bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Various Treatments on Induced Chronic Aflatoxicosis in Rabbits
Authors: Clark J. Derrell , Jain Anant V. , Hatch Roger C.
Published: February 2025

Male New Zealand White rabbits were orally given 0.05 mg of aflatoxin B1 (AFB1)/kg of body weight daily for 10 days and were treated with glutathione-precursors and depletor, antibacterial agents, or sodium thiosulfate. The drug administered, the mortality, and the mean survival time were as follows: corn-oil controls (0), euthanatized at 25 days; AFB1-controls (2), 21 days; AFB1 and saline controls (2), 22 days; cysteine and AFB1 (5), 13 days; methionine and AFB1 (5), 12 days; sodium thiosulfate and AFB1 (2), 21 days; sulfadimethoxine and AFB1 (1), 24 days; oxytetracycline and AFB1 (0), euthanatized at 25 days; and ethyl maleate and AFB1 (3), 21 days.

Clinical signs of toxicosis included decreased feed consumption during AFB1 administration, loss of body weight or failure to gain, and death. Clinicopathologic changes included increases in serum bilirubin concentration and alanine aminotransferase and aspartate aminotransferase activities. Prothrombin and activated partial thromboplastin times were lengthened. Plasma fibrinogen concentration was decreased. Changes in pcv, hemoglobin concentration, and serum alkaline phosphatase were unremarkable. Oxytetracycline had protective effects against chronic aflatoxicosis in rabbits. Cysteine and methionine enhanced chronic aflatoxicosis.
Toxicologic Study of Carboxyatractyloside (Active Principle in Cocklebur—Xanthium strumarium) in Rats Treated with Enzyme Inducers and Inhibitors and Glutathione Precursor and Depletor
Authors: Hatch Roger C. , Jain Anant V. , Weiss Raul , Clark J. Derrell
Published: February 2025

Male rats (10 rats/group) were treated with phenobarbital (pb), phenylbutazone (pbz), stanozolol (3 inducers of cytochrome P450-dependent enzymes), piperonyl butoxide (pbo; a P450 inhibitor), cobaltous chloride (CoCl2; an inhibitor of hemoprotein synthesis), 5,6-benzoflavone (bnf; an inducer of cytochrome P448 dependent enzymes), cysteine [cys; a glutathione (gsh) precursor], or ethyl maleate (em; a gsh depletor). The rats were then given a calculated LD50 dosage (13.5 mg/kg of body weight) of carboxyatractyloside (cat) intraperitoneally. Clinical signs of toxicosis, duration of illness, lethality, gross lesions, and hepatic and renal histopathologic lesions were recorded. Seemingly, (i) cat toxicosis has independent lethal and cytotoxic components (pbz decreased lethality and cytotoxicity; CoCl2 decreased cytotoxicity but not lethality; bnf decreased duration of illness, and perhaps lethality, but not cytotoxicity); (ii) cat cytotoxicity could be partly due to an active metabolite formed by de novo-synthesized, P450-/P448-independent hemoprotein (pbz and CoCl2 had anticytotoxic effects, but pb, stanozolol, pbo, and bnf did not); (iii) cat detoxification may occur partly through a hemoprotein-independent, pbz-inducible enzyme, and partly through a P448-dependent (bnf-inducible) enzyme; and (iv) cat detoxification apparently is not P450 or gsh-dependent because pb, stanozolol, and cys had no beneficial effects, and pbo, CoCl2, and em did not enhance toxicosis. Metabolism of cat may have a role in its cytotoxic and lethal effects.
Antibacterial Action of Combinations of Oxytetracycline, Dimethyl Sulfoxide, and EDTA-Tromethamine on Proteus, Salmonella, and Aeromonas
Authors: Wooley R. E. , Gilbert J. P. , Shotts E. B.
Published: February 2025

Antibacterial effects against Proteus mirabilis, Salmonella typhimurium, and Aeromonas hydrophila were obtained with subminimal inhibitory concentrations of oxytetracycline and EDTA-tromethamine. Antibacterial effects were not observed with subminimal inhibitory concentrations of dimethyl sulfoxide plus oxytetracycline or with dimethyl sulfoxide plus EDTA-tromethamine. Using a 2-dimensional Microtiter checkerboard technique, inhibitory activities of the various combinations of solutions were studied, and isobolograms were plotted. A synergistic effect was seen with combinations of oxytetracycline and EDTA-tromethamine. The greatest synergistic effect was observed when the mixture was caused to react with P mirabilis. These findings were confirmed by kinetic studies of microbial death, using one-fourth minimal inhibitory concentrations of these preparations.
In Vitro Depression of the Mitogenic Response of Lymphocytes from Turkeys Infected with Hemorrhagic Enteritis Virus
Authors: Nagaraja K. V. , Patel B. L. , Emery D. A. , Pomeroy B. S. , Newman J. A.
Published: February 2025

A depression in the mitogenic response of lymphocytes was demonstrated in turkeys inoculated with hemorrhagic enteritis virus. Blood samples were collected (in heparin) once a week, beginning 1 week after the turkeys were inoculated. The whole blood assay was used to study lymphoblastogenesis. Concanavalin-A and phytohemagglutinin were the mitogens used: the radioisotope used was (125I)deoxyuridine (125IudR; 125I, sp act 5 Ci/mg). Suppression in the lymphocyte response in vitro was seen up to 5 weeks after the inoculations were done, after which there was a gradual recovery from suppression in the lymphocyte blastogenesis.
Experimental Naegleria fowleri Meningoencephalitis in Sheep: Light and Electron Microscopic Studies
Authors: Simpson Charles F. , Willaert E. , Neal Fred C. , Stevens A. R. , Young Martin D.
Published: February 2025

A sheep infected intranasally with Naegleria fowleri of human origin died 7 days after inoculation. The olfactory lobes were distinctly soft and friable. Histologic findings indicated suppurative leptomeningitis and hemorrhagic necrosis in the olfactory lobes. Protozoa were disseminated in the necrotic areas, particularly in perivascular locations; vasculitis was also observed. Meningitis and perivascular cuffing with lymphocytes were evident in the cerebrum, cerebellum, pons, medulla, and cervical spinal cord.

