bluuebunny/crossref_metadata_2025 huggingface dataset:
Pathogenicity and immunogenicity of a mutagen-attenuated Rift Valley fever virus immunogen in pregnant ewes
Authors: Morrill J. C. , Jennings G. B. , Caplen H. , Turell M. J. , Johnson A. J. , Peters C. J.
Published: February 2025

A mutagenized clone of Rift Valley fever virus (rvfv; MV P12) used in inoculation of 3 pregnant ewes was immunogenic, nonpathogenic, and nonabortogenic. In contrast, inoculation of a matched group of 3 pregnant ewes with parent rvfv induced clinical disease and abortions. Ewes given MV P12 delivered healthy lambs that had rvfv antibody titers of < 1:10 at birth, increasing to s 1:80 after ingestion of colostrum. Ewes inoculated with parent rvfv developed marked viremia, followed by rvfv antibody titers s 1:1,280; ewes inoculated with MV P12 developed low viremia titers and rvfv antibody titers of 1:80 to 1:320. Postpartum challenge exposure of the previously MV P12-inoculated ewes with virulent Zagazig human 501 strain rvfv indicated that the ewes were protected from clinical disease. The rvfv-susceptible female Culex pipiens that fed on the MV P12-inoculated ewes failed to transmit rvfv to hamsters; mosquitoes that fed on the parent rvfv-inoculated ewes became infected and transmitted rvfv to hamsters.
Bluetongue and epizootic hemorrhagic disease in white-tailed deer from Oklahoma: Serologic evaluation and virus isolation
Authors: Kocan A. Alan , Castro Anthony E. , Shaw Michael G. , Rogers Sandra J.
Published: February 2025

Blood samples were collected from 194 white-tailed deer from 27 locations in Oklahoma from 1977 through 1984. Sixty-eight (35%) of the deer had antibody against blue-tongue virus (btv) and 78 (40%) had antibody against epizootic hemorrhagic disease virus. Seropositive deer were detected in each of the 4 geographic quadrants of the state. Virus isolation was attempted in 40 deer from the northeast quadrant of Oklahoma (1983 through 1984); btv was isolated from 11 deer, but epizootic hemorrhagic disease virus was not isolated. The isolation of btv serotype 11 from these deer from 1983 through 1984 coincided with reported isolations of this serotype in other ruminants in Oklahoma during this time.
Ceftiofur sodium, a broad-spectrum cephalosporin: Evaluation in vitro and in vivo in mice
Authors: Yancey Robert J. , Kinney Mary L. , Roberts Barbara J. , Goodenough Kenneth R. , Hamel Judith C. , Ford Charles W.
Published: February 2025

Ceftiofur sodium, a broad-spectrum β-lactamase-resistant cephalosporin, was evaluated in vitro and in vivo in mice. Ceftiofur is the sodium salt of (6R, 7R)-7{[2-amino-4-thiazolyl)-Z-(methoxyimino)acetyl]amino}-3-{[(2-furanylcarbonyl)thio]methyl}-8-oxo-5-thia-1-azabicyclo-[4.2.0]oct-2-ene-2-carboxylate. Minimal inhibitory concentration values were obtained with 264 strains representing 9 genera and 17 species of bacterial pathogens from cattle, swine, sheep, horses, poultry, dogs, cats, and human beings. Ceftiofur was more active than was ampicillin against all strains tested including β-lactamase-producing organisms. In mice with systemic infections, ceftiofur was more active than or equivalent to ampicillin, cephalothin, cefamandole, cloxacillin, cefoperazone, or pirlimycin. These protection tests included infections with Escherichia coli, Haemophilus pleuropneumoniae, H somnus, Pasteurella haemolytica, P multocida, Salmonella typhimurium, or Staphylococcus aureus. In infant mice with E coli-induced lethal diarrhea and in mice with S aureus and E coli-induced mastitis, ceftiofur was comparable or more active than was ampicillin.
Effects of treatment with cobra venom factor on experimentally induced feline leukemia
Authors: Kraut Eric H. , Rojko Jennifer L. , Olsen Richard G. , Tuomari Darrell L.
Published: February 2025

Five- to six-month-old specific-pathogen-free cats were exposed to cobra venom factor (cvf) alone (4 cats), Rickard feline leukemia virus (FeLV; 9 cats), or cvf and FeLV (6 cats). Host-virus relationships were evaluated by monitoring the development of viremia, production of antibody against feline oncornavirus-associated cell membrane antigen, and amount of circulating immune complexes (cic).

Exposure to cvf induced complement depletion, which lasted 8 to 15 days. However, complement depletion did not promote the development of persistent viremia nor alter the production of antibody to feline oncornavirus-associated cell membrane antigen or cic. Results indicated that the complement system did not protect cats during their initial exposure to FeLV and that an intact complement system was not necessary for the development of antibody against feline oncornavirus-associated antigen or for the formation of cic.
In vitro immune serum-mediated protection of pig monocytes against African swine fever virus
Authors: Knudsen Richard C. , Genouesi Eugene V. , Whyard Terry C.
Published: February 2025

