bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of flow-volume curves generated by forced-expiratory spirometry in anesthetized dogs
Authors: Knowlen Grant G. , Hamlin Robert L. , Rice David A.
Published: February 2025

Positive-pressure plethysmography was used to generate partial and maximal flow-volume data in 10 anesthetized dogs. Acetylcholine (ACh) administered iv induced significant (P < 0.05) changes in tidal breathing, as evidenced by decreased tidal volume, increased respiratory rate and dynamic resistance, and decreased dynamic compliance.

Partial forced-expiratory spirometry, determined from end inspiratory capacity and functional residual capacity, revealed changes in flow and volume as a result of ACh treatment. These changes were not seen in maximal curves (determined from total lung capacity). Peak expiratory flows were limited by the presence of an endotracheal tube. Use of instantaneous time-constant variables to evaluate the concavity or convexity of the downslope of a flow-volume curve did not reveal differences after iv ACh administration.

Seemingly, partial forced-expiratory spirometry was useful in detecting bronchoconstriction in anesthetized dogs. Accepted techniques of flow-volume curve analysis for the evaluation of small airway function were not sensitive enough to detect bronchoconstriction in the dog.
Relationship between Mycoplasma hyosynoviae infection and front limb weakness in Duroc swine
Authors: Lawrisuk L. S. , Rothschild M. F. , Ross R. F. , Christian L. L.
Published: February 2025

A relationship between degree of Mycoplasma hyosynoviae infection and front limb soundness was examined in 254 Duroc swine. These pigs represented 3 lines of pigs (structurally sound, control, and unsound) from a population divergently selected for 4 generations for front limb soundness. Analysis of sera collected every 4 weeks between 6 and 26 weeks of age yielded complement-fixing antibody titers that were believed to be indicative of the degree of natural infection with M hyosynoviae. Analysis of several variables defined by using titer values failed to reveal significant differences among the 3 selected lines, but trends indicated higher mean and peak titer values for pigs from the unsound line. Correlations between titer variables and front limb soundness variables within genetic groups were low and not significantly different from zero. Correlations between all titer variables were calculated; the correlation between mean titer and peak titer was 0.81 (P < 0.01), and between mean titer and age at detection of first titer, was −0.56 (P < 0.01). Pooled heritability estimates were 0.51 ± 0.28 for mean titer and 0.28 ± 0.25 for peak titer.
Papillomavirus genomes in experimentally induced fibromas in white-tailed deer
Authors: O'Banion M. Kerry , Sundberg John P.
Published: February 2025

Cutaneous fibromas of white-tailed deer were transmitted successfully to 5 young deer. Serial biopsy specimens of the induced lesions were analyzed for white-tailed deer papillomavirus, using Southern blot hybridization. Viral genomes were found in all specimens taken 1 to 7 weeks after inoculation and, in some cases, from specimens of the inoculation site obtained later. Viral dna was found before histologic evidence of fibroblast proliferation and persisted in low copy number, compared with viral dna of naturally developing fibromas.
Profiles of type-II pneumocytes in rats inoculated intratracheally with bacterial lipopolysaccharide
Authors: Lopez Alfonso , Albassam Mudher , Yong Shirley , Sharma Arvind , Lillie Leonard E. , Prior Michael G.
Published: February 2025

Ultrastructural and morphometric profiles of type-II pneumocytes (P-II) were investigated in rats killed 18 or 24 hours after a single intratracheal inoculation of bacterial (Escherichia coli) lipopolysaccharide (lps). Inoculation with lps induced pulmonary injury and inflammation, as measured by increased lactate dehydrogenase and alkaline phosphatase activities and increased numbers of polymorphonuclear neutrophils in fluid collected by bronchoalveolar lavage. Marked ultrastructural changes and desquamation of a few P-II developed at the time of high activity of lactate dehydrogenase and alkaline phosphatase in bronchoalveolar lavage fluid. Ultra-structural changes included swollen mitochondria and localized cisternal dilatation of the endoplasmic reticulum in which was contained membrane-bound homogenous material of medium electron density.

Twenty-four hours after lps inoculation, point-count stereologic analysis and digitizing morphometry revealed > 50% increase in P-II size. Changes in cell size corresponded with ultrastructural finding of swollen cells. Results obtained by point-count stereologic analysis and digitizing morphometry were highly correlated (r = 0.95). Lamellar bodies (lb) comprised 12 to 15% of P-II volume. Volume density and number of lb remained unaltered in lps-injured P-II, and evidence of accelerated release of lb was not detected after lps inoculation. Exudated polymorphonuclear neutrophils and pulmonary alveolar macrophages were involved actively in the phagocytosis of lb originating from necrotic and desquamated P-II. On the basis of measurement of enzyme activity (enzymes released into the bronchoalveolar space), considerable ultrastructural alterations developed in P-II when maximal lps-induced pulmonary cell injury took place.
Diarrhea associated with enterotoxigenic Bacteroides fragilis in foals
Authors: Myers Lyle L. , Shoop Douglas S. , Byars T. Douglas
Published: February 2025