Electron microscopy disclosed trophozoites only in the olfactory lobes. The amebae contained a central nucleus with a distinct, electron-dense nucleolus. The cytoplasm contained myelinated figures, lipid-like vacuoles, open vesicles, electron-dense granules, mitochondria, numerous free ribosomes, scant rough endoplasmic reticulum, and occasionally a phagocytized erythrocyte. Trophozoites were grouped close to arterioles, except when phagocytized by a neutrophil or endothelial cell.
DNA of Bovine Herpesvirus Type 1 in the Trigeminal Ganglia of Latently Infected Calves
Authors: Ackermann M. , Peterhans E. , Wyler R.
Published: February 2025

Twelve calves infected with bovine herpesvirus type 1 (bhv-1) were killed when in a latent state of infection. Latency was verified 30 days after virus inoculation of the calves by seroconversion, absence of virus shedding, and in 2 calves, by recrudescence of the infection after they were treated with dexamethasone.

By in situ hybridization techniques and autoradiography, DNA of bhv-1 was detected in 13 of 23 trigeminal ganglia of latently infected calves. Viral DNA was restricted to the nucleus of nerve cells. Single neurons harboring bhv-1 DNA were observed in 4.9% of the sections (n = 325) of the trigeminal ganglia. The results obtained correspond to those known from herpes simplex virus infections in mice.

The implications for the virus-host relationship are discussed.
Correct Occlusive Bladder Width for Indirect Blood Pressure Measurement in Horses
Authors: Parry B. W. , McCarthy M. A. , Anderson G. A. , Gay C. C.
Published: February 2025

The influence of occlusive bladder width on blood pressure, measured indirectly using a doppler ultrasound technique at the middle coccygeal artery, was studied in 6 anesthetized horses. The relationship was investigated on tails with and without hair, and the optimum bladder width (bw)/tail girth (tg) ratio was determined for systolic pressure (sp) and diastolic pressure (dp), with the data grouped as unclipped tails (tt-1), clipped tails (tt-2), and both unclipped and clipped tails collectively (ttb). The optimum bw/tg ratios for sp and dp were 0.296 and 0.866 for tt-1, 0.376 and 1.156 for tt-2, and 0.339 and 0.983 for ttb, respectively. Despite the differences in optimal bw/tg ratios between tt-1 and tt-2, their regression equations were not significantly (P > 0.05) different and therefore, data could be considered as ttb.

The regression equations for ttb showed that a bw/tg ratio of 0.482 underestimated sp and overestimated dp by approximately 8.8%. In mature Thoroughbreds (mean tg 21.5 cm), this value corresponded to a bw of 10.4 cm.

Blood pressure measured directly in the greater metatarsal artery was significantly different from that measured directly in the middle coccygeal artery in individual horses, but when averaged over all horses, there was no significant difference between the 2 sites.
Recovery Cycle of the Reflex-Evoked Muscle Potential (H Reflex): Excitability of Spinal Motor Neurons in the Healthy Dog
Authors: Sims Michael H.
Published: February 2025

The recovery cycle for a reflex-evoked muscle potential has been demonstrated in the healthy dog, using the ulnar nerve-interosseous muscle preparation. The amplitude of a test response, at various time intervals (2 to 1,000 ms) after a conditioning response, was compared with the amplitude of the unconditioned response. The resulting ratio was plotted as a function of interstimulus interval. The curve was shown to consist of 3 distinct phases. The 1st phase, called the phase of early responsiveness, lasted from 2 to 20 ms and was characterized by a rapid decrease in amplitude of the test response. The 2nd phase, the phase of unresponsiveness, was characterized by a reduced response, and eventually no response which occurred between 20 and 80 ms. The 3rd phase, the phase of late responsiveness, began with a small test reflex amplitude at 80 ms and increased to 200 ms where it plateaued thereafter. Between 200 and 1,000 ms, there was no significant change in amplitude. Only at 2 ms, where the conditioning and test responses were so close together that they fused, did the mean amplitude of the test response exceed the mean unconditioned response. The reflex-evoked muscle potential recovery curve provides additional proof that the reflex is the equivalent of the H-reflex, and it provides a quantitative measure of spinal cord lower motor neuron excitability in the dog.
Lymphocyte Blastogenesis in Dogs with Lymphosarcoma
Authors: Calvert Clay A. , Dawe Donald , Leifer Connie E. , Brown John
Published: February 2025

