bluuebunny/crossref_metadata_2025 huggingface dataset:
Electromyographic, myomechanical, and intraluminal pressure changes associated with acute extraluminal obstruction of the jejunum in conscious ponies
Authors: MacHarg Margaret A. , Adams Stephen B. , Lamar Carlton H. , Becht James L.
Published: February 2025

Bipolar electrodes, strain gauge force transducers, intraluminal pressure recording catheters, and extraluminal intestinal obstructors were surgically implanted in 4 ponies to record myoelectrical and mechanical activity of the distal portion of the jejunum and ileum. After determining normal intestinal activity and pressures, the distal portion of the jejunum was obstructed with an extraluminal obstructor. Myoelectrical and mechanical activity recorded from jejunal segments proximal to the obstruction increased significantly (P < 0.01), whereas activity distal to the obstruction remained unchanged. Intraluminal pressure increases were recorded during periods of intestinal spasm. Obstruction pressures remained unchanged from preobstruction pressures.
Studies on the pathogenesis of Salmonella typhimurium and Salmonella choleraesuis var kunzendorf infection in weanling pigs
Authors: Reed Willie M. , Olander Harvey J. , Thacker H. Leon
Published: February 2025

Twenty-six 4-week-old pigs were randomly allotted to 4 groups: group 1—orally inoculated with Salmonella typhimurium; group 2—orally dosed with S choleraesuis; and groups 3 and 4, with surgically constructed intestinal loops—loops inoculated with either S typhimurium or S choleraesuis. One pig each from groups 1 and 2 was killed at 8, 12, 24, 48, 72, 96, and 120 hours after inoculation. One pig each from groups 3 and 4 was killed at 2, 4, 6, 8, 12, and 24 hours after intestinal loop inoculation. Inoculation of S typhimurium resulted in acute enterocolitis of variable severity, whereas inoculation of S choleraesuis resulted initially in septicemia followed by formation of large necrotic and ulcerative lesions in the colonic mucosa. The most consistent systemic lesion of S choleraesuis infection was interstitial pneumonia and multifocal hepatic necrosis.

Salmonella typhimurium and S choleraesuis were ultrastructurally within enterocytes of ligated ileal loops. Intracellular bacteria were morphologically intact, occurred free in the cytoplasm and membrane bound, and caused no detectable cytotoxic effect to the cell. Both S typhimurium and S choleraesuis penetrated the intestinal mucosa and were isolated from mesenteric lymph nodes at 2 hours after inoculation.
Characteristics of Salmonella isolated from animals at a veterinary medical teaching hospital
Authors: Ikeda Jack S. , Hirsh Dwight C. , Jang Spencer S. , Biberstein Ernst L.
Published: February 2025

Salmonella belonging to 47 serotypes was isolated from animals at the University of California Veterinary Medical Teaching Hospital during the years 1974 to 1983. Salmonella belonging to 12 serotypes accounted for 89% of the 725 isolates. Salmonella typhimurium (including var copenliagen) was the most commonly isolated serotype, but during 1981 to 1983, S krefeld and S saint-paul were predominant. Certain serotypes seemed to be isolated more frequently from extraintestinal sources (S typhi-suis, S dublin). Although resistance to ampicillin, kanamycin, neomycin, streptomycin, and sulfonamides was common (> 60% of the isolates were resistant), resistance to chloramphenicol, gentamicin, and trimethoprim-sulfonamides was infrequent, except for isolates of S krefeld and S saint-paul.
Abortion in sheep caused by a nonclassified, anaerobic, flagellated bacterium
Authors: Kirkbride C. A. , Gates C. E. , Collins J. E.
Published: February 2025

Twenty-eight pregnant ewes were inoculated iv with approximately 6 × 108 nonclassified, anaerobic, flagellated bacteria (nafb) that had been isolated from an aborted lamb. Abortion occurred in 3 of the ewes and 1 ewe gave birth to a weak lamb. The remaining 24 ewes and 3 other ewes inoculated orally with nafb did not develop clinical signs of illness.

Suppuration and vasculitis were seen in the placentas of the 3 aborted lambs, 1 of which had necropurulent hepatitis indistinguishable from that usually attributed to Campylobacter fetus infection.

The nafb was isolated from fetal placenta, abomasal content, or internal organs of 2 aborted lambs and the weak lamb. A morphologically similar organism was seen in the abomasal content of the other aborted lamb, but the organism did not grow on bacteriologic culture medium.

Therefore, in susceptible pregnant ewes, nafb can cause fetal placentitis and hepatitis and subsequent birth of weak lambs or abortion.
Developmental alterations in the regulation of glucagon and insulin secretion in Holstein calves
Authors: Owens S. W. , Sartin J. L. , Kemppainen R. J. , Cummins K. A. , Bartol F. F. , Bowman M. A.
Published: February 2025

Twenty-one Holstein bull calves were randomly assigned at birth to 3 groups. Two groups (each of 7 calves) were raised as follows: fed a milk diet alone or fed milk with grain supplementation after 2 weeks of age; studies were done when calves reached 4 weeks of age. The 3rd group was fed on milk with grain supplementation until weaning after which the calves were maintained on grain and pasture. These calves (older calves) were studied at 12 weeks of age. Either propionate (0.28 mmol/kg) or glucose (0.56 mmol/kg) was injected iv in a random order. Samples of blood were obtained from the calves before and immediately after injections were done and at 2, 5, 10, 15, 30, 45, and 60 minutes after secretagogue injection. Plasma was examined for glucose by a glucose oxidase procedure and for immunoreactive insulin (iri) and glucagon (irg) by radioimmunoassay.

