bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetics of Gentamicin After Intravenous, Intramuscular, and Intratracheal Administration in Sheep
Authors: Wilson R. C. , Whelan S. C. , Coulter D. B. , Mahaffey E. A. , Mahaffey M. B. , Huber T. L. 
Published: February 2025

SUMMARY
Kinetics of gentamicin (2.2 mg/kg of body weight) were investigated in 7 sheep after iv bolus administration. The mean serum concentration profile could be described by a 2-compartment open model with a distribution rate constant (α) of 3.112 ± 1.681 hour−1 [half-life, t1/2(α) = 17.22 ± 8.63 minutes] and an overall elimination rate constant (β) of 0.485 ± 0.028 hour−1 [t1/2(β) ± 85.87 ± 5.03 minutes]. The apparent volume of distribution was somewhat restricted [Vd(area) = 0.194 ± 0.059 L/kg], and the total body clearance was 1.559 ± 0.400 ml/kg/min.
Equal dosages of gentamicin (2.2 mg/kg) were also given im and intratracheally (it). After im injection, gentamicin reached peak serum concentration at postinjection minutes (pim) 45, surpassing concentrations after the iv injection for the remainder of the experiment. The it injection produced detectable serum concentrations at pim 5, with a peak concentration at pim 60. The serum drug concentrations after it injections remained well below concentrations after iv and im injections.
Radiographic analysis of an it injection of a gentamicintantalum suspension revealed good distribution throughout the trachea and proximal bronchi, with physical clearance of the tantalum occurring after ≥ 10 minutes. Aspiration biopsy of a tracheal wash 6 hours after it gentamicin injection revealed no cytologic response to gentamicin in 6 of 7 sheep, with the single response that of a purulent exudate.
Induction of Protective Immunity to Strongyloides ransomi in Pigs
Authors: Murrell K. D. 
Published: February 2025

SUMMARY
Pigs inoculated once or twice with infective Strongyloides ransomi larvae (L3) developed a strong protective immunity to challenge exposure. Intestinal expulsion of adult worms resulting from initial infection occurred 3 to 4 weeks after inoculation; worm loss reached 68% by 52 days after inoculation. Necropsy of pigs at various times after challenge exposure with infective L3 revealed that the majority of migrating L3 were eliminated before reaching the intestine; based on parasitic recoveries from the lung, the reduction was manifested as early as 48 hours after challenge exposure. Evidence for enhanced migration of L3 to the fat tissue in immune pigs could not be detected. Data indicate that infective L3 possess functional antigens capable of inducing protective immunity. Treatment of infected pigs with ivermectin was effective in removing arrested L3 in the subventral fat; 85% of these larvae were eliminated in 3 weeks. The role of milk-transmitted arrested L3 in the immunology of porcine strongyloidiasis is discussed.
Somatic and Capsular Factors of Coliforms Which Affect Resistance to Bovine Serum Bactericidal Activity
Authors: Ward G. E. , Sebunya T. K. 
Published: February 2025

SUMMARY
Killing of bacteria which cause acute coliform mastitis was studied in vitro, using serum without exogenous complement. Using 10% freshly collected whole serum, it was found that some strains were killed rapidly and could be classified as serum sensitive and others were killed less rapidly and could be classified as intermediate serum sensitive. With other strains, fewer were killed, and then the survivors multiplied; these could be classified as serum resistant. A 50-percentage kill of serum-resistant strains could not be achieved with serum (even in concentrations of > 90% serum), whereas 15 strains showed 50-percentage kill at appropriate serum concentrations.
Resistance of Escherichia coli to serum bactericidal activity was greatest in strains with large amounts of heat-labile capsule present. The capsule could be demonstrated, using a test for somatic inagglutinability and a hemagglutination-inhibition test.
Resistance of Klebsiella pneumoniae to serum bactericidal activity was not related to somatic inagglutinability. In K pneumoniae, resistance to serum bactericidal activity was related to presence of somatic antigens on the resistant strain.
Clinicopathologic Evaluation of N-Acetylcysteine Therapy in Acetaminophen Toxicosis in the Cat
Authors: Gaunt Stephen D. , Baker Dale C. , Green Robert A. 
Published: February 2025

