bluuebunny/crossref_metadata_2025 huggingface dataset:
Brain stem auditory-evoked response of the nonanesthetized dog
Authors: Marshall A. Edward
Published: February 2025

The brain stem auditory evoked-response was measured from a group of 24 healthy dogs under conditions suitable for clinical diagnostic use. The waveforms were identified, and analysis of amplitude ratios, latencies, and interpeak latencies were done. The group was subdivided into subgroups based on tranquilization, nontranquilization, sex, and weight. Differences were not observed among any of these subgroups. All dogs responded to the click stimulus from 30 dB to 90 dB, but only 62.5% of the dogs responded at 5 dB. The total number of peaks averaged 1.6 at 5 dB, increased linearly to 6.5 at 50 dB, and remained at 6.5 to 90 dB. Frequency of recognizability of each wave was tabulated for each stimulus intensity tested; recognizability increased with increased stimulus intensity. Amplitudes of waves increased with increasing stimulus intensity, but were highly variable. The 4th wave had the greatest amplitude at the lower stimulus intensities, and the 1st wave had the greatest amplitude at the higher stimulus intensities. Amplitude ratio of the 1st to 5th wave was > 1 at ≤ 50 dB stimulus intensity, and was 1 for stimulus intensities > 50 dB. Interpeak latencies did not change relative to stimulus intensities. Peak latencies of each wave averaged at 5-dB hearing level for the 1st to 6th waves were 2.03, 2.72, 3.23, 4.14, 4.41, and 6.05 ms, respectively; latencies of these 6 waves at 90 dB were 0.92, 1.79, 2.46, 3.03, 3.47, and 4.86 ms, respectively. Latency decreased between 0.009 to 0.014 ms/dB for the waves.
Endometrial and serum gentamicin concentrations in pony mares given repeated intrauterine infusions
Authors: Pedersoli W. M. , Fazeli M. H. , Haddad N. S. , Ravis W. R. , Carson R. L.
Published: February 2025

Endometrial tissue and blood serum gentamicin (gt) concentrations were determined in 6 ovariectomized pony mares given intrauterine infusions (50 ml of a 5% commercial aqueous solution of gt) each day for 5 consecutive days. The mares were subjected to the following 3 treatments: (1) gt infusion only (trial A, control); (2) progesterone plus gt (trial B, P + G); and (3) estradiol plus gt (trial C, E + G). Endometrial tissue concentrations of gt (μg/g) at 24 and 120 hours were significantly higher (P < 0.05) in trials B (65.54 ± 15.57 and 100.33 ± 19.27) and C (73.33 ± 22.53 and 74.09 ± 8.60) than in trial A (4.23 ± 0.70). Endometrial concentration for trial A at 120 hours was also significantly higher than trial A at 24 hours. There was no significant difference (P > 0.05) in endometrial concentrations among trials A, B, and C at 120 hours. Serum gt concentrations were significantly lower than endometrial tissue concentrations. The highest serum concentrations of gt found in every trial occurred at 6 hours after each intrauterine infusion of gt. The highest overall serum concentration of gt (μg/ml) determined occurred in trial B (8.30 ± 1.28) at 78 hours. There was no significant difference in serum concentrations of gt between days of treatment, except for trial A at 78 and 102 hours, respectively. Serum concentrations of gt were significantly higher (P < 0.05) than trial A at 30, 54, 78, and 102 hours in trial B, and at 78 and 102 hours in trial C. There was no significant difference in serum concentrations of gt between trials B and C.
Susceptibility of cats, sheep, and swine to a rabbit isolate of Encephalitozoon cuniculi
Authors: Pang Victor F. , Shadduck John A.
Published: February 2025

Newborn cats, pigs, and sheep (3 to 14 days old) and postweanling cats (2.5 months old) that had been inoculated with Gardner feline sarcoma virus and feline leukemia virus at 10 days of age were infected experimentally with a rabbit isolate of the mammalian protozoan parasite Encephalitozoon cuniculi. Infection occurred in all cats and in some sheep, but was questionable in pigs. Brain and kidney were the 2 major target organs in cats. The lesions were compatible with, but less severe than, those of naturally infected cats and other carnivores. Of 13 cats, E cuniculi could be detected morphologically in the kidneys of 12 cats and in the brain of 1 cat. The organisms were reisolated from 2 cats with ground tissue suspension of kidney or urine sediment. The indirect immunofluorescence antibody (ifa) titers were 1:20 to 1:1,280 at the time the animals were killed, but antibodies were not detected before inoculation. Lesions were seen in the kidneys of 2 of 4 sheep. These lesions were mild, but were compatible with those in a spontaneously affected goat. Encephalitozoon cuniculi were found morphologically in the kidney of 1 sheep with lesions. All sheep had ifa titers of 1:10 to 1:20 before inoculation, and the titers were 1:20 to 1:320 when they were killed. Vasculitis, similar to the subacute-to-chronic stage of polyarteritis nodosa, was observed in 1 of 8 pigs. The lesions were primarily present in the kidney; comparable but milder lesions were also seen in the heart and brain. Antibody was not detected before inoculation. The ifa titers of 1:2 to 1:8 developed in 5 pigs, although the antibodies decreased to undetectable levels in 2 pigs at the time they were killed. The results confirmed that cats are susceptible to E cuniculi and indicated that sheep probably are also susceptible, although the susceptibility may be low.
Correlation of tissue infection and serologic findings in pigs fed Toxoplasma gondii oocysts
Authors: Prickett Michael D. , Dreesen David W. , Waltman W. Douglas , Blue Jack L. , Brown John
Published: February 2025