The iri response to the injection of glucose was greater in older calves (P < 0.02). Patterns of iri secretion, as determined by heterogeneity of regression, showed age differences for both secretagogues (P < 0.05). Base-line irg was greater in milk/grain-fed calves than in milk-fed calves (P < 0.05). Mean irg response to propionate injection was higher (P < 0.05) in milk/grain-fed calves than in milk-fed calves. Plasma glucose concentration increased in older calves, but decreased in milk-fed calves after propionate injection.

The data indicate that maturation in the ruminant is accompanied by altered regulation of insulin and glucagon secretion. These data also indicate that there may be a role for glucagon in the development of hepatic gluconeogenic mechanisms in the ruminant.
Pressures in the right side of the heart and esophagus (pleura) in ponies during exercise before and after furosemide administration
Authors: Goetz Thomas E. , Manohar Murli
Published: February 2025

Pressures in the right side of the heart and esophagus (pleural) have not been determined in the exercising equine subjects. In the present study, 8 healthy ponies were examined to determine the changes in these variables caused by 2 degrees of exercise done on a treadmill (heart rate:183 ± 5 beats/min [trot] and 220 ± 6 beats/min [canter]). Measurements were also made during both degrees of exertion 10 minutes and 120 minutes after furosemide (1.0 mg/kg) administration.

It was observed that both gaits resulted in significant increases in pulmonary artery, right ventricular, and right atrial pressures. The pulmonary artery systolic, mean, and diastolic pressures during strenuous exertion were 306%, 252%, and 242% of the respective resting values. At canter, when respiratory frequency (138 ± 4 breaths/min) is synchronized with stride frequency, the Δ esophageal pressure approached 30.4 ± 2.86 cm of water. During exercise 10 minutes after furosemide administration, the increment in right atrial pressure was markedly attenuated. During strenuous exertion 120 minutes after furosemide administration, the right atrial and pulmonary arterial pressures increased, but to a significantly lower level than did the prefurosemide values. However, the mean pulmonary artery pressure was still 240% of the resting value.

It is concluded that marked pulmonary hypertension is a consistent feature of moderate, as well as strenuous, exertion in the pony. Although furosemide administration attenuated the pulmonary hypertension somewhat, the significance remains unclear.
Effects of lateral recumbency on regional lung function in anesthetized horses
Authors: Hornof William J. , Dunlop Colin I. , Prestage Ron , Amis Terry C.
Published: February 2025

Six horses were anesthetized and placed in lateral recumbency for 1 hour and then were turned to the opposite side for an additional hour. A short-lived radioactive gas, 81mKr, was used to determine the relative spatial distribution of ventilation (V̇) and perfusion (Q̇) in these horses. Effects of time, side down, and turning on the distribution were evaluated. A consistent gradient of V̇/Q̇ was found at all times, with the highest V̇/Q̇ values at the top (non-dependent) portion of the lung field and the lowest at the bottom (dependent). This gradient was also present within each lung, as well as between lungs. Effects of time were not observed. Horses starting in right lateral recumbency had larger gradients of V̇/Q̇ than did those starting on the left. The gradient decreased after turning in both groups. After turning, the gradients in the right lung were again greater han those in the left lung.
Blood flow to the distal part of the teat (mammary papilla) of lactating dairy cows
Authors: Jankus E. F. , Baumann L. E.
Published: February 2025

Relative blood flow to tissues of the distal part of the teat (mammary papilla) in 5 lactating dairy cows was determined, using 15-μm nonradioactive carbonized microspheres. Highest relative blood flow occurred in the epithelial region (zone A) of the teat canal (papillary duct) which comprised both teat canal epithelium and papillated portion of the stratum papillare. Blood flow to these tissues was more than 4 times greater than blood flow to equivalent tissues of the mucosal rosette. The high rate of metabolic activity indicated by this relatively high blood flow may be required to support secretion of antimicrobial substances and continual synthesis of epithelial cells to replace those lost during milking.
Effect of method of collection on seminal characteristics of the domestic cat
Authors: Dooley M. P. , Pineda M. H.
Published: February 2025

The effect of level of voltage and method of collection on seminal characteristics were studied in the domestic cat. A Latin square design was used to determine the effects of voltage (1, 2, 4, or 6 V) on seminal characteristics of electroejaculates for 8 cats (experiment 1). There was a significant effect of cat on the total volume (P < 0.005), number of spermatozoa (P < 0.05), pH (P < 0.05), and osmolality (P < 0.025). There was an effect of week for the pH (P < 0.05) and osmolality (P < 0.005) of semen. Voltage of stimulation affected the total volume (P < 0.005), total number of spermatozoa (P < 0.025), and osmolality (P < 0.005) of semen. There were trends (P < 0.1) for an effect of cat and an effect of voltage on spermatozoal motility. Urine contamination was not observed in any of the electroejaculates.

A 2, 2 × 2 Latin square design was used in experiment 2 to determine the effect of method of collection (artificial vagina or electroejaculation) on seminal characteristics for 4 cats. Electroejaculation was performed, using the 6-V electrical stimulus selected from experiment 1. There was a significant (P < 0.025) effect of cat on the motility of the spermatozoa in the viability preparation and a trend (P < 0.1) for an effect of cat on spermatozoal viability. Seminal samples, obtained using an artificial vagina, had a significantly (P < 0.005) lower volume and pH, and tended (P = 0.065) to have more spermatozoa as compared with that in semen collected by electroejaculation. The percentage of viable spermatozoa, unstained by eosin B, was positively correlated with spermatozoal motility in the motility preparation (r = 0.91, P < 0.001) and with spermatozoal motility within the viability preparation (r = 0.83, P < 0.001).