SUMMARY
Acute acetaminophen (acm) toxicosis was induced in cats and the therapeutic benefit of N-acetylcysteine (nac) was demonstrated. Groups of 4 adult cats were treated as follows: group A—given acm only; group B—given acm and then treated with nac, starting at 0 hour; group C—given acm and then treated with nac, starting at 4 hours; and group D—treated with nac only. Acetaminophen was given as a single oral dose of 143 mg/kg, and the nac regimen consisted of 4 oral doses (200 mg/kg, given 3 times, and 100 mg/kg, given once) with 2 horn's between doses. Group A cats developed increased methemoglobin concentration, depletion of erythrocyte reduced glutathione, and increased Heinz body formation. Group B cats also developed methemoglobinemia, depletion of glutathione, and increased Heinz body formation, but the magnitude of these changes was significantly less (P < 0.05) than in group A. In group C, the findings were similar to group A through 4 hours, but thereafter, significant hematologic improvement was noted. The level of Heinz bodies in group C was intermediate between the values for groups A and B. In group D cats, no significant changes from base line were noted. Evidence of hepatotoxicity was not seen in any group as based on daily determinations of plasma alanine aminotransferase and sorbitol dehydrogenase activities.
Assay of Penetrability of Bovine Papillary Duct Implanted with Escherichia coli Endotoxin
Authors: Schultze W.D. 
Published: February 2025

SUMMARY
A method has been developed to assay the relative penetrability to a solute of the papillary duct (streak canal) of the bovine teat. Escherichia coli lipopolysaccharide endotoxin (1.0 μg in 2.5 μl of sterile distilled water) was implanted at a depth of 3 mm from the distal end (papillary orifice) of the papillary duct. If penetration by the irritant occurred after any one of 5 successive daily implantations, the inflammatory response of the mammary gland was detected by a precipitous increase (by at least 15 mm) in the Wisconsin mastitis test score of quarter foremilk samples, and the test was scored as positive.
Results of the penetrability assay were highly repeatable among quarters of certain cows. Cows differed as to the pattern of penetrability of their papillary ducts, with about half of 70 tested cows scoring 4 positive or 4 negative.
Decreased Motility of Bull Spermatozoa Caused by Mycoplasma bovigenitalium
Authors: Panangala V. S. , Winter A. J. , Wijesinha A. , Foote R. H. 
Published: February 2025

SUMMARY
Mycoplasma bovigenitalium mixed with bull semen in egg yolk-citrate buffer and held at 5C caused a highly significant time- and dose-dependent depression in sperm motility. Mycoplasma adhered to a majority of spermatozoa, principally to the acrosome, but also to the midpiece and tail. This may reflect the basis for a naturally observed condition in young bulls in which genital mycoplasmosis is associated with low sperm motility.
Anthelmintic Efficacy of Ivermectin Against Immature Gastrointestinal Pulmonary Nematodes of Calves
Authors: Benz G. W. , Ernst J. V. 
Published: February 2025

SUMMARY
Anthelmintic efficacy of ivermectin (≥ 80% 22,23-dihydroavermectin B1a and ≤ 20% 22,23-dihydroavennectin B2b) was evaluated in a controlled experiment against immature nematodes. Twenty calves raised to about 8 weeks of age under nematode-free conditions were allocated into 4 groups. Infective larvae of Haemonchus contortus, Ostertagia ostertagi, Trichostrongylus axei, T colubriformis, Cooperia oncophora, C punctata, Oesophagostomum radiation, and Dictyocaulus viviparus were given orally to each calf on a staggered schedule 6 to 14 days before treatments. The drug was given subcutaneously when the nematodes were in the early 4th stage of development, and the calves were killed 23 or 24 days later. Group 1 nonmedicated control calves had a geometric mean of 25,102 nematodes; groups 2, 3, and 4 calves given ivermectin at dose rates of 50,100, or 200 μg/kg had reductions of 88.2%, 98.0%, and 99.8%, respectively.
Purification and Biological Characterization of Endotoxin Fractions from Pasteurella haemolytica
Authors: Rimsay R. L. , Coyle-Dennis J. E. , Lauerman L. H. , Squire P. G. 
Published: February 2025

SUMMARY
A sequential extraction procedure was used to provide 3 endotoxin fractions from Pasteurella haemolytica with distinct biological and solubility properties. After acetone dessication, extraction with phenol, chloroform, and petroleum ether (2:5:8) provided a fraction designated rough lipopolysaccharide (lps). Subsequent extraction of the cells with 45% phenol at 68 C yielded a fraction designated smooth lps, which was further divided into smooth precipitate and smooth supernatant, based on sedimentation at 105,000 × g for 4 hours. Yields of the 3 fractions were 1.5%, 3%, and 5.5% of the dry weight of the cells. The polysaccharide moieties of the rough lps and smooth precipitate fractions were obtained by partial acid hydrolysis followed by chloroform extraction.
Biological activities of all 5 fractions were compared with activities of standard lps fractions from Serratia marcescens and Salmonella typhimurium. Results of chicken embryo lethality, the local Shwartzman's phenomenon, nonspecific resistance enhancement to challenge exposure by S typhimurium pyrogenicity, and the Limulus amebocyte lysate assay were reported.
Use of Solid Medium for Isolation of Leptospires of the Hebdomadis Serogroup from Bovine Milk and Urine
Authors: Thiermann A. B. 
Published: February 2025

