bluuebunny/crossref_metadata_2025 huggingface dataset:
Acid-Base Balance and Selected Hematologic, Electrolyte, and Blood Chemical Variables in Calves: Milk-Fed vs Conventionally Fed
Authors: Reece William O.
Published: February 2025

Several hematologic, acid-base, and electrolyte variables were characterized for newborn milk-fed calves and conventionally fed calves at weekly intervals for 15 weeks. Definition was given to the iron deficiency, microcytic, hypochromic anemia which developed in milk-fed calves. Acid-base variables in milk-fed calves differed from variables in conventionally fed calves only in having a greater value for base excess. Acid-base variables responded with decreasing magnitude by weeks for both feeding treatments, and responses associated with ambient temperature were suggested. Responses of the other variables and their comparisons between the feeding treatments also were analyzed.
Allergenic Activity and Biochemical Analysis of Three Soluble Antigen Preparations from Brucella abortus Strain 45/20
Authors: Woodard Lynn F. , Toone Nancy
Published: February 2025

Three Brucella abortus strain 45/20 antigen preparations were compared with regard to their chemical composition and allergenic potential. A popular method of extracting soluble antigens from whole cells with hypertonic saline solution and ethanol precipitation was compared with the method of trichloroacetic acid (tca) or ammonium sulfate (as) precipitation of antigens released into solution by ultrasonic cell disruption. Biochemical analysis of the preparations revealed that tca and as precipitates had considerably more protein and DNA and less carbohydrates and RNA than did the saline-ethanol extracts.

Strain 19-vaccinated cattle were simultaneously skin tested with the three antigen preparations which had been standardized to an equal protein content. Significant (P < 0.01) delayed hypersensitivity reactions were observed in response to all three antigen preparations. However, tca-prepared allergens were more active in eliciting delayed hypersensitivity (P < 0.05) than were the two other allergens. Increased agglutinating antibodies were not observed in response to the skin-test reagents.
Porcine Rotaviral Infection of Cell Culture: Effects of Certain Enzymes
Authors: Theil K. W. , Bohl E. H.
Published: February 2025

Porcine rotaviral infectivity for continuous porcine kidney (PK-15) cells was enhanced by incorporation of pancreatic endopeptidases into the cell culture maintenance medium. Marked enhancement of infectivity was induced by trypsin, whereas elastase and α-chymotrypsin enhanced infectivity to a lesser extent. Bacterial protease also induced some enhancement of porcine rotaviral infectivity. A synergistic enhancement of porcine rotaviral infectivity was noticed with trypsin and α-chymotrypsin combined. Porcine rotaviral infectivity was not affected by incorporation of α-amylase, alkaline phosphatase, β-galactosidase, carboxypeptidase-A, deoxyribonuclease, enterokinase, lipase, or ribonuclease into the maintenance medium.
Interaction Between Pasteurella haemolytica and Bovine Alveolar Macrophages: Cytotoxic Effect on Macrophages and Impaired Phagocytosis
Authors: Markham R. J. F. , Wilkie B. N.
Published: February 2025

Cultured bovine alveolar macrophages phagocytosed formalized 125I-labeled Pasteurella haemolytica organisms poorly when compared with uptake of an identical number of radiolabeled Yersinia enterocolitica organisms. The presence of immune serum enhanced uptake of P haemolytica, yet at high bacteria-to-macrophage ratios, a significant positive correlation existed between uptake and loss of cells from coverslips. This phenomenon was not observed with Y enterocolitica. While culture supernatant from P haemolytica either impaired phagocytosis or were cytotoxic to cultured macrophages, supernatant from Y enterocolitica did not show this effect. The observation of an apparent deterimental effect on bovine alveolar macrophages after uptake of P haemolytica may be used to explain events occurring in pneumonic pasteurellosis in cattle and may help in the development of immunization techniques.
Electrophysiologic Studies of Cutaneous Nerves of the Thoracic Limb of the Dog
Authors: Kitchell R. L. , Whalen L. R. , Bailey C. S. , Lohse C. L.
Published: February 2025