Voltage of stimulation influences the characteristics of electroejaculates from the domestic cat. For 4 of the 6 seminal characteristics that were analyzed, the 6-V electrical stimulus produced a seminal sample that was comparable with that obtained, using an artificial vagina.
Prevention and control of coccidiosis in goats with decoquinate
Authors: Foreyt William J. , Hancock Dale , Wescott Richard B.
Published: February 2025

Decoquinate was evaluated as a coccidiostat in domestic goats. Fifty goats < 4 months of age were assigned to 5 groups (pens) of 10 goats each and were treated for 87 days with 0 (control), 0.3, 0.5, 1.0, or 4.0 mg of decoquinate in feed/kg of body weight. Goats were inoculated orally with 30,000 oocysts, mainly Eimeria christenseni (74%) and E ninakohlyakimovae (20%) on day 19.

Nontreated goats developed profuse watery diarrhea and tenesmus and gained weight poorly; 2 died. Treated goats did not develop clinical coccidiosis and gained significantly more weight (P < 0.05), regardless of the dose used. Treated goats also had significantly fewer (P < 0.05) oocysts in feces than did nontreated controls. Oocyst numbers were inversely related to dose; a more rapid decrease in oocyst numbers occurred as the dose was increased. At the doses used, decoquinate was safe in goats and was an effective drug for the prevention of clinical coccidiosis.
Hemostatic abnormalities in equine colic
Authors: Johnstone I. B. , Crane S.
Published: February 2025

Hemostatic profiles were determined in 30 horses with clinical colic. Blood samples were obtained at the time of the animal's admission, and the following hemostatic tests were done: blood platelet count, plasma fibrinogen, plasma antithrombin, prothrombin time, partial thromboplastin time, thrombin time, protamine sulfate test for soluble fibrin monomer, and fibrin-fibrinogen degradation products. The patients were categorized in retrospect, according to the cause of the colic: group 1—colic associated with colitis and/or severe diarrhea, group 2—colic associated with torsion or obstruction of the intestine, and group 3—colic associated with impaction of the intestine or the presence of enteroliths.

Of the 30 horses with colic, 28 had at least 1 abnormality in their coagulogram—the most frequent abnormalities being high plasma fibrinogen concentration, high circulating soluble fibrin monomer, or a long partial thromboplastin time or thrombin time. The horses in group 1 seemed to have the most severe coagulopathies, as indicated by the average number of demonstrable abnormalities. The horses in group 3 showed the fewest abnormalities—usually a high plasma concentrations of fibrinogen and/or soluble fibrin monomer.

The results indicated that hemostatic abnormalities are not uncommon in horses with gastrointestinal disease and colic—the degree of severity depending to some extent on the cause of the colic.
Influence of market stress and protein level on feeder pig hematologic and blood chemical values
Authors: Clemens E. T. , Schultz B. D. , Brumm M. C. , Jesse G. W. , Mayes H. F.
Published: February 2025

One hundred twenty crossbred feeder pigs were used in 2 trials to determine the effects of food and water deprivation at the auction market and the effects of protein levels of receiving diet on blood chemical values. Food- and water-deprived animals had significantly higher packed-cell volume, colloid osmotic pressure, and cortisol values than did nondeprived animals. Total osmolality and plasma triiodothyronine values were significantly lower in deprived animals. Measurable effects of food and water deprivation were no longer apparent by 14 days after arrival at the research facility. Plasma colloid osmotic pressure had a positive linear relationship with increasing dietary protein level and was statistically different among levels of protein fed. Gilts had higher plasma triiodothyronine values than did barrows. Differential WBC ratios were not different between groups. Measurable differences for treatments (food and water deprivation vs food and water access; and level of protein in the receiving diet) were no longer apparent 84 days after pigs had arrived at the finishing unit.
Effects of storage temperature and time on canine plasma ammonia concentrations
Authors: Hitt Mark E. , Jones Brent D.
Published: February 2025

Stability of ammonia in canine plasma was determined, with regard to temperature and time of storage. Heparinized venous blood samples were collected from 8 healthy dogs, immediately placed in an ice water bath, and centrifuged at 5 C. Plasma was harvested from the blood samples, and the initial analysis of each sample for plasma ammonia was performed within 30 minutes after collection. Separate aliquots of the plasma from each dog were stored at 21 C, 4 C, −15 C, or −40 C. Ammonia concentrations of the aliquots stored at the various temperatures were determined at 24, 48, and 96 hours after collection. Statistical analysis of the data from each dog did not indicate a significant relationship between the initial concentration of plasma ammonia and subsequent determinations. Correlation or significance was not found among samples stored at similar temperatures and evaluated at similar times.
Adhesion of K99-positive Escherichia coli to intestinal brush borders of pigs
Authors: Grimes S. D. , Waxler G. L. , Newman J. P.
Published: February 2025

Ileal samples from 242 pigs, collected at 3 Michigan slaughterhouses, were studied to determine the prevalence of intestinal receptors for K99-positive Escherichia coli. A brush border adhesion test was used to identify the receptors. Of the 242 samples examined, receptors were demonstrated in 230 (95%). After storage of brush border preparations at 4 C, bacterial aggregates lacking identifiable brush border fragments were present in samples tested for adhesion, indicating that K99 receptors may be released from brush border membranes.