Each of thirteen 6-week-old pigs was inoculated per os with 10,000 sporulated oocysts of Toxoplasma gondii. By postinoculation day (pid) 13, pigs were seropositive by the indirect fluorescent antibody test. Beginning on pid 13 and every 7 days thereafter through pid 97, 1 pig was killed and 6 tissues were examined for T gondii. Of the 13 pigs, 11 were infected, including the 1st pig killed on pid 13, although none of the pigs had gross lesions of toxoplasmosis. Tissues harboring T gondii most frequently were the heart and brain; organisms were detected less frequently in the longissimus muscles, diaphragm, and liver. Toxoplasma gondii was not detected in the bronchial lymph nodes. There was good correlation between antibody and presence of T gondii in these pigs. One additional pig, maintained as a noninfected control, remained seronegative and had no evidence of infection when killed on pid 97.
Serologic diagnosis of toxoplasmosis in experimentally infected pregnant goats and transplacentally infected kids
Authors: Dubey J. P. , Desmonts George , Antunes F. , McDonald Connie
Published: February 2025

Eight pregnant goats were inoculated orally with 10 to 1,000 oocysts of Toxoplasma gondii at 83 to 102 days of gestation. Serum samples from the goats and from the kids born to them were analyzed, using the Sabin-Feldman dye test (dt), a commercially available modified agglutination test (mat), and a latex agglutination test. Six of the does were observed for > 1 year; during this time, they delivered twice. All does developed dt and mat antibody titers of ≥ 1:2,048 within 29 days after inoculation, and the high titers persisted through the 2nd pregnancy; therefore, serologic results alone should not be relied on for the diagnosis of T gondii-induced abortion in does. On the other hand, all transplacentally infected kids had dt or mat antibody titers of 1:2,048 before ingesting colostrum, indicating the usefulness of serologic evaluation of the fetus or stillborn kid in the diagnosis of abortion. Antibody was not found in the sera of noninfected kids born to Toxoplasma-infected does. The passively acquired colostral antibody declined by 5 months. Therefore, specific antibody found in adult goats is probably actively acquired. The commercially available mat was simple, sensitive, and reliable for the diagnosis of caprine toxoplasmosis. The latex agglutination test needs further improvement, as titers rarely exceeded 1:256.
Comparison of total white blood cell count and total protein content of lumbar and cisternal cerebrospinal fluid of healthy dogs
Authors: Bailey Cleta Sue , Higgins Robert J.
Published: February 2025

Lumbar and cisternal csf from 31 healthy dogs were analyzed and compared statistically. The mean total protein of the lumbar csf samples was 28.68 mg/dl; the mean total protein of cisternal csf was 13.97 mg/dl. The mean total wbc count of lumbar csf was 0.55 cells/μl; the mean wbc count of cisternal csf was 1.45 cells/μl. Statistical analysis indicated that the protein and wbc differences between the 2 types of csf were significant (P = < 0.001 and P = < 0.01, respectively).
Plasma fibronectin concentrations in dogs with disseminated intravascular coagulation
Authors: Feldman Bernard F. , Thomson Don B. , O’Neill Sharron
Published: February 2025

Plasma fibronectin concentrations were significantly (P < 0.001) below the reference range in dogs with disseminated intravascular coagulation (dic) secondary to nonlymphomatous neoplasia, acute necrotizing pancreatitis, sepsis, chronic active hepatitis, and heat stroke. There was no statistical evidence of a group effect. Decrease in fibronectin concentration was associated with severe dic, although no attempt was made to correlate fibronectin concentration with prognosis. These findings parallel those reported for severely ill human beings with diseases associated with dic. They exemplify the potential of spontaneous diseases in animals as models for the study of human disease.
Lesions induced in the respiratory tract of chickens by encapsulated or nonencapsulated variants of Haemophilus paragallinarum
Authors: Sawata Akira , Nakai Toyotsugu , Kume Katsumi , Yoshikawa Hiroyasu , Yoshikawa Takashi
Published: February 2025

Lesions induced in chickens by an encapsulated or nonencapsulated strain of Haemophilus paragallinarum were investigated.

In terms of lesion severity, major differences in pathogenicity were observed between the encapsulated and nonencapsulated variants. The principal lesion manifested by the encapsulated variant was an acute catarrhal inflammation of the upper respiratory tract, mainly of the nasal cavity and paranasal sinus. Infiltration of a large number of mast cells into the lamina propria of the mucous membrane of the nasal cavity was also characteristic. Numerous organisms were found on the cilia or on the surface of the epithelial cells of the nasal mucosa. Chickens with these histologic lesions had severe clinical signs of coryza, and organisms were recovered in high numbers from the nasal cavity and paranasal sinus. In contrast, chickens that were given the nonencapsulated variant did not have clinical signs of coryza, and the organisms were recovered in low numbers from the inoculated sites; slight histopathologic lesions were observed in the nasal mucosa at postinoculation day 1. Mast cell infiltration in the chickens inoculated with the encapsulated variant indicated that mast cells may be responsible for producing clinical signs of coryza via the activation of pharmacologic mediators. Adherence to and colonization of the encapsulated variant on the nasal mucosa seems to be a first step of the infection.
Comparison of minimal inhibitory concentration and disk-diffusion antimicrobic sensitivity testing of bacterial pathogens isolated from food animals
Authors: Libal Melissa C.
Published: February 2025