Mitogen-stimulated lymphocyte blastogenesis was evaluated, using lymphocytes from 37 dogs with multicentric lymphosarcoma. The majority of the test results was within a normal range, even for those dogs with more advanced disease. However, depressed lymphocyte blastogenesis, when present, almost always occurred in lymphocytes from dogs with clinical stage IV-B and V-B disease. Dogs weighing > 25 kg had a significantly (P = 0.04) higher occurrence of clinical stage IV or V disease as compared with dogs weighing < 15 kg. Dogs with diffuse lymphocytic well-differentiated lymphoma were statistically more likely to be designated clinical stage III at the time of diagnosis, as compared with dogs with diffuse lymphocytic poorly differentiated lymphoma.
Adrenocortical suppression in the dog given a single intramuscular dose of prednisone or triamcinolone acetonide
Authors: Kemppainen R. J. , Lorenz M. D. , Thompson F. N.
Published: February 2025

Adrenocortical function was assessed in dogs given a single intramuscular dose of either prednisone or triamcinolone acetonide (tca; or saline solution to controls) to determine the duration of adrenocortical suppression caused by 2 commonly used glucocorticoids. The glucocorticoids were administered at recommended therapeutic doses; therefore, dogs given prednisone received a greater amount of glucocorticoid activity than did dogs given tca. Basal and ACTH-stimulated plasma cortisol concentrations, as determined by radioimmunoassay, were obtained once a week. Total intravascular eosinophil concentration and skin responses to intradermally injected histamine phosphate were quantitated. Dogs given tca showed suppressed basal and ACTH-stimulated plasma cortisol concentrations 1 week after injection; the latter change persisted 2 weeks after injection. Adrenocortical function in 1 of 4 dogs given tca remained suppressed for 4 weeks. In contrast, prednisone did not significantly alter adrenocortical function. Although intravascular eosinophil concentrations did not vary among groups, skin responses to intradermally injected histamine phosphate were reduced 6 days after prednisone and tca were given.
Effect of some enzyme inducers, fluids, and methionine-thiosulfate on induced acute aflatoxicosis in goats
Authors: Hatch Roger C. , Clark J. Derrell , Jain Anant V. , Mahaffey Edward A. , Weiss Raul
Published: February 2025

Groups of four 6- to 12-month-old male goats were injected intraruminally with a lethal dose (3 mg/kg of body weight) of aflatoxin B1 (AFB1). Drugs were administered parenterally before (pretreatment) or beginning 8 hours after goats were dosed with AFB1. These drugs were phenobarbital (pb), phenylbutazone (pbz), piperonyl butoxide (pbo), benzoflavones, water, and 5% glucose solution (D5W). Most groups given the drugs after AFB1 was administered also were given intraperitoneal injections of methionine-sodium thiosulfate (met-ts) solution.

Clinical signs of toxicosis, serum aspartate aminotransferase activities, serum bilirubin concentrations, duration of illness, mortality, and gross and microscopic pathologic findings taken together indicated that toxicosis was increased with met-ts + pb therapy, pbz pretreatment, pbz therapy, benzoflavone pretreatment, benzoflavone therapy, met-ts + benzoflavone therapy, and met-ts + water therapy. Toxicosis was not altered appreciably by met-ts + pbo therapy.

Beneficial effects (less severe toxicosis) were produced by pb pretreatment; these effects were prolonged maintenance of strength, vigor, and appetite and (in 1 goat that recovered) absence of pathologic changes or serum bilirubin increase. Therapy with met-ts + D5W (but not met-ts alone) also lengthened maintenance of strength, vigor, and appetite, but did not prevent pathologic changes. The beneficial effect of met-ts therapy reported in a previous study (AFB1 dosage of 4 mg/kg) was not observed with the 3 mg/kg lethal dose.

In conclusion, therapy for acute aflatoxicosis with inducers of hepatic microsomal enzymes is ineffective (pbo) or contraindicated (pb, pbz, benzoflavones). Therapy with D5W may be a useful adjunct to other therapeutic drugs, but multiple intraperitoneal injections of D5W may decrease survival time because of stress.
Toxicity of tansy ragwort (Senecio jacobaea) to goats
Authors: Goeger D. E. , Cheeke P. R. , Schmitz J. A. , Buhler D. R.
Published: February 2025

Dried tansy ragwort, which contains pyrrolizidine alkaloids, was fed as 25% of a complete diet to goat kids and to lactating dairy goats. Of 11 animals, 4 died, showing signs of chronic pyrrolizidine alkaloid toxicosis, including hepatocellular degeneration, hepatocyte swelling, megalocytosis, and bile duct proliferation. The chronic lethal dose of tansy ragwort ranged from 1.25 to 4.04 kg/kg of body weight. Goats are more resistant to tansy ragwort toxicosis than are cattle and horses, in which tansy ragwort intakes of 0.05 to 0.20 kg/kg of body weight are lethal.
Duration of protection of calves against rhinovirus challenge exposure by infectious bovine rhinotracheitis virus-induced interferon in nasal secretions
Authors: MacLachlan N. James , Rosenquist Bruce D.
Published: February 2025

Six calves were inoculated intranasally with a vaccinal strain of infectious bovine rhinotracheitis (ibr) virus and 6 control calves were given a placebo. All calves were subsequently challenge exposed (by aerosol) with rhinovirus—3 of the calves from each group at 2 days after they were inoculated with ibr virus or with placebo and the remaining calves at 6 days. Nasal excretion of viruses, interferon (ifn) concentrations in nasal secretions (ns), and neutralizing antibody in sera and ns were determined.

All calves given the vaccinal ibr virus subsequently had ifn in their ns. Interferon was detected as early as 1 day, reached maximal titers at 2 to 4 days, and persisted in individual calves for 5 to 10 days after inoculation.

Rhinovirus shedding was not detected from ibr virus-inoculated calves whose ns contained both rhinovirus antibody and ifn at the time of challenge exposure; such calves were protected at either 2 or 6 days after ibr virus inoculation.