Seemingly, most, if not all, pigs have intestinal receptors for K99 pili, and an inheritance pattern similar to that observed for K88 receptors probably does not exist for K99 receptors.
Topography and differential growth of the nasal ventral concha (os conchae nasalis ventralis) of the pig from birth to six weeks of age
Authors: Martineau-Doizé B. , Martineau G. P.
Published: February 2025

To study the growth of nasal ventral concha (os conchae nasalis ventralis) of pigs between birth and 6 weeks of age, 7 undecalcified 80-μm thick nasal cross sections between the 3rd incisor and the 3rd premolar teeth were examined by microradiography and fluorescence microscopy, after labeling with tetracycline and alizarine red S. Conchal growth was particularly rapid in the pigs during the first 2 weeks of life. From the 3rd week, growth of the nasal ventral concha became slower. For a given age, the slow growing zone spread in the rostrocaudal direction. The transversely directed growth of the nasal ventral concha resulted in the optimal filling of the nasal cavities.
Effect of selenium deficiency on caprine polymorphonuclear leukocyte production of leukotriene B4 and its neutrophil chemotactic activity
Authors: Aziz Edith , Klesius P. H.
Published: February 2025

These studies were designed to measure leukotriene B4 (ltb4) production by polymorphonuclear leukocytes (pmn) from selenium (Se)-deficient and Se-adequate goats. Leukotriene B4 was measured by both radioimmune and chemotactic activity assays in supernatants of pmn stimulated by calcium ionophore A23187. The concentration of ltb4 produced by pmn from Se-deficient goats was significantly (P < 0.05) lower than the concentration of ltb4 produced by pmn from Se-adequate goats. Neutrophil chemotactic activity of ltb4 was found to be directly dependent (r2 = 0.85) on the ltb4 concentration. When supernatants from Se-deficient and Se-adequate goats were adsorbed with caprine neutrophils, significant (P < 0.05) reduction in ltb4 was found in supernatants from both groups. Furthermore, neutrophil adsorption of ltb4 from supernatants of both groups was indicated by significantly (P < 0.05) decreased chemotaxis to ltb4 supernatants. Decrease in chemotactic response was, however, significantly (P < 0.05) lower when neutrophils were treated with supernatants from Se-deficient goats. These results indicate that Se deficiency decreases the production of ltb4 by caprine pmn and, hence, ltb4-mediated neutrophil chemotaxis.
Pharmacokinetics of amikacin in pony foals after a single intramuscular injection
Authors: Brown Murray P. , Gronwall Ronald R. , Martinez Danise S. , Beal Carolyn
Published: February 2025

Six healthy pony foals, from 2 to 11 days of age, were given a single im injection of amikacin sulfate (250 mg/ml) at a dosage rate of 7 mg/kg of body weight. Serum amikacin concentrations were measured serially over a 24-hour period. The mean peak serum concentration was 14.7 μg/ml at 0.5 hour. The elimination rate constant for amikacin was 0.24/hour, the elimination half-life was 3.0 hours, and the apparent volume of distribution was 0.58 L/kg.
Electrocardiogram of the clinically normal, ketamine-sedated Macaca fascicularis
Authors: Atkins Clarke E. , Dickie Bruce C.
Published: February 2025

Electrocardiograms were obtained from 100 clinically normal cynomolgus macaques (Macaca fascicularis) sedated with ketamine hydrochloride. Calculations were made for heart rates and mean electrical axes (frontal, sagittal, and transverse planes) as well as for amplitudes and/or intervals for P, PR, QRS, Q, R, S, and QT. Proposed ecg reference ranges are set forth for this species.
Evaluation of a spectrophotometric method for canine serum lipase determination
Authors: Whitney Marlyn S. , Boon G. Daniel , Rebar Alan H. , Ford Richard B.
Published: February 2025

The British antilewisite butyrate-dithionitrobenzoate (balb-dtnb) spectrophotometric serum lipase assay was evaluated for precision, accuracy, and diagnostic usefulness in analyzing canine sera. Sera samples from clinically healthy dogs, dogs with experimentally induced pancreatitis, and dogs with spontaneous pancreatitis were analyzed. A titrimetric method of serum lipase determination was used for comparison. Although the balb-dtnb method was not found to be precise or accurate for determining the lipase activity of canine serum samples, it seemed to be at least as diagnostically useful as the titrimetric procedure. The small sample size requirement and the speed of analysis of the balb-dtnb procedure are advantages of this method over the titrimetric method, and thus, its use in place of the titrimetric method is justified. A laboratory reference range of 3 to 37 IU/L was determined for canine serum.
Dietary phosphorus for beef cows
Authors: Call J. W. , Butcher J. E. , Shupe J. L. , Blake J. T. , Olson A. E.
Published: February 2025

Hereford heifers (48 initially) were individually fed variable amounts of dietary phosphorus (P) from weaning through their 8th gestation. During phase I, 2 groups (24 cows each) were given 20.6 to 38.1 g of P/day and 6.0 to 12.1 g of P/day (increasing as animals grew). During phase II (the 4th gestation), half of the animals from each group were maintained with the same respective diets, and the other half were given 5.1 to 6.6 g of P/day. Within 6 months, animals given 5.1 to 6.6 g of P/day gradually developed signs of P deficiency. Clinical signs of deficiency and lesions included general unthriftiness, body weight loss, reduced feed consumption, reluctance to move, abnormal stance, spontaneous bone fractures, and finally, impaired reproductive performance. Cows given 7.8 to 8.9 g of P/day in diet 2 during phase II did not develop discernible clinical signs of P deficiency. Cows that were given 5.1 to 6.6 g of P/day apparently regained their health and reproductive capability when fed 11.7 to 12.6 or 17.1 to 20.5 g of P/day. The data indicate that bones serve as an effective storage source of P and support and buffer body needs until there is serious depletion of skeletal P. These results indicate that common recommendations for dietary P, such as those outlined by the National Research Council (17.5 g of P/day over the entire year for cows weighing 450 kg), exceed the basic requirements for beef cattle; 12 g of P/day is adequate for 450-kg beef cows.
Frequency and consequence of caseous lymphadenitis in sheep and lambs slaughtered at a Western Australian abattoir
Authors: Batey R. G.
Published: February 2025

