bluuebunny/crossref_metadata_2025 huggingface dataset:
Location of the instantaneous center of joint rotation in the normal canine stifle
Authors: Ireland W. P. , Rogers J. , Myers R. K.
Published: February 2025

Locations of 3 instantaneous centers of joint rotation (icr) were found in the stifles of 6 healthy dogs. A novel algorithm, verified by computer simulation, was used to determine icr from radiographs. Comparisons of icr locations were made between flexion and extension, between left and right limbs, and between living and dead dogs, using analysis of variance. All stifles were examined for evidence of lesions, but all were normal. The normal location of the icr in the stifle is near the joint surface, indicating that there is a predominantly rolling type of motion. As the limb flexes, the icr moves caudally; as the limb extends, the icr moves cranially. Significant differences in icr position were not found between left and right limbs or between living and dead dogs. The average icr position was significantly more caudal during extension than it was during flexion. Knowing the normal icr position is a preliminary to diagnosing joint abnormalities, using the icr.
Decreased complement and bacteriostatic activities in the sera of cattle given single or multiple doses of aflatoxin
Authors: Thurston John R. , Cook William , Driftmier Kim , Richard John L. , Sacks Jerome M.
Published: February 2025

Five steers given 1 dose of partially purified aflatoxin at concentrations sufficient to provide 0.2 mg to 0.8 mg of aflatoxin B1 equivalents/kg of body weight were compared with 4 steers given 14 daily doses of 0.25 mg of aflatoxin B1 equivalents/kg of body weight for complement activity and bacteriostasis. Complement activity was measured by hemolysis in gel, and bacteriostatic activity, by growth inhibition of Escherichia coli in liquid medium. In the single-dose group, complement activity and bacteriostatic activities decreased by 57 hours after dosing, and both returned to near base line by 168 hours. In the daily dose group, only bacteriostatic activity decreased, and the decrease persisted 2 weeks after the last dose of aflatoxin was given. Apparently, aflatoxin affects both complement-dependent and independent serum bacteriostatic activity.
Neutrophil Chemotaxis in rhesus macaques (Macaca mulatta)
Authors: Gonder J. C. , Thomas J. M. , Payne E. S.
Published: February 2025

Chemotactic responses of isolated peripheral blood neutrophils from rhesus macaques (Macaca mulatta) were studied, using a micropore filter method. Cell migration toward zymosan-activated serum was similar to that of human cells, whereas the response to N-formyl methionyl leucyl phenylalanine (fmlp) was weaker than was that in human cells, requiring higher concentrations of fmlp for maximal migration. Optimal fmlp concentrations for attraction of rhesus neutrophils and human neutrophils were 5.0 × 10−7M and 1.0 × 10−8M, respectively. The chemotactic responses of the 2 neutrophils to complement (zymosan-activated serum) were similar. However, rhesus neutrophils required a higher concentration of the formyl peptide, fmlp, for maximal migratory response.
Screen for anthelmintics, using larvae of Ascaris suum
Authors: Rew R. S. , Urban J. F. , Douvres F. W.
Published: February 2025

A multiwell culture system was used to assay the effects of 12 known anthelmintic compounds on Ascaris suum larval development from 2nd-stage (L2; hatched from eggs) to early 3rd-stage (L3) and from in vivo-derived late L3 to early 4th-stage (L4). Larval survival, development, and motility were monitored for drug effects. Development of L2 to L3 was sensitive to thiabendazole, albendazole (abz), abz/sulfoxide, abz/sulfone (so), mebendazole, l-tetramisole, d-tetramisole, piperazine, or closantel at a concentration of 0.01 μg/ml; however, the effects of these drugs on larval development did not correlate well with known effects in vivo. The development of L3 to L4 was blocked by abz or mebendazole at 0.01 μg/ml, by thiabendazole or abz/sulfoxide at 0.1 μg/ml, and by abz/so at 1.0 μg/ml; however, except for abz/so, most larvae were viable at these concentrations. In contrast, l-tetramisole or morantel appeared to inhibit development of L3 to L4 and to reduce survival at concentrations of ≥ 1 μg/ml; however, d-tetramisole was at least 10 times less effective. Haloxon, ivermectin, and closantel blocked development of L3 to L4 at 0.1, 1, and 10 μg/ml, respectively, in the absence of serum, but their activity was reduced by the presence of serum. Seemingly, in vitro development of A suum larvae was a convenient and sensitive bioassay for anthelmintic activity and could serve as a screen for anthelmintic residues in edible tissues.
Experimental Cryptosporidium infections in chickens: Oocyst structure and tissue specificity
Authors: Lindsay David S. , Blagburn Byron L. , Sundermann Christine A. , Hoerr Frederic J. , Ernest James A.
Published: February 2025

Oocysts of an avian isolate of Cryptosporidium were used to inoculate 21 chicks orally and 7 chicks intratracheally to determine the tissue specificity of this organism. Oocysts were passed in the feces 4 to 5 days after inoculation. Oocysts (6.8 by 5.0 μm) were fully sporulated and they were passed for at least 17 days by infected chicks. The mode of inoculation did not influence the distribution of cryptosporidia within the digestive tract. Cryptosporidia were found in the cloaca (100%), bursa of Fabricius (95.7%), terminal portion of the colon (26.1%), and cecum (4.3%) of chicks that were positive for developmental stages. Of 21 chicks inoculated orally, 4 had cryptosporidia in their trachea, whereas 6 of 7 chicks inoculated intratracheally had cryptosporidia in the trachea, bronchi, and air sacs. Cryptosporidium was found in the ducts of the salivary glands and nasal turbinates of chicks inoculated intratracheally that had clinical signs of respiratory tract disease. None of the chicks died or had intestinal disease.
Onchocerca spp: Frequency in Thoroughbreds at necropsy in Kentucky
Authors: Lyons Ε. T. , Tolliver S. C. , Drudge J. H. , Swerczek T. W. , Crowe M. W.
Published: February 2025

Examination of the ligamentum nuchae for Onchocerca spp was completed in 523 Thoroughbreds (1 to 29 years old) at necropsy in Kentucky during a 13-month period (1984 to 1985). Onchocerca spp were found in 306 (59%) of the horses. Frequencies of this parasite were 3%, 17%, 40%, 43%, and 42% in 1-, 2-, 3-, 4-, and 5-year-old horses, respectively. For 6- to 29-year-old horses, frequency varied from 71% to 100%, except for 26-year-old horses (50%); 87% of the 304 horses examined in the 6- to 29-year-old age groups was infected.

