bluuebunny/crossref_metadata_2025 huggingface dataset:
Resistance of Porcine Preimplantation Embryos to Pseudorabies Virus
Authors: Bolin S. R. , Runnels L. J. , Sawyer C. A. , Atcheson K. J. , Gustafson D. P.
Published: February 2025

Intact and zona pellucida-free 2- to 16-cell stage porcine embryos were exposed to a field strain of pseudorabies virus in vitro. Coculture of the exposed embryos with a virus-permissive porcine kidney cell line and direct fluorescent antibody procedures were used to test for interaction between virus and embryo. Pseudorabies virus was not detected either within the cells of the embryo or on the zona pellucida by these methods.
Effects of Bitterweed (Hymenoxys odorata) on Voluntary Feed Intake and Serum Constituents of Sheep
Authors: Calhoun M. C. , Ueckert D. N. , Livingston C. W. , Baldwin B. C.
Published: February 2025

Effects of daily dosing with bitterweed (Hymenoxys odorata) on voluntary feed consumption and concentrations of serum constituents were determined in 2 experiments, using 12 lambs each. Feed intake decreased linearly as the bitterweed dose increased. Serum total protein and albumin decreased and urea nitrogen, creatinine, and total bilirubin increased with the increasing bitterweed dose. Serum lactic dehydrogenase, aspartate transaminase, and creatine kinase activities increased at the highest bitterweed dose (0.264% of live body weight/day, air-dry basis). Depression in voluntary feed intake was more sensitive to the bitterweed dose than were serum constituents. This dose-related decrease in ad libitum feed intake provides a useful and less expensive short-term assay for assessing treatments for reducing bitterweed toxicosis, compared with the customary ld50 tests.
Effects of Segmental Subarachnoid Analgesia on Arterial Blood Pressure, Gas Tensions, and pH in Adult Conscious Cows
Authors: Skarda R. T. , Muir W. W.
Published: February 2025

Arterial blood pressure, blood gas tensions (Paco2, Pao2), and pH (pHa) were determined in 16 adult, nonpregnant Holstein cows (620 ± 54 kg) given subarachnoid injection of a 5% procaine hydrochloride solution at the T13-L1 intervertebral space. Analgesia, as determined by response to superficial and deep muscular pinpricks at the L1 dermatome, was delayed (onset) 7 to 15 minutes, and it lasted (duration) 28 to 83 minutes. Thoracolumbar analgesia extending between spinal cord segments T9 and L4 on 1 or both sides of the spine produced significant (P < 0.05) increases in heart rate and decreases in respiratory rate, but otherwise had no effect (P > 0.05) on systolic, diastolic, and mean arterial blood pressures, Paco2, Pao2, and pHa. Similarly, no significant changes (P < 0.05) of physiologic variables were observed in a control group of 5 cows given a subarachnoidal injection of 0.9% sodium chloride solution at 1 hour before procaine hydrochloride was injected. It was concluded that the unsedated, healthy cow tolerates segmental subarachnoid analgesia between spinal segments T9 and L4 well and that this analgesia is not adversely affected by hypoxemia, respiratory acidosis, or hypotension.
Blood Concentrations of Oxytocin Equivalents After Single Injections of Deamino-1-monocarba-[2-O-Methyltyrosine]-Oxytocin in Lactating Sows
Authors: Cort N. , Einarsson S. , Schams D. , Vilhardt H.
Published: February 2025

Four healthy lactating sows were given (iv or im) single 0.6-mg doses of the long-acting oxytocin analogue deamino-l-monocarba-[2-O-methyl-tyrosine]-oxytocin (d COMOT). Samples of blood were collected through 8 hours, and plasma concentrations of d(COMOT), expressed in oxytocin equivalents, were measured by radioimmunoassay. The disappearance rate of d(COMOT) from plasma was biphasic, with an initial rapid clearance (T½ = 7.5 to 10 minutes) followed by a more gradual decrease (T½ = 85 to 100 minutes). There were no apparent differences in the plasma kinetics of the analogue whether given iv or im. The dose of d(COMOT) used caused milk letdown in the sows for approximately 5 hours.
Intraocular Tension of the Horse: Effects of Succinylcholine and Halothane Anesthesia
Authors: Benson G. J. , Manning J. P. , Hartsfield S. M. , Thurmon J. C.
Published: February 2025

Succinylcholine chloride administered to horses anesthetized with halothane in oxygen and mechanically ventilated induced slight but insignificant (P 0.01) increases in intraocular pressure. Peak intraocular pressures were within reference limits reported for the horse.
Sterilization of the Male Dog and Cat by Laparoscopic Occlusion of the Ductus Deferens
Authors: Wildt David E. , Seager Stephen W. J. , Bridges Charles H.
Published: February 2025

A laparoscopic technique was developed to sterilize adult and prepubertal male dogs and adult male cats. The animals were anesthetized, and each ductus deferens was identified intra-abdominally, using a laparoscope. Adult and prepubertal (16 weeks of age) dogs were sterilized by occluding 1 to 2 cm of the ductus deferens bilaterally, using an ancillary bipolar forceps and electrocoagulation. Adult cats were treated similarly or the ductus deferens was severed, using an accessory scissors device.