Serum samples from pigs that had recovered from infection with a Dominican Republic isolate of African swine fever virus (asfv) were mixed with dilutions of the virus, then assayed in microcultures of normal pig mononuclear leukocytes to determine whether the samples contained antibodies that protected monocytes against the virus. Protection was determined by the difference in titer (log10) between virus mixed with healthy pig serum and virus mixed with immune pig serum, using 50% cytopathogenic effect end points; protection was expressed as an immune serum-protection index. After addition of virus-serum mixtures to mononuclear leukocyte microcultures, a time-dependent decrease in protective index and production of infectious virus (determined by use of yield reduction assays) were observed. Protective effects were associated with the immunoglobulin fraction of serum, were rapidly lost on dilution, and were independent of complement. Antibody was most protective for the homologous Dominican Republic isolate of asfv, with decreased protection against Lisbon '60 asfv, and no protection against foot-and-mouth disease virus or bluetongue virus. Low concentrations of protective antibody were found during the acute viremic phase in infected pigs; antibody increased to maximal concentrations as the viremia decreased.
Posologie evaluation of clindamycin, using a canine model of posttraumatic osteomyelitis
Authors: Braden T. D. , Johnson C. A. , Gabel C. L. , Lott G. A. , Caywood D. D.
Published: February 2025

Posttraumatic osteomyelitis attributable to Staphylococcus aureus infection was experimentally induced in 30 dogs, after which the dogs were treated with clindamycin at various dosage regimens. Of the regimens evaluated, oral administration of 11 mg of clindamycin/kg of body weight twice daily for 28 days was the most effective treatment for the osteomyelitis.
Technique for repeated collection of blood that has just perfused the pineal gland of sheep
Authors: Colombo Gaetano , Cozzi Bruno , Cremonesi Fausto , Reiter Russel J.
Published: February 2025

A long catheter was inserted into the superior sagittal sinus of sheep and was maneuvered to the level of the rectus sinus. The catheter was then secured to the head, neck, and shoulder of the animal. The distal end of the catheter was connected to a 3-way valve through which blood samples were collected and heparin was injected. Blood loss during surgery was minimal; recovery was quick and complete. The simple surgical technique enabled the collection of blood that has just perfused the pineal gland.
Identification of bluetongue virus protein-specific antibody responses in sheep by immunoblotting
Authors: Adkison Mark A. , Stott Jeffery L. , Osburn Bennie I.
Published: February 2025

A western immunoblotting procedure was developed for identifying bluetongue virus protein-specific antibody responses in sheep. Assay conditions were optimized and included electrophoretic transfer of viral proteins to a nitrocellulose membrane (ncm), blocking of unbound sites on the ncm, and detection of ncm-bound primary immune complexes. A biotin-avidin-enzyme system was determined to be superior in terms of sensitivity for identification of the ncm-bound virus protein-antibody complexes. The biotin-avidin-enzyme detection system made use of biotinylated rabbit anti-sheep IgG and horseradish peroxidase-conjugated egg white avidin. This system permitted identification of antibodies specific for up to 10 bluetongue virus-associated proteins, 4 of which have not been characterized.
Regulation of murine macrophage phagocytosis of sheep erythrocytes by T-2 toxin
Authors: Corrier Donald E. , Holt Peter S. , Mollenhauer Hilton H.
Published: February 2025

The effect of a single oral dose of 4 mg of T-2 toxin/kg of body weight on in vivo phagocytosis of sheep rbc by peritoneal macrophages was evaluated in nonsensitized mice and in mice sensitized with sheep rbc. T-2 toxin treatment had no effect on the viability or phagocytic activity of resident peritoneal macrophages in nonsensitized mice. However, a significant (P < 0.005) increase in phagocytic activity occurred in cells from mice treated with toxin and subsequently sensitized with sheep rbc. In contrast, phagocytosis of sheep rbc was significantly (P < 0.05) suppressed in cells from mice treated with toxin after sensitization. Toxin treatment induced necrosis of lymphocytes and significant decreases in thymus and spleen weights. Seemingly, T-2 toxin, administered at a dose that caused marked lymphoid depletion, suppressed or enhanced in vivo macrophage phagocytic activity in antigenically sensitized mice, and enhancement or suppression of phagocytosis was a function of the time of toxin treatment in relation to antigenic stimulation.
Buccal mucosa bleeding times of healthy dogs and of dogs in various pathologic states, including thrombocytopenia, uremia, and von Willebrand's disease
Authors: Jergens Albert E. , Turrentine Mark A. , Kraus Karl H. , Johnson Gary S.
Published: February 2025

The buccal mucosa bleeding time (bmbt; duration of hemorrhage from standardized cuts made with a spring-loaded disposable device in the mucosal surface of the upper lip) was used to evaluate the hemostatic competence of dogs. The mean (± sd) bmbt for 34 healthy dogs was 2.62 ± 0.49 minutes. The bmbt of healthy dogs anesthetized with halothane or tranquilized with xylazine were not significantly different from the bmbt of healthy dogs evaluated without chemical restraint. The bmbt was significantly (P < 0.01) prolonged 21 hours after aspirin (10 mg/kg of body weight) was administered orally to 10 healthy dogs; however, the mean aspirin-induced increase in bmbt was only 0.40 minutes. The bmbt of 28 of 30 dogs with various diseases not traditionally associated with hemostatic deficiencies were near or within the range of bmbt for healthy dogs; however, 2 dogs had bmbt of > 8 minutes. In contrast, bmbt were prolonged in most dogs with diseases known to induce deficient primary hemostasis; the 3 dogs with thrombocytopenia (≤ 20,000 platelets/μl), the 7 Doberman Pinschers with von Willebrand's disease (von Willebrand factor antigen; ≤ 18 U/dl), and 5 of the 6 dogs with severe azotemia (serum urea nitrogen; ≥ 124 mg/dl) had prolonged bmbt. The bmbt of 16 dogs were determined immediately before they were subjected to various surgical procedures, and the severity of the hemorrhage encountered during these procedures was subjectively evaluated; the amount of hemorrhage from 12 of the 16 dogs was considered to be appropriate for the corresponding surgical procedures, but the remaining 4 dogs bled excessively during surgery. The mean bmbt for the 12 dogs that had normal hemostasis during the surgical procedures was 3.00 ± 1.20 minutes, which was significantly shorter (P < 0.05) than the mean bmbt of the 4 dogs with deficient hemostasis during surgical procedures (9.36 ± 6.36 minutes).
Alterations in selected serum biochemical constituents in equids after induced hepatic disease
Authors: Hoffmann Walter E. , Baker Gordon , Rieser Suzanne , Dorner Joseph L.
Published: February 2025