SUMMARY
Leptospira interrogans serovars hardjo and szwajizak were isolated from the milk of experimentally infected cows only when using bovine albumin polysorbate-80 solid medium. Semisolid media, with and without the addition of 5-fluorouracil, and hamster inoculations were also used in the isolation attempts.
These cultural isolation methods were also compared using cows' urine. Semisolid medium with 5-fluorouracil proved to be the most successful. However, the other methods were satisfactory, with solid medium having the lowest percentage of cultural isolations.
Routine Isolation and Cultivation of Bovine Rotaviruses in Cell Culture
Authors: Bachmann P. A. , Hess R. G. 
Published: February 2025

SUMMARY
Using the bovine embryonic kidney cell line, Aubek, bovine rotaviruses were routinely isolated from fecal samples of calves with diarrhea. Of 125 fecal samples positive for rotavirus by immune electron microscopy and the enzyme-linked immunosorbent assay, 61 isolates were recovered and cultivated continuously.
Effects of Aflatoxins in Young Ponies
Authors: Aller Walter W. , Edds George T. , Asquith R. L. 
Published: February 2025

SUMMARY
Sixteen clinically normal, healthy ponies were randomly assigned to 4 groups and given aflatoxin B1 in doses of 0.045, 0.030, 0.015, and 0 (control) mg/kg of body weight per day for 21 days (or total doses of 0.945, 0.630, 0.315, and 0 mg/kg). The animals were allowed to recover for 3 months and then were reassigned to 4 treatment groups such that each group during the 2nd trial included a pony from each of the groups of the 1st trial. The animals in the new groups were intubated and were given aflatoxin in doses of 0.4, 0.2, 0.1, and 0 (control) mg/kg/day for 5 days (or total doses of 2.0, 1.0, 0.5, and 0 mg/kg).
Venous blood samples were drawn every other day to monitor for toxicosis; examinations were made for rbc and wbc counts, hemoglobin concentration, pcv, serum urea nitrogen, prothrombin time, and serum concentrations of aspartate aminotransferase, iditol dehydrogenase, alkaline phosphatase, albumin, γ-glutamyl transferase, and arginase.
There were no significant differences between treatment groups and controls (given no aflatoxin) in the toxicologic values examined for during the 1st trial. During the 2nd experiment, 2 of the ponies in the large-dose treatment group (2.0 mg/kg) demonstrated increased serum enzyme activities. These animals had been in the large-dose (0.945 mg/kg) and mediandose (0.63 mg/kg) groups during the 1st trial. Arginase, iditol dehydrogenase, and γ-glutamyl transpeptidase activities became increased on the 4th day of treatment and continued to increase until the 6th day of the experiment (1 day after treatment was terminated). These enzymes approached control group values at 10 days after cessation of treatment. These increases were indicative of hepatocellular toxicity.
It was concluded that the possibility of equine aflatoxicosis exists although ponies given high quality rations appear to be less susceptible than some other species. Prior exposure to aflatoxins may predispose to clinical toxicity on subsequent exposure, despite lack of expression of clinical signs.
Influences of Sequences of Environmental Factors on the Response of Chickens to Fasting and to Staphylococcus aureus Infection
Authors: Gross W. B. , Siegel P. B. 
Published: February 2025

SUMMARY
Weight gain of chickens following fasting was influenced by interactions between habituation to persons (socialization), stress (drinking water withheld) early in the life of the bird, and sex. Fasting affected socialized birds less than unsocialized birds. Body weight changes following Staphylococcus aureus infection were influenced by interactions between sex, stress early in life, socialization, and fasting. These 4 factors may also influence the occurrence of disease outbreaks in poultry farms.
Extraction, Separation, and Partial Characterization of Brucella abortus Antigens
Authors: Stone S. S. , Patterson J. M. , Deyoe B. L. 
Published: February 2025