The outcome of rhinovirus challenge exposure of calves whose ns contained ifn, but not rhinovirus antibody, varied with the day of challenge exposure. Rhinovirus excretion was detected from 2 of these calves challenge exposed 2 days after ibr virus inoculation, but was not detected from a calf challenge exposed 6 days after inoculation. However, while ifn was present in ns from the former 2 calves, rhinovirus shedding was markedly reduced as compared with that from control calves without ifn or ns antibody at the time of challenge exposure.

Consistent relationship was not observed between the rhinovirus neutralizing antibody titer of calves’ sera and ns. The antibody titer of ns more closely correlated with protective immunity to rhinovirus infection than did the serum antibody titer.
Lysates of turkey-grown Pasteurella multocida: Examination of vaccine preparations by electron microscopy
Authors: Brogden K. A. , Rimler R. B.
Published: February 2025

The effects of differential centrifugation, density gradient centrifugation, freeze-thawing, and chemical lysis on the morphology of Pasteurella multocida from the blood of infected turkeys were examined by electron microscopy. Morphologic differences were not seen between thin-section preparations of P multocida after differential and density gradient centrifugation procedures. The internal ultrastructure of in vivo-grown cells was different from that observed previously for P multocida grown in vitro. Large membranous blebs were also observed on the surface of negative-stained preparations of organisms from the plasma, but not in thin sections of cells from the same preparation. Freeze-thaw of bacterial suspensions in sucrose resulted in partial lysis, revealing bacteria in different phases of degradation. Complete lysis (but not solubilization) was enhanced by treatment with EDTA, lysozyme, and Triton X-100. Centrifuged lysate pellets were thin-sectioned or negative-stained. Pellets consisted of vesicles, ranging in size from 0.05 to 1.0 μm, that had a characteristic trilaminar membranous appearance similar to those reported from other gram-negative bacteria grown in vitro and treated similarly.
Inactivation of African swine fever virus in tissues by gamma radiation
Authors: McVicar John W. , Mebus Charles A. , Brynjolfsson Ari , Walker Jerry S.
Published: February 2025

Infectiousness of African swine fever virus in pieces (approx 8 × 6 × 3 mm) of spleen, tonsil, and lymph node from pigs killed during the acute stage of the disease was destroyed by gamma radiation in doses of 20 kilogray (kGy) or greater. Infectivity titers of virus in tissues before irradiation ranged from 104.6 to 107.8 median hemadsorption U/g. Immunofluorescence of virus-infected tissue irradiated at a 50-kGy dose and stored at −70 C for 18 months was the same as that of comparable tissues from recently killed pigs.
Recrudescence of bovine herpesvirus-5 in experimentally infected calves
Authors: Krogman Linda A. , McAdaragh John P.
Published: February 2025

A latent infection of bovine herpesvirus-5 (bhv-5) was established in 4 calves. These calves, plus 2 controls, were given dexamethasone (dm) to reactivate the latent virus.

The 4 principal calves developed antibodies to bhv-5 by postinoculation day (pid) 21. Antibody titers increased until pid 42 before decreasing to low levels at pid 75. After the first dm treatment (started on pid 76), an anamnestic antibody response was demonstrated in the 4 principal calves.

Calves 2, 3, and 4 were euthanatized and necropsied at pid 121, and their antibody titers were again decreasing. The virus bhv-5 was not isolated from the tissues by conventional techniques of viral isolation but was isolated from the trigeminal ganglion and spinal cord of calf 3 by explantation techniques. The bhv-5 was isolated, using conventional viral isolation techniques, from a nasal swab sample of calf 1 on pid 91 (15 days after the first dm treatment) and from the thoracic lymph node 6 days after the start of a 2nd dm treatment.

Seemingly, bhv-5 may be latently harbored in the nerve tissues of calves and this virus may be reactivated from the upper respiratory tract following subsequent dm treatment.
Stability of the canine shoulder joint: An in vitro analysis
Authors: Vasseur P. B. , Moore D. , Brown S. A.
Published: February 2025

The stability of the canine shoulder joint was assessed with and without the restraining effects of selected supporting structures. Shoulder joints from medium-sized (15 to 30 kg) canine cadavers were dissected, and all soft tissues were removed except for the 4 cuff muscles (supraspinous, infraspinous, teres minor, subscapular), the biceps muscle (m. biceps brachii) and the joint capsule with its associated glenohumeral ligaments.

The humerus was fixed in position, and with the shoulder extended, the joint was stressed into abduction, adduction, internal rotation, and external rotation. The range of motion was measured from transverse pins placed above and below the joint. Measurements were made before and after severance of the cuff tendons and joint capsule. In selected joints, medial and lateral luxations were created. The biceps tendon was then transposed medially or laterally, respectively, to aid joint stability. Selected medial luxations were stabilized by transferring a portion of the insertion of the supraspinous tendon to a medial location. All joints were stressed as just described, and the range of motion was measured before and after tendon transfer.