Effects of induced cholestasis and hepatocellular necrosis and of fasting on serum biochemical constituents including bile acids, IgA, bilirubin, alkaline phosphatase, γ-glutamyltransferase (ggt), arginase, and the clearance of sodium sulfobromophthalein were studied in 4 groups of equids. The reference value for serum bile acids, as determined by an enzymatic colorimetric procedure for horses and ponies was 5.94 ± 2.72 μmol/L, there being no statistical difference for horses and ponies. Sample collection at time of feeding had no effect on serum bile acid concentration. Seemingly, serum bile acids, arginase, and ggt were the most sensitive indicators of cholestasis and/or hepatocellular necrosis and would form an essential minimum effective battery of tests to diagnose and prognose hepatic disease in equids. These tests provided a measure of hepatobiliary transport function (bile acids), cell necrosis (arginase), and cholestasis (ggt and bile acids).
Monoclonal antibodies: Cell surface markers for canine keratinocytes
Authors: Suter Maja M. , Wilkinson John E. , Greenberger Leah , Smith Christina A. , Lewis Robert M.
Published: February 2025

Plasma membranes were isolated from cultured canine keratinocytes by paraformaldehyde-induced membrane vesiculation. The isolated plasma membrane vesicles retained cell surface antigens (eg, a pemphigus vulgaris antigen). These membrane vesicles were used as an antigen source for the production of monoclonal antibodies. Eight antibodies that had specific reactivity to the cytoplasmic membrane of keratinocytes on frozen sections of canine esophagus were identified by use of an indirect immunoperoxidase method. The stratified squamous epithelium of the esophageal mucosa had 4 staining patterns. When applied to frozen sections of canine skin, lip, and tongue, the antibodies had different tissue specificities for differing stratified squamous epithelia. Using sodium dodecyl sulfate polyacrylamide-gel electrophoresis and the western blot technique, one of the antibodies was specific for a 60-kD cell surface molecule. Therefore, such monoclonal antibodies may be useful in defining heterogeneity between different stratified squamous epithelia, in identifying biologically important surface antigens, or in the diagnosis of tumors.
Multimeric analysis of von Willebrand factor before and after desmopressin acetate (DDAVP) administration intravenously and subcutaneously in male Beagle dogs
Authors: Kraus Karl H. , Turrentine Mark A. , Johnson Gary S.
Published: February 2025

Eight adult male Beagles were given 1 μg of 1-deamino-8-d-arginine vasopressin (ddavp)/kg of body weight, sc or by slow iv infusion on separate occasions. Both routes of administration induced highly significant increases (P < 0.0001) in plasma concentrations of von Willebrand factor (vWf) antigen (Ag) and botrocetin cofactor (BCf) activity, an indication of platelet-associated vWf activity. In most instances, increases in plasma vWf:Ag and BCf values induced by sc injection were as large as or larger than those induced by slow iv infusion. With both routes of administration, BCf activity increased more than the vWf:Ag concentration, so that high BCf-to-vWf:Ag ratios were found in plasma after ddavp administration. In plasma samples obtained before ddavp administration, sodium dodecyl sulfate-electrophoresis resolved the vWf into a series of multimeric proteins with molecular weights similar to those of human vWf. Sodium dodecyl sulfate-electrophoresis of plasma samples obtained after ddavp administration revealed mainly the larger molecules of vWf that were increased by ddavp administration.
Efficacy of levamisole and netobimin against Haemonchus contortus in lambs in Louisiana
Authors: Miller James E. , Hembry F. Glen , Kearney Michael T. , Williams James C. , Stagg Lois C. , Sims David
Published: February 2025

Efficacy of levamisole was evaluated in a suspected levamisole-resistant population of Haemonchus contortus in the Louisiana State University sheep flock. The efficacy of netobimin also was evaluated against this population of Haemonchus. In trial 1,5 lambs naturally infected with H contortus were given 8 mg of levamisole/kg of body weight as a drench, and 5 lambs were not treated (controls). Nematode recovery after slaughter indicated 0% efficacy against H contortus.

In trial 2, 30 nematode-free lambs were each given 8,300 F1 generation infective larvae of H contortus, which were derived from parent H contortus that survived 2 levamisole treatments in lambs being maintained in a nematode-free environment. Ten lambs were treated with 8 mg of levamisole/kg as a drench, 10 were treated with 20 mg of netobimin/kg as a drench, and 10 were not treated (control). Nematode recovery after slaughter revealed 62.3% and 99.8% efficacy for levamisole and netobimin, respectively, against H contortus.
Effects of polysulfated glycosaminoglycan on chemical and physical defects in equine articular cartilage
Authors: Yovich John V. , Trotter Gayle W. , McIlwraith C. Wayne , Norrdin Robert W.
Published: February 2025

The effect of intra-articular polysulfated glycosaminoglycan (psg) on repair of chemical and physical articular cartilage injuries was evaluated in 8 horses. In each horse, a partial- and a full-thickness articular cartilage defect was made on the distal articular surface of the radial carpal bone. In the contralateral middle carpal joint, a chemical articular cartilage injury was induced by injecting 50 mg of Na monoiodoacetate (mia). Four of the 8 horses were not treated (controls), and 4 horses were treated by intra-articular injection of 250 mg of psg into both middle carpal joints once a week for 5 treatments starting 1 week after cartilage injury. Horses were maintained for 8 weeks.