The suspensory ligaments and flexor tendons from fetlocks (thoracic limb only) of 100 Thoroughbreds (3 to 24 years old) were examined at necropsy during a 4-month period (1984) for Onchocerca spp. Infected horses were not found.
Infectious bovine keratoconjunctivitis: Evidence for genetic modulation of resistance in purebred Hereford cattle
Authors: Pugh George W. , McDonald Timothy J. , Kopecky Kenneth E. , Kvasnicka William G.
Published: February 2025

A vaccination study was conducted in a herd of purebred Hereford cattle representing 4 selection (genetic) lines. For each of 2 years, half of the cattle were vaccinated with a pilus-enriched Moraxella bovis bacterin. Cows were vaccinated before parturition, and calves were vaccinated at 2 to 3 months of age. None of the cattle was vaccinated for 1 year preceding and 1 year after the 2 years in which cattle were vaccinated.

There was a significantly (P < 0.05) lower percentage of infectious bovine keratoconjunctivitis (ibk) in calves during years cattle were vaccinated than during years cattle were not vaccinated. During years cattle were vaccinated, there were lower percentages of ibk in vaccinated calves when compared with the percentages of ibk in nonvaccinated calves. When calves were compared on the basis of selection lines, regardless of the vaccination group, there were consistent differences in the percentages that developed ibk. Although calves with pigmented and nonpigmented eyes (representing all 4 genetic lines) developed ibk, the genetic line of calves with the most pigmented eyes had the lowest (P < 0.05) percentage of ibk. Also, across all genetic lines, there was less ibk in pigmented eyes than in nonpigmented eyes.

Seemingly, vaccination of dams, before parturition, and young calves reduced the occurrence of severe ibk in a herd situation under natural exposure conditions. The resistance or susceptibility in cattle under good management may be influenced by genetic factors.
Antithrombin III activity in horses with large colon torsion
Authors: Holland Melissa , Kelly Andrew B. , Snyder Jack R. , Steffey Eugene P. , Willits Neil , McNeal Dale
Published: February 2025

A chromogenic peptide substrate assay was used to determine serially plasma antithrombin III (AT III) activity in 4 groups of horses. Group I consisted of healthy, mature horses in which AT III activity was determined twice daily for 7 consecutive days. Groups 2 and 3 contained healthy horses in which AT III activity was monitored for 7 days after controlled, but varying, conditions of general anesthesia and surgery (median celiotomy). Group 4 was made up of patients with a presurgical diagnosis of colonic torsion. In healthy awake horses (group I), there was no difference in AT III values over time. Postoperative AT III activity in the halothane-anesthetized horses (group 2) and in the sham-operated horses (group 3) was not significantly (P = 0.05) different from base-line values at any time. A significant decrease (P = 0.05) in AT III activity was observed on postoperative days 1 through 3 in the group of horses with large colon torsion, but returned to preoperative values by day 4 after surgery in the horses that survived. In those horses that did not survive, AT III activity remained below base-line values for the duration of observation. Seemingly, plasma AT III activity in horses was not significantly affected by halothane anesthesia or surgery. Serial evaluation of AT III activity may be useful for predicting survival in horses with large colon torsion.
Effects of phenobarbital treatment on 3-methylindole toxicosis in ponies
Authors: Turk Margaret A. M. , Thomas David E.
Published: February 2025

To study the role of cytochrome P-450-dependent mixed function oxidase reactions in equine 3-methylindole (3MI) toxicosis, ponies were given 20 mg of phenobarbital/kg of body weight at 72, 60, 48, 36, and 24 hours before 100 mg of oral 3MI/kg to induce cytochrome P-450 or no treatment (controls). Maximal 3MI plasma concentration was decreased and clearance was faster in phenobarbital-treated ponies. Plasma 3MI was still detectable 12 and 36 hours after dosing in phenobarbital-treated and control ponies, respectively. Phenobarbital treatment induced a distribution phase with transition from a 1-compartment to a 2-compartment extravascular model. Bronchiolitis occurred in all ponies 72 hours after 3MI, but was more severe in those treated with phenobarbital. Appearance of a distribution phase, increased total body clearance, and more severe bronchiolitis in phenobarbital-treated ponies indicated that mixed function oxidases are involved in metabolism and conversion of 3MI to a toxic metabolite.
Effects of radiofrequency hyperthermia on the healthy canine cornea
Authors: Glaze Mary B. , Turk Margaret A. M.
Published: February 2025

Radiofrequency hyperthermia was used to induce axial corneal lesions in the eyes of 10 dogs. Clinical observations were continued for up to 6 months, using biomicroscopy and indirect ophthalmoscopy, Eyes were harvested at intervals for light and electron microscopic evaluation.

Clinical alterations included immediate corneal opacification and epithelial disruption at the site of electrode contact. Ulcerative keratitis persisted for 4 to 6 days, accompanied by anterior uveitis. Additional corneal changes included stromal thinning, edema, and vascularization. Final evaluation revealed negligible alterations in corneal contour or clarity 6 months after treatment.