Sperm counts in adult dogs decreased to zero within 48 hours of ductus deferens occlusion. Azoospermia also occurred in cats; however, live spermatozoa were detected in the ejaculates of some cats for as long as 120 hours after surgery. These observations indicated that, unlike in the dog, viable spermatozoa may ordinarily reside in the proximal abdominal portions of the reproductive tract of the cat. After sterilization, there was a nonsignificant (P > 0.05) tendency for testicular volume to decrease in dogs. Average and individual testicular volumes in cats were significantly increased (P < 0.05) after sterilization, which could have been related to increased epididymal fluid retention. Sterilization of prepubertal male dogs resulted in chronic azoospermia without influencing body weight or testis development.

Laparoscopic sterilization had no effect on libido or copulatory ability in adult dogs or cats. Prepubertal dogs with bilaterally occluded ductus deferens developed penile erections and produced azoospermic ejaculates at ages comparable with sham-sterilized control dogs. Histologic examination demonstrated that spermatogenesis was normally active in all dogs and cats. Spermatocelic lesions were observed on the ductus deferens or epididymis in 33% of the test animals. Granuloma formation was confirmed in the ductus deferens by biopsy in at least half of the animals in each group, but these findings had no apparent compromising effect on general animal health. Ductus deferens epididymal fluid of all sterilized animals contained large proportions of morphologically deformed spermatozoa, the latter primarily characterized as sperm heads with detached flagella or severe cellular torsions.

The laparoscopic sterilization technique resulted in rapid azoospermia in male dogs and cats without adversely affecting libido or testicular integrity. Such a procedure could have valuable application as a simple, practical means of sterilizing these species on a mass basis.
Hemagglutination-Inhibition Tests with Different Strains of Equine Infectious Anemia Virus
Authors: Sentsui Hiroshi , Kono Yuji
Published: February 2025

The serologic relationships between 6 strains of equine infectious anemia (eia) viruses were investigated by hemagglutination-inhibition (hi) tests. Cross hi tests, using sera from horses in the early stage of infection, revealed that all strains were inhibited only by homologous strain antisera and that hi antibody was always detectable before virus-neutralizing antibody. In the later stages of infection, both homologous and heterologous hi antibodies were detected in the sera of most of the horses, and the order of appearance of heterologous hi antibodies was random in 2 horses inoculated with the same virus strain. The viruses sequentially isolated from 1 horse had serologically the same hemagglutinating antigenicity to their parent virus. These results indicate that hemagglutinating antigens of eia virus were type specific, but different from the antigens detectable by neutralization. The possible role of eia virus hemagglutinin and hi antibody in causing periodic anemia is discussed.
Occurrence and Range of Dicumarol Concentrations in Sweet Clover
Authors: Benson M. E. , Casper H. H. , Johnson L. J.
Published: February 2025

The dicumarol concentration in 272 cured sweet clover samples from 4 counties in North Dakota was determined. Dicumarol concentrations ranged from 0 to 164.7 mg/kg of sweet clover, with 64.6% of the 272 samples containing < 10 mg/kg. Round bales were significantly (P < 0.05) higher in dicumarol concentration (mean of 22.9 ± 3.10 mg/kg) than were stacks or silage (means of 1.8 ± 6.3 mg/kg and 0.6 ± 2.1 mg/kg, respectively). The outer section of core samples taken from round bales contained significantly (P < 0.0021) higher concentrations of dicumarol than did the inner section of the core, with means of 30.8 mg/kg and 16.6 mg/kg, respectively. A significant (P < 0.0001) correlation existed between crude protein and dicumarol values (r = 0.44).
Adrenocortical Suppression in Cats Given Megestrol Acetate
Authors: Chastain C. B. , Graham C. L. , Nichols C. E.
Published: February 2025

Megestrol acetate was given orally to 8 cats at a dose of 2.5 mg every other day for 2 weeks and to 8 cats at a dose of 5.0 mg every day for 2 weeks. Four cats were designated nontreated controls. Pre-ACTH-stimulated plasma concentrations of cortisol (hydrocortisone) and ACTH-stimulated cortisol and tolerance to large-dose glucose infusion (iv) were determined on each of the 20 cats given megestrol acetate. Cats were restrained with acepromazine maleate and ketamine hydrochloride during blood sample collection and large-dose glucose infusion.

Adrenocortical function and tolerance to large-dose glucose infusion were reevaluated for 4 weeks—after 1st and 2nd weeks of megestrol acetate treatment of the treated groups, and after 1st and 2nd weeks when treatment was stopped (ie, experiment weeks 3 and 4). Each week a cat from the control group and 2 cats from the 2 treated groups were selected to determine the changes occurring during the experiment for that week; after collection of plasma samples, each week's 5 selected cats were euthanatized and necropsied.

Significant impairment of adrenocortical function and alteration of adrenocortical morphology occurred with both treated groups. The most severe adrenocortical alterations occurred in the cats 1 week after megestrol acetate was no longer given (ie, experiment week 3). Megestrol acetate-induced adrenocortical suppression contributed to the death of 1 cat. It was concluded that if stress occurs to cats on treatment or soon after treatment with megestrol acetate, glucocorticoids should be supplemented.

