bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of equine herpesvirus-1 antigen and the specific antibody by enzyme-linked immunosorbent assay
Authors: Dutta S. K. , Talbot N. C. , Myrup A. C.
Published: February 2025

Enzyme-linked immunosorbent assays (elisa) were developed to detect equine herpesvirus-1 (ehv-1) antigens and specific antibodies. Detection of ehv-1 antigens was done by a 4-layer elisa. In inoculated cell cultures, ehv-1 cell antigen was detected after postinoculation (pi) hour 4, reached approximately twice the value of ehv-1 viral antigen (extracellular virus) in pi hour 18, and peaked in pi hour 24, whereas ehv-1 viral antigen appeared after pi hour 12, increased steadily, and peaked higher than ehv-1 cell antigen in 24 hours. The elisa titer and infectivity titer of 24-hour pi cultures were 200 and 9.2 × 105 plaque-forming units/0.1 ml, respectively.

Equine anti-ehv-1 antibody (eaehv-1) from experimentally inoculated pony foals and rabbit anti-ehv-1 antibody (raehv-1) were detected by indirect elisa and direct elisa, respectively. The raehv-1 had elisa titers of 665,000 and 102,000 when rabbits were immunized with ehv-1 infected cell culture lysate and with sucrose-purified virus, respectively. The corresponding plaque-reduction virus-neutralization titers were 270 and 150 in the absence of complement and were 6,200 and 3,200 in the presence of complement. The eaehv-1 had a mean elisa titer of 60,000, and the corresponding mean virus-neutralization titer in the absence of complement was 34 and that in the presence of complement was 2,142.
Failure of bovine complement levels measured by radial hemolysis to correlate with tube titration
Authors: Nielsen K. , Rosenbaum B. , Harper S. , Adams L. G. , Williams J. D.
Published: February 2025

Hemolytic complement levels in 30 duplicate samples of normal bovine sera were determined by a tube titration method (ch50) and by a radial hemolysis in gel assay. Significant correlation was not observed between the values obtained by the 2 tests. This lack of correlation could be a result of considerable error observed in values obtained for duplicate samples in the ch50 method or to the relative insensitivity of the hemolysis in gel test. The hemolytic reaction in gel was found to depend on Mg2+, thus raising questions (i) about its validity in determining total hemolytic complement or (ii) about bovine C1q depending on Mg2+ rather than Ca2+ for binding to immune complexes.
Cardiac dimensions in severely anemic neonatal pigs
Authors: Lee John C. , Fagenholz S. Allen , Downing S. Evans
Published: February 2025

The effects of chronic severe anemia on weights and chamber volumes of hearts were studied in 9 spontaneously anemic neonatal pigs (mean hematocrit = 10.1%) and 10 healthy piglets (mean hematocrit = 28.3%) of approximately the same age and similar body weights. All cardiac chamber weights, as well as total heart weight/body weight ratios, were significantly higher in the anemic pigs than in the healthy pigs (P < 0.001). The left ventricular free wall/right ventricular free wall weight ratio was identical in the 2 groups. Calculated left ventricular volume/body weight ratio also was significantly greater in the anemic pigs (P < 0.05). It is concluded that cardiac dilatation and hypertrophy occur consistently in chronically anemic neonatal pigs. These changes are independent of age or body weight of the animal.
Lymphocyte transformation and humoral immune factors in Basenji dogs with immunoproliferative small intestinal disease
Authors: Barta Ota , Breitschwerdt Edward B. , Shaffer Linda M. , Pourciau Susan S.
Published: February 2025

Serum protein concentrations and 4 immunologic factors were determined in 5 Basenji dogs with immunoproliferative small intestinal disease. There was no correlation between the total serum proteins, immunoglobulin G and immunoglobulin M concentrations, and physical health status of the animals. The severity of clinical signs correlated roughly with decrease in albumin and increase in globulin concentrations. The main changes were detected in β- and fast γ-globulins. The total hemolytic complement levels were decreased in the 2 most severely affected animals below the minimal laboratory values observed in healthy animals. Alteration in the intrinsic responsiveness of lymphocytes to various mitogens did not correlate with progression in severity of the disease. Correlation between the appearance of blastogenesis-suppressing substances in serum and the severity of the disease was only partial: Sera (at 20% concentration) from the 2 most severely affected dogs completely suppressed blastogenesis induced by all 3 mitogens. The sera of 3 other dogs either did not suppress or suppressed only concanavalin A-induced mitogenesis and to a lesser extent phytohemagglutinin-induced mitogenesis without correlations to the overall clinical status. The disturbances of immunologic mechanisms were detected after the appearance of clinical disease, were not considered the cause of immunoproliferative small intestinal disease, may represent a manifestation of the secondary infection, and may contribute to aggravation of the clinical course.
Postural influence on systemic blood pressure, gas exchange, and acid/base status in the term-pregnant bitch during general anesthesia
Authors: Probst Curtis W. , Webb A. I.
Published: February 2025

Effects of positioning on certain physiologic parameters were done in 7 term-pregnant bitches during general anesthesia. Five positions (right and left lateral recumbency, right and left 10° to 15° tilt toward lateral recumbency, and dorsal recumbency) were examined. Anesthesia was induced with thiamylal sodium and was maintained with halothane and nitrous oxide in oxygen. Direct arterial blood pressure, arterial blood gases, pH, base excess, heart rate, respiratory rate, and a lead II ecg were recorded from the bitches during each position. Effects of positioning for each bitch during general anesthesia were reexamined after the bitch weaned its pups; therefore, each bitch served as its own control.