The joint capsule with its associated glenohumeral ligaments was an important restraint of joint motion. Lateral transfer of the biceps tendon partially corrected lateral joint instability by imposed marked rotational constraints on the joint. Medial transfer of the biceps tendon or the supraspinous tendon partially corrected medial joint instability, but did not resolve rotational abnormalities.
Evaluation of seven commercial oxidase test products with Pasteurella
Authors: Weaver Nancy , Collins Michael T.
Published: February 2025

Seven commercial oxidase reagents were tested with 50 isolates each of Pasteurella multocida and P haemolytica. Each group of organisms consisted of a variety of serotypes from many locations and animal sources. Pasteurella multocida and P haemolytica were expected to be 90% oxidase-positive; however, only 2 commercial reagents were positive for > 90% of P multocida isolates. These were the Taxo N Discs and the Bacto-Differentiation Disks Oxidase. Only the Taxo N Discs were positive for > 90% of P haemolytica isolates. The 5 other commercial reagents demonstrated a variety of results. Pathotec Cytochrome Oxidase Strips were not positive with any of the 100 isolates tested. Correlation was not observed between dimethyl-p-phenylenediamine vs tetramethyl-p-phenylenediamine and the percentage of positive reactions.
Experimental maedi virus infection in sheep: Early cellular and humoral immune response following parenteral inoculation
Authors: Larsen Hans Jørgen , Hyllseth Bjørn , Krogsrud Johan
Published: February 2025

The early immune response (19 weeks) in sheep inoculated parenterally with maedi virus was studied, using the lymphocyte transformation test, immunodiffusion test, complement-fixation test, and neutralization test. Cellular immune responses were detected between 3 and 7 weeks after the sheep were inoculated. Antibodies were detected by immunodiffusion test in 3 of 5 animals in weeks 7 to 11 and by complement-fixation test in weeks 15 to 19. Neutralizing antibodies were not detected. There was no sign of virus-induced immunosuppression as determined by lymphocyte responsiveness to mitogens or by in vivo and in vitro immune responses following BCG vaccination.
Experimental maedi virus infection in sheep: Cellular and humoral immune response during three years following intranasal inoculation
Authors: Larsen Hans Jørgen , Hyllseth Bjørn , Krogsrud Johan
Published: February 2025

A long-term experiment in sheep inoculated intranasally with 2 strains of Norwegian maedi virus was carried out in 2 groups of Norwegian Dala sheep (7 sheep/group). Virus-specific cellular immune response was assayed in the lymphocyte transformation test sequentially during 3 years after sheep were inoculated in group 1 and 4 times in the 3rd year in group 2. Humoral immune response was assayed by immunodiffusion, complement-fixation, and neutralization tests on sequential serum samples collected from the 2 groups. Attempts to isolate virus were made.

All group 1 sheep showed transient and irregularly recurring cellular immune responses. In group 2, 6 of the 7 sheep gave similar responses. The frequency of virus isolations was low compared with that reported by various research workers using other breeds for studying experimental maedi-visna infection.

Precipitating antibodies were detected earlier, and in more animals, than were complement-fixing antibodies. Both were, however, detected later and less frequently than were reported by other research workers. There was a marked difference in the capability of the 2 maedi virus strains to induce neutralizing antibodies. The sequential sera usually showed distinct differences in neutralizing capacity of the virus strains, indicating that they are antigenically different.
Distribution of Pasteurella haemolytica and Pasteurella multocida in the bovine lung following vaccination and challenge exposure as an indicator of lung resistance
Authors: Newman P. R. , Corstvet R. E. , Panciera R. J.
Published: February 2025

Experimental calves were vaccinated with virulent strains of Pasteurella haemolytica or Pasteurella multocida or with phosphate-buffered saline solution either by an aerosol method or by subcutaneous injection. Calves were subsequently challenge exposed by intrapulmonic inoculation of the homologous virulent Pasteurella species. Sections obtained from the resulting pulmonic lesion were stained, using a fluorescent antibody technique, to determine relative number, location, and integrity of the challenge organism. The resistance of the calf to challenge exposure, as determined by other factors, was compared with the capacity of the components of the lung to engulf or destroy pasteurellae. Calves vaccinated with an aerosol of the bacterium were most resistant to challenge exposure; most bacteria were engulfed or degraded by the phagocytic cells. Vaccination by subcutaneous injection was less effective in inducing resistance. Tissue sections from these calves contained many more extracellular intact bacteria and fewer intracellular intact or degraded bacteria than were seen in the sections of calves vaccinated by the aerosol method. The control calves were the least resistant; bacteria seen in tissue sections from these calves were numerous, predominantly extracellular, and intact.

A group of nonvaccinated calves experimentally inoculated with infectious bovine rhinotracheitis virus 5 days before intrapulmonic challenge exposure with P haemolytica developed severe pulmonic lesions. The lesions were larger and more invasive and contained many more extracellular bacteria than did the lungs of calves in control groups. As in other nonvaccinated calves, there were few intracellular bacteria; however, unlike in other calves, the extracellular bacteria were seen in large numbers, particularly in alveolar lumens.
Effect of localized trauma and temporary splinting on immature skeletal muscle and mobility of the femorotibial joint in the dog
Authors: Shires Peter K. , Braund Kyle G. , Milton James L. , Liu Wendy
Published: February 2025

The right pelvic limbs of 2 groups of dogs were splinted in extension for 3 weeks. In 1 of these groups, the dogs were anesthetized and the distal portion of the quadriceps femoris muscle was traumatized before splinting. Two groups of control dogs were also used; neither group was splinted, but 1 group was anesthetized, and their muscles were traumatized. The range of motion of the femorotibial joint was measured in all 4 groups before splinting and 3 and 9 weeks after splinting. Types I and II muscle fiber diameters and percentages were also recorded at 3 and 9 weeks in all groups.