The effects of megestrol acetate on glucose tolerance were overshadowed by the unforeseen intolerance caused by chemical restraint with acepromazine maleate and ketamine hydrochloride.
Concentrations of Corticosteroids, Leukocytes, and Immunoglobulins in Blood and Milk After Administration of ACTH to Lactating Dairy Cattle: Effects on Phagocytosis of Staphylococcus aureus by Polymorphonuclear Leukocytes
Authors: Paape M. J. , Gwazdauskas F. C. , Guidry A. J. , Weinland B. T.
Published: February 2025

A study was conducted to determine relationships among plasma and milk corticosteroids, milk immunoglobulins, and phagocytosis of Staphylococcus aureus by polymorphonuclear leukocytes (pmn) isolated from milk of cows given injections of 0 (saline solution only), 100, and 200 IU of ACTH. Also determined were the effects of ACTH on mobilization of pmn into milk from the mammary gland irritated by infusion of 100 ml of saline solution containing 0.1% oyster glycogen. Cows (n = 10) were injected 6 times within a 48-hour period with 0, 100, or 200 IU of ACTH. Immediately before cows were given the 5th injection, 2 mammary quarters were infused with the saline-glycogen solution. Five hours after the 6th injection, milk from infused quarters was collected, and pmn were isolated, washed, and resuspended in autologous skimmed milk collected 5 hours after the 4th injection and before the udder was infused. Isolated pmn were incubated with S aureus and percentage of phagocytosis was determined. Concentrations of total corticosteroids in plasma and milk increased after cows were given injections of 100 and 200 IU of ACTH. The concentrations of IgA, IgGl, IgG2, IgM, and bovine serum albumin in milk after 4 injections of 0, 100, and 200 IU of ACTH were similar to preinjection (base line) concentrations. Injections of 100 and 200 IU of ACTH significantly increased the concentrations of total circulating leukocytes. Concentrations of leukocytes in milk tended to increase with increasing doses of ACTH, but the differences were not significant. Injection of 100 and 200 IU of ACTH reduced phagocytosis of S aureus by pmn. After 60 minutes of incubation, phagocytosis averaged 57% and 54%, respectively, for the ACTH treatments and 70% for controls (saline only). Results indicate that injections of ACTH that result in physiologic and pharmacologic plasma concentrations of corticosteroids inhibit phagocytosis. Impairment of phagocytosis appeared to be a direct effect of corticosteroid concentration on pmn and was not due to reduced concentrations of immunoglobulins. These data indicate that reduced phagocytosis by pmn could be important in increased susceptibility to disease during stress in lactating dairy cows.
Sequential Mitogen Stimulation of Peripheral Blood Lymphocytes from Chickens Inoculated with Infectious Bursal Disease Virus
Authors: Confer Anthony W. , Springer Wilfred T. , Shane Simon M. , Donovan Judith F.
Published: February 2025

Chickens were inoculated with the pathogenic Edgar strain of infectious bursal disease virus at 1 week, 2 weeks, or 1 day of age. In the 3 experiments, phytohemagglutinin stimulation of peripheral blood lymphocytes was significantly decreased on day 3 or 4 after inoculation. Subsequently, on days 7 through 21, stimulations were similar between lymphocytes from inoculated birds and those from control birds. Pokeweed mitogen stimulation was affected minimally in virus-inoculated chickens. In each experiment, on day 7, the spontaneous [3H]thymidine uptake was greater in nonstimulated lymphocyte cultures from inoculated chickens than in such cultures from control chickens.

In an additional experiment, chickens 1 week of age were exposed to a pathogenic vaccinal virus given in their water. The vaccinal virus exposure resulted in significant decrease of phytohemagglutinin stimulation of lymphocytes on days 3 and 7 of the experiment. A significant decrease in pokeweed mitogen stimulation was observed on day 10 after inoculation.
Gentamicin Tissue Concentration in Various Avian Species Following Recommended Dosage Therapy
Authors: Bush Mitchell , Locke Diana , Neal Lawrence A. , Carpenter James W.
Published: February 2025

Plasma and tissue drug concentrations were compared in eastern bobwhite quail (Colinus virginianus virginianus) and pigeons (Columba livia) given gentamicin by im administration at the dosage of 10 mg/kg, and in greater sandhill cranes (Grus canadensis tabida) and hybrid rosybill ducks (Netta sp) given the same antibiotic at a dosage of 5 mg/kg.

Quail and cranes had significantly higher liver concentrations of gentamicin at 6 hours after injection than did pigeons and ducks. Cranes had significantly higher plasma concentrations than did ducks at 6 hours after injection. Compared with plasma values, gentamicin concentrations were significantly higher in the liver of cranes at 12 hours after injection, and in the kidneys at 18 hours.
Prevention of Abortion and Neonatal Death Due to Toxoplasmosis by Vaccination of Goats with the Nonpathogenic Coccidium Hammondia hammondi
Authors: Dubey J. P.
Published: February 2025

Six does serologically negative to Toxoplasma gondii were vaccinated with 1 million oocysts of the nonpathogenic coccidium Hammondia hammondi 17 to 73 days before breeding. Two does were not inoculated with H hammondi. All does were mated with a T gondii-free buck. Between the 51st and 119th days of their pregnancies, 5 of the 6 Hammondia-vaccinated does and the 2 controls were each inoculated orally with 1,000 infective oocysts of the GT-1 strain of T gondii.