The cutaneous innervation of the thoracic limb was investigated in 36 barbiturate-anesthetized dogs, using electrophysiologic techniques. The cutaneous area (ca) innervated by each cutaneous nerve was delineated in at least five dogs by stroking the hair in the area with a small watercolor brush while recording from the nerve. Mapping of adjacent ca revealed areas of considerable overlapping. The part of the ca of a given nerve supplied by only that nerve is referred to as its autonomous zone. Of all nerves arising from the brachial plexus, only the suprascapular, subscapular, lateral thoracic, thoracodorsal, and cranial and caudal pectoral nerves lacked cutaneous afferents. The dorsal cutaneous branch of C6 had a ca, but no grossly demonstrable dorsal cutaneous branches for C7, C8, or T1 were found. The cervical nerves had ventral cutaneous branches, but no lateral cutaneous branches. Thoracic nerves T2-T4 had dorsal, ventral, and lateral cutaneous branches. The cutaneous branches of the brachiocephalic, axillary, musculocutaneous, radial, median, and ulnar nerves all had ca which were overlapped by adjacent ca, thus their autonomous zones were much smaller than the cutaneous areas usually depicted for these nerves in anatomy and neurology textbooks.
Demonstration of an R Plasmid in a Strain of Pasteurella haemolytica Isolated from Feedlot Cattle
Authors: Zimmerman Mary L. , Hirsh Dwight C.
Published: February 2025

A strain of Pasteurella haemolytica isolated from the lungs of feedlot cattle with pneumonia was shown to be resistant to ampicillin, tetracycline, and streptomycin.

Two small, nontransmissible plasmids were shown to be responsible, for tetracycline resistance, a 5.7 × 106 dalton plasmid, and for streptomycin resistance, a 5.5 × 106 dalton plasmid. Ampicillin resistance passed by transformation to Escherichia coli could not be shown conclusively to be on a plasmid. Ampicillin resistance was shown to be mediated by means of a β-lactamase with high activity against cephaloridine.
Virus Isolation and Immunofluorescence in Different Organs of Pigs Infected with Hemagglutinating Encephalomyelitis Virus
Authors: Andries K. , Pensaert Μ. B.
Published: February 2025

Hemagglutinating encephalomyelitis virus (hev; also designated vomiting and wasting disease virus) was inoculated oronasally in 26 colostrum-deprived pigs. Anorexia and vomition were seen after an incubation period of 4 to 6 days. In pigs killed during the incubation period or within 2 days after the onset of the clinical signs, hev could be isolated regularly from the tonsils and the respiratory tract, irregularly from the digestive tract, rarely from the blood, and never from lymph nodes and spleen. The brainstem almost always contained virus after clinical signs appeared, but was only once positive during the incubation period. Olfactory bulb, cerebrum, cerebellum, and vagal nerve were also frequently virus positive in pigs which were ill when killed.

The results of the examination by immunofluorescent antibody technique indicated that hev multiplies in the epithelium lining the respiratory tract and the tonsillar crypts, in neuroepithelium of the nasal mucosa, and in neurons of the digestive tract. The neuronotropism of hev was also shown by the presence of fluorescence in the perikaryon of neurons in the brainstem and in the trigeminal ganglion without the involvement of other cell types. The presence of viral antigens in the perikaryon of trigeminal sensory ganglion cells in pigs killed during the incubation period was considered as positive evidence for viral spread via nerves.
Infectious Bovine Keratoconjunctivitis: Effects of Vaccination on Moraxella bovis Carrier State in Cattle
Authors: Pugh G. W. , McDonald T. J. , Kopecky K. E.
Published: February 2025

A study was conducted to determine whether vaccination of cattle while they were undergoing an acute episode of infectious bovine kerato-conjunctivitis (ibk), would cause vaccinated cattle to abort Moraxella bovis infection sooner than nonvaccinated cattle. Fourteen calves were allotted into two groups of seven calves each, and the eyes of each calf were exposed to a virulent culture of Μ bovis. Twenty days after calves were infected and showing signs of ibk, seven calves were vaccinated with Μ bovis pilus vaccine made from the exposure strain. Ocular and nasal discharges were collected and examined for Μ bovis for 64 days.