SUMMARY
Brucella abortus isolates strain 19 (a vaccinal strain) and 458 (a virulent field isolate) were analyzed for antigenic differences. Whole cell preparations were extracted with detergents, salt solutions, and phenol-acetic acid-water (paw). Antigens were separated by starch block electrophoresis and sucrose density gradient centrifugation, serotested, and chemically analyzed. Six distinct precipitin lines were observed for the paw extract against hyperimmune bovine antisera. With sucrose density centrifugation or starch block electrophoresis, antigens were separated into (i) complement-fixing (cf) antigens and (ii) antigens that did not fix complement but formed precipitin bands. Reciprocal cf tests with purified cf antigen could not differentiate between the antigens from either isolate of Brucella.
Feline Population Dynamics: A Study of the Manhattan, Kansas, Feline Population
Authors: Nassar R. , Mosier J. E. 
Published: February 2025

SUMMARY
Analysis of the age-specific birth and survival rates and the age distribution in the pet population of cats in Manhattan, Kansas, revealed that the rate of population change (λ) was about 1.18. This means that under present birth and death rates, the cat population can increase by about 18% per year. In reality, the increase may not be as high since pet ownership may not increase by as much.
The frequency of spayed females of reproductive age in the Manhattan population was about 59%. This may not be sufficient to curb population growth. With the present age-specific survival rates, about 88% of the females should be spayed if the population is to remain stable.
The ratio of people to cats in Manhattan was estimated to be 5.2:1. The average number of cats per household was 0.508. The percentage of households with cats was 28 with an average of 1.74 cats per household. In comparison, the average number of dogs per household was 0.43 and the percentage of households with dogs was 43 with an average of 1.36 dogs per household.
The methods used in this study are useful for collecting and analyzing data to be used by governmental bodies and veterinarians concerned with proposals to regulate pet population growth and reproduction.
Influence of Increased Temperature on Anaplasma marginale Theiler in the Gut of Dermacentor andersoni Stiles
Authors: Kocan Katherine M. , Barron Selwyn J. , Holbert Donald , Ewing S. A. , Hair Jakie A. 
Published: February 2025

SUMMARY
Three splenectomized dairy calves were inoculated with a Virginia isolate of Anaplasma marginale Theiler and served as an infective source for laboratory-reared Dermacentor andersoni Stiles nymphs. One month after molting, groups of adult ticks were incubated at 37 C for 0, 1.5, 2.5, and 7 days. Gut homogenates were made from ticks representing each incubation period. Twenty-four susceptible, splenectomized dairy calves were each inoculated iv with a gut homogenate extracted from 50 adult ticks and monitored for patent A marginale infection. The prepatent periods were determined and used as a measure of infectivity. Gut homogenates made from ticks that had been incubated for 2.5 days produced infections with the shortest prepatent periods, an average of 28.5 days among 3 trials.
Changes in Gut-Associated Lymphoid Tissues of the Small Intestine of Eight-Week-Old Pigs Infected with Transmissible Gastroenteritis Virus
Authors: Chu Redman M. , Glock Robert D. , Ross Richard F. 
Published: February 2025

SUMMARY
The responses of the interepithelial lymphocytes (iel) and aggregated lymph nodules (aln; Peyer's patches) of the small intestines of 8-week-old pigs to transmissible gastroenteritis virus (tgev) infection were characterized at 12, 18, and 24 hours after pigs were inoculated.
There was no significant difference in numbers of iel between control and tgev-infected pigs at 12 and 18 hours. However, in pigs examined at 24 hours, there was a significant decrease in the number of iel in the duodenum and cranial portion of the jejunum and an increase of iel numbers in the nuclear level of the intestinal epithelium. Number and distribution were unchanged in the middle portion of the jejunum and the ileum.
Microscopic changes in tgev-infected pigs included microulceration of the dome epithelium (de) over the aln, especially in the cranial portion of the intestine, and villous atrophy in the entire length of the small intestine. Generally, tgev was found by means of peroxidase-antiperoxidase staining in areas where microscopic lesions occurred.
Electron microscopy revealed that M cells and ordinary microvillus-covered epithelial cells in the de embraced one or more lymphocytes, and formed a specialized cell complex or de complex. Most of the lymphocytes in the de complex possessed many organelles indicative of an active cell state. The tgev was found between microvilli, in the cytoplasmic vesicles of M cells and microvillus-covered epithelial cells in the de, and in the cytoplasm of macrophages and lymphocytes and some degenerated cells of unidentified origin in the domes of the aln. The virus was also commonly found in cytoplasmic vesicles of macrophages and degenerated cells in the intestinal lumen near the base of the dome of the aln.
Lymphoscintigraphy in canine mammary neoplasia
Authors: Norris Alan M. , Harauz George , Ege Güneş N. , Broxup Brian , Valli V. E. O. , Leger Luc 
Published: February 2025