Four of the 5 Toxoplasma-inoculated vaccinated does gave birth to 8 apparently healthy kids at the expected gestation period. The 5th vaccinated doe gave birth to 3 kids that died during delivery or were born dead. Toxoplasma gondii was isolated in mice inoculated with tissues of all kids born to vaccinated does. The vaccinated doe which was not inoculated with T gondii gave birth to 2 healthy noninfected kids. Of the 2 control pregnant does (not vaccinated, but inoculated with T gondii), 1 aborted due to toxoplasmosis 17 days after inoculation. The other control doe had 2 dead fetuses and retained fetal membranes in uterus when necropsied at the expected parturition time. The results indicate that it might be possible to develop a vaccine against toxoplasmic abortions in animals.
Postnatal Morphogenesis of the Anconeal Process of the Ulna of Swine
Authors: Kincaid S. A. , Lidvall E. R.
Published: February 2025

The proximal ulnae of 79 swine ranging in age from 1 day to 2 years were radiographed and those of 46 of the swine were studied histologically. The anconeal process was a hyaline cartilaginous model at birth, but ossified by 6 months of age. Endochondral ossification began at the base of the anconeal process and progressed in a pyramidal manner toward its apex. Secondary center of ossification was not observed in the porcine anconeal processes examined. A lesion in the anconeal process of a 2-year-old animal was interpreted as a fracture of the anconeal process, and not a fracture of an anconeal physis. Implications of the development of the anconeal process as related to osteochondrosis in swine were discussed.
Clinical use of odds ratios in selecting antimicrobial therapy for bovine pasteurella pneumonia
Authors: Davidson J. N. , Babish J. G.
Published: February 2025

Resistance to 11 antimicrobials was determined for Pasteurella multocida (n = 229) and P haemolytiea (n = 245) from cases of bovine pneumonia. The degree of association of resistance for 2-way combinations of antimicrobials was calculated for each organism. Significantly high associations were reported. An association > 1 indicated an increased probability of resistance to the 2nd antimicrobial of a 2-way combination. Tables are presented which allow the determination of alternate antimicrobial therapy when the antimicrobial initially used fails to produce a clinical response.
Effect of postural changes on certain circulatory and respiratory values in the horse
Authors: Schatzmann U. , Koehli M. , Dudan F , Rohr W. , Jones R. S.
Published: February 2025

Certain circulatory and respiratory values were measured in horses in the standing, lateral, and supine positions. Twelve adult horses were kept in the standing position under the influence of glycerol guiacolate. Alterations in position to lateral and dorsal recumbencies were achieved without any further drug administration. The change from the standing to the lateral position decreased the arterial oxygen tension, but left the arterial carbon dioxide tension unchanged. There was no statistically significant effect of body position on respiratory flow rates or volumes. The shift from the lateral position to the supine position had no statistically significant effect on any of the measured values. It is assumed that the change from the standing to the lateral position results in an increase in ventilation of the uppermost parts of the lung. The perfusion inequalities are due mainly to the effect of gravity of the pulmonary circulation which may result in a decrease in arterial oxygen tension.
Antiparasitic effectiveness of ivermectin in the horse
Authors: Yazwinski T. A. , Hamm D. , Greenway T. , Tilley W.
Published: February 2025

By way of a controlled trial, the anthelmintic efficacies of the injectable and paste formulations of ivermectin were evaluated in the horse. Treatment was given at the rate of 200 μg/kg of body weight. Regardless of formulation, 100% removals were demonstrated for Strongylus vulgaris (intestinal), S edentatus, 2nd and 3rd instars of Gastrophilus nasalis and G intestinalis, “small strongyles”, Triodontophorus serratus and T tenuicollis. Adult Cylicocyclus insigne populations were eliminated at the rates of 99.9% and 96.3% by the injectable and paste formulations, respectively. Levels of 4th-stage Cylicocyclus spp larvae, as detected in the luminal contents of the colon, were reduced by 88.3% and 33.2% by the injectable and paste formulations, respectively. There were no adverse tissue or behavioral reactions induced by either preparation of ivermectin.
Immunoassay for the steroid-induced isoenzyme of alkaline phosphatase in the dog
Authors: Wellman Maxey L. , Hoffmann Walter E. , Dorner Joseph L. , Mock Richard E.
Published: February 2025

Antiserum directed against the steroid-induced alkaline phosphatase (alp) isoenzyme of the dog was produced in rabbits. This antiserum was used to develop a sensitive and quantitative assay for the detection of the steroid-induced alp isoenzyme in the serum of dogs. This antiserum was also used to enhance the electrophoretic separation of the steroid-induced and hepatic alp isoenzymes.
Multidirectional in vivo strain analysis of the equine radius and tibia during dynamic loading with and without a cast
Authors: Schneider R. K. , Milne D. W. , Gabel A. A. , Groom J. J. , Bramlage L. R.
Published: February 2025

Rosette strain gauges were applied to the equine radius and tibia. Three sites were examined on each bone on separate occasions (proximal metaphysis, middiaphysis, and distal metaphysis). At each site, 4 rosette gauges were applied around the bone (ie, cranial, caudal, medial, and lateral). Strain recordings were made while walking the horse with and without a full-limb plaster cast. The principal axis of tensile strain was on the craniolateral aspect of the radius. Distally, on the radius, the largest strains were torsional. The cast changed the principal axis of tensile strain on the radius from the craniolateral surface to the caudal surface. The principal tensile strain of the tibia was just to the lateral side of cranial in the proximal and diaphyseal regions. Distally, the principal axis of tensile strain was craniolateral; however, the largest strains measured here were torsional. The cast changed the principal axis of tensile strain on the distal metaphysis of the tibia, but it did not reduce the magnitude of the strains measured. Casts may not aid stabilization of radial or tibial fractures repaired with internal fixation and may in fact place additional stress on the fracture site.
Efficacy of a benzenedisulfonamide against experimental Fasciola hepatica infections in calves
Authors: Wyckoff J. H. , Bradley R. E.
Published: February 2025