A total of 8,711 sheep in 3 distinct age/sex groups were examined to determine for occurrence and extent of caseous lymphadenitis after slaughter at a major Western Australian abattoir. An adaptation of current mean inspection procedures to provide a numerical weighted evaluation according to number, site, and size of lesions was used to determine extent of involvement. Frequency in slaughter populations was estimated to be 3.4 ± 0.6% for lambs, 41.8 ± 3.9% for mixed-age rams, and 53.7 ± 1.5% for adult ewes at 95% confidence intervals. The results confirmed that frequency increased with age, but also revealed increases in extent of involvement and occurrence of visceral lesions, particularly in association with lesions of the body. Nevertheless, lesions occurred more frequently in the body than in the viscera. However, the mean visceral involvement was greater than mean body involvement in all groups, and the ratio was found to be more or less constant. Visceral involvement was found to be more extensive in rams than in ewes. Difficulties associated with complexity of current inspection procedures were also recorded. The relevance of these findings to pathogenesis and postmortem disposition after slaughter is discussed. It is suggested that current postmortem inspection criteria should be reevaluated.
Effect of induced prostatic infection on semen quality in the dog
Authors: Barsanti J. A. , Caudle A. B. , Crowell W. A. , Shotts E. B. , Brown J.
Published: February 2025

Chronic Escherichia coli prostatitis was induced in 6 dogs, with 5 sham-operated dogs serving as controls. Semen volume and sperm motility, concentration, and appearance were measured 3 times (every other day) before surgery and 3 times during the 3rd and 5th week after surgery. When values for these collections were compared, using a 2-factor analysis of variance, no significant differences (P > 0.05) were found. However, the percentage of normal sperm decreased markedly (from 92% to 61% to 64%) in 2 infected dogs because of an increase in primary (from 6% to 32%) or secondary (from 2% to 28%) sperm abnormalities. Testes from both of these dogs were histologically normal.
Inoculation of lambs with ovine adenovirus 5 (Mastadenovirus ovi 5) strain RTS-42
Authors: Lehmkuhl Howard D. , Cutlip Randall C.
Published: February 2025

Twelve 1-week-old colostrum-deprived lambs inoculated with the RTS-42 strain of Mastadenovirus ovi 5 were killed and necropsied (2 lambs/day) on postinoculation days (pid) 2, 4, 6, 8, 12, and 21. Four noninoculated lambs were killed and necropsied (2/day) on pid 6 and 12. Virus was isolated from nasal secretions and feces on pid 1 to pid 6, from tracheal fluids and lung tissue of lambs necropsied on pid 2, 4, and 6, and from lung tissue from 1 lamb necropsied on pid 8. Virus was not recovered from liver, kidney, or small intestine of inoculated lambs or samples from noninoculated lambs. Serum antibody was first detected on pid 6 in the inoculated lambs. Noninoculated lambs remained seronegative. None of the lambs in the study developed clinical signs of infection although lesions were produced in the respiratory tract.
Incubation of Pasteurella haemolytica and Pasteurella multocida lipopolysaccharide and with sheep lung surfactant
Authors: Brogden K. A. , Rimler R. B. , Cutlip R. C. , Lehmkuhl H. D.
Published: February 2025

Lipopolysaccharides (lps) were extracted from a serotype of each of 2 species of Pasteurella isolated from sheep with respiratory tract infections. Lipopolysaccharides from P haemolytica 82-25 (serotype 1A) or P multocida P-1573 (serotype 12) were mixed with sheep lung surfactant and were incubated for 6 hours at 37 C. After incubation, lps-surfactant mixtures were centrifuged overnight in sucrose density gradients, and fractions were analyzed. Binding occurred between lps and surfactant vesicles resulting in a stable complex with densities greater than those with the surfactant alone. The surfactant alone had a density of 1.052 to 1.060 g/ml. Diffuse bands of surfactant had a density of 1.075 to 1.092 when incubated with P haemolytica lps and a density of 1.069 to 1.105 when incubated with P multocida lps.
Pasteurella multocida isolated from rabbits and swine: Serologic types and toxin production
Authors: Rimler Richard B. , Brogden Kim A.
Published: February 2025

Pasteurella multocida isolates from rabbits and swine of different geographic origins were serologically grouped and typed. Similar capsule serogroups and somatic serotypes were common to both species. Selected serotypes of both serogroups A and D were tested for toxin production. Toxin-producing isolates from both rabbits and swine were found in serogroup D, but not serogroup A. A correlation was not found between somatic serotype and the capability of an isolate to produce toxin. Noncapsulated variants derived from parent capsulated toxin-producing isolates also produced toxin. The capability of an isolate to produce a toxin did not necessarily make it virulent. The toxins from rabbit and swine Ρ multocida of different geographic origins were antigenically similar.

Cell lysis was compared with sonication as a method to release cell-associated toxin for biochemical purification. The toxin was purified from lysates by ammonium sulfate precipitation, followed by ion exchange and gel-filtration chromatographic procedures. The purified toxin had a molecular weight of 112,000 to 158,000 and an apparent isoelectric point of 4.65 to 4.8. The toxin precipitated at pH near its isoelectric point.