Enterotoxigenic Bacteroides fragilis (etbf) was isolated from the feces of 10 of 40 Thoroughbred foals with naturally acquired diarrhea Of the 10 foals positive for etbf, 6 were ≤ 7 days old. Fecal specimens from 4 of the 10 foals also were positive for rotavirus, and one fecal specimen was positive for Salmonella enteritidis. Clinical or hematologic differences were not evident between foals infected with etbf only and those infected with etbf and another recognized enteric pathogen. Only 1 of 10 foals infected with etbf died. Of 25 adult rabbits with ligated ceca, 23 developed mucoid, often hemorrhagic, diarrhea after inoculation of 5 × 109 viable etbf cells into the ileum. Nine of 13 (69%) rabbits inoculated with 1 of 3 isolates of etbf died, but none of 12 inoculated with 1 of 6 other isolates of etbf died. Enteric disease did not develop in 15 rabbits inoculated with non-enterotoxigenic B fragilis.
Pulmonary dysfunction in neonatal calves after intratracheal inoculation of small volumes of fluid
Authors: Killingsworth C. R. , Slocombe R. F. , Alnoor S. A. , Robinson N. E. , Derksen F. J.
Published: February 2025

Intratracheal instillation of 20 ml of room temperature (21 to 24 C) fluid in anesthetized neonatal calves resulted in rapid onset of reversible pulmonary dysfunction. Arterial O2 tension and dynamic compliance decreased, whereas pulmonary arterial pressure, pulmonary vascular resistance, alveolar arterial O2 difference, and total pulmonary resistance increased from base-line values. Abnormalities of gas exchange and pulmonary mechanics were induced by intratracheal fluid instillation whether or not Pasteurella haemolytica was in the inoculum. Physical manipulation of the calf without intratracheal fluid instillation (sham inoculation) did not influence pulmonary function. Bilateral vagotomy eliminated the increase in pulmonary resistance and the decrease in dynamic compliance, but did not eliminate hypoxemia, increased alveolar arterial O2 difference, or pulmonary hypertension recorded after intratracheal fluid instillation. Seemingly, changes in pulmonary mechanics are mediated via the vagus nerve. However, one or more additional mechanisms must be responsible for the hypoxemia and pulmonary hypertension.
Distribution of methionine-enkephalin-Arg6-Gly7-Leu8-immunoreactive nerves in the forestomach of cattle
Authors: Kitamura Nobuo , Yamada Junzo , Yamashita Tadayuki , Yanaihara Noboru
Published: February 2025

The distribution of methionine-enkephalin-Arg6-Gly7-Leu8-immunoreactive nerves in the forestomach of calves and cows was studied, using immunohistochemical methods. Methionine-enkephalin-Arg6-Gly7-Leu8-immuno-reactive nerves were found in all regions of the bovine forestomach. Cell bodies were found mainly in myenteric ganglia, and nerve fibers were found principally in muscular layers. Nerve fibers and ganglia were concentrated in the lips of the reticular groove, but were least numerous in ruminai and omasal walls. The reduced number of immunoreactive nerves in cows, compared with the number of those in calves, was striking, especially in the lips of the reticular groove and the omasal leaves. Results may indicate that the importance of methionine-enke-phalin-Arg6-Gly7-Leu8-containing nerves in the physiologic regulation of the forestomach of the calf is different from that of the cow.
Estrone sulfate concentrations as an indicator of fetal demise in horses
Authors: Kasman Lonnie H. , Hughes John P. , Stabenfeldt George H. , Starr Mark D. , Lasley Bill L.
Published: February 2025

Serum and urinary estrone sulfate concentrations were determined in 7 pregnant mares before and after prostaglandin-induced abortion (n = 4) or surgical removal of the fetus (n = 3) to determine the source of estrogen during early pregnancy (gestation days [gd] 44 to 89). Estrone sulfate concentrations also were determined in serum samples (stored frozen for 2 years) from 3 mares that had been ovariectomized between gd 51 and 58. Estrone sulfate concentrations decreased in serum and urine after expulsion or removal of the fetus (urinary patterns were more definitive than were patterns for serum), whereas a transient decrease in serum estrone sulfate concentration was observed after ovariectomy. Seemingly, products of conception are the major source of estrone sulfate during early pregnancy, although there appears to be some ovarian contribution. Serum or urinary estrone sulfate measurements provide a simple and accurate test for fetal viability after gd 44 in the mare.
Antigenic analysis of Pasteurella haemolytica serovars 1 through 15 by crossed immunoelectrophoresis
Authors: Tsai Li-Huei , Collins Michael T. , Høiby Niels
Published: February 2025

Pasteurella haemolytica serovars 1 through 12, grown in broth and on agar plates, and 2 field isolates (types Al and T10) were used to develop polyvalent crossed immunoelectrophoresis (xie) reference systems. The maximal number of antigens was revealed by xie when sonicates of agar plate-grown organisms were used as the immunogen (to produce antibodies) and as the soluble antigen for xie. Antigens produced from agar plate-grown organisms were less contaminated (by antigenic components of the medium) than were those produced from organisms grown in broth. Seventy-two antigens were detected in sonicated preparations of agar plate-grown P haemolytica. The common antigen of gram-negative bacteria was identified in the P haemolytica xie reference system; precipitation was observed with rabbit antiserum to the common antigen of gram-negative bacteria isolated from Escherichia coli, as well as with rabbit immunoglobulins (obtained from unvaccinated rabbits). Most preimmune sera from our vaccinated rabbits also precipitated the common antigen. Serovar-specific antigens in the P haemolytica xie reference system were defined and presumptively identified as part of the bacterial lipopolysaccharide complex by use of the limulus amebocyte lysate test. Partial cross-reactions were found between serovar-specific antigens within each biovar (A and T). Pasteurella haemolytica biovar A-specific and biovar T-specific antigens were defined by crossed-line immunoelectrophoresis. When serovars A13, A14, and T15 were tested in the P haemolytica xie reference system, they gave high matching coefficient values of 0.98, 0.98, and 0.87, respectively. The proposal to separate P haemolytica biovars A and T into 2 different species was supported by immunotaxonomic data obtained from crossed immunoelectrophoresis, but more extensive studies will be necessary to establish the appropriate taxonomic position of these 2 groups of organisms.
Hematologic and serum biochemical alterations associated with multiple halothane anesthesia exposures and minor surgical trauma in horses
Authors: Stover Susan M. , Steffey Eugene P. , Dybdal Nöel O. , Franti Charles E.
Published: February 2025