The anthelmintic efficacy of a benzenedisulfonamide was evaluated by administering the drug parenterally at dosage levels of 2, 4, 8, and 16 mg/kg of body weight to crossbred Brahman calves with experimental Fasciola hepatica infections. In the 3-week period after treatment, fluke ova counts of treated calves were markedly reduced from counts obtained just before treatment. At necropsy, the mean fluke recovery for all 4 benzenedisulfonamide dosages were significantly (P less than 0.01) reduced. The efficacy of benzenedisulfonamide against F hepatica at dosage levels of 2, 4, 8, and 16 mg/kg was 97.5%, 99.5%, 100%, and 100%, respectively.
Plasma pyruvate kinase activity vs creatine kinase activity as an indicator of the porcine stress syndrome
Authors: Duthie Garry G. , Arthur John R. , Simpson S. Patricia , Nicol Fergus
Published: February 2025

Plasma pyruvate kinase (pk) and creatine kinase (ck) activities were increased significantly (P < 0.001 and P < 0.05, respectively) in homozygote halothane-reacting pigs (nn), compared with those activities in homozygote nonreacting pigs (NN). Pyruvate kinase activity was less variable within groups than was ck activity, allowing more effective discrimination between nn and NN genotypes. The pk and ck activities in plasma increase with age in halothane-reacting pigs and the nonreacting pigs. Enzyme activities in heterozygote (Nn) nonreacting pigs did not differ significantly (P > 0.05) from enzyme activities of homozygote (NN) nonreacting pigs. Although pk was better than ck in identifying stress-susceptible pigs, age-related effects and the failure to identify heterozygotes may restrict the use of plasma pk activity as a diagnostic test for the stress syndrome.
Influence of alterations in heart rate on echocardiographic measurements in the dog
Authors: Jacobs Gilbert , Mahjoob Kooros
Published: February 2025

M-mode echocardiograms were recorded from 10 conscious, clinically normal dogs at various heart rates during atrial pacing. Heart rate was recorded as cycle length (seconds), and measurements were made only during sustained 1:1 atrial-to-ventricular conduction. In all dogs studied, there was a significant (P < 0.01) positive correlation of left ventricular internal chamber dimension in diastole and systole to cycle length. Also, there was positive correlation between these left ventricular dimensions and the square root of cycle length, which predicted a plateau in dimensional changes as cycle length increased. Echocardiographic shortening fraction and left ventricular and septal wall thickness measurements did not change consistently during pacing. We concluded that left ventricular chamber dimensions in the dog may be significantly affected by alterations in heart rate.
Seasonal prevalence of gastrointestinal nematodes of beef calves grazed on irrigated pastures in the lower Sacramento Valley of California
Authors: Charles T. P. , Baker N. F.
Published: February 2025

Two worm-free calves were allowed to graze on irrigated pasture with a naturally infected herd for each of 34 one-month periods from November 1979 to August 1982. After each grazing period, the calves were transferred to a cement-floored pen for 3 weeks and then were euthanatized and necropsied.

Ostertagia ostertagi and Cooperia oncophora were the most prevalent species of nematodes recovered. Adults and larvae of Ostertagia spp and Cooperia spp were most numerous in winter and spring and least numerous during summer. The proportions of Ostertagia spp that were inhibited as fourth-stage larvae increased in late fall, peaked from March through April, and then decreased to low values during summer. The maximal inhibition in 1980, 1981, and 1982 was 72, 65, and 62%, respectively. The number of larval Cooperia spp was highest in winter months and, except for one grazing period when 55% of the Cooperia spp were larvae, the total numbers represented < 15% of the nematode population during all grazing periods. Other nematodes encountered were Trichostrongylus axei, Haemonchus spp, O lyrata, and O occidentalis in the abomasum; C surnabata, C punctata, Nematodirus helvetianus, T colubriformis, and Bunostomum phlebotomum in the small intestine; and Oesopha-gostomum venulosum and Trichuris ovis in the large intestine.
In vitro comparison of three fixation methods for humeral fracture repair in adult horses
Authors: Markel Mark D. , Nunamaker David M. , Wheat J. D. , Sams Andrew E.
Published: February 2025

The stiffness, load to failure, and bending moments of adult intact equine humeri and humeri repaired with 3 fixation techniques were determined in vitro. Bones were tested in axial compression (30 pairs), mediolateral 3-point bending (15 pairs), and caudocranial 3-point bending (15 pairs). An oblique osteotomy of 1 humerus of each pair was performed to simulate the long spiral oblique fractures that occur clinically in horses. Bones were repaired in 3 ways: group 1—nylon band cerclage fixation (20 bones); group 2—multiple intramedullary pinning (20 bones); and group 3—nylon band cerclage fixation and multiple intramedullary pinning (20 bones).

Intact bones were significantly (P < 0.05) stronger than repaired bones in each testing mode. Bones repaired with bands only were significantly less stiff in bending than were bones repaired with pins only or with pins and bands. In compression, only specimens repaired with pins and bands were significantly stiffer than were bones repaired with bands only. Bones repaired with bands only required significantly less load to failure in compression and in caudocranial bending than did bones repaired with pins only or with pins and bands.