There was less joint circumference enlargement in psg-treated horses in mia-injected and physical defect carpi, compared with that in controls. In mia-injected joints, there was less articular cartilage fibrillation and erosion, less chondrocyte death, and greater safranin-O staining for glycosaminoglycans in psg-treated horses. Evalution of joints in which physical defects were made revealed no differences between control and psg-injected joints. None of the partial-thickness defects had healed. Full-thickness defects were repaired with fibrous tissue (which was more vascular and cellular in psg-injected joints) and occasionally small amounts of fibrocartilage. Seemingly, psg had chondroprotective properties in a model of chemically induced articular cartilage damage, whereas psg had no obvious effect in a physical articular cartilage-defect model.
Pneumonia in pigs induced by intranasal challenge exposure with Pseudorabies virus and Pasteurella multocida
Authors: Fuentes Martha C. , Pijoan Carlos
Published: February 2025

The interaction between Pseudorabies virus (prv) and Pasteurella multocida was investigated to determine whether single or combined infections result in pneumonia in 6- to 7-week-old pigs. The effect of the prv-P multocida challenge exposure on feed consumption, rate of gain, and extent of pneumonic lesions appeared dependent on the prv dose; however, pneumonic lesions were of bacterial pneumonia. Pigs inoculated with a virulent strain of prv plus P multocida developed severe pneumonia, whereas pigs given prv only did not develop pneumonia. Modified-live prv vaccine had no effect on the occurrence of pneumonia. Average daily gain was most depressed in pigs given the highest dose of virulent prv plus P multocida.
Specificity of the indirect enzyme-linked immunosorbent assay for detection of Pseudorabies virus antibodies in pigs exposed to bovine herpesvirus-1
Authors: Afshar A. , Wright P. F. , Myers D. J. , Bouffard A. , Dulae G. C.
Published: February 2025

Six 5-week-old pigs were inoculated intranasally (in) with 107.6 tcid50 of bovine herpesvirus-1 (bhv-1). Three of the pigs also were inoculated iv with a similar dose of bhv-1. Clinical responses were not observed in these 6 pigs before oronasal challenge exposure with 107.8 tcid50 of virulent Pseudorabies virus (prv) at postinoculation day 42. Two pigs inoculated in with bhv-1 and challenge exposed with prv remained healthy, whereas the remaining 4 pigs developed severe clinical signs of Pseudorabies and were moribund at postinoculation day 50 (8 days after challenge exposure). Anti-bhv-1 antibodies were demonstrable by elisa in all 6 pigs and by serum neutralization (sn) in 5 pigs before challenge exposure with prv. Anti-prv antibody was not detected by elisa or sn before challenge exposure to prv. After challenge exposure to prv, pigs with humoral antibody to bhv-1 responded anamnestically, and anti-prv antibody activity was demonstrable by elisa and sn in the 2 surviving pigs.
Histochemical morphologic features of growth cartilages in long bones of pigs of various ages
Authors: Hill Michael A. , Ruth George R. , Van Sickle David C. , Hilley Harvey D. , Torrison Jerry L. , Bagent Jack K. , Lemon Alan D.
Published: February 2025

Growth cartilages were obtained from humeri, femora, and ulnae of 31 pigs between 1 and 169 days old. On the basis of stain uptake and distribution, distinct layers were identified in articular-epiphyseal cartilage complexes and growth plates. The laminated appearance was dependent on stain uptake by territorial and interterritorial matrices and was more distinct in pigs > 15 days old. There was morphologic heterogeneity, which probably represented a functional heterogeneity, among chondrocytes in all layers and zones of both types of growth cartilage. The laminar appearance of growth cartilages and the distribution of different types of cells were similar for all pigs in each age category and for all sites.
Systemic distribution of blood flow in ponies during 1.45%, 1.96%, and 2.39% end-tidal isoflurane-02 anesthesia
Authors: Manohar Murli , Gustafson Rand , Goetz Thomas E. , Nganwa David
Published: February 2025

Effects of 1.1,1.5, and 1.8 minimal alveolar concentration (mac) isoflurane-O2 (1.45%, 1.96%, and 2.39% end-tidal isoflurane, respectively) anesthesia on cardiac output, blood pressure, and blood flow to the brain, thyroid giands, adrenal glands, kidneys, and splanchnic organs were examined in 9 healthy isocapnic adult ponies. Tissue blood flows were studied using 15-μm diameter radio-nuclide-labeled microspheres that were injected into the left ventricle, and comparisons were made with data obtained from ponies in the conscious state.

Isoflurane anesthesia caused dose-related reduction in cardiac output and arterial blood pressure, but total peripheral resistance was not significantly altered (P > 0.05). In the brain, vasodilation occurred with exposure to isoflurane that peaked at 1.5 mac Vasodilation was more pronounced in the cerebellum, pons, and medulla, compared with that in the cerebrum. Perfusion increased in cerebellar gray, as well as white, matter. However, in the cerebrum, blood flow increased in the white matter, whereas it decreased in caudate nuclei and was similar to value in the cortex of awake ponies. In thyroid glands and pancreas, intense vasoconstriction occurred during isoflurane anesthesia which caused precipitous reduction in blood flow in these organs. By contrast, adrenal gland blood flow was not affected during the 3 levels of isoflurane anesthesia because vasodilation occurred. The renal blood flow registered dose-dependent reductions during isoflurane-02 anesthesia, but renal vasoconstriction occurred only during the deepest level (1.8 mac) of anesthesia. Although the small intestine and colon blood flow decreased with each concentration of isoflurane, the splenic blood flow remained unaffected. In isocapnic ponies, isoflurane-02 anesthesia caused marked vasoconstriction in thyroid glands, pancreas, and kidneys (only at 1.8 mac), but vasodilatation occurred in the brain and adrenal glands. Isoflurane anesthesia decreased renal, small intestine, and colon blood flows.
Monensin toxicosis in swine: Potentiation by tiamulin administration and ameliorative effect of treatment with selenium and/or vitamin E
Authors: Van Vleet John F. , Runnels Lewis J. , Cook James R. , Scheidt Alan B.
Published: February 2025