Microscopically, epithelial and superficial stromal necrosis preceded epithelial loss. Stromal alterations included edema (associated with focal endothelial detachments), vascularization, and inflammatory cell infiltration. Recovery was characterized by keratocytic hyperplasia and hypertrophy, epithelial proliferation, and stromal condensation.
Chicken embryonal vaccination with avian infectious bronchitis virus
Authors: Wakenell P. S. , Sharma J. M.
Published: February 2025

A commercial infectious bronchitis virus (ibv) vaccine of the Massachusetts 41 strain was injected in embryonating chicken eggs on embryonation day (ed) 18. The ibv vaccine was pathogenic for embryos, and it was passaged in chicken kidney tissue culture to reduce the pathogenicity. At the 40th tissue culture passage (P40-ibv), the virus became apathogenic for the embryos. Maternal antibody-positive or -negative chicks hatching from eggs injected with P40-ibv developed antibody to ibv and were protected against challenge exposure at 4 weeks of age with virulent Massachusetts 41 ibv. Although P40-ibv protected chicks when administered on ed 18, this virus did not protect chicks well if given at hatch. When combined with the turkey herpesvirus (hvt), P40-ibv given on ed 18 did not interfere with the protection against challenge exposure with virulent Marek's disease virus, nor did the presence of hvt interfere with protection by P40-ibv. Thus, under laboratory conditions, ibv vaccine could be combined with hvt to form a bivalent embryonal vaccine.
Effects of small and large face masks and translaryngeal and tracheostomy intubation on ventilation, upper-airway dead space, and arterial blood gases
Authors: Haskins Steve C. , Patz John D.
Published: February 2025

Pulmonary function was examined in pentobarbital-anesthetized dogs that were spontaneously breathing through a large poorly fitted face mask, a small snug-fitted face mask, an endotracheal tube, and a tracheostomy tube. Increasing upper-airway dead space volumes were associated with higher minute ventilation and faster breathing rates. Minute and tidal alveolar ventilation, calculated ideal alveolar oxygen, alveolar-arterial oxygen gradient, venous admixture, arterial pH and blood gases, cardiac output, and systemic and pulmonary arterial blood pressure were not changed.

The functional dead space of each mask was considerably less than that measured by water displacement. The small mask only slightly increased, and the endotracheal tube slightly decreased, the dead space estimated for a nasally breathing healthy dog.
DNA homology studies of leptospires of serogroups Sejroe and Pomona from cattle and swine
Authors: Le Febvre Rance B. , Thiermann Alex B.
Published: February 2025

Hybridization studies of chromosomal DNA from leptospiral strains representing Leptospira interrogans, serogroups Sejroe and Pomona from cattle and swine were performed to determine the degree of homology among their DNA sequences. Chromosomal DNA isolated from leptospires of the Sejroe and Pomona serogroups was radiolabeled and used to probe DNA isolated from other strains in these serogroups. Serovars hardjo (hardjoprajitno), hardjo (hardjo-bovis), balcanica (1627 Burgas), pomona (pomona), and kennewicki (LT-1026) were probed to determine the degree of homology among their chromosomes. Serovars pomona and kennewicki were homologous to each other. They also had a high degree of homology with hardjo (hardjoprajitno) and, to a lesser extent, with hardjo (hardjo-bovis) strains. However, hardjoprajitno and hardjo-bovis had little homology to each other. Serovar balcanica had a high degree of homology with hardjo-bovis isolates, but little homology with hardjoprajitno. Although serologically indistinguishable, the reference strain hardjoprajitno was genetically dissimilar to hardjo-bovis strains isolated from North American cattle.
Lymphangiographic evaluation of experimentally induced chylothorax after ligation of the cranial vena cava in dogs
Authors: Fossum Theresa W. , Birchard Stephen J.
Published: February 2025

Ligation of the cranial vena cava (CrVC) distal to the entrance of the azygous vein resulted in chylothorax in 7 of 10 dogs. Of the remaining 3 dogs, 1 developed a serosanguineous effusion that did not become chylous, and 2 dogs did not develop pleural effusion. In 2 of the 7 dogs developing chylothorax, the pleural effusion became serosanguineous within 2.5 weeks after CrVC ligation. Mesenteric lymphangiography was performed 2 to 6 weeks after ligation of the CrVC. Lymphangiectasia was seen in 4 dogs with chylothorax, but was not seen in the 3 dogs with serosanguineous effusions or the 2 dogs that did not develop effusions. One dog with chylothorax died prior to repeat lymphangiography. Less dye entered the thoracic duct, and alternate lymphaticovenous communications to the caudal vena cava were evident in the dogs without chylothorax.

Ligation of the thoracic duct at the lymphaticovenous junction was performed in 3 dogs. These dogs did not develop pleural effusion. Lymphangiography was performed immediately after ligation and indicated filling of abdominal lymphatics but not of the thoracic duct. Lymphangiographic findings 6 weeks after ligation also indicated filling of intestinal lymphatics.