Maternal posture had no significant (P < 0.05) effect on any measured parameters in bitches before or after parturition. Pregnancy had a significant (P < 0.05) effect on every parameter, except heart rate. Pregnant bitches had a lower systolic blood pressure, lower Pao2, lower pcv, higher Paco2, higher respiratory rate, and a more severe acidosis than did the bitches after parturition.

Seemingly, supine hypotension did not occur in anesthetized term pregnant bitches (9 to 16 kg). Tilting the bitch 10° to 15° toward right or left lateral recumbency or true lateral recumbency was not preferable to dorsal recumbency for doing cesarean sections using general anesthesia.
Survey of bacteriologic flora of conjunctiva and cornea in healthy psittacine birds
Authors: Zenoble R. D. , Griffith R. W. , Clubb S. L.
Published: February 2025

A total of 151 eyes from healthy psittacine birds were examined by bacteriologic cultural methods. Bacterial growth was not found in 41% of eyes cultured, Staphylococcus epidermidis was found in 25%, α-hemolytic streptococci in 25%, Corynebacterium spp in 7%, and Staphylococcus aureus in 5%. Each of the following organisms were found in 1% of the eyes; Pasteurella spp, Actinobacillus spp, Escherichia coli, Klebsiella spp, Enterobacter spp, Pseudomonas spp, Proteus spp, and Bacillus spp. More than one bacterial species was found in numerous eyes. Psittacines from an import station had a greater occurrence of ocular bacterial growth than did birds from private owners. The frequency of ocular bacterial growth and types of bacteria isolated were similar to studies from dogs and cats.
Investigation of the nature and specificity of antinuclear antibody in dogs
Authors: Shull Robert M. , Miller Hugh A. , Chilina Allen R.
Published: February 2025

A liquid phase radioimmunoassay was used to test sera from 34 dogs in 3 categories, determined by presence of antinuclear antibody (ana) and disease, for antibodies against native canine DNA and dAdT, a synthetic double-stranded DNA analog. Antibodies to dAdT were absent in healthy dogs which, as a group, had levels of DNA antibodies consistent with those reported for healthy persons. Canine patients with a variety of illnesses, but which remained ana negative, had slightly increased levels of binding of DNA and dAdT. As a group, ana-positive dogs had significantly increased binding of dAdT and native DNA, which was shown to be mainly, but not entirely, double stranded. In the ana-positive group, no correlation was found among ana titer, % DNA binding, and % dAdT binding, indicating that these 3 procedures detect antibodies with differing specificities. In dogs, ana are heterogeneous in antigenic specificity. Antibodies to double-stranded nucleic acid in dogs do not appear to be as specific for systemic lupus erythematosus as they are reported to be in persons with autoimmune disease.
Dose response of topical pilocarpine-epinephrine combinations in normotensive and glaucomatous Beagles
Authors: Gelatt Kirk N. , Gum Glenwood G. , Brooks Dennis E. , Wolf E. Daniel , Bromberg Nancy M.
Published: February 2025

Dose responses to single-dose loadings with a placebo (0.50% methylcellulose) and 1%, 2%, 3%, 4%, and 6% pilocarpine combined with 1% epinephrine were determined in normotensive and glaucomatous Beagle dogs. All combinations of pilocarpine and 1% epinephrine significantly (P < 0.007) reduced pupil size and intraocular pressure in the normotensive and glaucomatous-treated eyes at most measurement times, as compared with base-line (predrug) values, untreated fellow eyes, and placebo-treated eyes. There were no significant (P < 0.11 or greater) contralateral effects on pupil size and intraocular pressure by unilateral pilocarpine-epinephrine instillations as compared with base-line values or placebo-treated eyes.
Shedding patterns in swine of virulent and attenuated pseudorabies virus
Authors: Maes Roger K. , Kanitz C. L. , Gustafson D. P.
Published: February 2025

Shedding patterns of 2 virulent (P-2208 and KC-152-D) and 1 attenuated (BUK) strains of pseudorabies virus (prv) were determined in groups of intranasally inoculated feeder pigs.

Clinical signs observed following inoculation with the P-2208 and KC-152-D strains included increase in rectal temperatures up to 42.2 C, anorexia, severe respiratory disturbance, and fatal cns signs in 2 cases. Clinical signs in pigs inoculated with 7.2 × 107 median tissue culture infective dose (tcid50) of the BUK strain were limited to depression and a rise in rectal temperatures to 40.5 C for 3 to 4 days.

Evaluation of the efficacy of the virus isolation method used showed that the presence on swabs of only 12.5 tcid50 of the P-2208 strain or 8.4 tcid50 of the BUK strain resulted in a 50% chance of virus recovery. Intranasal inoculations with 500 tcid50 of the P-2208 or KC-152-D strain did not result in synchronous infection of the whole group. Intranasal inoculations with 5,000 tcid50 of the KC-152-D strain or 50,000 tcid50 of the P-2208 strain resulted in continuous virus shedding in all pigs between postinoculation days (pid) 4 and 13 (KC-152-D strain) or 14 (P-2208 strain). Some of the pigs in these 2 groups further shed the P-2208 or KC-152-D strain in a continuous or discontinuous pattern up to pid 19 (P-2208 strain) or 20 (KC-152-D strain). The time of onset or the level of virus neutralizing antibody production in individual pigs was not found to have an influence on their shedding patterns. Three of 4 pigs inoculated intranasally with 106 tcid50 of the P-2208 strain were still shedding prv on the 22nd day after inoculation. Pigs inoculated intranasally with 500 or 5,000 tcid50 of the attenuated BUK strain did not shed detectable amounts of virus. Shedding of this strain by 4 pigs inoculated intranasally with 7.2 × 107 tcid50 was detected between pid 3 and 7.
Observations on the postnatal morphogenesis of the porcine humeral condyle and the pathogenesis of osteochondrosis
Authors: Kincaid S. A. , Lidvall E. R.
Published: February 2025