Modulation of acute monensin toxicosis in swine was evaluated in 2 studies. In study 1, 56 weanling male pigs were allotted to 14 groups of 4 each. Pigs in 7 groups were given tiamulin in the drinking water (to supply 7.7 mg/kg of body weight/day) for 3 days before and for 2 days after monensin administration. Monensin was given as a single oral dose (at 0, 7.5, 15, 25, 50, 75, or 100 mg/kg) to pigs in groups with or without tiamulin exposure. Prominent acute clinical signs of monensin toxicosis (hypermetria, hind limb ataxia, paresis, knuckling of hind limbs, and recumbency) developed by 2 to 6 hours after dosing in pigs given 15 or 25 mg of monensin/kg with tiamulin exposure, but not in pigs given the 15 or 25 mg of monensin/kg without tiamulin exposure. Also, the extent of monensin-induced skeletal muscle damage at 4 days after monensin dosing was enhanced in pigs given 7.5,15, or 25 mg of monensin/kg and exposed to tiamulin.

In study 2, 48 weanling male pigs were allotted to 8 groups of 6 each. Four groups of pigs were given 20 mg of monensin/kg orally, and 4 groups were given 100 mg of monensin/kg orally. For each monensin dose, a group was treated 24 hours before monensin administration with (i) selenium (Se)-vitamin E preparation, 0.25 mg of Se and 68 IU of d-ot-tocopheryl acetate (vitamin E)/kg, im; (ii) vitamin E only, 68 IU of d-a-tocopheryl acetate/kg; (iii) Se only, 0.25 mg of Se/kg; or (iv) vehicle. Treatment with Se-vitamin E or with vitamin E only gave protection against monensin-induced skeletal muscle damage and indicated that vitamin E, rather than Se, was essential to provide this protection. However, treatments with Se-vitamin E, Se, or vitamin E did not alter the severity of acute clinical signs of monensin toxicosis. In swine, different pathogenetic mechanisms may be responsible for early transient clinical signs of monensin toxicosis and for the late-appearing lesions of skeletal muscle damage.
Spinal-evoked potentials in dogs with acute compressive thoracolumbar spinal cord disease
Authors: Shores Andy , Redding Richard W. , Knecht Charles D.
Published: February 2025

Spinal evoked potentials (SpEP) were recorded on an electromyograph from electrodes placed percutaneously in the ligamentum flava at the lumbosacral junction and between the 10th and 11th thoracic vertebrae following tibial nerve stimulation in 31 anesthetized dogs with acute compressive spinal cord injuries.

The neurologic status of each dog was determined by clinical examination before SpEP recordings, and the neurologic status was monitored for 2 months in dogs that had surgical or conservative treatment. Two months after spinal injury, the response to treatment (outcome) of each dog was evaluated and graded as favorable (ambulatory and urinary continent) or unfavorable (nonambulatory, urinary incontinent, or euthanatized with confirmation of myelomalacia). Onset latencies, conduction velocities, amplitudes and durations of the wave forms, and the ratio of conduction velocity to combined durations of the first positive (P1) and first negative (N1) waves (cv/dpn index) were determined and were compared with reference data from clinically normal (control) dogs.

Single SpEP recordings were of value in determining the prognosis for recovery. Significant differences were not found in the L7-S1 recordings between the reference (control) and spinal injury groups. Analysis of data from the T10-11 recordings indicated significant differences between the reference and spinal injury groups and between the favorable and unfavorable outcome groups within the spinal injury group. A cv/dpn index was < 30 in dogs with unfavorable outcomes and > 30 in dogs with favorable outcomes. Stepwise discriminant analysis of data from the spinal injury group predicted outcome correctly in all dogs.
Early embryonic death in heifers after inoculation with bovine herpesvirus-1 and reactivation of latent virus in reproductive tissues
Authors: Miller J. M. , Van Der Maaten M. J.
Published: February 2025

Thirteen crossbred heifers seronegative for bovine her-pesvirus-1 (bhv-1) were bred naturally to a seronegative bull. Eight heifers were inoculated with bhv-1, iv, on postbreeding day (pbd) 7 or 14. Viremia was detected in heifers 1 through 7, and virus also was isolated from nasal and vaginal secretions of heifers 2, 3, 4, 6, and 7.

The pregnancy status of all heifers was monitored from pbd 14 to pbd 35 by determining plasma progesterone concentrations at 1- to 3-day intervals. Decreased progesterone values indicated that pregnancy was not maintained in bhv-l-inoculated heifers 2, 3, 4, 6, 7, and 8. The postbreeding interestrual period of these 6 heifers was normal or only slightly longer than would be expected in the absence of conception. All 5 noninoculated heifers were pregnant on pbd 35.

Three to 4 months after acute infection, all bhv-1 inoculated heifers were treated with dexamethasone for 5 days and were euthanatized. Nasal and vaginal swab specimens were tested daily during dexamethasone treatment for excreted bhv-1, and reproductive tissues and adrenal glands were collected at necropsy for virologie tests and histopathologic examination.