Flexion of the femorotibial joint was limited after splinting (P < 0.001), but less so after trauma and splinting than after splinting alone (P < 0.0001). A reversible type I fiber atrophy occurred in most restricted muscles (P < 0.001) and early type II fiber atrophy was seen in a few muscles after trauma and splinting (P < 0.002). Multifocal fiber necrosis was the only irreversible change seen after 3 weeks of splinting with or without concurrent muscle trauma. Relative fiber percentages did not change appreciably during splinting or recovery.
Evaluation of treatment for pancreatic exocrine insufficiency in dogs with ligated pancreatic ducts
Authors: Pidgeon Guy , Strombeck Donald R.
Published: February 2025

Clinical evaluations and measurements of maldigestion and malabsorption were made in dogs before and after ligation of pancreatic ducts. Fecal wet and dry weights were 300% greater after duct ligation. Fecal fat excretion of dietary intake increased from 9% to 84%. An indirect test of pancreatic function revealed a disappearance of intestinal chymotrypsin activity. All values tested improved during replacement with 5 ml of enzyme powder/day. Little additional improvement was observed after doubling or quadrupling this dose. Little or no additional improvement was seen with the following additions to enzymes: 30-minute preincubation of enzymes with food, antacids, cimetidine (except high dose), neomycin, or bile acids. Enzymes in uncoated tablets were less effective, unless the tablets were crushed.
Epizootiologic patterns of diabetes mellitus in dogs
Authors: Marmor Michael , Willeberg Preben , Glickman Lawrence T. , Priester William A. , Cypess Raymond H. , Hurvitz Arthur I.
Published: February 2025

A case-control study of spontaneous diabetes mellitus in dogs was undertaken, using 2 veterinary data bases. The Veterinary Medical Data Program (VMDP) contained records of 1,019 cases of canine diabetes from 14 university-affiliated veterinary hospitals. The Animal Medical Center (AMC), a private veterinary hospital which has not participated in the VMDP, contained records of 449 diabetes cases. Each data base was analyzed separately, control groups being chosen from all admissions, excluding diabetic animals.

Summary odds ratios by sex adjusted for age and breed indicated significantly (P < 0.05) elevated risks for entire females and neutered females compared with that for entire males. The VMDP data indicated a significantly elevated risk for castrated males, whereas the risk derived from AMC data was not significantly different from 1. Analysis of risks by breed adjusting for age and sex identified Poodles as being at significantly excess risk, and German Shepherd Dogs, Cocker Spaniels, Collies, and Boxers at significantly decreased risk in both data sets. The male:female risk ratio changed with age from 1 at less than 1 year of age to a predominance of females at older ages. In the AMC data base, diabetes was significantly associated with cataracts in dogs of both sexes combined. Diabetes was also significantly associated with benign mammary tumors in female dogs.
Vaccination studies of aspergillosis in turkeys: Subcutaneous inoculation with several vaccine preparations followed by aerosol challenge exposure
Authors: Richard J. L. , Thurston J. R. , Cutlip R. C. , Pier A. C.
Published: February 2025

Five vaccines were prepared from an isolate of Aspergillus fumigatus: a culture filtrate vaccine (I), a spore vaccine (II), a mycelial vaccine (III), and 2 germling vaccines (IV and V). The 2 germling vaccines were produced on different media. Two experiments were conducted to test the vaccines for efficacy in groups of 21 turkey poults by giving each bird 2 subcutaneous inoculations of the respective vaccine at 1 and 2 weeks of age. The birds were challenge exposed to an aerosol of spores of A fumigatus at 1 month of age. The 2 experiments differed only in the challenge exposure. In experiment 1, 38% of the poults were protected when vaccinated with an A fumigatus germling vaccine (IV) and challenge exposed with a dose of aerosolized A fumigatus spores that killed 100% of the nonvaccinated controls. Onset of postchallenge-exposure deaths were delayed by 2 days in the turkeys given vaccine IV. In experiment 2, 48% of the poults were protected when given germling vaccine IV, whereas 62% to 86% of the poults in the nonvaccinated and 3 other vaccine groups died. In experiment 2, 50% of the poults given a mycelial vaccine (III) were protected. Torticollis was a frequent sign of the disease in experiment 2.
In vitro evaluation of B-lymphocyte function in turkeys infected with hemorrhagic enteritis virus
Authors: Nagaraja K. V. , Emery D. A. , Patel B. L. , Pomeroy B. S. , Newman J. A.
Published: February 2025

Studies were conducted on B-lymphocyte function in turkeys infected with hemorrhagic enteritis (he) virus. Hemolytic plaque-forming technique was used to detect antibody-forming cells in turkeys. The plaque-forming cell responses in he virus-infected and noninfected controls were compared. Results of this study indicated a decreased capability of he virus-infected turkeys to produce antibodies to sheep rbc. The greatest inhibition of antibody-forming cell production was seen in the turkeys 19 days after exposure to the virus. However, after this period, the turkeys gradually recovered their immunocompetence to sheep rbc.
Characterization and chemical nature of Haemophilus avium hemagglutinin
Authors: Iritani Y. , Yamaguchi T.
Published: February 2025

Haemophilus avium hemagglutinin properties were studied. Hemaggutination titer was decreased by proteolytic enzyme treatments, but was not affected by glycosidase, lipase, phospholipase, and neuraminidase treatments. Cell-free hemagglutinin was found in supernatants of centrifuged sonicate and centrifuged agitate of H avium and was precipitated with ammonium sulfate with no loss of hemagglutinating activity. The H avium hemagglutinin showed different patterns of activity against the rbc of different avian species. Hemagglutination of chicken rbc was not inhibited by d-mannose.
Reduced intestinal absorption in broilers during Eimeria mitis infection
Authors: Ruff M. D. , Edgar S. A.
Published: February 2025