The condyles of the distal humeri of 75 pigs ranging in age from 1 day to 9 months were studied by gross observation and radiography. Twenty-eight pigs were reared on pasture, necropsied, and were studied histologically. The portion of the secondary center of ossification of the distal humeral epiphysis located in the lateral condyle of neonatal pigs was larger than that observed in the medial condyle and assumed the contour of the articular surface at an earlier age. Thus, the articular-epiphyseal cartilage of the medial condyle had an inherent propensity to be thicker than that of the lateral condyle and might be predisposed to the influence of deleterious biomechanical insult. Projections of cartilage containing degenerating chondrocytes from the epiphyseal cartilage into the subadjacent trabecular bone may have been early lesions of osteochondrosis in pigs ≤ 3 months of age.

Osteochondral and articular fractures of the medial condyles and intercondylar cristae of the distal humeri of 6- to 9-month-old pigs were observed. Seemingly, fractures resulted from shearing forces within the humeral articular surfaces at the junction of the articular-epiphyseal cartilage continuum and the subchondral epiphyseal bone with subsequent separation of the tissues at the osteochondral interface. Such shearing forces could result from a torque and/or laterally to medially directed forces of unusually great magnitude generated by movement of the proximal radius against the distal humerus. The cause of the transversely oriented forces may be of biomechanical origin from potentially unbalanced development, tone, or contractile activity of skeletal muscle and/or nervous system influence.
Regional distribution and variation of γ-globulin absorption from the small intestine of the neonatal calf
Authors: Fetcher A. , Gay C. C. , McGuire T. C. , Barbee D. D. , Parish S. M.
Published: February 2025

125I-labeled immunoglobulin (Ig)G1 in colostral whey was used to determine the region of maximum absorption of Ig from the small intestine of the neonatal calf and the variation in Ig absorption among calves at the intestinal level.

In experiment 1, 5 segments (approx 5%, 35%, 60%, 80%, and 95% of the duodenocecal length) were formed in the small intestine of 9 colostrum-deprived calves shortly after birth. These segments were injected with colostral whey containing 125I-IgG1 4 hours after birth, and uptake, transfer, and absorption (defined as uptake plus transfer) were determined for each segment 2 hours later. Raw data were adjusted for the milligrams of IgG1 injected per gram of intestinal tissue to obtain the least squares mean (lsm) value. The lsm values for absorption of IgG1 from distal segments 3, 4, and 5 were significantly greater (P < 0.05) than those values for proximal segments 1 and 2. The region of the maximum IgG1 absorption was the lower small intestine, 60% to 80% of the duodenocecal length. There was also an indication of independence between uptake and transfer in each of the segments. Significant differences (P < 0.05) were present among calves in the lsm values for uptake and absorption, but not for transfer.

In experiment 2, thoracic ducts of 8 newborn calves were cannulated 4 to 5 hours after birth. At 6 hours after birth, colostral whey with 125I-IgG1 was injected into an intestinal segment (approx 60% to 80% of the duodenocecal length). Thoracic duct fluid was collected for 6 hours after injection. The total amount of IgG1 recovered in the thoracic duct fluid, and the amounts taken-up, transferred, and absorbed by the segment were determined for each calf. The amount of IgG1 in the thoracic duct fluid from each calf was inconsistent and did not reflect the amount that was transferred by the segment. This discrepancy was explained by evidence of 125I-IgG1 degradation and transfer of free 125I or 125I-IgG1 fragments. However, based on the calculated values for uptake, transfer, and absorption of IgG1 by the segments, variation among these calves was minimal.
Indirect immunoperoxidase test for the diagnosis of paratuberculosis
Authors: Nguyen Hai T. , Buergelt Claus D.
Published: February 2025

An indirect immunoperoxidase procedure for the diagnosis of paratuberculosis was described. Formalin-fixed ileocecal tissue containing large numbers of Mycobacterium paratuberculosis organisms was used as the source of antigen. Goat anti-bovine immunoglobulin G labeled with peroxidase was used as the conjugate in the test system. The method is relatively simple to do and may prove to be valuable as a routine screening test.
Phloroglucinol microassay for plasma xylose in dogs and horses
Authors: Merritt A. M. , Duelly Pamela
Published: February 2025

The phloroglucinol microassay technique for measuring plasma concentrations of xylose was compared with the more tedious orcinolferric chloride technique. Sequential blood samples were collected from 5 dogs and 6 horses every 30 minutes after oral administration of 0.5 g of d-xylose/kg of body weight. Comparison of the results by regression analysis shows a highly significant (P < 0.01) positive linear correlation for both dogs (r = 0.95) and horses (r = 0.77). These results indicate that xylose in canine and equine plasma can be accurately measured by the phloroglucinol technique.
Use of enzyme-linked immunosorbent assay for detection of K88 pili in fecal specimens from swine
Authors: Mills K. W. , Tietze K. L. , Phillips R. M.
Published: February 2025

Enterotoxigenic Escherichia coli are important in neonatal pig diarrhea. To be pathogenic, E coli must possess the ability to produce toxin and adherence structures called pili. An enzyme-linked immunosorbent assay was used to detect K88 pili in feces of swine. Results were compared with standard isolation and identification techniques. Isolates were tested for labile toxin production by the Y-1 mouse adrenal gland test and presence of pili by the enzyme-linked immunosorbent assay test. The ability to detect K88 pili in feces correlated with the isolation of labile toxin-positive, K88-positive E coli.
Reduction of the red blood cell mass of horses: Toxic effect of heparin anticoagulant therapy
Authors: Duncan S. G. , Meyers K. M. , Reed S. M.
Published: February 2025

This study was designed to test the efficacy of heparin anticoagulant therapy in the horse and its effect on the formed elements of blood. Nine clinically normal, nontraumatized adult horses were subjected to 4 different heparin maintenance regimens (dosages of 320, 240, 160, and 40 U/kg of body weight). Porcine intestinal mucosa heparin (20,000 U/ml) was injected subcutaneously every 12 hours for 96 hours (total 9 times). A loading dose of one-third the maintenance dose was given iv just before the first heparin injection. Three control horses were given an equivalent volume of 0.9% saline solution.