Electrofocusing-electrophoresis titration curves of the purified toxin preparation showed it consisted of 2 similar proteins which varied in their capabilities to stain with Coomassie brilliant blue. The proteins precipitated together near their apparent isoelectric point and interacted at pH 9.7.
Detection of antibody in rams with contagious epididymitis, using the enzyme-linked immunosorbent assay
Authors: Cardenas A. Lucia , Maki Leroy R.
Published: February 2025

An enzyme-linked immunosorbent assay, using whole-cell and sonicated antigens prepared from Brucella ovis, Actinobacillus seminis, and Actinobacillus seminis-like cultures isolated from rams in Wyoming, was able to detect antibody to these antigens in rams with epididymitis. The whole-cell antigens used in this procedure gave lower background values, compared with those of the sonicated antigens. The procedure was able to detect antibody in rams before clinical signs of epididymitis became apparent.
Detection of bovine herpesvirus-specific nucleic acids by in situ hybridization with biotinylated DNA probes
Authors: Dunn Donna C. , Blair Carol D. , Ward David C. , Beaty Barry J.
Published: February 2025

Biotin-labeled DNA probes for bovine herpesvirus type 1 (bhv-1) were used to detect viral nucleic acids in infected cell cultures and clinical specimens by in situ hybridization. Hybridization signal was detected 2 hours after inoculation in the cytoplasm of infected cells, presumably representing input virus. Hybridization was first detected in the nucleus at 4 hours after inoculation; by 10 hours after inoculation, hybridization signal was detected in both nucleus and cytoplasm of almost 50% of the cells. By 15 hours after inoculation, 95% of the cells were positive. Treatment of specimens with ribonuclease or deoxyribonuclease before hybridization allowed clear differentiation of virus-specified DNA and RNA within infected cells. The bhv-1 nucleic acid sequences were detected in nasal epithelial cells obtained from inoculated calves.

Since in situ hybridization provides a rapid technique for the detection of bhv-l-specified nucleic acid sequences, it should facilitate studies on the replication, pathogenesis, and diagnosis of bhv-1 infections.
In vitro interference between equine herpesvirus types 1 and 2
Authors: Dutta S. K. , Myrup A. C. , Thaker S. R.
Published: February 2025

Interference between equine herpesvirus types 1 (ehv-1) and 2 (ehv-2) was studied in equine dermis (ed) monolayer cell cultures and equine lymphocyte cultures. Cell cultures were infected with ehv-2, and after a short incubation period, the cultures were superinfected with ehv-1. At various intervals, different measurements of ehv-1 expression in dually infected cultures, compared with those in cultures infected with ehv-1 alone, were studied. In dually infected ed cell cultures, the ehv-1 cytopathic effect, ehv-1 titer, and ehv-1 enzyme-linked immunosorbent assay antigen titer were maximally reduced to values of 40%, 58.5%, and 54.9%, respectively, at postsuperinfection hour (psih) 36. Values of these ehv-1 expressions were subsequently increased at psih 48. However, thymidine kinase activity was reduced to a maximum of 67.3% reduction at psih 48. In dually infected lymphocyte cultures, the ehv-1 titer, ehv-1 infective centers, ehv-1 enzyme-linked immunosorbent assay antigen titer, and thymidine kinase activity were maximally reduced to values of 77.4%, 78.7%, 98.3%, and 72.9%, respectively, at psih 24. These reductions of ehv-1 expressions were completely abrogated at psih 48 to 72. In both cell culture systems, a marked interference of ehv-1 by ehv-2 was observed; this was transient in the lymphocyte cultures, but was more prolonged in ed cell cultures. This interference appeared not to be interferon mediated. The multiplication of ehv-2 in the dually infected ed cell cultures appeared unaffected.
Effect of recombinant DNA-derived bovine and human interferons on replication of bovine herpesvirus-1, parainfluenza-3, and respiratory syncytial viruses
Authors: Fulton Robert W. , Burge Lurinda J. , McCraken J. S.
Published: February 2025

Antiviral effects of recombinant DNA-derived bovine (Bo) and human (Hu) interferons (ifn) on the replication of bovine herpesvirus-1, parainfluenza-3, and respiratory syncytial viruses were studied. Bovine monolayer cultures were treated with recombinant DNA-produced Bo ifn-α 1, Bo ifn-β 2, Hu ifn-α A, or Hu ifn-α A/D and then challenge exposed with bovine herpesvirus-1, bovine parainfluenza-3 virus, bovine respiratory syncytial virus, or vesicular stomatitis virus. Treatment with each ifn reduced the viral yield for each of these viruses, compared with that of control cultures.
Virion polypeptide specificity of immune complexes and antibodies in cats inoculated with feline infectious peritonitis virus
Authors: Horzinek Marian C. , Ederveen Joke , Egberink Herman , Jacobse-Geels Helen E. L. , Niewold Theo , Prins Jan
Published: February 2025

Immune complexes purified from sera and ascitic fluids of cats after inoculation with feline infectious peritonitis (fip) virus contained proteins and proteolytic fragments of the peplomer, nucleocapsid, and envelope polypeptides; in addition, host proteins were demonstrated in the immune complexes. Free (uncomplexed) antibodies against the 3 classes of virion polypeptides were detected and quantitated; the weakest and latest response was directed against the peplomer protein.