Disk-diffusion sensitivity tests were conducted with the antimicrobics sulfathiazole, gentamicin, erythromycin, kanamycin, penicillin, ampicillin, and spectinomycin on 300 to 350 bacterial isolates of food animal origin. The minimal inhibitory concentration of each antimicrobic was also determined for each bacterial isolate, using a microdilution technique. Results indicated that inhibitory zone sizes should be larger for some antimicrobics when testing animal pathogens than those zone sizes recommended for testing human pathogens. In addition, zone interpretive data are reported for spectinomycin, a drug for which such data were previously lacking.
Pasteurella haemolytica bacteriophage; Identification, partial characterization, and relationship of temperate bacteriophages from isolates of Pasteurella haemolytica (biotype A, serotype 1)
Authors: Richards Alan B. , Renshaw Harland W. , Sneed Loyd W.
Published: February 2025

Pasteurella haemolytica (biotype A, serotype 1) isolates (n = 15) from the upper respiratory tract of clinically normal cattle, as well as from lung lesions from cases of fatal bovine pasteurellosis, were examined for the presence of bacteriophage after irradiation with uv light. Treatment of all P haemolytica isolates with uv irradiation resulted in lysis of bacteria due to the induction of vegetative development of bacteriophages. The extent of growth inhibition and bacterial lysis in irradiated cultures was uv dose-dependent. Bacterial cultures exposed to uv light for 20 s reached peak culture density between 60 and 70 minutes after irradiation; thereafter, culture density declined rapidly, so that by 120 minutes, it was approximately 60% of the original value. When examined ultrastructurally, lytic cultures from each isolate revealed bacteriophages with an overall length of approximately 200 nm and that appeared to have a head with icosahedral symmetry and a contractile tail.

Cell-free filtrate from each noninduced bacterial isolate was inoculated onto the other bacterial isolates in a cross-culture sensitivity assay for the presence of phages lytic for the host bacterial isolates. Zones of lysis (plaques) did not develop when bacterial lawns grown from the different isolates were inoculated with filtrates from the heterologous isolates.
Bluetongue virus-induced interferon in cattle
Authors: MacLachlan N. James , Thompson Joanne
Published: February 2025

Calves were inoculated iv with bluetongue virus (btv), serotype 10. Titers of interferon (ifn) in serum and btv in peripheral blood were determined. All inoculated calves produced circulating ifn that persisted for 2 to 4 days. Highest titers of btv in peripheral blood were present after serum ifn was no longer detected. The persistence of btv in peripheral blood, as compared with the transient ifn response, indicated that ifn was most important in the initial antiviral response of cattle to btv infection. Bluetongue virus is probably not a suitable model inducer of circulating ifn in cattle because the profound neutropenia that accompanied btv infection may predispose cattle to infections with other agents.
Storage stability of some bovine plasma enzymes
Authors: Blincoe Clifton , Marble Donald W.
Published: February 2025

Blood samples taken from domestic or wild ruminant animals typically require transportation to an analytical laboratory. Depending on circumstances, several hours or even a few days may pass between sampling and analysis. Several diagnostic plasma enzymes were measured in bovine blood samples immediately after sampling and after storage under a variety of conditions. Conditions studied included storing whole heparinized blood at 20 C for 6 hours, storage at 4 C for 3 and 5 days, and freezing freshly prepared plasma once and 4 times before analysis. For studies of erythrocyte enzymes, fresh erythrocytes were compared with erythrocytes frozen once, frozen 4 times, and prepared from whole blood stored for one week at 4 C. None of these conditions deteriorated erythrocyte acetylcholinesterase. The serum pseudoacetylcholinesterase and lactate dehydrogenase were not affected by any storage condition used. By contrast, acid phosphatase was significantly decreased by all storage conditions used. Ornithine carbamoyltransferase, alkaline phosphatase, aspartate aminotransferase and alanine aminotransferase were stable under some of the storage conditions tested.
Hemorrhagic septicemia: Naturally acquired antibodies against Pasteurella multocida types B and E in calves in the United States
Authors: Sawada Takuo , Rimler Richard B. , Rhoades Keith R.
Published: February 2025

Antibodies against Pasteurella multocida capsular types B and E, which cause hemorrhagic septicemia, were demonstrated in a high percentage of sera from domestic feeder calves. Since the calves had not been vaccinated with any Pasteurella organisms, the antibodies were considered to be naturally acquired. The antibodies were demonstrated by passively immunizing mice and by indirect hemagglutination and agglutination tests, Sera from 81% (44 of 54) of the calves protected mice that were challenge exposed with a capsular type B organism, and sera from 91% (49 of 54) of the calves protected mice that were challenge exposed with a capsular type E organism. Indirect hemagglutination and agglutination tests demonstrated antibody in nearly all sera. Since capsular type E organisms have been isolated only in Africa and there is only 1 report of capsular type B isolation from cattle in the United States, these organisms were not considered likely sources of the antigenic stimulation that provoked production of these antibodies.
Isolation of mononuclear cells from bovine milk by continuous-flow and density gradient centrifugation: Response of cells to mitogens
Authors: Nonnecke Brian J. , Kehrli Marcus E.
Published: February 2025

Continuous-flow centrifugation (cfc) and 2 types of discontinuous density gradients (Ficoll-diatrizoate or polyvinylpyrrolidone-coated colloidal silica) were used to obtain bovine mononuclear cells from milk. Determinants considered were efficiency of cell recovery, cell viability, and functional activity of the enriched cell population in a lymphocyte blastogenesis (lbt) assay. Milk leukocytes were recovered by cfc with an efficiency of 46% and a viability of 63%. Selective loss of a cell population due to cfc was not observed. Using density gradients, enrichment was marginally effective (73% mononuclear cells with polyvinylpyrrolidone-coated colloidal silica and 82% mononuclear cells with Ficoll-diatrizoate) and overall mononuclear cell efficiency of recovery was reduced. In comparison, using either density gradient, blood mononuclear cells were harvested with efficiencies of 61.5% and 63.4%, with 85.6% and 89.3% viability and > 99% purity. Compared with peripheral blood lymphocytes, milk mononuclear cells were less viable. When evaluated using the lbt assay, milk mononuclear cells were hyporesponsive to mitogenic stimulation, regardless of the density gradient used. The methods used allowed for the collection of a sufficient number of nonelicited milk mononuclear cells for replicate evaluation of several mitogens or antigens, using the lbt assay. Mononuclear cells recovered had a consistently reproducible blastogenic response to T-cell mitogens.
Photomicrographic evaluation of stallion spermatozoal motility characteristics
Authors: Huffel Xavier M. Van , Varner Dickson D. , Hinrichs Katrin , Garcia Marolo C. , Strzemienski Paul J. , Kenney Robert M.
Published: February 2025