Most calves developed signs of ibk after exposure and all but one calf (nonvaccinated) developed ocular infection with Μ bovis. The mean number of days (33 and 33.3, respectively) of ocular infection was not significantly (P = 0.05) different in the vaccinated calves than in the nonvaccinated calves. The eyes of the calf that did not become infected with Μ bovis were infected with nearly a pure culture of Escherichia coli.This calf failed to develop ocular infection, but had Μ bovis in its nasal discharge throughout the study (64 days). Moraxella bovis was isolated from the nasal discharge of other calves only when there were concurrent ocular infections.
Ultrastructure of Babesia equi in Ponies Treated with Imidocarb
Authors: Simpson Charles F. , Neal F. C.
Published: February 2025

Four splenectomized ponies were infected with Babesia equi. Two ponies were not treated, and two were treated with 5 mg of imidocarb/kg of body weight when 20% of their erythrocytes were parasitized. The nucleus of the parasite in erythrocytes from blood smears of nontreated ponies was roundish, deep red-staining, and usually composed two-thirds of the organism. The parasite in erythrocytes from blood smears of treated ponies was swollen and vacuolated except for an area just beneath the plasma membrane where the compressed nucleus was marginated, elongated, and clumpy.

Parasites in erythrocytes from nontreated and treated ponies were examined by electron microscopy. Babesia equi in erythrocytes of nontreated ponies contained food vacuoles, a prominent nucleus, smooth and rough endoplasmic reticulums, and ribosomes. There were four stages of degeneration of B equi in erythrocytes of ponies treated with imidocarb. The first stage was dilatation of the nuclear cisterna and clumping of chromatin. The second stage included dissolution of the nuclear envelope and passage of nuclear matrix into the cytoplasm. The third stage consisted of vacuolation of the cytoplasm and compression of the chromatin to the periphery of the cell. In the fourth stage of degeneration, the organism consisted essentially of a vacuole, and chromatin was condensed into an irregular mass of clumped material.
Isolation of Staphylococcus hyicus subsp hyicus from a Pig with Septic Polyarthritis
Authors: Phillips Walter E. , King Robert E. , Kloos Wesley E.
Published: February 2025

Staphylococcus hyicus subsp hyicus (coagulase-positive) was isolated in pure culture from the left coxafemoral and right shoulder joints of a 4-week-old pig with septic polyarthritis. Present taxonomic criteria and DNA-DNA hybridization studies with reference strains were utilized to identify the isolate. There were no clinical signs or generalized skin lesions of porcine exudative epidermitis noticed in this pig.
Canine Distemper Virus: Review of Structural and Functional Modulations in Lymphoid Tissues
Authors: Krakowka Steven , Higgins R. J. , Koestner Adalbert
Published: February 2025

A review is made of the morphologic and functional aspects of canine distemper-virus (cdv) infection on lymphoid tissues. Fatal infection is associated with virus-related systemic depletion of T and B lymphocyte-dependent areas in lymphoid tissues. Massive lymphoid necrosis, a feature of infection in conventional animals, does not occur with cdv infection in gnotobiotes. Additional lesions seen are focal and then diffuse reticulum cell hyperplasia, occasionally virus-associated syncytial giant cells, and intracytoplasmic viral inclusion bodies. In subacutely affected or convalescent dogs, repopulation of lymphoid tissues with associated germinal center formation commences 16 to 20 days after infection. Germinal center formation in the medullary portion of the thymus may be present as a residual lesion in these animals.