Five horses were anesthetized similarly by use of xylazine, guaifenesin, thiamylal sodium, and halothane in oxygen on 3 consecutive days, and minor surgical procedures were performed. For 1 to 10 days after the last anesthetic exposure, clinical, hematologic, and serum biochemical features were monitored, and after necropsy, histologic examination of major organ tissues was performed. Predominant hematologic changes from base-line values included leukocytosis (maximal at 27 hours, 10,500 ± 1,750 cells/μl), neutrophilia (maximal at 51 hours, 7,485 ± 1,719 cells/μl), and lymphopenia (minimal at 51 hours, 1,636 ± 564 cells/μl). Alterations observed in other clinicopathologic features were minor and indicative of mild renal disturbance and nonspecific cellular necrosis. Histopathologic lesions in the liver were mild.
Moderately virulent African swine fever virus infection: Blood cell changes and infective virus distribution among blood components
Authors: Genovesi Eugene V. , Knudsen Richard C. , Whyard Terry C. , Mebus Charles A.
Published: February 2025

Blood samples of pigs infected with a moderately virulent African swine fever virus (asfv) isolate, obtained from the Dominican Republic (DR-II), were monitored temporally for viremia, infective asfv association with major blood components, differential changes in blood cell composition, and plasma antibodies to asfv. After intranasal/oral virus inoculation, pigs underwent acute infection and illness that resolved. Acute illness began on postinoculation day (pid) 4 and continued to pid 11, and pigs were febrile, with maximal infective asfv titers detected in blood. By pid 11, initial antibody titers to asfv antigens were detected in plasma.

The wbc numbers were maintained near preinoculation counts; however, lymphocyte counts decreased slightly with a compensatory increment in neutrophil and monocyte numbers. From pid 11 to pid 25, rectal temperatures gradually returned to preinoculation values, titers of viremia began to decrease, plasma antibody to asfv antigens increased to peak titers, and wbc numbers increased slightly. Percentages of lymphocytes returned to preinoculation values, neutrophil percentages decreased to slightly below preinoculation values, monocyte percentages were mildly increased, and eosinophil percentages were unaffected. From pid 25 to pid 46, titers of viremia further decreased, and plasma titers of antibodies to asfv antigens remained high. In pigs with DR-II viremia (pid 4 to pid 46), most viral infectivity (> 95%) was rbc associated. Plasma contained < 1% infectivity, and < 0.1% of virus was in the wbc fraction (monocytes, lymphocytes, and granulocytes). After pid 46, viremia was no longer detectable.
Prolactin, estradiol, and progesterone changes in paretic and nonparetic cows during the periparturient period
Authors: Sechen Suzanne J. , Bremel Robert D. , Jorgensen Neal A.
Published: February 2025

We studied the relationship of serum prolactin, estradiol-17β, and progesterone concentrations to plasma calcium, phosphorus, and free hydroxyproline concentrations, as well as to dry matter intake, in 14 aged dairy cows (mean of 4.5 parities), 7 of which became paretic, from 28 days before to 4 days after calving. Plasma calcium and phosphorus concentrations and dry matter intake decreased more at parturition in paretic cows than in nonparetic cows. Prolactin concentrations were not different between paretic and nonparetic cows, but were variable. Concentrations of estradiol were higher in paretic cows from 15 to 5 days before parturition, whereas hydroxyproline concentration was lower in paretic cows on days 10 through 3 before parturition. Progesterone concentration was lower in paretic cows and decreased earlier at parturition, compared with that in nonparetic cows.

The findings suggested that high estradiol concentrations in late pregnancy inhibit bone resorption and predispose aged cows to parturient paresis. The earlier decrease in progesterone concentration at parturition and lower concentrations throughout late pregnancy might have contributed to the greater inappetence in paretic cows at parturition. The importance of prolactin in the pathogenesis of parturient paresis is not clear.
Identification of protein A from Staphylococcus intermedius isolated from canine skin
Authors: Fehrer Susan L. , Boyle Michael D. P. , Halliwell Richard E. W.
Published: February 2025

Protein A was identified in cell wall-bound and secreted forms from Staphylococcus intermedius isolated from canine skin. A direct binding radioimmunoassay for the detection of bacterial surface Fc receptors identified 48 of 50 S intermedius isolates that contained cell wall-bound protein A. Using a competitive binding radioimmunoassay for the detection of Fc-reactive proteins in bacterial culture supernatants, we identified 9 of 50 clinical isolates of S intermedius that secreted measurable quantities of an Fc receptor into the culture medium. Concentrated culture supernatants from these isolates were analyzed by western blotting techniques and probed with either a radiolabeled human IgG Fc-specific probe or a radiolabeled affinity-purified chicken antibody against protein A. The studies reported here confirmed that Fc receptors are secreted by S intermedius isolates from dogs and are antigenically and functionally similar or are identical to staphylococcal protein A. Analysis of Fc receptor secretion by S intermedius strains, isolated from dogs with a variety of dermatologic conditions, suggested a trend between severity of skin disease and the extent of Fc receptor secretion.
Temporal study of staphylococcal species on healthy dogs
Authors: Cox Hollis Utah , Hoskins Johnny D. , Newman Susan S. , Foil Carol S. , Turnwald Grant H. , Roy Alma F.
Published: February 2025