Results of the present study indicated that ligation of the CrVC causes chylothorax, and that thoracic lymphangiectasia is a consistent finding in animals with experimental chylothorax. Obstruction of the thoracic duct did not induce lymphangiectasia or chylothorax. Impedence of thoracic duct flow into the CrVC may be a cause of clinical chylothorax in the dog.
Gastric emptying of liquids in the dog: Effect of volume
Authors: Leib Michael S. , Wingfield Wayne E. , Twedt David C. , Williams Anne R.
Published: February 2025

Effect of liquid test meal volume on gastric emptying was investigated in healthy nonoperated dogs fed meal sizes of 6.6 to 110 ml/kg of body weight. For meals ≤ 66 ml/kg, the amount of test meal emptied from the stomach in 30 minutes vs meal size could be described as following a linear, exponential, or square root pattern. Deviation from these patterns was seen with test meals of 77, 88, and 110 ml/kg. A mean ± sem maximum of 0.99 ± 0.06 ml/kg/min of liquid test meal was emptied from the stomach of dogs fed test meals of 77, 88, and 110 ml/kg. Massive gastric distension induced in dogs during this study did not alter gastric emptying of the liquid test meal.
Inoculation of dogs with artificial larvae similar to those of Dirofilaria immitis: Distribution within the pulmonary arteries
Authors: Atwell R. B. , Rezakhani A.
Published: February 2025

Two hundred artificial larvae, similar in size to those of Dirofilaria immitis, were inoculated into the venous system of 20 clinically healthy dogs and the distribution pattern was evaluated. One hundred forty-four (73%) of the larvae were located in the right lung and fifty-one (26%) in the left lung. Of those larvae in the lung, 50% were in the right caudal branch and 21% in the left caudal branch of the pulmonary artery. These findings help to explain why the right caudal lung lobe usually is more affected in canine dirofilariasis.
Field evaluation of the enzyme-linked immunosorbent assay for swine trichinosis: Efficacy of the excretory-secretory antigen
Authors: Murrell K. D. , Anderson W. R. , Schad G. A. , Hanbury R. D. , Kazacos Κ. R. , Gamble H. R. , Brown J.
Published: February 2025

A field evaluation of an enzyme-linked immunosorbent assay (elisa) for swine trichinosis was done with sera obtained from 5 herds experiencing ongoing transmission of Trichinella spiralis. Epizootiologic studies conducted on these herds offered an opportunity to evaluate the accuracy of an elisa, using larval T spiralis excretory-secretory antigens. Sera from 162 infected pigs and 143 serum samples from noninfected pigs originating from the same farms were tested. The infection status of the pigs was determined by digestion of diaphragm or tongue muscle samples. Two criteria were established to classify the elisa optical density (OD) readings: Criterion I stated that an OD ≥ 5 times the mean OD of several normal swine sera pools was positive; criterion II stated that a OD ≥ 4 times the normal sera values was positive. The results obtained did not reveal obvious serologic variations among infected herds located in the 4 states involved. Overall, the test detected 93% (criterion I) and 96% (criterion II) of infected pigs.

The majority of false-negative sera was from hogs that had < 5 larvae/g of muscle; 1 hog had 73.8 larvae/g of diaphragm muscle. The false-positive rates were 8% for criterion I and 9% for criterion II. The actual rate for these false-positive samples may have been overestimated, because generally, only small tissue samples (0.4 to 10 g) were digested; larger sample sizes might have altered the results. The relevance of this qualification is that these pigs originated from herds with prevalence rates > 50%. Other factors that may account for occasional false-positive sera or false-negative sera in the swine trichinosis elisa are discussed. Finally, the liabilities and assets of this serologic test are considered in relation to its application for herd screening and its use as an antemortem test.
Sarcocystis infections in mule deer (Odocoileus hemionus) in Montana and the descriptions of three new species
Authors: Dubey J. P. , Speer C. A.
Published: February 2025

Four structural types of sarcocysts of Sarcocystis were found in skeletal muscles of mule deer in Montana. Type I sarcocysts were thin walled (1 to 3 μm) and belonged to S hemionilatrantis. Types II to IV sarcocysts were thick walled (2 to 10 μm) and new names were proposed for them. Type II sarcocysts with long villar projections were named S hemioni. Type III sarcocysts with club-shaped villi of uneven thickness were named S youngi. Type IV sarcocysts with walls of uneven thickness and containing hair-like protrusions were named S americana.
Effect of captopril on the progression of induced pyelonephritis in the rat
Authors: Hall Robert L. , Wilke W. Lee , Fettman Martin J.
Published: February 2025

The effect of captopril, an angiotensin-converting enzyme inhibitor, was studied in rats subjected to Escherichia coli pyelonephritis. Eight weeks after pyelonephritis was induced in male Sprague-Dawley rats, the rats were randomly assigned to treatment groups based on urinary protein excretion. In experiment 1, rats were given captopril, 50 mg/kg of body weight, or saline solution via daily intraperitoneal injection. To eliminate complications with captopril-induced peritonitis, experiment 2 was performed in which rats were given the same treatment by daily gavage. In both experiments, 24-hour urinary protein excretion in the saline-treated rats was significantly greater than that of the captopril-treated rats after 12 weeks of treatment (P < 0.05). Plasma urea nitrogen, plasma creatinine, and endogenous creatinine clearance did not differ between treatment groups during the course of therapy in experiment 1. There were no differences in these values in experiment 2, except at week 8 of treatment when the captopril-treated rats had significantly lower plasma creatinine and higher endogenous creatinine clearance than did the saline-treated rats (P < 0.05). There was also no difference between treatment groups in the degree of morphologic renal damage based on light microscopic evaluation of kidneys at the end of treatment.
Effect of Clonidine, quipazine, and LY 53857 on the prolactin-suppressant action of bromocriptine in rats
Authors: Lipham Luke B. , Booth Nicholas H. , Jernigan Antoinette D. , Robbins Joe D. , Hatch Roger C.
Published: February 2025

The α2-adrenergic agonist clonidine hydrochloride, the serotonin agonist quipazine maleate, and the serotonin (5-HT2) antagonist LY 53857 were tested alone and in various combinations for their capabilities to increase mean serum prolactin (msp) concentrations in rats given the synthetic ergot alkaloid CB-154 (2-bromo-α-ergocriptine), a known prolactin suppressor.