The absorption of glucose and l-methionine was as much as 52% less in the intestine of broilers inoculated with 2 strains of Eimeria mitis than in the intestine of noninoculated controls. This malabsorption was observed in the region of, and caudad to, the yolk sac diverticulum. Malabsorption was greater in birds given 500,000 sporulated oocysts than in those given 50,000 sporulated oocysts/bird. Depigmentation of the plasma was also considered an indication of malabsorption. Gross lesions were not evident in the intestine of these infected birds, even though histopathologic sections showed the presence of numerous parasites. Body weight was also less in inoculated birds, but pcv and plasma protein concentrations were not affected.
Neutrophilic movement of a Basenji with Pelger-Huët anoxmaly
Authors: Latimer Kenneth S. , Prasse Keith W.
Published: February 2025

Random and chemotactic neutrophilic movements in a Basenji with Pelger-Huët (P-H) anomaly was compared with such movement in 5 healthy control dogs. Duplicate samples of neutrophils were quantitated after 5, 10, 15, 30, and 45 minutes of incubation. On the basis of population mean responses, no significant difference (P > 0.05) was found between P-H and control neutrophils for any type of movement at any time interval examined. These findings indicate that the movement of neutrophils with P-H anomaly may be unaffected by the nuclear abnormality.
Isolation of an adenovirus antigenically distinct from equine adenovirus type 1 from diarrheic foal feces
Authors: Studdert M. J. , Blackney M. H.
Published: February 2025

Adenovirus was isolated in equine fetal kidney cell cultures from the feces of 2 foals with diarrhea that also had large numbers (> 106/g) of rotavirus particles in their feces. Unlike equine adenovirus type 1 (EAdV1), the fecal EAdV did not hemagglutinate human O, rhesus macaque, or equine rbc. By serum neutralization, the fecal viruses were identical with each other, but showed no relationship to EAdV1. Antiserum prepared against the fecal viruses did not contain hemagglutination-inhibiting antibody to EAdV1. It is proposed that the fecal viruses be considered prototypic of EAdV2. The frequency of neutralizing antibody to EAdV2 in 339 equine serum samples was 77%. Neither EAdV1 nor EAdV2 is related by serum neutralization to any of 30 human adenovirus serotypes.
Gel electrophoresis-derived enzyme-linked immunosorbent assay of serum from cows resistant to and cows susceptible to challenge exposure with Mycoplasma bovis
Authors: Boothby J. T. , Jasper D. E. , Lutz H. , Rollins M. H.
Published: February 2025

The gel electrophoresis-derived enzyme-linked immunosorbent assay (ged-elisa) technique combines the high resolving power of sodium dodecyl sulfate polyacrylamide gel electrophoresis (sds-page) to separate complex molecules by their molecular weights, with the high sensitivity of the eusa to detect specific antibody. Sera from 4 cows that demonstrated resistance to challenge exposure and 4 cows that were susceptible to challenge exposure with live virulent Mycoplasma bovis strain 201 were subjected to ged-elisa to determine reactivity with M bovis antigenic components separated by sds-page. The ged-elisa mean reactivity of sera from the 2 groups did not differ significantly (P = 0.17) when subjected to analysis of variance. Sera from both groups recognized distinct fractions of M bovis.
Electron microscopic study of the African strain of malignant catarrhal fever virus in bovine cell cultures
Authors: Castro Anthony E. , Daley Gerald G.
Published: February 2025

Malignant catarrhal fever (African strain) is a viral disease of ruminants which is considered an exotic disease in the United States. Viral isolates obtained from one clinically ill gaur (Bos gaurus) and a greater kudu (Tragelaphus strepsiceros) located in a zoologic park in Oklahoma, and from one heifer (Bos taurus) and a domestic whitetailed deer (Odocoileus virginianus) experimentally inoculated with the isolated and identified African strain of malignant catarrhal fever virus (mcfv), were each studied in bovine cell cultures by electron microscopy. Certain of the viral isolates were previously characterized as mcfv by serologic and morphologic examinations, their cytopathic effect in cell cultures, and their ability to reproduce disease in a ruminant host. The virions of mcfv (African) examined by electron microscopy were icosahedral similar to herpesvirus, were between 98 and 194 nm, developed in the nucleus and matured in the cytoplasm of the cell, and exhibited budding. The virus in infected cells passed through the nuclear and plasma membranes and also into cytoplasmic vesicles from which it acquired one or more envelopes. Virions of malignant catarrhal fever were closely associated with the cellular endoplasmic reticulum, and aberrant morphologic forms of mcfv were observed in virus-infected cells.
Radiographic characterization of diaphragmatic excursion in halothane-anesthetized ponies: Spontaneous and controlled ventilation systems
Authors: Benson G. J. , Manohar M. , Kneller S. K. , Thurmon J. C. , Steffey E. P.
Published: February 2025

A radiograph technique for identification of diaphragmatic segments and quantitation of their contribution to total diaphragmatic function was developed. Five anesthetized ponies were studied on 3 separate occasions. Studies were made of the ponies in left lateral recumbency at 2 anesthetic levels (1 and 2 minimal alveolar anesthetic concentrations; halothane) and under spontaneous and controlled ventilation systems.