Virus reactivation was demonstrated in heifers 2 through 8. The bhv-1 isolations were made from adrenal glands of heifers 2, 3, 5, 6, 7, and 8, vaginal swab specimens of heifers 2, 3, 4, 6, and 7, and nasal swab specimens of heifers 2, 3, and 6. Only heifer 3 had virus in reproductive tissues; these isolations were made from ovary, infundi-bulum, and uterine tube, but not from endometrium. The only histopathologic changes were in adrenal glands of heifers 2 through 7, the most characteristic lesion being a lymphohistiocytic infiltrate. Adrenal glands of heifers 4 and 7 had foci of mineralization, and necrotic foci also were observed in the glands of heifer 7. The necrotic tissue had cells with typical herpesvirus-type intranuclear inclusions, and bhv-1 antigen was demonstrated in these areas by immunohistochemical examination. Antigen was not found in the other infected adrenal glands or in the reproductive tissues from which virus was isolated.
Effects of body position and ventilation/compression ratios during cardiopulmonary resuscitation in cats
Authors: Henik Rosemary A. , Wingfield Wayne E. , Angleton George M. , Porter Robert E.
Published: February 2025

Eighteen cats were anesthetized and were randomly assigned to 2 groups (9 cats/group). Cardiopulmonary resuscitation (cpr) was performed on each cat, with the cat in dorsal (group 1) or lateral (group 2) recumbency, by administering 5 external cardiac compressions/1 interposed (diastolic) ventilation (American Heart Association [AHA] technique; n = 3 cats/technique), simultaneous compression and ventilation (scv; n = 3 cats/technique), or scv with 1 interposed (diastolic) ventilation every tenth compression (scv/dv; n = 3 cats/technique). Fourteen of the 18 cats were resuscitated.

Central aortic and venous pressures were determined concurrently with lead II electrocardiography. Arterial blood samples were collected during the base-line period (after pressure fluctuations had stabilized, with the cats spontaneously breathing room air), 2.5 minutes after the onset of arrest (defined as the cessation of aortic pressure fluctuations), and after 10 minutes of cpr.

Arterial blood gas values during the base-line period or during the period of arrest were not significantly different between group-1 and group-2 cats. After cpr, arterial pH and bicarbonate values were not significantly different between groups or between technique categories. The Paco2 values were significantly lower in cats resuscitated by scv or by scv/dv than in cats resuscitated by AHA (P < 0.05). The Pao2 values were significantly (P < 0.001) higher in group-2 cats than in group-1 cats and were significantly (P < 0.001) different between each technique category, with cats resuscitated by AHA having the lowest Pao2 and cats resuscitated by scv/dv having the highest Pao2. Body position, cpr technique, sex, weight, or arterial blood gas values after cpr were not predictors of successful resuscitation.
Oxymorphone: Cardiovascular, pulmonary, and behavioral effects in dogs
Authors: Copland Virginia S. , Haskins Steve C. , Patz John D.
Published: February 2025

Cardiovascular, pulmonary, and behavioral effects of multiple doses of oxymorphone in 10 nonanesthetized, spontaneously breathing, healthy dogs were studied, Oxymorphone (0.4 mg/kg of body weight) was administered iv, and at 20, 40, and 60 minutes after the first injection was given, 0.2 mg of oxymorphone/kg was administered. Cardiovascular and pulmonary variables were measured before (base line) and at 5, 15, 35, 55, 75, 100, 120, 150, 180, 210, 240, 270, and 300 minutes after the first oxymorphone injection. Degree of sedation and behavioral effects also were recorded. Naloxone (0.04 mg/kg, iv) was administered 4.5 hours after the 4th oxymorphone injection, and behavioral changes were recorded.

Oxymorphone induced mild respiratory depression. After transient apnea developed, respiratory rate increased to a pant, tidal volume decreased, and minute ventilation increased, but these values were not significantly (P=0.05) different from base line. The PaCO2, physiologic dead space, and base deficit increased; alveolar tidal volume decreased; and alveolar minute ventilation did not change. The PaO2 decreased, hemoglobin and arterial O2 content increased, and O2 transport did not change. Venous admixture transiently increased.

Oxymorphone induced minimal cardiovascular depression. Mean arterial blood pressure, stroke volume, central venous pressure, pulmonary artery pressure, and pulmonary wedge pressure increased. Heart rate decreased, systemic vascular resistance transiently increased, and cardiac output transiently decreased. Because the dogs moved spontaneously, responded to sound with sudden, vigorous movements, and breathed with excessive effort, oxymorphone alone was considered inadequate as a general anesthetic.
Activity of β-lactamase inhibitor sulbactam plus ampicillin against animal isolates of Pasteurella, Haemophilus, and Staphylococcus
Authors: Girard Arthur E. , Schelkly William U. , Murphy Kathryn T. , Sawyer Perry S.
Published: February 2025

Antibiotic susceptibilities of Pasteurella sp, Haemophilus pleuropneumoniae, and Staphylococcus aureus isolates were determined. The combination of sodium sulbactam, a β-lactamase inhibitor, and ampicillin had a synergistic effect against all ampicillin-resistant pathogens, rendering them susceptible to ampicillin. Studies of cell-free β-lactamase from Pasteurella and Haemophilus isolates confirmed the presence of a constitutive penicillinase. Inhibitory concentrations of sulbactam-ampicillin were bactericidal, as demonstrated by killing curves. Ampicillin-resistant Pasteurella and Haemophilus isolates did not develop resistance to sulbactam-am-picillin when passed as many as 8 times in the presence of sublethal concentrations of sulbactam-ampicillin. The in vitro synergistic activity of sulbactam-penicillin also was seen in an in vivo synergistic response in mice challenge exposed to an ampicillin-resistant P haemolytica.
Unipolar thoracic electrocardiography that induces QRS complexes of relative uniformity from male horses
Authors: Illera J. C. , Illera M. , Hamlin R. L.
Published: February 2025