During a 1-year period, specimens were obtained monthly from 5 hair coat and 7 mucous membrane sites of 11 healthy dogs. Among 804 isolates of staphylococci, 13 species were identified. Staphylococcus intermedius was the most frequently isolated (40.2% of total isolates) coagulase-positive species, and S xylosus was the most frequently isolated (17.3%) coagulase-negative species. Moreover, S intermedius was the most frequently isolated species from the 12 sites evaluated and was isolated persistently from 8 of the 9 dogs that completed the 1-year study. On the basis of a commercial identification system, 14 profile numbers were identified for isolates of S intermedius. However, 2 profile numbers accounted for a majority (70.9%) of the isolates. Specific S intermedius biotypes identified on the basis of hemolysis, coagulase production, β-lactamase activity, and antimicrobial susceptibility patterns were found repeatedly in 3 dogs. Seemingly, S intermedius was a resident of the normal bacterial microflora of these dogs; however, the inability to isolate S intermedius from 1 dog during the study year indicated that not all dogs harbor S intermedius as a resident microorganism.
Clinical and serologic evaluations of induced Borrelia burgdorferi infection in dogs
Authors: Greene Russell T. , Levine Jay F. , Breitschwerdt Edward B. , Walker Richard L. , Berkhoff Herman A. , Cullen John , Nicholson William L.
Published: February 2025

Adult Beagles were used to evaluate clinical signs and serologic response after inoculation with, or exposure to, Borrelia burgdorferi. An indirect immunofluorescent assay (ifa) and 2 elisa were used to monitor the serologic response to B burgdorferi. Feeding infected ticks on 4 dogs (group 1) failed to cause seroconversion, and sc inoculation with 500 organisms caused minimal seroconversion in 2 of 4 dogs (group 2). At 56 days, approximately 3.01 × 108 B burgdorferi organisms were injected iv into group-1 dogs, and intraperitoneally into group-2 dogs. A control group of 4 dogs (group 3) had noninfected ticks feed on them, and then were given iv injection of physiologic saline solution.

Increases in immunoglobulin M (IgM) titers were detected in 2 of 4 group-2 dogs approximately 7 days after the initial exposure. These titers returned to negligible values 20 days later. Immunoglobulin G titers increased approximately 10 days after the initial exposure and were mildly increased 56 days later, when dogs were exposed a second time. Both the iv and intraperitoneal injections (second exposures) resulted in increased IgM titers, which in both groups eventually returned to preexposure values after approximately 2 months. Immunoglobulin G titers increased within a week after the second exposure, and in 3 dogs monitored for 8 months, returned to negligible values after the 8-month period. One control dog had a slightly increased IgG titer 24 days after the second inoculation. The possibility of urine transmission is suggested.

Clinical status, hemograms, serum biochemical profiles, ecg and results of urinalyses remained normal throughout the study. Borrelia burgdorferi was not isolated from either the blood or urine of these dogs. Gross or microscopic pathologic changes were not detected on necropsy.
Beaded agarose affinity chromatography of bovine fibroblast interferon
Authors: Allen Gary K. , Rosenquist Bruce D.
Published: February 2025

Bovine fibroblast interferon (BoF-ifn), produced in bovine embryonic kidney cell cultures by priming and infection with bluetongue virus, was partially purified by controlled pore glass chromatography. The partially purified BoF-ifn then was subjected to beaded agarose affinity chromatography. The ifn eluted by affinity chromatography in 2 distinct fractions—1 after the addition of 1M NaCl and the other one after the addition of 1.5M NaCl containing 50% ethylene glycol. Analysis of fractions by sodium dodecyl sulfate/polyacrylamide-gel electrophoresis revealed a broad molecular weight range (14,900 to 27,900) for the ifn eluted by 1M NaCl, and 2 discrete molecular weight ranges (16,000 to 19,500 and 28,300 to 34,000) for ifn eluted by 1.5M NaCl containing 50% ethylene glycol. The specific activity of the ifn eluted with 1.5M NaCl containing ethylene glycol was 2.85 × 106 U/mg of protein, compared with 5.7 × 105 U/mg of protein in the controlled pore glass-purified ifn.
Effect of abraded intramammary device on outcome in lactating cows after challenge exposure with Streptococcus uberis
Authors: Paape M. J. , Schultze W. D. , Cortlett N. J. , Weinland B. T.
Published: February 2025

Intramammary devices (imd) were abraded with medium-grade emery cloth or were left smooth. One imd of each type was inserted into a mammary quarter of each of 5 lactating cows. The remaining 2 quarters served as controls. Quarter foremilk, bucket milk, and stripping milk samples were collected for 3 consecutive days at 2 weeks after imd insertion, and milk somatic cell counts (scc) were determined. Milk samples also were collected immediately after and 0.5, 1, 2, 4, 6, 8, and 11 hours after milking. All quarters were challenge exposed with 250 colony-forming units of Streptococcus uberis at 2 months after imd insertion. Foremilk and stripping milk samples were collected for bacteriologic culture and scc at the next 10 milkings. Mean foremilk, bucket milk, and stripping milk scc (× 106 cells/ml) were 0.18, 0.07, and 0.91, respectively, for quarters with abraded imd; 0.06, 0.05, and 0.43, respectively, for quarters with smooth imd; and 0 03, 0.03, and 0.15,. respectively for control quarters. Mean scc after milking (× 106 cells/ml) for the various intervals were 0.70, 1.29, 0.70, 0.97, 1.15, 1.17, 0.77, and 0.85 for quarters with abraded imd; 0.43, 0.62, 0.61, 0.45, 0.64, 0.60, 0.31, and 0.26 for quarters with smooth imd; and 0.15, 0.24, 0.15, 0.19, 0.15, 0.15, 0.14, and 0.06 for control quarters. After challenge exposure, 2 of 5 of the quarters with abraded imd, 4 of 5 of the quarters with smooth imd, and 8 of 9 control quarters became infected. Results indicated that abraded imd increased scc in stripping milk to concentrations that provided 60% protection against challenge exposure with S uberis.
Histologic evaluation of lung and bronchus-associated lymphoid tissue in young turkeys infected with Bordetella avium
Authors: Van Alstine W. G. , Arp L. H.
Published: February 2025