A photomicrographic method for evaluation of stallion spermatozoal motility was developed, and spermatozoal image and velocity characteristics were defined. The photomicrographic method was compared with visual estimation of motility in the same semen sample over time. Using photomicrography, velocities and percentages of individual spermatozoal image characteristics were determined. Although there was a high correlation between results of the 2 methods, results of the photomicrographic method were more repeatable than were those of the visual method.
Antagonism of xylazine-pentobarbital anesthesia by yohimbine in ponies
Authors: McGruder John P. , Hsu Walter H.
Published: February 2025

Effects of yohimbine on xylazine-pentobarbital anesthesia were evaluated in ponies. Five minutes after the iv injection of xylazine (1.1 mg/kg of body weight), pentobarbital sodium (12.7 mg/kg, iv) and additional xylazine (2.2 mg/kg, im) were given and produced anesthesia in 12 ponies for 64.0 ± 16.4 minutes (mean ± sd) as well as immobilization for 89.8 ± 34.2 minutes. Eleven ponies were given yohimbine (0.1 mg/kg, iv) 50 minutes after pentobarbital dosing. In these 11 ponies, durations of anesthesia and immobilization were shorter, 52.0 ± 1.4 and 65.5 ± 14.8 minutes, respectively.

The xylazine-pentobarbital combination caused bradycardia that was reversed by yohimbine injection. Xylazine-pentobarbital produced a small, but steady, decrease of mean arterial blood pressure, which was compounded by yohimbine administration and was evident for approximately 2 minutes.

Within a minute after yohimbine injection, the ponies’ respiratory rate decreased and the length of inspiration and expiration and thoracic breathing increased. This lasted approximately 2 to 3 minutes and was followed by an increase in respiratory rate. The anesthesia also produced a decrease in PaO2 that gradually returned to base line in 12 control ponies, but was more pronounced in 11 ponies given yohimbine. The PaCO2, although remaining moderately high in control ponies, returned to base line after yohimbine injection. An increased pHa was seen 60 minutes after induction of anesthesia and was especially noticeable after yohimbine administration.

Decreases in the number of wbc, hemoglobin content, pcv, plasma protein and serum aspartate transaminase resulting from xylazine-pentobarbital were reversed by yohimbine. Conversely, serum glucose values and creatine kinase activities were increased by xylazine-pentobarbital. After administration of yohimbine, the hyperglycemia was unchanged when compared with that in the controls, but the serum creatine kinase activities were increased further.

Seemingly, the xylazine-pentobarbital combination was safe and effective for 1 hour of anesthesia in ponies, and yohimbine was an effective antagonist for this combination.
Blastogenesis-suppressing serum factors, decreased immunoglobulin A, and increased β1-globulins in Airedale Terriers with diskospondylitis
Authors: Barta Ota , Turnwald Grant H , Shaffer Linda M. , Pourciau Susan S.
Published: February 2025

In Airedale Terriers with diskospondylitis, immunologic tests revealed heat-stable blastogenesis-suppressing serum factors affecting primarily the effector (phytohemagglutinin-sensitive) lymphocytes; decreased serum concentrations of immunoglobulin A; and increased serum concentrations of undetermined [β1-globulins. Data indicated that the dogs had decreased immunoglobulin A production and were immunosuppressed, which probably contributed to penetration of bacteria into the body and subsequent spreading to the disks. Eosinophilia and basophilia were also detected, which indicated a potential for a type-I hypersensitivity reaction that may have ameliorated the inflammatory reaction.
Evaluation of the zetacrit and zeta sedimentation ratio in dogs
Authors: Martin Dale G. , Hall James E. , Patrick Darryl H.
Published: February 2025

The Wintrobe erythrocyte sedimentation rate (esr) has been used in animals and persons as a screening test for inflammatory disease and as a monitor for disease progression in individuals. Now, the zetacrit (zc) and zeta sedimentation ratio (zsr) are suggested as suitable rapid laboratory tests to replace the esr in dogs. In 65 dogs, a strong inverse correlation between esr and zc was observed (r = -0.961, P < 0.05). Significant correlations of similar magnitude between zc and hematocrit (r = 0.587, P < 0.05) and esr and Hct (r = 0.569, P < 0.05) were observed. In addition, influences of various protein fractions, such as fibrinogen, globulin, and albumin, on the esr and zc were evaluated and found to be of similar magnitude. These data indicate that esr and zc are equivalent methods for determining erythrocyte sedimentation rates in dogs. A strong correlation (r = 0.900, P < 0.05) between Wintrobe esr, adjusted for the effect of Hct (esrHct), and zsr was observed. The influence of plasma proteins on esrHct and zsr was of similar magnitude. However, a weak yet significant correlation between esrHct and the microhematocrit remained (r = 0.291, P < 0.05). Data indicate that the latter more effectively factors out the influence of Hct on sedimentation.