Bones repaired with pins only deformed through the full displacement of the actuator (5 cm), and pins deformed plastically. Bones repaired with pins and bands were stiffer and had higher bending moments than did bones repaired with pins only, but the differences were not significant.
Cutaneous fungal flora in twenty horses free of skin or ocular disease
Authors: Ihrke Peter J. , Wong Anita , Stannard Anthony A. , Vivrette Sarah L.
Published: February 2025

The fungal flora of the hair and underlying skin from 2 sites was examined qualitatively in 20 horses free of skin or ocular disease. Fungi were isolated from both the hair and the underlying skin of all 20 horses. Twenty-two genera regarded commonly as saprophytes were identified and an additional 2 fungi resembled the perfect state of the cutaneous pathogenic genera Microsporum and Trichophyton. Cladosporium spp, Penicillium spp, and Rhizopus spp were the most frequently isolated saprophytes. In general, similar fungi were isolated from the hair and underlying skin, and differences were not noted in isolates from the saddle and rump regions.
Column chromatographic characterization of cytoplasmic proteins in Eimeria maxima oocysts from chickens
Authors: Ainsworth A. Jerald , Pote Linda , Haney Judith , Brown Jesse
Published: February 2025

Cytoplasmic proteins from unsporulated and sporulated Eimeria maxima oocysts were analyzed by gel-filtration column chromatography. Unsporulated oocysts were characterized as having 3 major cytoplasmic proteins and sporulated oocysts as having 5 major cytoplasmic proteins. Molecular weights ranged from 5 × 103 to 1.4 × 106. Larger molecular weight proteins were detected in sporulated and unsporulated oocysts, but were associated more with sporocysts of sporulated oocysts.
Effects of Moraxella bovis and culture filtrates on 51Cr-labeled bovine neutrophils
Authors: Kagonyera George M. , George Lisle , Miller Michael
Published: February 2025

The cytotoxicity of Moraxella bovis whole cells and culture filtrates was studied, using 51Cr-labeled bovine and human blood neutrophils. The cytotoxicity of living M bovis was directly related to the concentration of bacteria in the neutrophil cultures, and was maximal at an approximate neutrophil to bacteria ratio of 1:10. Cytotoxicity was maximal by 30 minutes after living bacteria were added to the suspension of the 51Cr-labeled neutrophils. Expression of the cytotoxicity was dependent on the presence of Ca2+ in the media, and was independent of the presence of Mg2+. Cytotoxic activity was eliminated by inactivating M bovis in buffers containing formalin or sodium azide. Hemolytic and nonhemolytic isolates of M bovis were examined for cytotoxic activity. All 7 of the hemolytic isolates were cytotoxic for bovine neutrophils, but all 4 of the nonhemolytic isolates were devoid of cytotoxic activity. None of the 11 isolates were cytotoxic for human neutrophils.

Sterile filtrates from 6-hour shaker cultures of a hemolytic M bovis isolate were cytotoxic for bovine neutrophils. Cytotoxicity of the filtrate was eliminated by heating, incubation with trypsin, or addition of EDTA to the media. Bacterial homogenates or sterile filtrates prepared from statically incubated cultures of M bovis were not toxic for bovine neutrophils.
Comparison of bovine and human platelet deformability, using micropipette elastimetry
Authors: Smith Clark M. , Burris Steven M. , Weiss Douglas J. , White James G.
Published: February 2025

We evaluated the deformability of bovine platelets and contrasted the effects of pharmacologic and thermal perturbations on cytoskeletal structure of human and bovine platelets. Platelets were aspirated into micropipettes (0.7 to 0.8 μm in diameter) by stepwise increments in tension. The resulting lengths of the cell extensions were recorded. The cell extensions aspirated from bovine platelets were shorter than the extensions drawn from human platelelets. Disassembly of the circumferential microtubule coil allowed human platelets to pass through the pipette, but the same treatments only slightly increased the deformability of bovine platelets. Alteration of the actin filament cytoskeleton caused increased mechanical fragility of human platelets. In contrast, even the combined use of microtubule and actin filament-disrupting agents only modestly increased the deformability of bovine platelets and did not cause premature fragmentation of the cells. Unusual cytoskeletal structure, absence of an open canalicular system, and disparity in granule size may all contribute to the variance in deformability between the platelets of the 2 species. Reduced cell deformability may impair bovine platelet surface interactions by diminishing the ease of cell spreading and formation of areas of contact between the platelet and other cell surfaces.
Comparative study of continuous lumbar segmental epidural and subarachnoid analgesia in Holstein cows
Authors: Skarda Roman T. , Muir William W. , Hubbell John A. E.
Published: February 2025

Eight adult Holstein cows were used to compare the effects of lumbar segmental epidural analgesia (SEA) and lumbar segmental subarachnoid analgesia (SSA). A modified 17-gauge Huber point (Tuohy) needle was used to place a catheter with stylet into either the epidural space at the thoracolumbar (T13-L1) intervertebral space or the subarachnoid space at the lumbosacral intervertebral junction. The catheters were advanced so that their tips lay at the anterior lumbar (L1-L2) epidural space or at the thoracolumbar (T13-L1) subarachnoid space. The position of the catheter was confirmed radiographically. A 5% solution of procaine HCl was used at mean doses of 300 mg (6 ml) to induce SEA and 84.4 ± 12.9 mg (1.7 ± 0.3 ml) to induce SSA. Onset of analgesia to superficial and deep muscular pinprick stimulation was significantly (P < 0.05) faster in cows with SSA than in those with SEA (10.4 ± 2.3 minutes vs 15.9 ± 3.8 minutes). Maximal thoracolumbar analgesia extended from spinal cord segments T12 to L4 on one or both sides of the vertebral column during SEA and from T10 to L3 on one or both sides during SSA. Duration of analgesia lasted significantly (P < 0.05) longer in cows with SEA than in those with SSA (76.2 ± 16.2 minutes vs 53.7 ± 14.3 minutes). The advantages and disadvantages of the SEA catheter technique are discussed.
Neutralizing antibodies for infectious hematopoietic necrosis virus in eggs of Steelhead trout (Salmo gairdneri)
Authors: Shors Scott T. , Winston Vern
Published: February 2025