Immunofluorescence titers showed the best correlation with the antibody response directed against the envelope polypeptides. Differences in reactivity were not found between sera and ascitic fluids from the same animals and between seropositive healthy cats and cats which had died of fip. Humoral antibody and hypergammaglobulinemia showed a linear correlation, but the wide variation in antiviral titers at a given concentration of γ-globulin indicated that additional (autoimmune) reactions occur during the pathogenesis of fip.
Genetic stability in calves of a single strain of bluetongue virus
Authors: MacLachlan N. James , Fuller Frederick J.
Published: February 2025

Newborn calves were inoculated iv with highly plaque-purified bluetongue virus (btv), serotype 10. The electrophoretic migration patterns of RNA segments and proteins of viruses isolated from calves at intervals after inoculation were compared. In addition, sera collected from calves at intervals after inoculation were compared for their abilities to neutralize several virus isolates from the same calf. Viremia persisted in calves for up to 56 days. Differences were not detected in the electrophoretic migration pattern of RNA segments or proteins of any of the btv isolates. All calves produced high titers of neutralizing antibody to the original btv inoculum by 28 days after inoculation, and significant (≥ 4-fold) differences were not detected in the neutralizing titers of sera to viruses collected at intervals after inoculation. The plaque-purified strain of btv appeared to be stable genetically in infected calves, and failure to demonstrate antigenic variation among isolates indicated that antigenic shift was not the mechanism that allowed viremia to persist in btv-infected calves.
Prevalence of feline leukemia virus infection among adult cats at an animal control center: Association of viremia with phenotype and season
Authors: McMichael John C. , Stiers Susan , Coffin Susan
Published: February 2025

The overall frequency of feline leukemia virus infection among 555 cats tested from the Hillsborough County Florida Animal Control facility, using a commercial enzyme-linked immunosorbent assay, was 9.4%. Among male cats, the frequency was 13.8%, which was statistically higher (P = 0.003) than that for females (5.9%). There was no statistical evidence to associate frequency of viral infection with hair length or coloration. There was an association with color distribution. The frequency of viral infection in cats with a solid color in their coat, excluding tabby, calico, and tortoise, was higher (12.2%) than the frequency in the remainder of the cats (5.5%; Ρ = 0.011). Finally, there was a difference in frequency related to season. For the 10 months of the study, cats collected in the 5 cooler months (January, February, March, April, and October) had a frequency of 14.6%; cats obtained in the 5 warmer months (May, June, July, August, and September) had a frequency of 7.2% (P = 0.038).
Use of tolazoline as an antagonist to xylazine-ketamine-induced immobilization in African elephants
Authors: Allen Jack L.
Published: February 2025

A group of 15 African elephants (Loxodonta africana) were immobilized with a combination of xylazine (0.2 mg/kg of body weight, im) and ketamine (1 to 1.5 mg/kg of body weight, im). Ten of the African elephants were allowed to remain recumbent for 30 minutes and the remaining 5 elephants, for 45 minutes before they were given tolazoline (0.5 mg/kg of body weight, iv).

For the group of 15, the mean induction time (the time required from injection of the xylazine-ketamine combination until onset of recumbency) was 14.2 ± 4.35 minutes (mean ± sd), and standing time (the time required from the tolazoline injection until the elephant stood without stimulation or assistance) was 2.8 ± 0.68 minutes. All of the elephants were physically stimulated (by pushing, slapping, shouting) before they were given tolazoline, and none could be aroused. After tolazoline was given and the elephant was aroused, relapses to recumbency did not occur. Recovery was characterized by mild somnolence in an otherwise alert and responsive animal.

Failure (no arousal) rates were 0% (95% confidence interval, 0 to 0.3085) for elephants given tolazoline after 30 minutes of recumbency and 100% for elephants that were not given tolazoline. There was no significant (P < 0.05) difference in standing time 30 or 45 minutes after tolazoline injection.
Dose-dependent pharmacokinetics of gentamicin in sheep
Authors: Brown Scott Anthony , Coppoc Gordon L. , Riviere J. Edmond , Anderson Virgil L.
Published: February 2025

Dose-related changes in the pharmacokinetics of gentamicin sulfate were investigated in 9 sheep given 3, 10, or 20 mg/kg of body weight iv in a crossover design with a 24-day washout period. The pharmacokinetics of the 3 mg/kg single dose were compared with that of the terminal phase pharmacokinetics of 3 mg of gentamicin/kg iv every 8 hours for 7 days in 8 additional sheep. Serum concentrations were monitored for 21 to 24 days after the dose. Polyexponential equations were fit to each data set. The number of exponential terms was determined by optimizing the fit for each data set. The pharmacokinetics of the 3 mg/kg single dose were mainly described by triexponential equations. The 10 mg/kg and the 20 mg/kg single doses and the 3 mg/kg multiple-dose data were described by a tetraexponential equation. The elimination rate constant was significantly smaller (P < 0.05) after the larger single doses, and the serum gentamicin clearance increased as the dose increased (P < 0.05). The crossover design sequence had a significant effect on serum gentamicin clearance and the area under the curve normalized to unit dose (P < 0.01). The final exponential phase was not detectable with the present assay sensitivity after the 3 mg/kg single dose. The triexponential equation underpredicted the terminal serum concentrations determined after the 3 mg/kg multiple dose, whereas the 4 phase equation overpredicted the same terminal serum concentrations, perhaps reflecting saturation of the tissue pools that were mirrored by the serum gentamicin concentrations after 24 hours. The present study emphasized the complexity of the terminal phase gentamicin pharmacokinetics and acknowledged the need for a long-term washout period when using the crossover design for gentamicin pharmacokinetic studies.
Cardiovascular changes in dogs given diazepam and diazepam-ketamine
Authors: Haskins Steve C. , Farver Tom B. , Patz John D.
Published: February 2025