General pattern of diaphragmatic displacement was unchanged by increased depth of anesthesia. Controlled ventilation altered the pattern of diaphragmatic displacement. Diaphragmatic displacement and regional volume changes were a function of active contraction or passive movement.
Effect of reversible upper respiratory bypass on the electroretinogram in sheep
Authors: Ohale Levi O. C. , Ghoshal Nani G.
Published: February 2025

Ten Rambouillet ewes (2 groups of 5 each) were surgically implanted with a reversible tracheal bypass cannula constructed so that the sheep could breathe normally through the nostrils when the flow-through insert was in place or through the tracheal opening when the bypass insert was adjusted.

In 1 group, an electroretinogram recorded an increased amplitude and decreased duration of the b wave during bypassed breathing. When the ewes were allowed to breathe simultaneously through the tracheal opening and nostrils, the b-wave amplitude was decreased, compared with the amplitude during normal nasal breathing alone. Several recordings for individual breathing phases were consistent for each animal. In the 2nd group, arterial blood gas analysis showed no differences in the partial pressures (Pco2 and Po2) during both breathing phases. Seemingly, functional elimination of the upper respiratory cooling of venous blood influences the heat exchange in the ophthalmic plexus and cavernous sinus, resulting in relatively warmer blood reaching the eye.
Effect of antibacterials, anabolic steroid, and diethyldithiocarbamate on induced acute aflatoxicosis in goats
Authors: Hatch Roger C. , Clark J. Derrell , Jain Anant V. , Mahaffey Edward A. , Weiss Raul
Published: February 2025

Groups of four 6- to 12-month-old male goats were injected intraruminally with a lethal dose (3 mg/kg of body weight) of aflatoxin B1 (afb1). Drugs administered parenterally before or beginning 8 hours after afb1 included oxytetracycline (otc; given once or twice daily), ampicillin (amp), sulfadimethoxine (sdm), the anabolic steroid stanozolol, or the hemoprotein synthesis-inhibitor diethyldithiocarbamate (dedc).

Goats pretreated with otc once daily had two-thirds less hepatic destruction than did control goats. Compared with control animals, goats given otc therapy once daily had milder respiratory signs, increased maintenance of appetite, strength, and vigor, mortality of 50%, an apparent decrease in average serum aspartate aminotransferase (ast) response to afb1, and a 33% decrease in average percentage of hepatic destruction. These beneficial effects were not observed in goats given pretreatment or therapy with amp or sdm.

Goats given otc therapy twice daily had 25% mortality, the average serum ast response to afb1 was significantly decreased (P < 0.05), and gross lesions were absent in 2 of 3 survivors. However, otc therapy given twice daily did not improve the clinical condition of the goats. Moreover, hepatic destruction was not decreased further than with otc therapy given once daily. Beneficial effects of otc may have been due to enzyme induction or interference with afb1 toxic mechanisms, rather than to antibacterial action.

Goats pretreated with stanozolol had prolonged maintenance of appetite, strength, and vigor, and the average serum ast response to afb1 and average percentage of hepatic destruction were decreased. Mortality and duration of illness were not altered. Beneficial effects of stanozolol pretreatment seemed to be due to appetite stimulation, to anabolic effects, and possibly to slow-onset induction of afb1-degradative enzymes. Stanozolol therapy hastened death, possibly by competition for afb1 degradative enzymes.

Diethyldithiocarbamate had adverse effects. Goats pretreated with dedc had shortened mean survival time, the gross lesions were worse than those of control goats, and the average percentage of hepatic destruction was increased. Possibly, afb1 activation does not require de novo synthesis of the activating cytochrome. Adverse effects of dedc also may have been due to toxic effects of the dosage of dedc used.

In conclusion, otc (10 mg/kg of body weight given parenterally once or twice daily) may be useful for treatment of acute aflatoxicosis in ruminants, but amp and sdm may not be useful. Stanozolol should not be used, unless other agents are administered that will prolong the lives of the animals sufficiently for the drug to exert its beneficial effects. Therapy with dedc alone (in the dosage used) is contraindicated.
Evaluation of three immunodiagnostic procedures for porcine strongyloidiasis
Authors: Murrell K. D. , Graham C. E. , Anderson W. R.
Published: February 2025

An indirect fluorescent antibody test (ifat), an indirect radioimmune antibody test (irat), and an enzyme-linked immunosorbent antibody assay (elisa) were compared for their efficacies in detecting antibody to Strongyloides ransomi in pigs. The greatest sensitivity was exhibited by the elisa, using a soluble, whole larval extract. The 2 indirect antibody assays, ifat and irat, using intact 3rd-stage larvae (L3) were comparable in sensitivities. The use of live L3 in the ifat and irat presented technical problems, because the larvae shed antibody complexes at ambient room temperature. This could be inhibited by the addition of 20 mM of sodium azide to all working solutions or by doing the tests at 4 C. Fixation of the L3 by either formalin or heat also eliminated the shedding problem. The specificities of the elisa and ifat were supported by the negative results obtained with serum from pigs infected with Ascaris suum, Stephanurus dentatus, and Trichinella spiralis.
Salmonella in the mesenteric lymph nodes of healthy sows and hogs
Authors: Keteran K. , Brown J. , Shotts E. B.
Published: February 2025

Mesenteric lymph nodes were collected from healthy sow and slaughter hogs that had been kept in holding pens for an average of 10 and 2 days, respectively, before slaughter at an abattoir.

Salmonella was isolated from 58.2% (67/115) of the sows and 31.3% (16/51) of the slaughter hogs. This difference in Salmonella prevalence was significant (X2 = 10.22, P < 0.005); therefore, the hypothesis that there would be no significant difference in the infection rates of sows and slaughter hogs was rejected.