The 2 large doses of heparin (320, 240 U/kg) resulted in an extension of the therapeutic range for heparin anticoagulant therapy (1.5 to 2.5 × data base-line prolongation of the activated partial thromboplastin time [aptt]). The 160-U/kg dose maintained the aptt in the therapeutic range, and the 40-U/kg dose had no effect on the aptt.

Heparin was shown to exert a profound influence on the rbc mass of the horse. Three of the heparin regimens (320, 240, and 160 U/kg) resulted in a significant decrease in rbc numbers, pcv, and total hemoglobin content. Platelet count also was reduced in the horses when given the 320 and 240 U/kg doses. The observed increase in the mean corpuscular volume was associated with decreasing rbc numbers. Plasma proteins, serum bilirubin, free hemoglobin (plasma), haptoglobin (plasma), and urine and fecal hemoglobin values remained unchanged in all groups. Heparin anticoagulation therapy with the smallest dose (40 U/kg) had no detectable effects on the measured values, nor did the saline solution.
Succinylcholine infusion associated with hyperthermia in ponies anesthetized with halothane
Authors: Hildebrand S. V. , Howitt G. A.
Published: February 2025

Succinylcholine was administered by infusion to halothane-anesthetized ponies to determine dosage requirements for surgical relaxation up to 3 hours’ duration. This was not possible to do, since 4 of 6 ponies studied developed severe reactions characterized by prolonged muscle fasciculations after the initial succinylcholine dose, muscle rigidity, hyperthermia, hypercapnia, tachycardia, increasing pulse pressure, and metabolic acidosis. The reactions resembled those associated with malignant hyperthermia, a disease recognized in persons and swine.

Two ponies showed signs of the phase II or desensitization block of succinylcholine. All ponies recovered from anesthesia without signs of muscle injury.
Effectiveness of fenbendazole against later 4th-stage Strongylus vulgaris in ponies
Authors: Slocombe J. O. D. , McCraw B. M. , Pennock P. W. , Baird J. D.
Published: February 2025

Twelve pony foals (reared worm-free) were inoculated with Strongylus vulgaris. Approximately 8 weeks later, 4 of the foals were given fenbendazole (10% suspension) at a dosage rate of 10 mg/kg of body weight daily for 5 days and 4 foals were given the suspension at a dosage rate of 50 mg/kg daily for 3 days; the remaining foals were given a placebo. All treatments were administered by stomach tube. Fenbendazole was 99.6 and 97.9% effective in the 2 treatment groups, respectively, in eliminating later 4th-stage S vulgaris larvae located near the origin of major intestinal arteries. On microscopic examination of the ileocolic artery from fenbendazole-treated foals, a few larval remnants were found beneath the tunica intima in small organized mural thrombi overgrown with endothelium. It would appear that larvae are rapidly destroyed after administration of fenbendazole.

A pony foal reared on pasture and with arteriographic evidence of arteritis of the cranial mesenteric and ileocolic arteries was treated with fenbendazole (10% suspension) by stomach tube at a dosage rate of 50 mg/kg of body weight daily for 3 days. By arteriographic examination made 4 weeks later, there was evidence of regression of the lesion, and at necropsy done a week later, there was no arteritis or larvae in the lumen of those arteries.
Leptospiral vaccines: Immunogenicity of protein-free medium cultivated whole cell bacterins in swine
Authors: Bey Russell F. , Johnson Russell C.
Published: February 2025

Swine serologically negative for anti-Leptospira antibodies were given 2 doses of a pentavalent vaccine (3 weeks between doses) prepared from Leptospira serovars canicola, icterohaemorrhagiae, hardjo, pomona, and grippotyphosa (0.2 mg/serovar/dose). Leptospires used for vaccinal production were cultivated in a protein-free medium or in a bovine albumin-containing medium. All vaccinated swine had demonstrable antibody titers within 1 week of the initial vaccination. Peak microscopic agglutination titers were between 256 and 1,024 after the 2nd vaccinal dose was given. After challenge exposure with serovar canicola, control swine had titers of at least 13,653 and the vaccinated swine had titers of 3,403 to 8,192, depending on the vaccine.

Leptospiremia and kidney infections were not detected in any canicola Moulton immunized swine, but did appear in control swine. The Al(OH)3 adjuvant had no obvious influence on any of the vaccinal titers.
Comparison of five preanesthetic medicaments in pentobarbital-anesthetized dogs: Antagonism by 4-aminopyridine, yohimbine, and naloxone
Authors: Hatch Roger C. , Clark J. Derrell , Booth Nicholas H. , Kitzman Joseph V.
Published: February 2025

Effects of saline solution (groups 1, 2, and 3), xylazine (2.2 mg/kg of body weight, groups 4 and 5), acepromazine (0.1 mg/kg, groups 6 and 7), diazepam (1.0 mg/kg, groups 8 and 9), morphine (1.0 mg/kg, groups 10 and 11), or fentanyl-droperidol (0.055 ml/kg, groups 12 and 13), im were compared in groups of atropinized dogs. Treated dogs were anesthetized to stage III, plane 2 with pentobarbital, iv. After stabilization of anesthesia, the dogs were given iv 0.5 mg of 4-aminopyridine (4-ap)/kg + 0.25 mg of yohimbine/kg (groups 2, 5, 7, and 9), or 4-ap + yohimbine + 0.04 mg of naloxone/kg (groups 3, 11, and 13). Groups 1, 4, 6, 8, 10, and 12 were given saline solution instead of test antagonists. Required dosage of pentobarbital, arousal and walk times (measured from injection of antagonists), respiratory rate, and heart rate were measured. Emergence phenomena were recorded and graded as smooth, fairly smooth, smooth in some dogs to rough in other dogs, rough, or very rough.