One-day-old turkeys were inoculated intranasally with Bordetella avium. Noninoculated hatchmates were housed separately. At postinoculation weeks 1, 2, 3, 4, and 5, B avium-infected (ba +) and B avium-free (ba−) turkeys were necropsied; specimens of tracheas, intrapulmonary primary bronchi, and lung adjacent to primary bronchi were bacteriologically cultured. Lung tissue was collected for histologic examination. Lungs perfused with acetic acid were collected for evaluation to determine the size, number, and distribution of lymphoid nodules associated with primary bronchi. Bordetella avium was isolated from trachea and primary bronchi of all ba + turkeys, but was never isolated from lung parenchyma. Acute purulent bronchitis was associated with colonization of the primary bronchi by B avium from postinoculation weeks 1 to 3. Macrophages and lymphocytes persisted in the peribronchial connective tissue for 5 weeks after inoculation. Bronchus-associated lymphoid tissue consisted of discrete, lymphoid nodules protruding into the lumens of primary bronchi. Lymphoid nodules, morphologically similar in ba + and ba − turkeys, were composed of nonciliated, cuboidal epithelium covering a zone of loosely arranged lymphocytes and macrophages and a deeper, sharply demarcated lymphoid follicle. Compared with bronchus-associated lymphoid tissue of ba − turkeys, lymphoid nodules of bronchus-associated lymphoid tissue in ba + turkeys were more numerous and widely distributed along primary bronchi. In both ba − and ba + turkeys, the mean diameter of lymphoid nodules doubled between 1 and 5 weeks of age.
Brucella abortus-specific immunoglobulin in isotypes in serum and vaginal mucus from cattle vaccinated with strain 19 and challenge exposed with virulent strain 2308
Authors: Hall Stephen M. , Confer Anthony W. , Patterson Judith M.
Published: February 2025

The immunoglobulins (IgG1, IgG2, IgM, and IgA) of the Brucella-specific antibody response of 69 crossbred beef heifer were studied after Brucella abortus strain 19 vaccination and strain 2308 challenge exposure. The immunoglobulin isotype responses in serum and vaginal mucus were measured by use of fluorescent immunoassay. Serum antibody responses were detected also by 3 standard serologic tests (complement fixation [cf], Rivanol precipitation, and the card test] and 2 primary binding assays that detect IgG antibodies.

One month after vaccination, mean antibody titers for all immunoglobulin isotypes were higher for vaccinated cattle (n = 46) than for nonvaccinated controls (n = 23). After vaccination, IgA antibody responses in vaccinated cattle were only 2-fold higher than those for controls, whereas IgG1, IgG2, and IgM antibody responses were 3- to 90-fold greater than those for controls. Measurement of IgA antibody responses classified 21 of 39 vaccinates as seropositive after vaccination, whereas the other isotypes classified 28 or 34 cattle as seropositive. Three months after challenge exposure, the mean antibody responses for each isotype were higher in cattle that aborted or were culture positive than in cattle that did not abort and were culture negative. Although IgG1, IgG2, and IgM antibody titers were each of benefit in identifying B abortus-infected cattle, it did not appear that the magnitude of the antibody responses provided sufficient discrimination between S19-vaccinated cattle and S2308 challenge-exposed cattle. Serum IgA antibody responses were 10-fold higher after challenge exposure than after vaccination and may be a response to mucosal infection with the virulent organism. Of the isotypes studied, serum IgA antibody responses most mimicked the cf and card test results in identifying seropositive cattle after challenge exposure. Serum IgG2 identified the most false-positive reactions.

Vaginal mucus antibody responses were measured 3 to 4 months after abortion or normal calving. The mean vaginal mucus IgG1, IgG2, and IgA antibody responses were higher in challenge-exposed cattle than in controls. Brucella-specific antibodies were highest in the vaginal mucus of culture-positive cattle that aborted.
Biomechanical properties of canine cortical bone allografts: Effects of preparation and storage
Authors: Roe Simon C. , Pijanowski Gerald J. , Johnson Ann L.
Published: February 2025

The effects of various preparation and storage procedures and of different storage times on structural properties of canine cortical bone allografts were determined by evaluation of the compressive load to failure of a whole diaphyseal segment, the ability of a screw to resist being pulled from a cortical segment, and the torque required to strip the threads of a screw hole in a cortical segment. Preparation and storage procedures evaluated were sterile collection and storage at −20 C; ethylene oxide sterilization and storage at room temperature (22 C); chemical sterilization (methanol and chloroform, then iodoacetic acid) and storage at −20 C; and chemical sterilization, partial decalcification, and storage at − 20 C. Storage times were 1, 16, and 32 weeks for each procedure.