Neutralizing antibodies specific for infectious hematopoietic necrosis virus (IHNV) were isolated from eggs of spawning Steelhead trout (Salmo gairdneri) , using sodium sulfate precipitation. The isolated material was used in place of the primary antibody (rabbit anti-IHNV) in a protein immunoblotting assay to detect IHNV proteins specifically. The egg component that bound specifically to IHNV proteins was determined to be trout antibody by using antiserum toward trout immune globulins as the second antibody conjugate in the protein immunoblotting assay. The antibody recovered from eggs neutralized IHNV infectivity in cell culture. An average of 87.5% decrease in infectivity was observed.
Actinobacillus (Haemophilus) pleuropneumoniae serotype-8 isolates and their antigenic relationships with other A pleuropneumoniae serotypes
Authors: Mittal K. R. , Higgins R. , Larivière S.
Published: February 2025

Antigenic relationship of Actinobacillus (Haemophilus) pleuropneumoniae serotype-8 isolates with other sero-types was studied, using tube agglutination, with and without 2-mercaptoethanol, indirect hemagglutination with and without 2-mercaptoethanol, ring precipitation, coagglutination, and immunodiffusion tests. Serotype-8 isolates possessed serotype-specific, group-specific common antigens cross-reactive with serotypes 3 and 6 and species-specific common antigens cross-reactive with other serotypes.

Absorption studies were done to study the antigenic relationship of serotype 8 with serotypes 3 and 6. Rabbit antisera against whole-cell (WC) suspensions of reference strains of serotypes 3, 6, and 8 were used for absorption studies with wc and boiled WC suspensions of homologous and heterologous serotypes. Unabsorbed and absorbed sera were tested for antibodies against wc and boiled wc antigen preparations of serotype 8, using various serotests. Absorption studies revealed that serotype-8 strains possessed 2 main types of epitopes, one of which was serotype-specific and did not have cross-reactivity with other serotypes. The second type of epitopes was group specific and was cross-reactive with serotypes 3 and 6.
Effect of subchondral drilling on repair of partial-thickness cartilage defects of third carpal bones in horses
Authors: Shamis Lawrence D. , Bramlage Lawrence R. , Gabel A. A. , Weisbrode Steven
Published: February 2025

Arthrotomies of middle carpal joints were done on 13 horses, and a 1-cm partial thickness, round defect was made on the radial facet of both third carpal bones. In one joint, 1-mm diameter 1-cm deep holes were drilled within the defect, and one joint was used as a control. Horses were assigned to 2 groups-group 1 (n = 6 horses), 5 drill holes; group 2 (n = 7 horses), 11 drill holes.

At 1 and 3 weeks after surgery, differences between joints in synovial fluid total protein values, WBC counts, or results of mucin precipitate tests were not significant (P = 0.005). Physically and radiographically, horses were the same during the 12 initial weeks they were housed in stalls and the 9 weeks they were kept in paddocks.

Twenty-one weeks after surgery, horses were euthanatized. Joints with drill holes had a significantly greater area(P < 0.05) of healthy fibrocartilage new tissue: group 1-33 to 68% new tissue, compared with 0 to 23% new tissue in controls; and group 2-22 to 64% new tissue, compared with 0 to 37% new tissue in controls. Differences between healing of defects with drill holes in groups 1 and 2 were not significant.

Thickness of new tissue over drill holes was 33 to 61% of thickness of cartilage adjacent to the defect, and thickness of tissue between drill holes was 11 to 43% (group 1) and 8 to 79% (group 2) of the thickness of cartilage adjacent to the defect. In all defects with drill holes, new tissue in the form of fibrocartilage was detected deep in drill holes, whereas fibrous tissue was observed superficially and adjacent to drill holes.
Effect of zearalenone on the growth of mouse embryos from blastocysts to the egg cylinder stage in vitro
Authors: Long Gerald G. , Turek John J.
Published: February 2025

Embryos were harvested at the blastocyst stage from nontreated outbred mice and were grown in vitro for 4 days. Embryos cultured in control medium hatched and grew to the egg cylinder stage. Purified zearalenone (ZEN) added to the culture medium at concentrations of 8.5 to 68 μg/ml decreased the number of embryos growing, with a 50% decrease in the number growing in 32 μg of ZEN/ml of medium. Embryos growing in ZEN had decreased numbers of cells derived from the inner cell mass, normal growth of the trophoblast, less cellular differentiation than was seen in control embryos, and increased numbers of phagosomes. Undifferentiated cells of the inner cell mass of control and treated embryos were of the same size, as determined by morphometric analysis. Addition of 25 μg of estradiol/ml of culture medium caused no decrease in number of embryos growing or in embryonic size. Saturation of culture medium with ZEN (68 μg/ml) did not inhibit the growth of a tissue culture line of goat synovial cells. Seemingly, ZEN at concentrations near saturation inhibited the growth of mouse embryos in vitro. This effect was not duplicated with similar concentrations of estradiol and was not manifested in culture-adapted cells.
Chemical and protective properties of Brucella lipopolysaccharide obtained by butanol extraction
Authors: Phillips Marshall , Pugh George W. , Deyoe Billy L.
Published: February 2025

Lipopolysaccharide (lps) fractions were obtained from smooth cultures of Brucella abortus strains 2308 and S-19 by butanol extraction procedures. The lps from the initial butanol extraction contained 10 to 15% protein and was reduced to < 1% protein by treatment with proteinase K. The lps fractions were identified and characterized on the basis of the chemical analysis, sodium dodecyl sulfate gel electrophoresis, cesium chloride gradients, electron microscopy, and gel immunodiffusion. Results indicated that the butanol procedure is a reliable method in the extraction of lps from Brucella abortus cells.