Electrocardiograms were obtained from 100 male crossbred horses. In addition to standard limb leads, leads were taken from 12 points on the thorax. The QRS complexes were categorized into 1 of 8 forms on the basis of configuration and amplitudes of component deflections. Relative uniformity of QRS was determined for each lead, using the percentage of horses that possess a particular configuration. All unipolar thoracic leads, except those coplanar with the frontal plane, and lead aVR had great uniformity, with > 80% of the horses with a QRS of similar contour.
Evaluation of plasma aldosterone concentrations before and after ACTH administration in clinically normal dogs and in dogs with various diseases
Authors: Willard M. D. , Refsal K. , Thacker E.
Published: February 2025

Plasma aldosterone concentrations were measured in response to adrenocorticotropic hormone (acth) gel administration in clinically normal dogs, in dogs with hypoadrenocorticism, and in dogs (with electrolyte abnormalities) that did not have hypoadrenocorticism. Baseline plasma aldosterone concentrations were determined from specimens obtained every 10 minutes for 3 hours from 2 dogs and every 30 minutes for 7.5 hours from 2 other dogs. During the evaluation period, plasma aldosterone concentrations varied by at least 50% in each dog.

A randomized crossover design was used to compare changes in plasma aldosterone concentrations after administration of acth gel and physiologic NaCl solution. Dogs had significantly (P = 0.002) higher plasma aldosterone concentrations after administration of acth gel than after administration of NaCl solution. Plasma Cortisol concentrations increased as expected after acth gel administration. Analysis of Cortisol and aldosterone concentrations in the same specimens obtained at 7 sample collection times did not reveal significant linear correlation, and scatterplots did not indicate a nonlinear association. In addition, plasma aldosterone concentrations were determined in response to acth administration alone and to acth combined with a high dose of dexamethasone (0.1 mg/kg, iv). The plasma aldosterone response to acth alone was not significantly different from the response to acth combined with dexamethasone. For both tests, plasma aldosterone concentrations at 60 and 120 minutes after acth administration were significantly (P < 0.0005 and P = 0.0001, respectively), increased, compared with base-line values. Six dogs with adrenocortical hypofunction, as determined by plasma Cortisol concentrations before and after acth administration, had plasma aldosterone concentrations that were diminished or did not increase after acth administration. Six hyponatremic (± hyperkalemia dogs with diseases not attributable to generalized adrenocortical hypofunction had base-line or acth-stimulated aldosterone concentrations that were different from values determined in normal dogs.
Effects of halothane anesthesia on the clearance of gentamicin sulfate in horses
Authors: Smith C. M. , Steffey E. P. , Baggot J. D. , Dunlop C. I. , Farver T. B.
Published: February 2025

Inhalation anesthetics decrease the clearance of some drugs that are eliminated by renal excretion. The purpose of the study reported here was to investigate the effects of halothane anesthesia on the pharmacokinetics and urinary excretion of gentamicin sulfate, using the horse as a model. Using a crossover design, pharmacokinetic values after a single iv dose of gentamicin (4 mg/kg) were compared in halothane-anesthetized and unanesthetized horses. Compared with unanesthetized horses, the anesthetized horses had significant decreases in total body clearance (P < 0.01) and apparent volume of distribution (P < 0.05), and a significant increase in half-life (P < 0.05) of gentamicin.
Efficacy and toxicity of tamoxifen citrate for prevention and termination of pregnancy in bitches
Authors: Bowen R. A. , Olson P. N. , Young S. , Withrow S. J.
Published: February 2025

Five groups of bitches were given tamoxifen citrate (1 mg/kg of body weight) orally twice daily for 10 days. Drug administration commenced during late proestrus, day 4 of estrus, day 2 of diestrus, day 15 of diestrus, or day 30 of diestrus (n = 4/group). Nineteen of the bitches accepted natural mating by 1 or more of 3 stud dogs of known fertility (1 bitch did not). Twenty days after cessation of drug administration, ovarian, uterine, and hepatic specimens were obtained from each bitch in 4 of the groups. Pregnancy proceeded to natural termination in bitches of the remaining group (diestrous day 30). Pregnancy was not detected in any bitch of the proestrus, estrous, or early diestrous groups. Of 4 bitches of each of the remaining groups (diestrous day 15 and diestrous day 30), 2 aborted fetuses and/or resorbed placental remnants; the other 2 bitches in each of these groups had normal-appearing fetuses (diestrous day-15 group) or clinically normal pups (diestrous day-30 group). Of the 20 bitches given tamoxifen citrate, 5 developed endometritis with or without pyometra, and 4 of these had ovarian cysts.

Although tamoxifen citrate is effective for preventing or terminating pregnancy in the bitch, the regimen used in the study reported here was associated with high frequency of pathologic changes in the reproductive tract.
Systemic lupus erythematosus in a colony of dogs
Authors: Monier J. C. , Fournel C. , Lapras M. , Dardenne M. , Randle T. , Fontaine C. M.
Published: February 2025