After 1 week of storage, aseptically collected frozen bone and ethylene oxide-sterilized bone had an increase, compared with matched controls, in load to failure in compression, but pullout load or screw-stripping torque did not change. Chemically sterilized bone had not changed after 1 week of storage, whereas chemically sterilized and partially decalcified bone had a 40% to 60% decrease in compressive load to failure, pullout load, and screw-stripping torque. Chemically sterilized and partially decalcified bone remained weak after 16 and 32 weeks of storage. Significant structural alterations were not detected in aseptically collected bone after 16 or 32 weeks of storage. Ethylene oxide-sterilized bone had a reduced pullout load after 32 weeks of storage. Chemically sterilized bone had significantly reduced compressive load to failure and pullout load after 16 and 32 weeks of storage.

The use of aseptically collected, ethylene oxide-sterilized, or chemically sterilized bone within 1 week of preparation would be acceptable for grafts used for diaphyseal replacement, whereas chemically sterilized and partially decalcified bone would be unacceptable, regardless of storage time. Aseptically collected bone still would be acceptable for use after 32 weeks of storage. Ethylene oxide sterilized bone and chemically sterilized bone developed structural alterations during storage, making it questionable whether their use for diaphyseal replacement after lengthy storage of the graft would be successful.
Comparison of clinical judgment, Doppler ultrasound, and fluorescein fluorescence as methods for predicting intestinal viability in the pony
Authors: Freeman David E. , Gentile Dennis G. , Richardson Dean W. , Fetrow John P. , Tulleners Eric P. , Orsini James A. , Cimprich Ronnie
Published: February 2025

Strangulation obstruction was induced in anesthetized ponies for periods of 2 and 3 hours by clamping 45-cm segments of jejunum and associated veins (venous strangulation obstruction) and arteries and veins (arterial and venous strangulation obstruction). Four segments were studied in each of 7 ponies allowed to survive 12 hours, 2 segments in a pony that was allowed to survive 1 hour, and 1 segment in each of 10 ponies allowed to survive 42 days after the strangulation periods ended. Fifteen minutes after the periods of strangulation obstruction ended, the viability of test segments was assessed by clinical judgment (40 segments), fluorescein fluorescence (40 segments), and Doppler ultrasound (32 segments). Because the test segments were normal at necropsy in long-term survivors, all segments were designated as viable.

The overall accuracy of the methods used to predict viability was 88% for Doppler ultrasound and 53% each for clinical judgment and fluorescein fluorescence (P < 0.005). Failures in the last 2 techniques could be attributed to their tendency to score venous strangulation obstruction segments as nonviable (90% for each). Doppler ultrasound was 94% accurate in these segments.
Pharmacokinetics and body fluid and endometrial concentrations of trimethoprim-sulfamethoxazole in mares
Authors: Brown Murray P. , Gronwall Ronald , Castro Luis
Published: February 2025

Six healthy adult mares were each given a single iv injection of trimethoprim (tmp)-sulfamethoxazole (smz) at a dosage of 2.5 mg of tmp/kg of body weight and 12.5 mg of smz/kg. Serum concentrations of each drug were measured serially over a 24-hour period. For tmp, the mean overall elimination rate constant (K) was 0.43/hr and the elimination half-life (t1/2) was 1.9 hours. The apparent volume of distribution (at steady state) was 1.62 L/kg and tmp clearance was 886 ml/hr/kg. For smz, K was 0.22/hr and t1/2 was 3.53 hours. The apparent volume of distribution at steady state was 0.33 L/kg and smz clearance was 78.2 ml/hr/kg. Each mare was then given 5 consecutive oral doses of tmp-smz at a rate of 2.5 mg of tmp/kg and 12.5 mg of smz/kg at 12-hour intervals. Trimethoprim and smz concentrations were measured in serum, synovial fluid, peritoneal fluid, csf, urine, and endometrium. Although both mean tmp and smz serum concentrations were higher after the 5th dose than after the 1st dose, only the mean tmp concentration was significantly (P < 0.05) different. After the 5th oral dose, concentrations of tmp and smz attained in body fluids (except csf) and endometrial tissue were equal to or exceeded reported minimum inhibitory concentrations for Corynebacterium pseudotuberculosis, Staphylococcus sp, Streptococcus zooepidemicus, and several obligate anaerobes. Absorption of both drugs was variable after oral administration.
Alterations in epinephrine-induced arrhythmogenesis after xylazine and subsequent yohimbine administration in isoflurane-anesthetized dogs
Authors: Tranquilli William J. , Thurmon John C. , Benson G. John
Published: February 2025

Effects of xylazine (1.1 mg/kg of body weight, iv bolus, plus 1.1 mg/kg/h infusion) and subsequent yohimbine (0.125 mg/kg, iv bolus) administration on the arrhythmogenic dose of epinephrine (ade) in isoflurane (1.8% endtidal)-anesthetized dogs were evaluated. The ade was defined as the total dose of epinephrine that induced ≥ 4 premature ventricular contractions within 15 seconds during a 3-minute infusion period or within 1 minute after the end of infusion.