Infection results in a leukocyte-associated viremia and viral strain-dependent lymphopenia of both B and T cells which may persist long into convalescence. Accompanying this alteration is loss of in vitro lymphocyte responses to phytomitogens. In vitro and in vivo cellular responses to test antigens are transiently suppressed in actively infected and in vaccinated challenge exposed animals. Outcome of infection is correlated with prompt development of cdv-specific humoral and cellular immunity. Dogs surviving cdv infection are less able to make antibodies to an immunogen than are noninfected controls. The results of these studies indicate that cdv has profound immediate and long-term effects on normal lymphoid tissue structure and function in dogs.
Further Observations on Chloramphenicol Toxicosis in Cats
Authors: Watson A. D. J.
Published: February 2025

After a base-line period (14 days), five cats were orally given 50 mg of chloramphenicol every 12 hours for 21 days. Clinical signs of toxicosis were cns depression, reduced intake of food and water, and weight loss. Changes in peripheral blood included lower platelet counts after treatment for 1 week and fewer neutrophils after treatment for 3 weeks; one cat developed lymphocytopenia after 1 week and neutropenia after 2 weeks. Changes in bone marrow at the end of treatment comprised vacuolation of early myeloid cells and lymphocytes, and reduced myeloid maturation ratio, and some cats also had reduced marrow cellularity, or increased myeloid:erythroid ratio, or both of these.
Application of a Leukocyte Migration-Inhibition Agarose Test to Swine Dysentery
Authors: Jenkins E. M.
Published: February 2025

Cell-mediated immunity (cmi) was demonstrated in swine naturally affected with swine dysentery (sd) by a leukocyte migration-inhibition agarose test (lmat). Migration of leukocytes from sd-affected pigs was inhibited in the presence of soluble antigen of Treponema hyodysenteriae, whereas migration of leukocytes from noninfected swine was not inhibited by exposure to the same antigen. Cell-mediated immunity was detected initially after the appearance of clinical signs of the disease, and a peak migration index (mi) of 0.11 (P < 0.01) was detected at 2 weeks thereafter. The mi gradually decreased over the remaining 3 weeks of the experiment. Humoral antibody correlated well with cmi, since both showed maximum production within the same time interval. Leukocytes of swine naturally affected with sd 4 months previously had a significant mi response of 0.73 (P < 0.05), whereas uninfected swine of comparable age and weight showed a mi of 0.94 that was not significant (P > 0.05). The results indicated that the lmat may be useful for the diagnosis of sd.
Experimentally Induced Toxicoinfectious Botulism in Horses and Foals
Authors: Swerczek T. W.
Published: February 2025

Four experiments were performed to elucidate the pathogenesis of toxicoinfectious botulism in horses and foals. Groups of horses and foals were inoculated with one of the following: (1) crude toxin of Clostridium botulinum, type B, given iv, (2) C botulinum spores, given im, (3) C botulinum spores, given im, in necrotic lesions, and (4) C botulinum spores, given orally with and without dexamethasone.

Toxin of C botulinum in minute amounts is toxic to horses. Clostridium botulinum spores produced toxicosis only when necrotic lesions were present. When C botulinum spores were given orally, they were innocuous. Toxicosis occurred when dexamethasone and C botulinum spores were given orally to a foal with necrotic lesions. Corticosteroids appear to predispose foals to the disease. In the animals where C botulinum organisms infected necrotic lesions, the clinical signs and the lesions seen on necropsy were identical with those seen in spontaneously occurring toxicoinfectious botulism.
Effect of Dehydrocholic, Chenodeoxycholic, and Taurocholic Acids on the Excretion of Bilirubin
Authors: Engelking L. R. , Gronwall R. , Anwer Μ. S.
Published: February 2025