In group 1 dogs, mean arousal time (mat) was 279.5 minutes, mean walk time (mwt) was 583.3 minutes, and emergence was rough. In groups 4, 6, 8, 10, and 12, mat was decreased by the sedatives to the range of 52 to 115.3 minutes and mwt was decreased to the range of 82.3 to 188.5 minutes. Emergence was smooth (groups 4 and 6), fairly smooth (groups 10 and 12), or smooth to rough (group 8). In groups given 4-ap + yohimbine, mat and mwt (in minutes) and emergence, respectively, were: group 5—3.3, 4.9, smooth; group 7—33.2, 119.7, smooth to rough; and group 9—77.5, 307.8, smooth to rough. In groups given 4-ap + yohimbine + naloxone, these values were: group 11—1.8, 55.6, rough (with mild tonic seizures in 3 dogs); and group 13—3.6, 53.3, very rough (with defensive biting and snapping in 4 dogs).

The 5 preanesthetic sedatives decreased the required dosage of pentobarbital by different amounts. The greatest reduction was 78% (with xylazine). Differences in required dosage of pentobarbital probably influenced mat, mwt, and emergence.

Seemingly, pentobarbital anesthesia can be reversed rapidly, safely, smoothly, and permanently in atropinized dogs that are given xylazine premedication and given 4-ap + yohimbine iv. The results also provide a basis for dose-response studies, using 4-ap + yohimbine or 4-ap + yohimbine + naloxone as antagonists of sedative-barbiturate anesthesia.
Nephrotoxicity of sodium arsenate in dogs
Authors: Tsukamoto Hidekazu , Parker Harold R. , Gribble D. H. , Mariassy A. , Peoples S. A.
Published: February 2025

Nephrotoxicity of sodium arsenate was evaluated in dogs to determine the pathophysiologic basis for renal lesions caused by this heavy metal. Examination of biopsy specimens indicated that the low dose of the As salt (0.73 mg/kg of body weight) produced histologic changes consisting of mild degeneration and vacuolation of renal tubular epithelium. Vacuolation involved mainly the ascending thick portion of the nephron. Clinical pathologic changes were not demonstrable at this dosage level according to glomerular filtration rate (creatinine clearance), fractional reabsorption of sodium, potassium, and chloride; plasma osmolar and free water clearance; and urinalysis.

The medium dose (7.33 mg/kg) resulted in alterations determined by urinalysis, but did not markedly affect other clinical pathologic measurements. Histopathologic changes were equal to or greater than those seen with the low dose. Tubular necrosis was observed in the cortical portion of the nephron and the ascending thick limb.

The high dose (14.66 mg/kg) consistently produced marked changes in all parameters evaluated. Clinical pathologic alterations were compatible with acute tubular necrosis involving all segments of the nephron. Histologically, moderate glomerular sclerosis and severe tubular necrosis were observed. During recovery from the high dose of As, a gradual compensatory healing process was observed that was evident in all clinical pathologic parameters and was confirmed from sequential renal biopsy specimens.
Arrhythmogenicity of dopamine, dobutamine, and epinephrine in thiamylal-halothane anesthetized dogs
Authors: Bednarski Richard M. , Muir William W.
Published: February 2025

The arrhythmogenicity of epinephrine, dopamine, and dobutamine, administered by constant-rate infusion, was determined in vagotomized and nonvagotomized thiamylal-halothane anesthetized dogs. Electrocardiograms and atrioventricular bundle electrograms revealed the development of atrial, junctional, and ventricular arrhythmias. The 3 drugs produced atrial arrhythmias at dosages smaller than those required to produce ventricular arrhythmias. The mean dosages (µg/kg−1/min−1) required to produce ventricular arrhythmias on duplicate trials in vagotomized dogs were for epinephrine, 0.6 ± 0.2; dopamine, 22.8 ± 14.8; and dobutamine, 11.6 ± 5.2. The corresponding doses for nonvagotomized dogs were for epinephrine, 0.8 ± 0.3; dopamine, 35.3 ± 13.5; and dobutamine, 21.9 ± 13.9. Most ventricular arrhythmias originated from a single focus in the left ventricle. Heart rate and blood pressure were significantly increased immediately before ventricular arrhythmia appeared. We conclude that epinephrine, dopamine, and dobutamine are capable of producing cardiac arrhythmias in vagotomized and nonvagotomized thiamylal-halothane anesthetized dogs and that bilateral vagotomy decreases the dosage of epinephrine, dopamine, and dobutamine required to produce cardiac arrhythmias.
Suppression of neutrophil and lymphocyte function induced by a vaccinal strain of bovine viral diarrhea virus with and without the administration of ACTH
Authors: Roth James A. , Kaeberle Merlin L.
Published: February 2025

Effects of a modified live vaccine (mlv) strain of bovine viral diarrhea virus (bvd) on lymphocyte and neutrophil function were determined in cattle with and without increased plasma cortisol (hydrocortisone) concentrations. Cattle were given mlv-bvd vaccine im and intranasally. Cattle given ACTH received 200 IU every 12 hours for 10 doses.