Total ade values during isoflurane anesthesia, after xylazine administration, and after yohimbine injection were 36.6 ± 8.45 μg/kg, 24.1 ± 6.10 μg/kg, and 45.7 ± 6.19 μg/kg, respectively. Intravenous xylazine administration significantly (P < 0.05) increased blood pressure and decreased heart rate, whereas yohimbine administration induced a significant (P < 0.05) decrease in blood pressure. After yohimbine administration, the ade significantly (P < 0.05) increased above that after isoflurane plus xylazine administration. After yohimbine administration, blood pressure measured immediately before epinephrine-induced arrhythmia was significantly (P < 0.05) less than the value recorded during isoflurane plus xylazine anesthesia. Heart rate was unchanged among treatments immediately before epinephrine-induced arrhythmia. Seemingly, yohimbine possessed a protective action against catecholamine-induced arrhythmias in dogs anesthetized with isoflurane and xylazine.
Morphologic changes in the bovine mammary gland during involution and lactogenesis
Authors: Sordillo L. M. , Nickerson S. C.
Published: February 2025

Morphologic changes developing during bovine mammary involution were examined. Quarter biopsy specimens were obtained weekly from 5 cows beginning the day milking was discontinued through parturition. Light and electron microscopic examination of mammary tissue indicated a gradual reduction in synthetic and secretory activity of alveolar epithelium as involution progressed. Light microscopic morphologic analysis revealed increases in stroma and nonactive secretory epithelium, with concomitant decreases in epithelium, lumen, and fully active secretory epithelium during the first 2 weeks of involution. Electron microscopic analysis of alveolar epithelium revealed decreased number of organelles associated with milk synthesis and secretion during this time. These changes reversed gradually beginning 2 weeks before parturition, and by the time of calving, cell structure was typical of lactating glands. Tissue from infected quarters had less synthetic and secretory ability as indicated by significantly higher percentages of stroma and nonactive cells, but lower percentages of lumen and moderately active cells, compared with uninfected quarters. Infected quarters also had more leukocytes infiltrating the epithelium, lumen, and stroma, compared with uninfected quarters. Microscopic examination of macrophages and neutrophils suggested these cells removed milk components and cellular debris during involution. Large numbers of plasma cells, with distended cisternae of rough endoplasmic reticulum, suggested local antibody production during the periparturient period.
Effect of splenectomy on exercise-induced pulmonary and systemic hypertension in ponies
Authors: Davis Jane L. , Manohar Murli
Published: February 2025

Large increases in systemic and pulmonary arterial pressures of exercising healthy ponies have been observed. Because exercise causes a considerable increase in pcv of ponies, we examined the effect of splenectomy on exercise-induced changes in systemic and pulmonary pressures. These pressures (taken with catheter-tip micromanometers) and indicator dilution cardiac output were determined on 9 healthy ponies that had undergone splenectomy 4 to 9 weeks before the study. Data obtained at rest and during submaximal (10.5 to 11.0 mph) and maximal (14 to 15 mph) exercise from these ponies were compared with similar data from clinically normal ponies. Following splenectomy, pcv increased by only 4 vol% during maximal exercise, but cardiac output of splenectomized ponies reached values similar to those of clinically normal ponies. Despite this similarity in cardiac output, the systemic and pulmonary arterial pressures of exercising splenectornized ponies increased to significantly lower levels than those in clinically normal ponies (P < 0.01); total pulmonary vascular resistance and total peripheral resistance decreased to values significantly less than those in clinically normal ponies (P < 0.01). Thus, it appears that increases in blood viscosity induced by increases in pcv may contribute substantially to the pulmonary and systemic hypertension of exercise in clinically normal ponies.
In vitro and in vivo effects of dichlorvos on blood cholinesterase activities of cattle
Authors: Khan A. A. , Coppock R. W. , Schuler M. M. , Lillie L. E.
Published: February 2025

Studies were conducted to ascertain in vitro effects and effects of percutaneous application (in vivo) of dichlorvos (2,2-dichlorovinyl dimethyl phosphate; ddvp) on cholinesterase activities in bovine erythrocytes and plasma. Treatment in vitro of erythrocytes and plasma with ddvp resulted in concentration- and time-dependent inhibition of erythrocyte acetylcholinesterase (AChE) and plasma cholinesterase (ChE) activities. Mean (± sd) ddvp concentrations required to cause 50% enzyme inhibition were 15.7 ± 3.3 μM and 43.1 ± 5.7 μM for AChE and ChE, respectively; however, these values required to achieve this inhibition were markedly decreased with increasing incubation time. The inhibited AChE activity failed to be reactivated after incubation of erythrocytes with 2-pyridine aldoxime methiodide (2-pam); however, limited reactivation of inhibited AChE and ChE activities was observed with excess concentration of 2-pam. Percutaneous application of a ddvp-containing livestock spray on cattle also caused a marked decrease in the in vivo activities of AChE and ChE; however, the inhibited enzyme activities were reactivated rapidly after incubation with 2-pam.
Differential effect of T-2 toxin on murine host resistance to three facultative intracellular bacterial pathogens: Listeria monocytogenes, Salmonella typhimurium, and Mycobacterium bovis
Authors: Ziprin Richard L. , McMurray David N.
Published: February 2025

The effect of T-2 toxin, a radiomimetic immunosuppressive agent, on resistance to the facultative intracellular bacterial pathogens Listeria monocytogenes (strain EGD), Mycobacterium bovis (BCG Copenhagen 1331), and Salmonella typhimurium was determined. Female Swiss ICR mice were given a single dose of T-2 toxin (4 mg/kg of body weight) by gastric gavage. On the seventh day after toxin administration, the mice were infected by intraperitoneal inoculation with L monocytogenes, S typhimurium, or M bovis. Mice given the toxin also were exposed to respirable droplet nuclei containing L monocytogenes or M bovis. The effect of the toxin on the course of infection was monitored by observing mortality or by enumeration of bacteria in the spleen or lungs of infected mice. The toxin increased resistance to infection with L monocytogenes initiated by intraperitoneal inoculation, but reduced resistance to M bovis infection initiated by intraperitoneal inoculation. The toxin had no appreciable effect on the course of salmonellosis or on resistance to infection initiated by inhalation of L monocytogenes or M bovis aerosols. Therefore, it was concluded that T-2 toxin does not necessarily reduce resistance to infection in mice. The toxin's effect on the course of in vivo bacterial infections depends on the nature of the infective agent and the route of inoculation.
Possible resistance of small strongyles from female ponies in The Netherlands against albendazole
Authors: Eysker M. , Boersema J. H. , Kooyman F. N. J. , Berghen P.
Published: February 2025