The effects of iv bile acid infusion (at approx 20% of normal excretion rate) on the biliary excretion of 3-α-hydroxy bile acids and bilirubin were investigated in ponies prepared surgically with chronic external biliary fistulas. Endogenous bile acid excretion (approx 45 µmol/min) decreased to the hepatic synthesis rate (approx 1.5 µmol/min) during the initial 4 to 5 hours of bile drainage. In type 1 studies, both chenodeoxycholic and taurocholic acid infusion (8 to 9 µmol/min) increased bilirubin excretion by 58% to 82% following 5 hours of biliary diversion. During type 2 studies, 3-hour iv infusions (10.5 µmol/min) of dehydrocholic acid, 4 hours following biliary diversion, increased bile flow by 45% to 62% and excretion of 3-α-hydroxy bile acid by 34% to 36% above preinfusion (hepatic synthesis) levels. Bilirubin excretion was not significantly changed during those increases in bile flow and bile acid excretion. Immediately after dehydrocholic acid infusion, taurocholic acid infusion (8.1 µmol/min) greatly increased bilirubin excretion for 1 hour (a reversal of hepatic storage identical to that found during type 1 studies), prolonged excretion (mg/2 hours) being two to three times that caused by dehydrocholic acid infusion. Bilirubin excretion appeared to correlate with the micelle-forming capacity of endogenous bile acids as opposed to the nonmicelle-forming characteristic of synthetic dehydrocholic acid.
National and International Viral Reagents Programs
Authors: Byrne Robert J.
Published: February 2025

Reagents for research on virus diseases of persons and animals have been produced through the effort of government, international agencies, and the private sector. These reagents are essential in the development and the evaluation of new technology, which in turn finds application in the detection and the prevention of disease. Ideally, viral reagents consisting of purified seed virus or viral antigen(s) and corresponding antisera should be independently certified for purity, specificity, and potency.
Mouse Pathogenicity of Toxoplasma gondii Isolated from a Goat
Authors: Dubey J. P.
Published: February 2025

Characteristics of Toxoplasma gondii (strain GT-1) isolated from skeletal muscle of a goat are described. One oocyst, bradyzoite, or tachyzoite of GT-1 strain was lethal to mice. Toxoplasma tachyzoites were found in the peritoneal exudates and in the lungs 9 to 34 days after infection in mice inoculated intraperitoneally with tissues infected with strain GT-1.
Bluetongue Virus in Bovine Semen: Viral Isolation
Authors: Breckon R. D. , Luedke A. J. , Walton T. E.
Published: February 2025

Vero cell cultures and embryonating chicken eggs were used for direct isolation of bluetongue virus from cattle blood and from semen samples. Cell culture and embryonating chicken eggs each were more effective than was the blood autograft inoculation of susceptible sheep with selected blood and semen samples. Evaluation of the cell culture technique indicated that the quality of the distilled water was the primary factor responsible for the increased sensitivity of the Vero cell cultures for the present bluetongue viral isolations. Test results showed that urine was a poor specimen for viral isolation when assayed in chicken eggs. A comparison of tests for precipitating and complement-fixing antibodies to bluetongue virus indicated that the precipitin test was the more accurate of the two tests.
Effects of Intramuscular Injections of Selenium and Vitamin E on Peripheral Blood and Bone Marrow of Selenium-Vitamin E Deficient Pigs
Authors: Niyo Y. , Glock R. D. , Ledet A. E. , Ramsey F. K. , Ewan R. C.
Published: February 2025

The influence of im injections of vitamin E and selenium on the hematopoietic system of selenium-vitamin E (Se-E) deficient pigs was studied in neonatal, suckling, and weaned pigs. The study was divided into two factorial experiments. Experiment 1 used 1-day-old pigs from sows that were fed a Se-E depletion ration during gestation and lactation. Experiment 2 used 21-day-old pigs from sows fed a cornsoybean meal ration during gestation and lactation. Treatments in both experiments were similar and consisted of weekly im injections of isotonic saline solution, vitamin E, selenium (as selenous acid), or selenium and vitamin E. The dosages were 20 IU of vitamin E/kg of body weight and 0.05 mg of selenium/kg. Treatments were started in pigs at 7 days of age for experiment 1 and at 21 days of age for experiment 2. All pigs were weaned at 21 days of age and were fed a Se-E deficient ration for 35 days. Values evaluated included blood values and morphologic changes in circulating erythrocytes and bone marrow cells. Sections of liver, heart, and skeletal (semitendinosus, semimembranosus, psoas) muscles were evaluated microscopically for lesions of Se-E deficiency.