SUMMARY
Radionuclide lymphoscintigraphy, using an interstitial injection of 99mTcSb2S3 colloid, provided scintigraphic images of diagnostic quality of lymph nodes draining the mammary glands in 4 clinically normal dogs and in 13 dogs with mammary neoplasia. This simple, noninvasive technique demonstrated anatomic variants of the canine lymphatic system. Lymphoscintigraphy correctly identified 100% of all lymph nodes with metastases and 82% of lymph nodes free of metastases, as determined by histologic findings.
Effects of alpha chymotrypsin on the canine eye
Authors: Barrie Kathleen P. , Gelatt Kirk N. , Gum Glenwood G. , Samuelson Don A. 
Published: February 2025

SUMMARY
Injection of 150, 500, or 750 U of α chymotrypsin into the posterior chamber of clinically normal Beagles resulted in changes in intraocular pressure and iridocyclitis. In the 6 eyes treated with 500 or 750 U, lens subluxation occurred in 4 eyes, retinal detachment in 1 eye, retinal degeneration in 1 eye, and optic nerve degeneration in 6 eyes. Scanning electron microscopic changes included dose-related zonu-lolysis and zonulary remnants within the aqueous humor outflow pathways. Ultrastructural changes by transmission microscopy of the optic nerve degeneration revealed loss of axoplasm and organelles and disruption of the myelin sheaths. Retinal and optic nerve changes may represent the direct toxic effects of α chymotrypsin and/or the indirect effects of increased intraocular pressure.
Experimental infection of lambs with bovine respiratory syncytial virus and Pasteurella haemolytica: Pathologic studies
Authors: Al-Darraji A. M. , Cutlip R. C. , Lehmkuhl H. D. , Graham D. L. 
Published: February 2025

SUMMARY
Nineteen 4-week-old, colostrum-deprived lambs were transtracheally inoculated with respiratory syncytial virus (rsv), Pasteurella haemolytica biotype A serotype 1, or rsv and P haemolytica. Pneumonic lesions were more frequent, more extensive, and more severe in lambs inoculated with rsv and P haemolytica than in lambs inoculated with either agent alone. Lesions were seen in 2 of 4 lambs inoculated with P haemolytica alone, in 3 of 4 lambs inoculated with rsv alone, and in 11 of 11 lambs inoculated with rsv and P haemolytica. Grossly, lambs given P haemolytica alone had fibrinous pleuritis and pneumonic lesions with hemorrhagic and necrotic centers which involved approximately 14% of the lung surface. Lambs inoculated with rsv alone had multifocal areas of consolidation and hemorrhage that involved 5% of the lung surface. Lambs in 2 groups inoculated with rsv and P haemolytica had lesions characteristic of both agents over 15% to 21% of the lung surface. Histologically, P haemolytica alone caused acute fibrinous pneumonia with necrosis of the lung parenchyma and fibrinous pleuritis; rsv alone caused interstitial pneumonitis, bronchiolitis, and hemorrhage. In combination, the agents caused interstitial pneumonitis and severe exudative pneumonia with focal necrosis and hemorrhage.
Lesions seen in lambs given rsv and P haemolytica or in lambs given P haemolytica alone were grossly and histologically similar to those seen in naturally occurring cases of acute pneumonic pasteurellosis. Seemingly, the virus caused a lesion that compromised the lungs and thus permitted P haemolytica to become established and to produce a more severe pneumonic lesion than it could produce alone.
Abnormal spermatozoa, testicular degeneration, and varicocele in a ram
Authors: Ott R. S. , Heath E. H. , Bane A. 
Published: February 2025

SUMMARY
A 4-year-old Corriedale ram, with a history of infertility, had 50% abnormal acrosomes in the ejaculate resembling knobbed spermatozoa. Electron microscopic profiles of the apical segment of the affected acrosomes revealed a membrane-enclosed inclusion or cyst filled with particulate matter. The abnormal acrosomes were combined with a high prevalence of other degenerative changes such as head abnormalities, proximal droplets, and loose heads. Spermatozoa were examined from 9 ejaculates collected over an 8-month period. Abnormal acrosomes decreased to 5% after 4 months, but increased to 83% a month later. Examination of the testes after castration revealed bilateral varicocele and degeneration of seminiferous epithelium.