To determine resistance of small strongyles to albendazole, 3 female ponies (group 1) were grazed on a pasture from May to November 1985 and were treated with 7.5 mg of albendazole/kg of body weight, po, 2 days before turnout in May and again in June and in July. Three other female ponies (group 2) grazed on a similar pasture from May to July, were treated with 7.5 mg of albendazole/kg, and were removed to another pasture until November. In December, ponies from both groups were treated with 7.5 mg of albendazole/kg, and 8 days later, they were euthanatized and necropsied for a critical test.

Worm egg counts in the ponies’ feces revealed that the May treatment of group 1 and the July treatment of group 2 were more effective than were later treatments. Numbers of small strongyles were higher in group 1 than in group 2. Efficacy of treatment against all developmental stages of small strongyles was higher in group 2 than in group 1. Efficacy was low in both groups against parasitic 3rd- and 4th-stage larvae. Fifteen species of small strongyles were identified at necropsy. Efficacy was limited against adult Cyathostomum coronatum, Cya labratum, Cylicostephanus calicatus, and Cyl poculatus in both groups; Cylicocyclus nassatus, Cyl minutus, and Cyl longibursatus in group 1; and Cya labiatum in group 2. Efficacy was 100% against Cya catinatum, Cyl goldi, and 5 other species that were found in low numbers.
Evaluation of immune complexes and collagen type-specific antibodies in sera and synovial fluids of horses with secondary osteoarthritis
Authors: Niebauer Gert W. , Wolf Benjamin , Yarmush Martin , Richardson Dean W.
Published: February 2025

Thirty-one horses with secondary osteoarthritis as a sequel of trauma (chip fractures) or osteochondritis dissecans were screened for immune complexes (ic) and anticollagen antibodies. Eighty-two percent of horses with joint disease had circulating C1q-binding ic; 77% of those horses had ic in synovial fluids of affected joints. Although only a few horses had anticollagen type-II antibodies, anticollagen type-I antibodies were found in sera of 25% of the horses and in 41% of their synovial fluids. This correlated well with the clinical data and suggested that antibodies might have been elicited by antigens derived from detached intra-articular osteochondral fragments. Immunologic reactivity is a new concept in equine secondary osteoarthritis and might be involved in the mechanisms of chronic inflammation and progressive collagen destruction in degenerative joint disease.
Analysis of neurotransmitter metabolite concentrations in canine cerebrospinal fluid
Authors: Vaughn Dana M. , Coleman Elaine , Simpson Stephen T. , Satjawatcharaphong Chiradath
Published: February 2025

The concentrations of dihydroxyphenylacetic acid (dopac), homovanillic acid (hva), and 5-hydroxyindole-3-acetic acid (5-hiaa) in csf obtained from the cisterna magna of 21 nonneurologically compromised dogs were determined by high-pressure liquid chromatography and electrochemical detection. A rapid method of sample preparation, which involved single filtration through a deproteinizing membrane, was used. Canine csf obtained in this manner contained 5.78 ± 0.78 ng of dopac/ml, 72.19 ± 4.09 ng of hva/ml, and 29.95 ± 1.67 ng of 5-hiaa/ml. Linear regression analysis between hva and 5-hiaa yielded a correlation coefficient of 0.4804. The neurotransmitter index, hva/5-hiaa, was found to be more indicative of the dopaminergic metabolite hva than the acid metabolite of serotonin, 5-hiaa (correlation coefficient with hva = 0.5529 vs a correlation coefficient with 5-hiaa = - 0.4462). A poor relationship (correlation coefficient = -0.1715) was found to exist between the 2 dopaminergic metabolites dopac and hva in the csf.
Characterization of the structural proteins of porcine epizootic diarrhea virus, strain CV777
Authors: Egberink Herman F. , Ederveen Joke , Callebaut Paul , Horzinek Marian C.
Published: February 2025

Pig epizootic diarrhea virus cannot be grown in cell culture; for its characterization, intestinal perfusate material from a pig infected with the strain CV777 had to be used. In isopyknic sucrose gradients, a peak of virus-specific elisa activity was detected at a density of 1.17 g/ml. Using immunoprecipitation of radioiodinated-purified virus material followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, 3 proteins of low molecular weight (20,000 to 32,000 daltons [D]) were found; after blotting nitrocellulose and glycoprotein identification with concanavalin A and horseradish peroxidase, 1 of the proteins (23,000 D) gave a signal. Another protein of 58,000 D was encountered, which was the only protein binding an rna probe. Finally, a protein of 85,000 D was visible, associated with minor bands of about 110,000 and 135,000 D in most experiments. Using the concanavalin A-blotting technique, the same bands were visualized. The demonstration of a polydisperse cluster of proteins from 20,000 to 32,000 D (of which at least 1 is glycosylated), of glycosylated proteins from 85,000 to 135,000 D, and of an rna-binding protein of 58,000 D is taken as structural evidence that pig epizootic diarrhea virus should be classified with the Coronaviridae, irrespective of the apparent lack of an antigenic relationship with other members of that family.