Advantages of zc and zsr over esr in dogs include; (i) rapid results (6 minutes vs 1 hour); (ii) small sample sizes (less than 0.2 ml vs 1.0 ml whole blood); (iii) improved reproducibility; and (iv) a suitable correction for Hct.
Regional hypoxic pulmonary vasoconstriction in dogs with asymptomatic dirofilariasis
Authors: Chapleau Mark W. , Fish Richard E. , Levitzky Michael G
Published: February 2025

The pulmonary hemodynamic response to unilateral alveolar hypoxia was investigated in pentobarbital-anesthetized dogs with mild heartworm (hw) disease and in dogs free of hw (hwf). Left lung nitrogen ventilation in hwf dogs resulted in a decrease in the fraction of the cardiac output (qt) perfusing the left lung (QL) from 0.37 ± 0.03 (sem) to 0.20 ± 0.02 (P < 0.01). In contrast, dogs with mild hw disease did not develop a significant decrease in ql/qt which decreased from 0.38 ± 0.02 to 0.33 ± 0.02. This attenuated pulmonary vascular response to regional alveolar hypoxia in dogs with hw disease was associated with a normal pulmonary arterial pressure (14.8 ± 1.5 mm of Hg) that was not different from that seen in hwf dogs (15.8 ± 1.7 mm of Hg). These results indicate that mild hw disease interferes with the ability of hypoxic pulmonary vasoconstriction to redistribute pulmonary blood flow away from hypoxic regions of the lung.
Attenuated properties of thymidine kinase-negative deletion mutant of pseudorabies virus
Authors: Kit Saul , Kit Malon , Pirtle Eugene C.
Published: February 2025

A thymidine kinase (tk)-negative (tk-) deletion mutant of the Bucharest (BUK) strain of pseudorabies virus (prv) was isolated. The mutant, designated as prv (BUK d13), did not revert to tk-positive (tk+), even when propagated in medium that selected for tk+ viruses. The mutant also replicated equally well at 39.1 C and 34.5 C, and was easily distinguished from other prv strains by molecular hybridization experiments, restriction nuclease fingerprints, and plaque autoradiography or other assays for the tk phenotype. The prv (BUK d13) had greatly reduced virulence for mice and rabbits, compared with parental tk+ strains, prv (BUK-5) and prv (BUK-5A-R1), and provided mice with solid protection against the tk+ BUK and Aujeszky strains of prv. Experiments were done in 5- to 6-week-old pigs to assess the safety and efficacy of prv (BUK d13) in the natural host. In one experiment, pigs were vaccinated im with 7.5 × 108 plaque-forming units of tk- prv (BUK d13), and were then challenge exposed intranasally (in) with 4.3 × 108 tcid50 of virulent prv [Indiana-Funkhauser (IND-F)]. Vaccinated pigs did not have clinical signs of illness after vaccination or after challenge exposure. One nonvaccinated control pig died on postchallenge day 4; a 2nd nonvaccinated control pig became moribund, but eventually recovered. Pigs developed virus-neutralizing antibodies after vaccination, and had a secondary immunologic response after challenge exposure; however, prv was not isolated from the tonsils or trigeminal ganglia of vaccinated pigs at postchallenge exposure day 11. In a 2nd experiment, pigs were vaccinated im or in, with approximately 7.5 × 108 plaque-forming units of tk prv (BUK dl3), and were challenge exposed in with either 105 or 107 tcid50 prv (IND-F). Vaccinated and challenge-exposed pigs were also treated with dexamethasone to induce recrudescence of latent virus. Vaccination reduced the duration and amount of in replication of prv (INDF) challenge virus, but an anamnestic response was observed. After dexamethasone treatment, prv was not isolated from nasal swabs, tonsillar scrapings, tonsillar tissue, and trigeminal ganglia of pigs that had been vaccinated, but not challenge exposed. After dexamethasone treatment of pigs that had been vaccinated im and then challenge exposed, prv (IND-F) was isolated only from tonsillar tissue. However, prv (INDF) was recovered from nasal swabs, tonsillar scrapings, and tonsillar tissues of pigs that had been vaccinated in and challenge exposed. Results indicated that prv (BUK dl3) may be defective in establishing latency, that prv (BUK dl3) is efficacious in protecting pigs from clinical signs of disease caused by large doses of virulent prv, and that prv (BUK dl3) administered im reduces virulent virus shedding, but does not totally prevent persistent tonsillar infection by virulent prv.
Comparison of carbonated lidocaine and lidocaine hydrochloride for caudal epidural anesthesia in horses
Authors: Schelling Curtis G. , Klein Lin V.
Published: February 2025

A double-blind comparison of carbonated lidocaine and lidocaine hydrochloride in caudal epidural anesthesia was performed in 8 horses. Among 5 horses with successfully paired bilateral caudal epidural blockades, no significant differences in onset time, duration, or sensory blockade were demonstrated. In the present study, carbonated lidocaine did not offer an advantage over the hydrochloride salt for caudal epidural anesthesia in the horse.
Histologic and immunocytochemical study of endocrine cells in the gastrointestinal tract of the cow and calf
Authors: Kitamura Nobuo , Yamada Junzo , Calingasan Noel Y. , Yamashita Tadayuki
Published: February 2025