The LY 53857 and the combination of clonidine, quipazine, and LY 53857 significantly decreased msp concentrations. Quipazine given alone (10 mg/kg of body weight) was best able to increase msp concentration and has potential to antagonize prolactin-depressant effects of ergot alkaloids.
Neuromuscular and cardiovascular effects of atracurium in ponies anesthetized with halothane
Authors: Hildebrand S. V. , Howitt G. A. , Arpin D.
Published: February 2025

Atracurium besylate, a recently developed, intermediate-duration acting, neuromuscular-blocking agent, was given to 15 halothane-anesthetized ponies to produce surgical relaxation (95% to 99% reduction of hoof twitch). All 15 ponies were given 3 injections; 8 of the 15 ponies were given 2 additional injections. Initial dosage of 0.11 ± 0.01 mg/kg (mean ± sd) and all subsequent injections of 0.052 mg/kg produced desired relaxation.

Paralysis phase (maximum twitch reduction to 10% twitch recovery) lasted 24 ± 5 minutes for the initial injection. Paralysis from subsequent injections lasted for a slightly shorter time. Recovery phase (10% to 75% twitch recovery) was similar for all injections (initial and repeated) and lasted approximately 11 minutes. Cardiovascular side effects were not seen.

Reversal of effects of atracurium with administration of 0.5 mg of edrophonium/kg was achieved when the evoked digital extensor tension (twitch height) had returned to 95% of base line after the last atracurium injection. Edrophonium caused systolic blood pressure to increase 121% ± 7% of base-line pressure, which was 133 ± 18 mm of Hg. Heart rate changed to 93% ± 9% of base line after edrophonium was given, which was 49 ± 7 beat/min, but this change did not occur until after the blood pressure increased.

Recovery to standing was smooth and strong. Five ponies stood on their first attempt to rise, 5 on the 2nd attempt, 2 on the 3rd, and 1 on the 4th. Seven ponies stood within 30 minutes after transportation to the recovery stall, 7 within an hour. One pony took 70 minutes to regain its standing posture. Total anesthesia time was approximately 5 hours before transportation to the recovery area. Evidence of residual weakness was not noted.

Action of atracurium in ponies was similar to its action in other species, since atracurium gave reproducible magnitude and duration of relaxant effect, did not have a cumulative effect, and did not have cardiovascular side effects.
Use of a toxoid vaccine to protect goats against intradermal challenge exposure to Corynebacterium pseudotuberculosis
Authors: Brown Corrie C. , Olander Harvey J. , Biberstein Ernst L. , Morse Susan M.
Published: February 2025

Two groups of male, 9-week-old goats (5 goats/group) were vaccinated subcutaneously with formalized exotoxin of Corynebacterium pseudotuberculosis, with Freund's incomplete adjuvant. Each goat was given 2 vaccinations, 2 weeks apart. At each vaccination, each group 1 goat was given 0.5 ml of toxoid, and each group 2 goat was given 1 ml of toxoid. Twenty days after the 2nd vaccination, vaccinated goats and 5 nonvaccinated 12-week-old goats (controls) were inoculated intradermally (challenge exposed) with live C pseudotuberculosis, monitored for 13 weeks, and euthanatized. At necropsy, 5 of the 10 vaccinated goats did not have C pseudotuberculosis lesions, 3 had abscesses limited to the inoculation site and draining lymph node, and 2 had disseminated bacterial lesions. Of the 5 nonvaccinated controls, 4 had disseminated abscesses and 1 had a single abscess in an internal node. Serologically, 9 of the 10 vaccinated goats developed positive (≥ 1:8) antibody titers against the exotoxin within 1 week after inoculation; the 10th goat seroconverted 2 weeks after inoculation, whereas control goats required 3 weeks to develop a positive antibody response. Therefore, early during an infection with C pseudotuberculosis, antibodies against the exotoxin may protect a goat against spread of the organism.

All goats were injected intradermally before challenge exposure, 10 days after challenge exposure, and at 4, 8, and 12 weeks after challenge exposure with a skin-test reagent composed of fragmented bacterial cells. Skin-test reactions were not seen before challenge exposure. After challenge exposure, observable skin-test responses increased throughout the study.
Colostral transfer of Clostridium perfringens type C beta antitoxin in swine
Authors: Matisheck Peter H. , McGinley Michael
Published: February 2025

Nine bred gilts were vaccinated with 2 doses of a Clostridium perfringens type C toxoid at a 5-week interval. Time of vaccination during gestation differed among the gilts. Clostridium perfringens β antitoxin in colostral samples and in serum samples was titrated in mice. Blood was collected from 2 to 5 neonatal pigs from each dam (total = 32 pigs) when the pigs were 36 to 48 hours old. Antitoxin titers in colostrum were 123 to 4.5 IU/ml, indicating considerable variation in individual responses of the gilts to toxoid. Serum titers of neonatal pigs reflected colostrum titers of their dams. This colostrum-to-serum titer correlation was essentially a straight-line fit by least-squares linear regression analysis, establishing a direct proportional relationship between colostrum titers and serum titers of neonatal pigs. In the dams, a correlation was not found between colostral titers and serum titers of blood samples collected 2 weeks after collection of colostrum.
Serum antibodies to Pasteurella haemolytica lipopolysaccharide: Relationship to experimental bovine pneumonic pasteurellosis
Authors: Confer A. W. , Panciera R. J. , Mosier D. A.
Published: February 2025

An enzyme-linked immunosorbent assay was used to determine the serum antibody response to Pasteurella haemolytica lipopolysaccharide (lps) for calves vaccinated with saline solution, a formalin-killed Ρ haemolytica bacterin, or live Ρ haemolytica. Bacterin-vaccinated calves had a lower antibody response to lps than did calves vaccinated with live Ρ haemolytica. Calves vaccinated with either saline solution or the bacterin were more susceptible to intrapulmonic challenge exposure with Ρ haemolytica than were calves vaccinated with live organisms.