The mlv-bvd virus when administered alone caused no apparent clinical signs or body temperature response. Of 4 mlv-bvd-treated calves that were also given ACTH, 2 developed increased body temperature and respiratory distress. The mlv-bvd virus caused a decrease in circulating lymphocytes and neutrophils, whereas administration of ACTH and mlv-bvd induced a neutrophilia and lymphopenia. The mlv-bvd virus and ACTH when administered separately or in combination caused a depression of lymphocyte blastogenesis in response to selected mitogens.

Neutrophils were separated from the peripheral blood and their function was evaluated, using the following procedures: (i) random migration under agarose, (ii) ingestion of 125I-labeled Staphylococcus aureus, (iii) quantitative nitroblue tetrazolium reduction, (iv) iodination, and (v) antibody-dependent cell-mediated cytotoxicity (adcc). The mlv-bvd virus produced a significant (P < 0.05) suppression of neutrophil iodination and adcc. Neutrophils from cattle given mlv-bvd virus and ACTH had enhanced random migration, enhanced S aureus ingestion, suppressed iodination, and suppressed adcc activity.
Scanning electron microscopy of porcine jejunal loops infused with Escherichia coli endotoxin
Authors: Vogelweid C. M. , Elmore R. G.
Published: February 2025

Phenol-extracted Escherichia coli endotoxin was infused into ligated jejunal loops in 3 pigs. Tissue samples were collected from the center of each loop 6 hours later and examined with scanning electron microscopy. Control loops infused with pyrogen-free water were examined, as well as nonligated biopsy and blind-loop samples. Loops infused with endotoxin had predominantly ridge-shaped villi, many actively secreting goblet cells, and numerous large epithelial ulcerations involving the tips and sides of villi. Tight junction disruption between epithelial cells was observed in 1 pig. In contrast, small ulcers were rarely seen in ligated control loops. Villi were predominantly tongue-shaped, and goblet cell activity was moderate. Pathologic changes were greater in endotoxin-infused loops than in water-infused loops at 6 hours after infusion.
Activity of flubendazole against developing stages of Dirofilaria immitis in dogs
Authors: Guerrero J. , Seibert B. P. Campbell , Newcomb K. M. , Michael B. F. , McCall J. W.
Published: February 2025

A formulation of flubendazole was studied to determine the activity against developing stages of Dirofilaria immitis in artificially infected pups. Flubendazole suspension was administered subcutaneously at a dose rate of 50 mg/kg of body weight once a day for 1, 3, or 5 consecutive days at various times during the experimental period. The pups were necropsied 6 months after the experimental infection, and the heart and pulmonary arteries were examined for adult worms.

Optimal activity was obtained when flubendazole suspension was administered subcutaneously for 5 consecutive days, either 1 or 2 months after infection. The formation of encapsulated deposits, containing white viscous fluid, was observed at the injection sites of all treated pups.
Effects of herbicides on the concentration of poisonous compounds in plants: A review
Authors: Williams M. C. , James L. F.
Published: February 2025

Herbicides may raise, lower, or not affect the concentration of poisonous compounds in plants. Herbicides, 2,4,5-T and silvex controlled Wasatch milkvetch (Astragalus miser var oblongifolius) and markedly reduced the concentration of miserotoxin, a poisonous aliphatic nitro compound. The concentration of phototoxic furocoumarins in the leaves of spring parsley (Cymopterus watsonii) decreased to nontoxic concentrations 4 to 5 weeks after treatment with 2,4-D. The hydrocyanic acid content of wild cherry (Prunus spp) decreased after treatment with 2,4-D and 2,4,5-T, but increased in Sudangrass (Sorghum halapense) after treatment with 2,4-D. The alkaloid concentration in Barbey larkspur (Delphinium barbeyi) increased after treatment with 2,4,5-T or silvex, decreased in horsetail (Equisetum palustre) after treatment with MCPA, and was unaffected in Datura after treatment with several herbicides. The effect of herbicides on nitrate concentration in plants was dependent upon the species of plant and the herbicide used.
Cardiovascular adjustments to various degrees of acute isocapnic hypoxia in dogs
Authors: Tucker Alan , Grover Robert F. , Reeves John T.
Published: February 2025

Cardiovascular responses to various degrees of acute isocapnic hypoxia were determined in spontaneously breathing anesthetized dogs. Cardiac output (co), heart rate, stroke volume, systemic blood pressure, and systemic vascular resistance were measured at frequent intervals during 20-minute exposures to hypoxia (7% to 17% O2). Cardiac output increased during hypoxia, with the most severe degree of hypoxia producing the greatest increase in co. Stroke volume increased significantly (P < 0.05), whereas tachycardia was inconsistent. Systemic vascular resistance declined with hypoxia, with the greatest vasodilation observed with the most severe hypoxia. During the first 3 minutes of hypoxia, co increased at all 3 degrees of hypoxia, whereas systemic vascular resistance remained relatively unchanged during this initial portion of the hypoxic exposures.