The regional distribution and relative frequency of argyrophil cells, and of cells immunoreactive for 5-hydroxytryptamine (5-ht), substance P (sp), somatostatin, glicentin, glucagon, bovine pancreatic polypeptide (bpp), gastrin, leucine-enkephalin, gastric inhibitory polypeptide (gip), cholecystokinin, secretin, motilin, and neurotensin were studied in 9 segments from the gastrointestinal tract of cows (> 1 year old) and calves (< 3 months old). Argyrophil cells, 5-ht-immunoreactive cells, and somatostatin-immunoreactive cells were distributed throughout the gastrointestinal tract, whereas the other immunoreactive cells were more restricted in distribution. Most endocrine cells were more numerous in the calf than in the cow. This feature was most conspicuous in the abomasum. In the abomasum, argyrophil cells in the cow and calf and 5-ht-immunoreactive cells in the calf were found predominantly in the fundic region, whereas somatostatin-immunoreactive cells and gastrin-immunoreactive cells in the cow and calf and 5-ht-immunoreactive cells in the cow were most numerous in the pyloric region. Substance P-, glucagon-, bpp-, and leucine-enkephalin-immunoreactive cells were rarely detected. In the small intestine, argyrophil cells, 5-ht-, sp-, somatostatin-, gastrin-, gip-, cholecystokinin-, secretin-, and motilin-immunoreactive cells were most numerous in the duodenum. Neurotensin-, glicentin-, glucagon-, and bpp-immunoreactive cells were detected with the highest frequency in the ileum. In the large intestine, argyrophil cells and 5-ht-, glicentin-, bpp-, somatostatin-, glucagon-, and sp-immunoreactive cells occurred with the highest frequency in the rectum.
Longitudinal study of the effects of lungworm infection on bovine pulmonary function
Authors: Lekeux P. , Hajer R. , Breukink H. J.
Published: February 2025

Clinical and physiologic investigations were done weekly in 5 nonsedated Friesian calves before, during, and after an induced infection with Dictyocaulus viviparus infective larvae.

Clinical, hematologic, serologic, and parasitologic findings were all compatible with the classic picture of moderate subacute verminous bronchitis. Most pulmonary function values revealed significant (P ≤ 0.05) changes in the 2nd or 3rd week after inoculation and maximal changes at 5 weeks after inoculation. Most marked changes included a decrease in tidal volume, dynamic lung compliance, and arterial oxygen tension, and an increase in minute ventilation, minute viscous work of breathing, and alveolar-arterial oxygen difference. Minute ventilation, dynamic lung compliance, minute viscous work of breathing, and PaO2 revealed the most homogeneous change. Conversely, maximal change of intrapleural pressure, total pulmonary resistance, and viscous work of breathing had higher variability from week to week.
Porcine malignant hyperthermia susceptibility: Erythrocytic osmotic fragility
Authors: O'Brien Peter J. , Rooney Michèle T. , Reik Theresa R. , Thatte Hemant S. , Rempel William E. , Addis Paul B. , Louis Charles F.
Published: February 2025

Erythrocyte osmotic fragility was determined in 27 Pie-train swine which were susceptible to malignant hyperthermia (mh), 29 Yorkshire swine which were resistant to mh (controls), and 50 crossbred swine (Pietrain × Yorkshire), half of which were mh susceptible. Halothane challenge tests and blood creatine kinase activity were used as criteria for determining mh susceptibility. Mean values for osmotic fragility of erythrocytes in concentrations of NaCl between 60 and 120 mM were significantly different for the 3 groups (P < 0.001). Hemolysis (50%) of erythrocytes occurred at NaCl concentrations of 90 mM for Pietrains, 85 mM for crossbreds, and 78 mM for controls. Increased fragility values occurred in 96% of the Pietrains, 3% of the controls, and 42% of crossbred swine that were halothane test-positive, and 58% of halothane test-negative crossbreds (P < 0.05). The mean time of onset of signs of mh in response to halothane challenge testing was twice as long in the crossbreds as in Pietrains (P < 0.01). Reticulocyte counts were moderately high in blood samples from both the Pietrains (P < 0.001) and the crossbreds (P < 0.05).

Of the swine which were tested for erythrocyte selenium-dependent glutathione peroxidase activity, values were within acceptable laboratory limits in 18 of 20 Pietrains, 14 of 14 halothane test-negative crossbreds, and 8 of 8 halothane test-positive crossbreds. In 2 of 20 Pietrains, a 35% deficiency of this enzyme was found. Heinz bodies were not detected in erythrocytes examined from 21 Pietrains, 20 crossbred swine (8 halothane test positives), and 12 controls.

In Pietrains which were homozygous for the mh defect, the genetic defect resulting in erythrocyte osmotic fragility demonstrated a high correlation with mh susceptibility. Two-thirds of the Pietrain-Yorkshire crossbred swine which were predicted to be heterozygous for the mh defect had increased erythrocyte fragility. In crossbreeding experiments, increased erythrocyte fragility was inherited independently of the inheritance of a positive halothane challenge test and increased blood creatine kinase activity. The pattern of inheritance of erythrocyte fragility was most consistent with a dominant mode, whereas the halothane-challenge test response was inherited as a recessive trait. Results of the present study are consistent with the proposals that susceptibility to mh is multifactorial and associated with a generalized membrane defect in swine and that erythrocyte osmotic fragility may be used as an aid in the determination of mh susceptibility.
Experimental infection of fattening pigs with Pseudorabies (Aujeszky's disease) virus: Efficacy of attenuated live- and inactivated-virus vaccines in pigs with or without passive immunity
Authors: Vannier P.
Published: February 2025