Serum antibody responses to Ρ haemolytica lps did not seem important for resistance to challenge exposure, because there was no significant correlation (P > 0.05) between the lung lesion score and antibody response to Ρ haemolytica lps. There was a highly significant correlation (P < 0.001) between antibody detected against Ρ haemolytica lps and that against formalin-killed Ρ haemolytica. Competitive binding studies indicated that Ρ haemolytica lps is a major antigenic determinant on the surface of Ρ haemolytica. There did not seem to be substantial cross-reaction between lps from Ρ haemolytica and that from Escherichia coli (serotype O26:B6).
Hybridization of bovine Escherichia coli isolates with gene probes for four enterotoxins (STaP, STaH, STb, LT) and one adhesion factor (K99)
Authors: Mainil Jacques G. , Moseley Steve L. , Schneider Robert A. , Sutch Kathleen , Casey Thomas A. , Moon Harley W.
Published: February 2025

Colony hybridizations with 4 enterotoxins (STaP, STaH, STb, and LT) and 1 adherence factor (K99) gene probes were done on Escherichia coli isolated from calves. Agreement between the K99 probing and a serologic assay to detect the K99 antigen was 99% for the identification of K99+ and K99- isolates. Ninety-five of the isolates (22%) hybridized with at least 1 enterotoxin gene probe (Ent+ isolates), and 82 (19%), with the K99 gene probe. The majority of Ent+ isolates (85%) reacted with probes for STaP and K99 genes. The STaP gene was present by itself in 4 of the Ent+ isolates (4%) and with the STb gene in 6 of the Ent+ isolates (6%). Five of the Ent+ isolates (5%) carried the STb and LT genes, and none (0%) of the isolates carried the STaH gene. All but 2 of the isolates with the K99 gene also had the STaP gene. Twenty-eight isolates shown to produce STa enterotoxin in previous studies failed to hybridize with any of the enterotoxin gene probes. These 28 isolates were also phenotypically negative when the tests for enterotoxin production were repeated. These isolates probably lost their genes for enterotoxin production during storage in the laboratory.
Effect of recombinant DNA-derived bovine α-1 interferon on transmissible gastroenteritis virus infection in swine
Authors: MacLachlan Ν. James , Anderson Kevin P.
Published: February 2025

Recombinant DNA-derived bovine interferon α1-1 (BoIFN) inhibited replication of both vesicular stomatitis virus and transmissible gastroenteritis virus in cultures of swine testicular cells. Newborn pigs were orally inoculated with BoIFN and subsequently had interferon in their gastric contents and serum; however, interferon was found only occasionally in intestinal washings. Incubation of BoIFN with gastric contents from a newborn suckling pig did not affect antiviral activity, whereas intestinal (small intestine) contents from the same animal inactivated BoIFN within 1 minute. Beginning at 6 hours of age, newborn, colostrum-deprived pigs were given 1 mg of BoIFN orally every 12 hours. These pigs were not protected against challenge exposure to virulent transmissible gastroenteritis virus at 48 hours of age; disease and mortality were similar for these pigs and for control pigs not given BoIFN prior to challenge exposure. The BoIFN did not impair growth rate of pigs and did not cause obvious disease or lesions.
Nitrogen metabolism of calves inoculated with bovine adenovirus-3 or with infectious bovine rhinotracheitis virus
Authors: Cole N. A. , Delaney D. D. , Cummins J. M. , Hutcheson D. P.
Published: February 2025

Beef calves were inoculated with bovine adenovirus-3 or infectious bovine rhinotracheitis virus. After inoculation, plasma fibrinogen increased, serum phosphorus decreased, and nitrogen and phosphorus digestibility decreased compared with preinoculation values. Urinary Ν excretion increased when calves developed rectal temperatures > 39.7 C.

Results indicated that clinical infection of calves with infectious bovine rhinotracheitis virus increases urinary Ν excretion and reduces Ν and phosphorus balance, and that clinical and subclinical infections with either virus reduce dietary Ν digestibility.
Toxicologie and immunologic effects of sublethal doses of cyclopiazonic acid in rats
Authors: Hill Joseph E. , Lomax Larry G. , Cole Richard J. , Dorner Joe W.
Published: February 2025

Effects of cyclopiazonic acid (cpa) on humoral immunity, cell-mediated immunity, weight gain, organ weights, clinical chemical and hematologic values, and gross and microscopic lesions were evaluated. Four groups of rats, each containing 3 males and 3 females, were given 0, 0.1, 1, and 5 mg of cpa/kg of body weight intraperitoneally for 28 days.

A dosage level of 5 mg/kg produced a significant (P < 0.05) decrease in weight gain. Rats given 0.1 or 1 mg of cpa/kg had a significant (P < 0.05) reduction in antibody titer against sheep rbc 5 days after injection. The 0.1 mg/kg group also had a significant reduction in antibody titer 7 days after injection. Microscopic lesions were limited to liver and kidneys and were characterized by vacuolated to granular hepatocyte cytoplasm and dilated renal convoluted tubules, many having pyknotic nuclei and scattered hyaline casts.
Effects of spontaneous, assisted, and controlled ventilatory modes in halothane-anesthetized geldings
Authors: Hodgson D. S. , Steffey E. P. , Grandy J. L. , Woliner M. J.
Published: February 2025