A colony of dogs was obtained by the mating of a female German Shepherd Dog crossbred and a male Belgian Shepherd Dog crossbred, both with systemic lupus erythematosus (sle). The colony also contained 16 dogs representing Fl, F2, and F3 generations. Ten colony dogs had circulating antinuclear antibodies, and 5 of the 10 had clinical signs of sle. Two F3-generation females had signs of severe sle. Two dogs had antibodies to extractable nuclear antigen, notably 1 dog had antibodies to Smith (Sm) antigen and 1 had antibodies to Sjogren syndrome A (ssa) antigen. Thymulin (serum thymic factor associated with zinc) titers were generally low in the descendants, but fluctuations were detected within the same dog. In vitro response of lymphocytes from these colony dogs to concanavalin A was maximal for lower mitogenic concentrations, compared with response of lymphocytes from 10 healthy dogs. The suppressive lymphocyte activity in 6 autoimmune colony dogs was diminished in comparison with the activity in 5 nonautoimmune colony dogs and 6 healthy dogs.
Bacteriologic and histologic studies of hepatic abscesses in cattle
Authors: Lechtenberg K. F. , Nagaraja T. G. , Leipold H. W. , Chengappa M. M.
Published: February 2025

Twenty-eight abscessed livers were collected from feed-lot cattle at an abattoir; specimens were obtained from 49 abscesses for bacteriologic culture and for histologic examination. Cultural procedures included techniques to enumerate and isolate facultative and obligate anaerobic bacteria. Anaerobic bacteria were isolated from all 49 abscesses, whereas facultative bacteria were isolated from only 22. Mean bacterial counts for anaerobic and facultative bacteria were 3 × 108 and 8 × 108 bacteria/g of purulent material, respectively. Fusobacterium necrophorum, the only anaerobe isolated, was detected in 100% of the abscesses. Fusobacterium necrophorum biotype A was isolated from 57% of the abscesses (in pure culture from 75%), and F necrophorum biotype B was isolated from 47% of the abscesses (from 96% with mixed infections). Corynebacterium pyogenes was the predominant facultative bacterium isolated. Histologic changes in abscesses were qualitatively similar; abscesses were pyogranulomatous, with a necrotic center surrounded by zones of inflammatory tissue. However, the severity of lesions varied, depending on the F necrophorum biotype involved. Portal triad fibrosis and bile-duct proliferation were most severe in biotype A and mixed biotype B infections and less severe in abscesses from which biotype B was isolated in pure culture.
Bovine adenovirus type-3 infection in feedlot calves
Authors: Mattson D. E. , Norman B. B. , Dunbar J. R.
Published: February 2025

The frequency of bovine adenovirus type-3 (BA3) infection in 84 of 165 light feeder calves and the possible role of BA3 in inducing febrile disease and affecting weight gain performance were studied for 56 days after the calves entered a feedlot. Samples of blood for serotesting were obtained periodically, and samples for virus isolation were collected on days 28 and 56. At the time the calves entered the feedlot, 17.8% (15 of 84) had serum virus-neutralizing antibodies to BA3. During 56 days, 54.8% (46 of 84) seroconverted to BA3. Of these seroconversions, 87% took place during the first 28 days. Bovine adenovirus type-3 was isolated from 2 calves (1 isolate each on days 28 and 56). Pyrexia (≥ 39.2 C) was observed more often in BA3-infected calves than in noninfected calves. However, there was no significant (P < 0.05) difference in weight gain between the BA3-infected and noninfected calves.
Lidocaine treatment of dogs with Escherichia coli septicemia
Authors: Hardie Elizabeth M. , Rowlings Clarence A. , Shotts Emmet B. , Waltman Douglas W. , Rakich Pauline M.
Published: February 2025

Effects of lidocaine on organ localization of neutrophils and bacteria and on hemodynamic and metabolic variables were determined during septic shock in dogs. Twelve anesthetized dogs were infused with 1010 Escherichia coli/kg of body weight through a portal vein catheter over a 1-hour period. Six of these 12 dogs were treated with 2 mg of lidocaine HCl/kg (6 mg/kg/h) 15 minutes after the bacterial infusion had begun. Six dogs not given E coli (surgical controls) were given saline solution at the same rate as the bacterial and lidocaine infusions.

Over 4 hours, nontreated dogs with septicemia developed systemic hypotension, decreased cardiac output, increased portal pressure, increased serum alanine transaminase activity, increased liver extravascular water, increased liver glycogen depletion, and decreased Pao2, compared with control dogs. Accumulations of polymorphonuclear leukocytes and E coli were found in the liver and lungs of dogs with septicemia. Lidocaine treatment did not alter the hemodynamic measurements and resulted in metabolic acidosis and hypoalbuminemia. Decreased numbers of E coli were recovered from the liver of lidocaine-treated dogs, whereas increased numbers of organisms were recovered from the blood. Neutrophil sequestration was increased in the liver, but not the lungs of lidocaine-treated dogs.
Effect of anti-Ia monoclonal antibodies on in vitro immune responses of canine cells
Authors: Ladiges Warren , Deeg H. Joachim , Pesando John , Storb Rainer
Published: February 2025

Four murine monoclonal antibodies (mab) B1F6, ISCR3, HB10a, and 7.2, specific for framework determinants of murine and human Ia, were tested for their effect on mixed lymphocyte culture, cell-mediated lympholysis, and mitogen assays of canine cells. All 4 mab were reactive with monocytes and surface immunoglobulin-positive, as well as Thy-1 antigen-positive mononuclear cells, as determined by immunocytofluorescence. The mixed lymphocyte culture response was inhibited when B1F6 or HB10a was added to cultures at the beginning of the assay (day 0). However, cultures underwent a normal response in the presence of ISCR3 or 7.2. None of the mab was able to inhibit cell-mediated lympholysis or mitogen reactivity to concanavalin A, pokeweed mitogen, or phytohemagglutinin. When effector cell populations of the 3 assays were cytolytically treated with each of the 4 mab and complement, immune reactivity was consistently lost, indicating that effector cells or accessory cells supporting the cell populations had been eliminated. These data indicate that Ia-like antigens are expressed on canine mononuclear cells and that antigens recognized by different mab may have different functional relevance, as defined by the mixed lymphocyte culture assay.