The efficacies of attenuated live-and inactivated-virus vaccines against Pseudorabies (pr) in fattening pigs were compared. Pigs born from vaccinated or nonvaccinated sows were vaccinated with one or the other vaccine and were challenge exposed at the end of the fattening period. The particular form of pr observed in fattening units in the field could be reproduced. A marked difference was seen between the control lot and the lots of the pigs vaccinated with the attenuated live- and inactivated-virus vaccines. The protection was real, but not absolute, in the vaccinated pigs. The inactivated-virus vaccine conferred a strong passive immunity to the young pigs of vaccinated dams which interfered with the development of an active immunity. The titer of the colostral antibodies in the sera of pigs born from the sows vaccinated with the attenuated-live virus vaccine was low and decreased rapidly. The active protection obtained with this vaccine was similar to that observed with the inactivated-virus vaccine. Thermal curves, weight losses, and time necessary for recovering the weight of pigs at the time of challenge exposure seemed to be good criteria for measuring the protection of fattening pigs against this particular form of pr. The conditions of the outcome of respiratory tract disorders in these pigs are discussed.
Detection of β-lactamase produced by Staphylococcus intermedius
Authors: Hoskins Johnny D. , Newman Susan S. , Roy Alma F. , Foil Carol S. , Cox Hollis Utah
Published: February 2025

One iodometric, 2 chromogenic, and 3 acidometric methods were compared for the detection of β-lactamase produced by Staphylococcus intermedius (n = 105) isolated from dogs. Of 575 tests performed, using the 6 methods evaluated, 316 (55.0%) were positive for β-lactamase production. The iodometric method was the reference method. With the exception of a high correlation (r = 0.962) between 1 acidometric method and 1 chromogenic method, the 5 commercial methods had correlation coefficients < 0.900 when comparisons were made among them. The 6 methods were in agreement for 69 (65.7%) of the isolates. Based on the findings of this study, an inexpensive, laboratory-prepared, paper strip iodometric method was as reliable as 5 commercial methods for β-lactamase detection and is recommended for routine use in clinical laboratories.
Sensitivity and specificity of the indirect-fluorescent antibody test and two enzyme-linked immunosorbent assays in canine dirofilariasis
Authors: Sisson David , Dilling George , Wong Ming M. , Thomas William P.
Published: February 2025

Ninety dogs naturally infected with Dirofilaria immitis and 103 noninfected dogs, as determined by necropsy, were used to compare the sensitivity and specificity of the cuticular and somatic reactions of the indirect fluorescent antibody test (ifa-c and ifa-s, respectively) and 2 enzyme-linked immunosorbent assays (elisa). In microfilaremic and amicrofilaremic heartworm-infected dogs, negative results were common for all serotests. In dogs without adult heartworms at necropsy, 32% to 49% were positive, using 1 elisa, 27% to 29% were positive with the other elisa, 15% to 36% were positive with the ifa-s, and 0% to 1% were positive using the ifa-c, depending on the classification of borderline reactions. The prevalence of false positive serotests was probably not due to the detection of precardial stages of D immitis in dogs obtained from areas of low endemicity. Until the causes of the false-positive tests are resolved, the use of currently available serotests for routine diagnostic screening or as criteria for instituting treatment is not recommended.
Comparative efficacy of clorsulon and albendazole against Fasciola hepatica in cattle
Authors: Kilgore R. L. , Williams M. L. , Benz G. W. , Gross S. J.
Published: February 2025

In a dosage-confirmation trial, anthelmintic activities of clorsulon and albendazole against Fasciola hepatica were evaluated and compared. Twenty-eight cattle (8 to 12 months old) with natural F hepatica infections were randomly allotted to 4 groups of 7 cattle each: group 1, no treatment (controls); group 2, clorsulon suspension given orally at 3.5 mg/kg of body weight; group 3, clorsulon suspension given orally at 7 mg/kg; and group 4, albendazole paste given orally at 10 mg/kg. At necropsies, performed 7 and 8 days after treatment, control cattle harbored a geometric mean of 133.2 F hepatica, 16.0 of which were immature. Clorsulon administered at 3.5 mg/kg or 7 mg/kg resulted in > 99% removal of F hepatica, including immatures. Albendazole treatment resulted in a 76% overall reduction in F hepatica, including a 91% reduction of immatures. Fascioloides magna also were found in the cattle, but neither clorsulon nor albendazole caused significant reductions of the parasite. Adverse reactions to the 2 drugs were not observed.
Serum selenium concentrations and glutathione peroxidase activities in cattle grazing forages of various selenium concentrations
Authors: Stevens J. B. , Olson W. G. , Kraemer R. , Archambeau J.
Published: February 2025

In cows from 15 dairy herds (n = 210), serum selenium (Se) concentrations ranged from 0.021 to 0.789 μg/ml, whereas 0.05 to 0.40 μg/ml is the reported range for adequate serum Se concentrations in cattle.

Serum Se concentrations of dairy cattle appeared to follow a geographic distribution pattern. On the basis of herd mean serum Se concentrations, adequate serum Se concentrations were found in cattle from only 1 of 5 herds grazing forage in the geographic area classified as Se deficient for cattle.

Adequate mean serum Se concentrations were found in cattle from 4 of 5 herds located in geographic areas described as having variable forage Se concentrations (Se-marginal areas). Of the 10 herds from these 2 areas, there were only 2 herds in which 95% of the cattle had serum Se concentrations in the Se-adequate range (0.05 to 0.40 μg/ml). In 2 selected neighboring farms in the Se-deficient area, cattle in 1 herd had adequate serum Se concentrations and cattle in the other herd had less than adequate serum Se concentrations (< 0.05 μg/ml). Therefore, more cattle are at risk of developing Se-deficiency disease than is commonly believed and forage of neighboring farms may have different Se concentrations. Serum Se concentrations (up to 0.789 μg/ml) correlated with glutathione peroxidase enzyme activity; this serum Se concentration (0.789 μg/ml) is approximately 6.2 times higher than previously reported in dairy cattle. Therefore, rbc glutathione peroxidase activity may be useful in determining the diagnosis of chronic Se toxicosis.
Transmission of Anaplasma marginale by adult Dermacentor andersoni during feeding on calves
Authors: Kocan Katherine M. , Barron Selwyn J. , Ewing S. A. , Hair Jakie A.
Published: February 2025