Cardiopulmonary effects of spontaneous, assisted, and controlled ventilatory modes were determined with 6 young, healthy geldings anesthetized with halothane at a constant dose (1.3 minimum alveolar concentration). All horses were in lateral recumbency, and all modes of ventilation were studied at least once during each anesthetic exposure. Cardiac output did not differ between spontaneous and assisted ventilation modes, but both modes were associated with significantly (P < 0.05) higher cardiac output than that with controlled ventilation. The PaCO2 differed significantly (P < 0.01) between all modes of ventilation. Although controlled ventilation maintained a normal PaCO2, assisted ventilation reduced PaCO2 as compared with spontaneous ventilation with less cardiovascular depression than that with controlled ventilation. Mixed venous O2 tensions were higher with spontaneous and assisted ventilation modes than with controlled ventilation. Except for shorter inspiratory time and smaller inspiratory/expiratory ratio associated with spontaneous ventilation, there were no ventilatory mode-related effects on ventilatory variables.
Monoclonal antibodies produced to Streptococcus agalactiae
Authors: Ainsworth A. J. , Capley Gina
Published: February 2025

Two monoclonal antibodies produced against Streptococcus agalactiae were studied for their specificity and sensitivity. Both reacted strongly in the enzyme-linked immunosorbent assay and indirect fluorescent antibody test with S agalactiae, but did not react with other gram-positive organisms frequently found in test herds in Mississippi. A procedure for using monoclonal antibodies in the detection of S agalactiae-infected milk samples is proposed.
Efficacy of avridine as an adjuvant for Newcastle disease virus antigen in chickens
Authors: Rweyemamu Mark M. , Umehara Ossamuro , de Lucca-Neto Domingos , de C. Baltazar Mário , Vicente Fausto E. , da R. Medeiros-Neto Raul
Published: February 2025

Avridine, a lipoidal amine with interferon-inducing and adjuvant properties, was an effective adjuvant for Newcastle disease antigen (nda) in chickens. Eleven vaccine lots were evaluated: 2 commercial water-in-oil vaccines, 4 experimental oil emulsion vaccines, 4 avridine-containing vaccines, and a control lot of nonadjuvanted antigen. Avridine significantly enhanced the immunologic responses of chickens against nda. Chickens vaccinated with the avridine-containing vaccines had significantly higher antibody titers (hemagglutination inhibition) than did chickens vaccinated with the commercial vaccines. Experimental oil emulsion vaccines prepared from the same antigens as avridine-adjuvanted vaccines induced higher hemagglutination inhibition antibody titers after primary but not after booster vaccination. Use of avridine as an adjuvant for nda in vaccines for chickens induced immunologic protection rates similar to those induced by oil emulsion vaccines, without causing the reactogenic and tissue residue problems associated with the use of oil vaccines in chickens.
Contributions of the glossopharyngeal nerve and the pharyngeal branch of the vagus nerve to the swallowing process in dogs
Authors: Venker-van Haagen A. J. , Hartman W. , Wolvekamp W. Th. C.
Published: February 2025

The separate contributions of the glossopharyngeal nerve and the pharyngeal branch of the vagus nerve to the innervation of the pharyngeal muscles were studied first in 10 canine cadavers by dissection of the pharyngeal plexus and the pharyngeal muscles. In 10 other dogs, the parent trunks and 1st division of the glossopharyngeal nerve and the pharyngeal branch of the vagus nerve were electrically stimulated. The evoked stimulation potentials were recorded from the stylopharyngeal, hyopharyngeal, thyropharyngeal, and cricopharyngeal muscles. One of the parent trunks was then transected, and the effects on the swallowing process were observed clinically and by contrast videofluorography. Denervation potentials resulting from nerve transection were recorded in the soft palate, the hyopharyngeal, thyropharyngeal, and cricopharyngeal muscles.

The pharyngeal plexus was composed of branches originating from the glossopharyngeal nerve and the pharyngeal branch of the vagus nerve. In most dogs, the pharyngeal muscles and the soft palate were innervated ipsilaterally by both nerves. The swallowing process was more severely disturbed after bilateral transection of the pharyngeal branch of the vagus nerve than after bilateral transection of the glossopharyngeal nerve.
Acute intravascular hemolytic anemia in the black rhinoceros: Hematologic and immunohematologic observations
Authors: Chaplin Hugh , Malecek Anne C. , Miller R. Eric , Bell C. Elliott , Gray Lloyd S. , Hunter Vickie L.
Published: February 2025

To investigate the syndrome of acute intravascular hemolytic anemia in the black rhinoceros (Diceros bicornis), laboratory techniques used in the differential diagnosis of hemolytic anemias were performed on blood samples from 6 black rhinoceroses: 3 nonrelated healthy rhinoceroses, 1 rhinoceros with iron deficiency anemia, and 2 rhinoceroses with intravascular hemolysis. Osmotic fragility, erythrocyte membrane protein composition, hemoglobin electrophoresis, and hemoglobin stability did not distinguish between healthy and affected (anemia or hemolysis) rhinoceroses. Polyclonal antiglobulin reagents were prepared in rabbits, using whole rhinoceros serum and purified rhinoceros immunoglobulin G. These reagents were nonreactive against erythrocytes of the healthy and iron-deficient rhinoceroses. Reactions with rbc from the rhinoceros with fatal hemolytic anemia indicated increased membrane coating by the third component of complement; this was not evident in a second rhinoceros that survived a hemolytic event.
Acute intravascular hemolysis in the black rhinoceros: Erythrocyte enzymes and metabolic intermediates
Authors: Paglia Donald E. , Valentine William N. , Miller R. Eric , Nakatani Misae , Brockway Richard A.
Published: February 2025