Prevention of the hypoxia-induced increase in co by partial caudal vena caval obstruction (reducing venous return) resulted in a maintenance of systemic vascular resistance at or above the base-line value before hypoxia. Seemingly, hypoxia can increase co before systemic vasodilation is evident and systemic vasodilation depends, partly, on the increase in co.
Keratoconjunctivitis sicca: Histopathologic study of nictitating membrane and lacrimal glands from 28 dogs
Authors: Kaswan Renee L. , Martin Charles L. , Chapman Willie L.
Published: February 2025

Forty nictitating membrane glands and 9 main lacrimal glands were obtained for histologic evaluation from 28 dogs with keratoconjunctivitis sicca as the result of azosulfapyridine toxicity, canine distemper, multisystemic autoimmune disease (Sjogren's syndrorher-like syndrome), congenital origin, and unilateral and bilateral idiopathic keratoconjunctivitis sicca. Similar glands from 6 control dogs were studied. The most prevalent (87%) histopathologic finding was variable degrees of multifocal chronic adenitis, characterized by acinar atrophy and replacement with increased numbers of plasma cells and lymphocytes within increased amounts of interacinar fibrous connective tissue stroma. Occasional tubular structures were dilated and filled with neutrophils and cellular debris.
Acquisition and aggregation of canine blood platelets; Basic mechanisms of function and differences because of breed origin
Authors: Clemmons R. M. , Meyers Κ. M.
Published: February 2025

A method for obtaining reliable blood platelet yields in canine platelet-rich plasma, using increased sodium citrate concentration, is presented. Maintaining a quiet environment or anesthetizing the animals with thiamylal sodium aids in collection of platelets. Aggregation of platelets from 60 dogs of various breeds in response to arachidonic acid, collagen, adenosine diphosphate, epinephrine, and serotonin was monitored. Canine platelets reversibly or irreversibly aggregated to arachidonic acid. The percentage of arachidonate-irreversible platelets varied from 0% to 100% depending upon the breed of dogs examined. Arachidonate-irreversible platelets also aggregated irreversibly at lower concentrations of collagen and exhibited biphasic irreversible aggregation to adenosine diphosphate and serotonin. Serotonin-induced irreversible aggregation was dependent upon receptor activation and upon arachidonic acid metabolism. Irreversible aggregation to serotonin was associated with release of 3H-serotonin and thromboxane B2 formation, indicating that a couple between the serotonergic receptor and arachidonic acid metabolism may exist.
Histomorphologic structure of the carotid rete-cavernous sinus complex and its functional importance in sheep (Ovis aries)
Authors: Khamas Wael A. , Ghoshal Nani G. , Bal Harpal S.
Published: February 2025

Paraffin sections of the carotid rete-cavernous sinus complex of sheep were studied, using different stains. The carotid rete of sheep was composed of medium-sized arteries with smooth muscle layers that were oriented in different directions. The carotid body cells may have migrated proximally in the adventitia of the intracranial portion of the internal carotid artery as its extracranial portion degenerates early in life. The cavernous sinus shared a common tunica adventitia with surrounding rete branches. At places, the wall of the cavernous sinus had a distinct tunica media interposed between the endothelial cells and the tunica adventitia. Therefore, the name cavernous venous plexus has been proposed for the cavernous sinus in sheep.
Anthelmintic efficacy, safety, and residue evaluation of levamisole gel formulation in cattle
Authors: Berger H. , Garces T. R. , Wang G. T. , Gale G. O. , Steller W. A. , Simkins Κ. L.
Published: February 2025

Anthelmintic efficacy, safety, and residue studies were conducted in beef calves using a levamisole gel formulation. The effectiveness of levamisole gel and tablet formulations was studied in 30 calves with experimental infection of Ostertagia ostertagi. Removal of 33- to 34-day-old Ο ostertagi was 99.6% and 97.7%, for the gel and tablet formulation, respectively, when administered orally to supply 8 mg of levamisole HCl equivalent/kg of body weight. A comparative blood concentration study was also used to demonstrate bioequivalence of the levamisole gel to the tablet formulation. In a cross-over-designed test, 5 cattle/treatment group were dosed orally with levamisole 11.5% gel or levamisole tablets at the dosage rate of 8 mg of levamisole HCl/kg. Blood levamisole values were similar with the levamisole gel and tablet formulations.

In a safety study, 3 groups of 6 calves each were given levamisole gel orally to provide 8, 24, or 40 mg of levamisole HCl/kg. A 4th group served as controls. Adverse clinical signs were not observed in cattle treated with the recommended dosage level of 8 mg/kg. Transient salivation was noticed in 1 placebo control calf, 2 calves given 24 mg/kg, and 4 calves given 40 mg/kg.

Edible tissues from cattle given a single oral dose of levamisole gel (8 mg/kg) were analyzed for drug residues 2 hours and 2, 3, 5, and 7 days after treatment. Muscle, fat, and kidney samples were < 0.1 mg/kg of tissue in cattle killed 2 days after treatment, whereas residue in liver samples were < 0.1 mg/kg of tissue in cattle killed 5 days after treatment.
Use of an immunoperoxidase stain for the demonstration of bovine viral diarrhea virus by light and electron microscopies
Authors: Ward A. C. S. , Kaeberle M. L.
Published: February 2025

Bovine viral diarrhea (bvd) virus-specific antiserum eluted from an immunoabsorbent column was conjugated with horseradish peroxidase. The immunoperoxidase (ip) conjugate was used to stain bvd virus-inoculated and control tissue cultures processed for light and electron microscopies.

Infected cells (in the inoculated cultures) viewed by light microscopy had diffuse staining of the cytoplasm of nonvacuolated cells and a more predominant staining associated with vacuoles as vacuolation occurred. The peroxidase label as demonstrated by electron microscopy was associated primarily with nonenveloped and membrane-associated viral particles. Viral particles 20 to > 100 nm (diam) were observed. Some of the particles which were > 30 mm in diameter contained multiple nuclear cores. The most intensely stained viral particles were outside of the cells.
Oxalate urinary calculi in beef steers
Authors: Huntington Gerald B. , Emerick Royce J.
Published: February 2025

Hereford × Angus steers (10/treatment) were fed 90% concentrate diets containing 0.3%, 0.6%, 0.9%, or 1.2% of calcium for 92 days (trial 1) or 114 days (trial 2). Ground limestone was the supplemental calcium source. At slaughter, 12 of 20 steers fed 0.3% calcium had calculi in the urinary bladder or kidneys, compared with 5 of 20 fed 0.6% calcium, 5 of 20 fed 0.9% calcium, and 4 of 20 fed 1.2% calcium. Analyses of calculi indicated they were oxalate calculi.