Laboratory-reared Dermacentor andersoni ticks experimentally infected as nymphs with Anaplasma marginale were allowed to feed as adults from 1 to 9 days on susceptible, splenectomized calves to determine when, during feeding, the hematozoan was transmitted from ticks to cattle. In experiment 1, ticks were allowed to feed on calves for 1, 2, 3, 4,5, or 6 days and anaplasmosis did not result. The same calves were used for experiment 2, and ticks were allowed to feed for 1, 3, 6, 7, 8, or 9 days and anaplasmosis occurred in all calves on which ticks fed for ≥ 6 days. In 2 trials in experiment 3, ticks were allowed to feed on calves for 1 to 9 days. Anaplasmosis developed only in calves on which ticks fed for 7, 8, or 9 days. The prepatent periods shortened with longer tick feeding, and linear regression analysis of combined prepatent periods of both trials of experiment 3 indicated a significant (P = 0.05) slope with an estimated daily decrease of 7.75 days from day 7 to 9 of feeding. There was no apparent correlation between length of tick feeding and severity of clinical signs in those calves that developed anaplasmosis. Seemingly, A marginale can be transmitted to cattle by adult D andersoni ticks no earlier than the 6th or 7th day of feeding.
Factors influencing enhanced Salmonella typhimurium infection in Eimeria tenella-infected chickens
Authors: Baba E. , Fukata T. , Arakawa A.
Published: February 2025

To investigate a possible mechanism involved in the enhancement of Salmonella typhimurium infection in chickens concurrently infected with Eimeria tenella, S typhimurium was given orally to chickens 7 days after E tenella inoculation. The number of viable S typhimurium decreased in the ceca of chickens not inoculated with E tenella, whereas the number gradually increased in the ceca of chickens inoculated with E tenella. Cecal contents were analyzed for pH value, oxidation-reduction potential, and amounts of short-chain fatty acids and bile acids. In the ceca of E tenella-inoculated chickens, the oxidation-reduction potential significantly (P < 0.05) shifted to the oxidative phase, and the concentration of volatile fatty acids (acetic acid, propionic acid, and butyric acid) significantly (P < 0.05) decreased. In both aerobic and anaerobic incubations, the number of viable S typhimurium in vitro decreased as the molar concentration of fatty acids increased. Experimental evidence indicated that multiplication of S typhimurium in the ceca of E tenella-inoculated chickens was associated with decreased concentrations of volatile fatty acids.
Experimentally induced phenylbutazone toxicosis in ponies; Description of the syndrome and its prevention with synthetic prostaglandin E2
Authors: Collins Lynda G. , Tyler David E.
Published: February 2025

Phenylbutazone (pbz) toxicosis was induced in 9 ponies to further define the clinical and pathologic changes occurring with this syndrome. Six additional ponies were treated with pbz and a synthetic prostaglandin E2 to determine the role of prostaglandins in the pathogenesis of pbz toxicosis.

Ponies given only pbz exhibited cns depression, anorexia, weight loss, diarrhea, cyanotic mucous membranes, and oral ulcers. Total serum protein concentration gradually decreased during the 10-day treatment period. Marked mucosal atrophy, focal erosions, and ulcers characterized the lesions in the alimentary tract. Ponies given PBZ and prostaglandin E2 remained clinically healthy and did not develop hypoproteinemia or mucosal atrophy. A few erosions were seen, but ulcers were not observed. The results of the present study indicate that mucosal atrophy is a characteristic lesion of pbz toxicosis. It is also evident that inhibition of prostaglandin synthesis has an important role in the development of this syndrome.
Use of enzyme-linked immunosorbent assay for detection of antibodies to Brucella ovis in sheep; Field trial
Authors: Walker Richard L. , LeaMaster Brad R. , Stellflug John N. , Biberstein Ernst L.
Published: February 2025

An enzyme-linked immunosorbent assay (elisa), using an autoclave-extracted soluble antigen, for the detection of serum antibodies to Brucella ovis in sheep was developed. The test seemed to be both sensitive and specific, on the basis of the control groups studied. The antigen showed no deterioration in prepared plates stored at −70 C for up to a year.

The elisa was used in conjunction with palpation of rams for epididymal lesions as a means to detect and control B ovis infection in a naturally infected flock. All rams were evaluated by the elisa. At the time that the first blood sample was obtained, all positive and suspicious reactors were removed. With subsequent blood sample collections, only the positive reactors were removed. Brucella ovis was not isolated from any rams during the following year, and none of the mature breeding rams developed epididymal lesions.
Comparative pharmacokinetics and anesthetic effects of methohexital, pentobarbital, thiamylal, and thiopental in Greyhound dogs and non-Greyhound, mixed-breed dogs
Authors: Sams R. A. , Muir W. W. , Detra R. L. , Robinson E. P.
Published: February 2025

Pharmacokinetics and duration of anesthesia of methohexital, pentobarbital, thiamylal, and thiopental in Greyhound and non-Greyhound, mixed-breed dogs were compared. In all dogs evaluated, pentobarbital induced the longest duration of anesthesia and methohexital induced the shortest duration. Pharmacokinetics of pentobarbital and methohexital were similar in both groups of dogs.

Thiobarbiturates induced longer anesthetic effects in Greyhound dogs than in mixed-breed dogs. Plasma thiobarbiturate concentrations remained above normal longer in Greyhound dogs than in mixed-breed dogs. Disposition of thiobarbiturates in Greyhound dogs was characterized by nonlinearity from 45 minutes to 8 hours after dosing.