Enzymes of aerobic and anaerobic glycolysis, glutathione cycling, and nucleotide metabolism were assayed on erythrocytes from 7 healthy rhinoceroses, 2 rhinoceroses during periods of intravascular hemolysis, and 1 rhinoceros without clinical signs of illness, which was the mother of 3 offspring with intravascular hemolytic syndrome. Measurements also were made of erythrocyte concentrations of glycolytic intermediates, adenine nucleotides, and glutathione. Although comparison of results for healthy and affected rhinoceroses did not identify an enzyme abnormality as a cause for the hemolytic syndrome, the data provided information regarding the metabolic characteristics of erythrocytes from healthy rhinoceroses.
Activity of ivermectin against natural infections by abomasal nematodes in lambs in controlled tests: Evaluation of equine and bovine injectable formulations administered intraorally
Authors: Lyons Ε. T. , Drudge J. H. , Tolliver S. C.
Published: February 2025

The efficacy of 2 injectable formulations of ivermectin, administered intraorally at the dosage of 200 μg/kg of body weight, was evaluated against naturally occurring infections by abomasal nematodes in lambs in 2 controlled tests. One test (A) included 17 lambs treated with the equine formulation and 16 nontreated lambs. For the other test (B), 14 lambs were treated with the bovine formulation, and 12 were nontreated.

In controlled test A, only mature nematodes were recovered, and removals were 98% to 100% for Haemonchus contortus, Ostertagia circumcincta ♂, Ο trifurcata ♂, Ostertagia spp ♀, and Trichostrongylus axei. For controlled test B, removals were 99% to 100% for Haemonchus spp (immature), H contortus (mature), Ostertagia spp (immature), Ο circumcincta ♂ (mature), Ο trifurcata ♂ (mature), Ostertagia spp ♀ (mature), Trichostrongylus spp (immature), and T axei (mature).

Toxicosis was not evident in treated lambs.
Critical test and safety evaluations of an oral paste preparation of mebendazole and trichlorfon in horses
Authors: Seibert Barbara P. , Newcomb Kathleen M. , Michael Bruce F.
Published: February 2025

Critical tests were done on 24 naturally parasitized horses to compare the antiparasitic activity of an oral paste preparation of mebendazole and trichlorfon with that of the marketed powder formulation. Each formulation was administered at the recommended dosages of 8.8 mg of mebendazole and 40 mg of trichlorfon/kg of body weight. Efficacy of the paste formulation ranged from 97.7% to 100% against 2nd- and 3rd-stage Gasterophilus spp, adult Strongylus vulgaris, S edentatus, Parascaris equorum, small strongyles; and larval and adult forms of Oxyuris equi. Adverse effects were generally limited to slight softening of the feces. Mild and transient restlessness or sweating were also observed in 2 of 12 horses treated with the paste formulation.

The toxic effects of the paste, administered at 2.2 times the therapeutic dose, were examined in 6 horses and compared with the effects of a nonmedicated paste, administered in similar volumes to 6 other horses. Drug-related changes were not detected in clinical chemical analyses, hematologic values, or liver function tests. Transient clinical signs of organophosphate toxicosis (primarily the passage of loose feces) and prolonged inhibition of erythrocyte cholinesterase activity were evident within 1 hour after drug treatment. These effects were similar to those reported for the 2.2 × dose of marketed powder formulation.
Streptokinase treatment of cats with experimentally induced aortic thrombosis
Authors: Killingsworth Cheryl R. , Eyster George E. , Adams Thomas , Bartlett Paul C. , Bell T. G.
Published: February 2025

An investigation was initiated to determine the dosage of streptokinase (given iv) that would consistently produce systemic fibrinolysis, as determined by laboratory evaluation, and to determine the relative safety of this drug in the cat. Results indicated that a loading dose of 90,000 IU of streptokinase (given by continuous infusion over 20 to 30 minutes) and a maintenance dosage (iv) of 45,000 IU of streptokinase/hr predictably produced systemic fibrinolysis in the cat. There were no detectable adverse affects seen on physical examination, necropsy, or histopathologic examination.

Using the foregoing dosage regimen, investigation was begun to evaluate the use of streptokinase for treatment of feline thromboembolism. Aortic thrombosis was created experimentally in 15 cats. There was no clearly predictable improvement in nonspecific venous angiograms or thermal circulatory indices for the cats given streptokinase, compared with the values for the control cats. After a total of 180 minutes of treatment, the mean weight of remaining clot removed at necropsy from the aortic trifurcation was 7.3 mg in the streptokinase-treated cats, compared with 13.4 mg in the control cats.
Efficacy of flunixin meglumine for the treatment of endotoxin-induced bovine mastitis
Authors: Anderson K. L. , Smith A. R. , Shanks R. D. , Davis L. E. , Gustafsson B. K.
Published: February 2025

The clinical effect of flunixin meglumine administration was determined in cows with acute mastitis induced by intramammary administration of endotoxin. In 12 lactating cows, 10 μg of Escherichia coli 026:B6 endotoxin were administered via a teat cannula into the teat cistern of single randomly selected rear quarters. Cows were challenge exposed as pairs. One cow in each pair was administered parenteral flunixin meglumine (6 cows) and 1 cow per pair was administered saline solution (6 cows). Multiple doses (7) of 1.1 mg of flunixin meglumine/kg of body weight or saline solution were administered at 8-hour intervals beginning 2 hours after endotoxin. Cow and quarter clinical signs as well as milk somatic cell concentrations, bovine serum albumin, electrical conductivity, and milk production were determined before and for 14 days after endotoxin inoculation.

Intramammary endotoxin produced signs characteristic of acute coliform mastitis. Quarter and systemic abnormalities occurred and milk production was reduced by approximately 50% at 12 hours after endotoxin. Flunixin meglumine therapy significantly (P ≤ 0.05) reduced rectal temperatures and quarter signs of inflammation and improved clinically graded depression when compared with these signs in saline solution-treated controls. Milk production and laboratory indicators of inflammation in milk were not significantly (P > 0.05) different for flunixin meglumine vs saline solution controls. The clinical response observed was consistent with the antipyretic, analgesic, and anti-inflammatory properties of flunixin meglumine.