During the first 49 days of trial 2, plasma hydroxyproline concentrations were higher (P < 0.10) for steers fed 0.3% calcium than for steers fed higher calcium concentrations. Increased bone resorption in steers fed concentrations of 0.3% calcium, resulting in increased plasma hydroxyproline, an oxalate precursor, was indicated as a source of oxalate in calculi and as an explanation of lower occurrence of calculi in steers fed higher concentrations of calcium.
Efficacy of ivermectin in injectable and oral paste formulations against eight-week-old Strongylus vulgaris larvae in ponies
Authors: Klei Thomas. R. , Torbert Betty J. , Chapman Melanie R. , Turk Margaret A. M.
Published: February 2025

A controlled test method was used to evaluate the efficacy of injectable micelle and oral paste formulations of ivermectin (22,23-dihydroavermectin B1) against 8-week-old Strongylus vulgaris larvae in experimentally infected pony foals. The dosage level of the drug in both formulations tested was 0.2 mg/kg. Ponies were euthanatized and necropsied 5 weeks after treatment.

Based on the recovery of live vs dead S vulgaris from mesenteric arteries, both formulations were > 99% effective. Increased weight gains and marked reductions in the severity of arterial lesions were observed in treated ponies.
Times of appearance and disappearance of colostral IgG in the mare
Authors: Pearson Renée C. , Hallowell A. L. , Bayly Warwick M. , Torbeck Richard L. , Perryman Lance E.
Published: February 2025

Pre- and postpartum colostral samples collected from 14 Arabian and 22 Thoroughbred mares were examined for color, consistency, and immunoglobulin (Ig)G concentration. Initial samples, obtained 3 to 28 days before mares had foaled, contained > 1,000 mg of IgG/dl. Mean concentration of IgG in colostrum of the Arabian mares at the time of parturition (T0) was 9,691 mg/dl and was significantly (P < 0.05) higher than the average, 4,608 mg/dl, for the Thoroughbreds. Average times lapsed from T0 until the colostral IgG decreased to 1,000 mg/dl (T1,000) was 19.1 hours for the Arabian mares and 8.9 hours for the Thoroughbred mares—the former being significantly (P < 0.01) longer. Induction of parturition by injection of oxytocin had no significant effect either upon the colostral IgG concentration at T0 or upon the T1,000.
Detection of equine infectious anemia virus in horse leukocyte cultures derived from horses in various stages of equine infectious anemia viral infection
Authors: Evans Karin Schiffer , Carpenter Susan L. , Sevoian Martin
Published: February 2025

The enzyme-linked immunosorbent assay (elisa) antigen-positive and agar-gel immunodiffusion test (agid)-negative horses do not have infective equine infectious anemia (eia) virus. The elisa testing of horse leukocyte culture (hlc) supernatants did detect eia virus in a hlc that was infected with the Wyoming strain of eia virus and in hlc derived from horses in febrile, acute, or subacute stages of eia infection. In supernatants of hlc derived from chronic and inapparent carrier horses, eia virus was not detected with elisa.

Direct fluorescent antibody tests detected eia virus in hlc infected with 106tcid50 of the Wyoming strain of eia virus and in 50% of the hlc from febrile acute or subacute horses. The direct fluorescent antibody testing of hlc derived from chronic and inapparent carrier horses did not detect cell-associated eia virus. The pony inoculation test proved to be the most reliable and accurate method for detecting infective eia virus in horses in various stages of eia infection and accurately correlated with the agid test.
Toxicity of threadleaf groundsel (Senecio douglasii var longilobus) to cattle
Authors: Johnson A. Earl , Molyneux Russell J.
Published: February 2025

Threadleaf groundsel (Senecio douglasii var longilobus), a common plant on much of the rangeland of southwestern United States, was experimentally fed to 55 cattle by gastric gavage, mixed in alfalfa hay, or pelleted in feed. Since the pyrrolizidine alkaloid (pa) content of threadleaf groundsel fluctuates greatly, dosage was determined by the plant pa content.

Animals that died survived up to 506 days. Whether they were acutely or chronically affected they had typical signs of seneciosis. Major gross and histopathologic changes are reported.

The estimated minimum lethal plant dose by gavage was sufficient plant to provide 13 mg of pa/kg of calf body weight/day for 15 days or a total of approximately 200 mg of pa/kg in a 15-day period. Cattle that consumed up to 600 mg of pa/kg total in 20- to 100-day periods in hay or pellets were unaffected or minimally affected. These findings emphasize the importance of the time-dose relationship in pa toxicosis in cattle and indicate that there is a threshold level of pa that must be exceeded for the toxicosis to develop.
Response of dogs to subcutaneous injections of various concentrations of propylene glycol with water
Authors: Brown J. M. , Kasson C. W.
Published: February 2025

Each of 85 dogs was injected, subcutaneously, with 5 different mixtures of propylene glycol (pg) and aqueous vehicles. Each dog was observed for immediate (within 15 minutes) and delayed (at 24, 48, and 72 hours) reactions. The reactions were classified as none, mild, moderate, and severe for the different observation periods.

The study indicated that a mixture containing between 20% and 50% pg caused the fewest immediate reactions and that the number of delayed reactions increased as the proportion of pg in the solutions increased. Viscosity of the mixture also should be considered when selecting a vehicle.