate constant = 0.8/hour-1, (ii) half-life = 0.8 hour, (iii) serum clearance = 292 ml/hr/kg, and (iv) apparent volume of distribution = 347 ml/kg. Estimated values after im administration were (i) elimination rate constant = 0.6/hour, (ii) half-life = 1.1 hours, (iii) serum clearance = 218 ml/hr/kg, and (iv) apparent volume of distribution = 345 ml/kg; only the elimination rate constants were significantly different between the 2 routes of administration.