The cardiopulmonary consequences of diazepam (0.5 mg/kg, iv) followed by ketamine (10 mg/kg, iv) were evaluated in 11 dogs. Diazepam did not exhibit a tranquilizing effect and was frequently associated with excessive excitement. It produced minimal cardiopulmonary effects, except for a significant increase in heart rate. Ketamine administration was associated with less cardiovascular stimulation when administered after diazepam than it did when administered alone; the respiratory depression was greater. Compared with ketamine alone, the diazepam-ketamine combination was associated with more vomition, less muscle hypertonus, less seizure activity, and less salivation.
Fate of [14C]xanthotoxin (8-methoxypsoralen) in a goat and in bovine ruminai fluid
Authors: Ivie G. Wayne , Beier Ross C. , Bull Don L. , Oertli Ernest H.
Published: February 2025

A lactating Nubian goat was treated with [14C]xanthotoxin, a photosensitizing psoralen that occurs naturally in some phototoxic range plants, as a single oral dose equivalent to 10.0 mg of xanthotoxin/kg of body weight. The radiochemical was rapidly absorbed, metabolized, and excreted. Although expired air was not monitored for the presence of volatile radiocarbon, the data indicated that > 50% of the administered [14C]xanthotoxin was metabolized by cleavage of the O-[14C]methyl moiety, with subsequent loss of the label as, presumably, [14C]C02. Studies with bovine ruminai fluid in vitro indicated that cleavage of the O-methyl moiety of xanthotoxin could occur rapidly in the rumen. In the goat, nonmetabolized xanthotoxin was not excreted in urine, and of several metabolites in urine extracts, 3 were identified as resulting from opening of the furan or lactone ring. Only about 2% of the dose was recovered in the feces, and this consisted mainly of unmetabolized xanthotoxin. Although appreciable amounts of radiocarbon were secreted into milk, this radiocarbon was not in the form of xanthotoxin or any identifiable metabolites. The radiocarbon in milk likely resulted from the biosynthetic incorporation of [14C]CO2 into normal milk components.
Electrocardiographic evaluation of the healthy raccoon (Procyon lotor)
Authors: Hamlin Robert L. , Hren J. , Sparrow P. V.
Published: February 2025

Leads I, aVF, V3, and V10 ecg were obtained from 12 healthy raccoons anesthetized with xylazine and ketamine. Intervals and amplitudes of component deflections were remarkably uniform among the individuals. Vector orientation of QRS mimicked that for the dog; but the relatively low voltages to QRS mimicked those of cats. The QT interval varied inversely with heart rate, whereas the PQ interval varied directly with body weight. Relationship between heart rate and body weight was not significant (P > 0.05).
Copper inhibition of the thiobarbituric acid reaction in Bedlington Terriers
Authors: Hultgren Bruce D. , Menken B. Zaspel , Csallany A. Saari
Published: February 2025

The effect of copper on thiobarbituric acid (tba) reaction values, an index of lipid peroxidation, was examined in Bedlington Terriers, healthy dogs, and rats. High hepatic concentrations of copper appeared to lower tba values in the inherited, chronic, progressive hepatic degeneration of Bedlington Terriers, a disease associated with copper toxicosis. The suspected tba inhibition was confirmed when Cu2+ was added to homogenates of healthy dog or rat liver or a malondialdehyde standard. The amount of copper added approximated that in diseased Bedlington Terriers. Because of the interference by copper, the tba test was judged to be an inappropriate test for the evaluation of lipid peroxidation in samples containing high copper concentrations such as those in diseased Bedlington Terriers.
Electroencephalogram and evoked potentials in naturally occurring scrapie in sheep
Authors: Strain George M. , Olcott Bruce M. , Braun William F.
Published: February 2025

Electroencephalogram (eeg), brain stem auditory-evoked potential, and flash visual-evoked potential recordings were taken from healthy sheep and from 3 sheep with scrapie, a cns slow virus infection. The eeg changes included semi-periodic, polyphasic, high-voltage sharp waves (bilaterally synchronous and symmetric in all channels), and a cyclic alternating pattern consisting of a high-voltage low-frequency phase, followed by a low-voltage high-frequency phase. The high-voltage phase occurred with increased arousal, and the low-voltage phase occurred with decreased arousal. Myoclonic jerks were coincident with eeg sharp waves in one sheep with scrapie. Several spontaneous focal seizures were observed. Wave-form amplitudes were greatly reduced in the brain stem auditory-evoked potential and flash visual-evoked potential; degree of reduction did not always correlate with disease severity. The eeg and evoked potential changes were seen in an exposed sheep that had not yet developed clinical signs of scrapie.
Effect of cortisol in vitro and in vivo on production of bovine interleukin 2
Authors: Blecha Frank , Baker Paul E.
Published: February 2025

The influence of cortisol in vitro and in vivo on lymphocyte proliferative responses and interleukin 2 (IL2) production was evaluated in Hereford feeder calves. Cortisol, added to bovine mononuclear cell cultures, reduced (P < 0.05) mitogen-stimulated lymphocyte proliferative responses and IL2 production. Lower IL2 activity from cortisol-treated cell cultures was not caused by a cortisol-mediated cytotoxicity or a residual cortisol effect on the IL2-indicator cell line.

Calves given ACTH (1.0 IU/kg of body weight, im) twice daily for 2 days had increased (P < 0.001) plasma cortisol concentrations when compared with those of saline-treated controls. Leukocytosis (P < 0.002), characterized mainly by a neutrophilia (P < 0.007), was evident in ACTH-treated calves. Lymphocyte proliferative responses to the phytomitogens, concanavalin A, phytohemagglutinin, and pokeweed mitogen were decreased (P < 0.05) in calves with increased plasma cortisol concentrations. Interleukin 2 production was lower (P < 0.05) in concanavalin A-stimulated lymphocyte cultures from ACTH-treated calves. Seemingly, lower lymphocyte proliferative responses in cortisol-treated mononuclear cell cultures and in ACTH-treated calves were caused partly by lower IL2 production.