Proteinase K-treated lps containing < 1% protein from strain 2308 was used to vaccinate BALB/cByJ mice. Immune and protective criteria for vaccinated and nonvaccinated mice were increased immunoglobulin (IgG and IgM) titers in sera of prechallenge-exposed mice, reduced colony-forming units/spleen, and splenomegaly in post-challenge-exposed mice. Results indicated that proteinase K-treated lps was immunogenic as well as protective for mice.
Sites of virus replication in the genital organs of boars inoculated in the cavum vaginale with pseudorabies virus
Authors: Miry C. , Pensaert M. B.
Published: February 2025

To determine the sites of replication and the evolution of pseudorabies virus infection in boar genital organs, 5 Belgian Landrace boars were inoculated with pseudorabies virus unilaterally in the cavum vaginale of the testis. Virus replication took place only in cells of the tunica vaginalis of both cava vaginalia. Infection of the serosa led to exudative periorchitis and increased scrotal fluid, resulting in a severely swollen scrotal region. These experimental findings were similar to findings in boars with naturally acquired pseudorabies virus infection. Scrotal fluid contained large amounts of virus, making it a useful specimen for diagnosis of the disease in affected boars.
Arterial supply to the spinal cord of dogs and cats
Authors: Caulkins S. E. , Purinton P. T. , Oliver J. E.
Published: February 2025

The blood supply patterns to the spinal cord were examined and compared in 15 dogs and 10 cats by use of dissection and radiographic visualization. The lowest percentages of radicular contributions and the smallest diameter vessels were found in the thoracic part of the spinal cord. The central arteries were fewest in number in the thoracic region and unilaterally or bilaterally supplied the gray matter. The percentages of bilaterally distributed central arteries increased from the cervical to the lumbar regions. The anastomotic plexus on the surface of the spinal cord was found to be most dense in the cervical and lumbar regions.
Antibodies to Pasteurella haemolytica somatic antigens in two models of the bovine respiratory disease complex
Authors: McVey D. Scott , Loan Raymond W. , Purdy Charles W. , Richards Alan E.
Published: February 2025

Serum samples obtained from feeder calves before and after entry into the market system (days 0 to 7) were assayed for antibodies to Pasteurella haemolytica biotype A, serotype 1 capsular polysaccharide (cps) and lipopolysaccharide/outer membrane protein (lpsp) by isotype in a kinetic-augmented, antigen-capture elisa. These test results, plus indirect hemagglutination (iha) antibody titers, and hemolysin-in-gel test (higt) findings were compared with clinical performance data during the initial 4 weeks in the feedlot (receiving period).

High concentrations of higt antibody, at the point of initial assembly of feeder calves at weaning and during the subsequent 7-day marketing period, were associated with freedom from bovine respiratory disease (brd) during the receiving period. High or rapidly increasing concentrations of anti-cps IgG1 during the marketing period were also associated with less brd. However, high concentrations of anti-lpsp IgGl during the marketing period were associated with increased brd during the receiving period. There was no correlation between the concentrations of antibody determined by iha tests early in the marketing period and freedom from brd during the receiving period. High concentrations of antibody determined by this test at entry into the feedlot (day 7) were associated with a high incidence of brd.

Calves vaccinated with a P haemolytica bacterin had significantly (P < 0.05) higher higt values and concentrations of anti-lpsp IgGl and iha antibody than did non-vaccinated calves on entry into the feedlot (day 7). Vaccination appeared to have little effect on the amount of anti-CPS IgG1. Of all the tests used to quantitate antibody, the higt correlated best with clinical performance. High concentrations of higt antibody during the marketing period predicted freedom from brd during the receiving period.

When calves were vaccinated with tissue culture-derived and conventional P haemolytica bacterins in oil adjuvant at 28-day intervals and tested for antibody responses by isotype on days 0, 28, and 35, there were clear and highly significant increases in anti-lpsp IgG1 activity. Also, the amount of anti-lpsp IgM and the higt and iha antibody titers increased significantly. In all tests, the antibody response was highest to the tissue culture-derived bacterin. High concentrations of higt antibody, as found in vaccinated animals, were correlated with resistance to transthoracic inoculation of virulent P haemolytica.
Macrophage function in mammary glands of Brucella abortus-infected cows and cows that resisted infection after inoculation of Brucella abortus
Authors: Harmon Barry G. , Adams L. Garry , Templeton Joe W. , Smith Roger
Published: February 2025

Nonvaccinated pregnant cows were segregated retrospectively into 2 groups following inoculation with Brucella abortus strain 2308. One group resisted infection (resistant cows) and the other group developed active infections (susceptible cows) and subsequently aborted. Mammary gland macrophages collected from the 2 groups of cows were compared, using in vitro functional assays. In a chemiluminescence assay, mammary gland macrophages from resistant cows produced significantly (P = 0.014) higher oxidative burst activity than did macrophages from susceptible cows. Macrophages from resistant cows had significantly (P = 0.038) greater bacteriostatic activity against B abortus than did macrophages from susceptible cows. Differences in lysosomal enzymatic activity or Fc receptor expression were not observed for macrophages from the 2 groups of cows. Differences in macrophage function may be one factor responsible for natural resistance to Brucella infection in cattle.