Lesions of Se-E deficiency occurred only in skeletal muscles, liver, and heart muscle of pigs that were deficient in selenium and vitamin E. Anemia did not develop in any of the pigs and morphologic abnormalities were not detected in circulating erythrocytes and leukocytes. Changes relative to the deficiency syndrome were not detected in pcv, hemoglobin concentrations, total erythrocyte and leukocyte numbers, erythrocyte indices, activity values of erythrocyte Δ-aminolevulinic acid dehydratase, viscosity of whole blood, total plasma protein content, or fibrinogen concentration.

Binucleated erythrocyte precursor cells were found in bone marrow smears of neonatal, suckling, and weaned pigs among all treatment groups. The presence of these cells was considered a normal finding. However, bone marrow abnormalities, which included erythrocytic hyperplasia and erythrocyte precursor cells with three or more nuclei per cell, were mainly seen in pigs deficient in Se-E. This indicated a defect in erythrocyte maturation. The Se-E deficiency did not have an effect on cells of the myeloid series.
The Antagonistic Effect of l-Cysteine in Experimental Hymenoxon Intoxication in Sheep
Authors: Rowe L. D. , Kim H. L. , Camp B. J.
Published: February 2025

l-Cysteine was given iv at dosages of 34.5, 48.8, 69.0, 97.6, or 138.0 mg/kg of body weight to groups of sheep previously treated (10.6 minutes) intraperitoneally with an LD92 of hymenoxon (12.8 mg/kg). l-Cysteine at dosages of 69.0, 97.6, and 138.0 mg/kg significantly increased survival rate 8.4-, 10-, and 12.5-fold, respectively, over that of hymenoxon-treated sheep not given l-cysteine. l-Cysteine at dosages of 34.5 and 48.8 mg/kg failed to significantly reduce mortality. Surviving hymenoxon-treated sheep given 97.6 or 138.0 mg of l-cysteine/kg showed mild or no clinical signs of toxicosis. There was no dosage of l-cysteine that significantly changed the survival time for fatally intoxicated sheep.
Metal-binding Proteins in Bovine and Porcine Hepatic and Renal Tissues: Isolation and Characterization
Authors: Sharma Raghubir P. , Verma Mahendra P.
Published: February 2025

Cadmium-binding proteins of single band electrophoretic purity were obtained from the hepatic and renal tissues of cows and pigs fed 2 and 10 mg of cadmium/kg of feed. Zinc, cadmium, and copper constituted a total of 4 to 5 g-atom/mole of protein. Zinc and cadmium were the major metal ions of the hepatic and renal proteins, respectively. Amino acid analysis of the proteins revealed the presence of 26.1% to 28.4% cysteine and 4.3% to 5.7% histidine residues. Small amounts of hexose also were in the proteins. Molecular weights (mol wt) of the bovine and porcine hepatic proteins were 15,200 and 14,400, respectively, whereas the mol wt of their renal proteins were 7,900. Hepatic proteins seem to be in the form of two monomers chemically bound together. Large metal and cysteine concentrations and low mol wt indicated that the proteins were metallothioneins.
Effects of Maternal Protein-Energy Malnutrition on Lymphoblastogenic Responses of Bovine Neonates Subjected to Cold Stress
Authors: Woodard L. F. , Eckblad W. P. , Olson D. P. , Bull R. C. , Everson D. O.
Published: February 2025

Effects of maternal protein or calorie deprivation (or both) on mitogen-induced blastogenesis of lymphocytes from 60 bovine neonates were studied. Energy deficiency in the ration of dams during the last 150 days of gestation resulted in lymphocytes of the newborn calves having significantly suppressed (P < 0.05) mitogenic responses to concanavalin A and to pokeweed mitogen. Conversely, maternal protein deficiency had the tendency to increase the lymphoblastogenic responses of the progeny if the dam's energy levels were adequate. A combination of protein and energy deficiencies in the dams resulted in mean lymphocyte mitogenic responses of their calves that were inclined to be lower than were the responses found in calves from dams with energy deficiency alone.

After birth, the calves were placed in environmental chambers at 1 C or 21 C for 3 days. With regard to nutritional group, lymphocytes taken at the end of this period did not markedly vary in mitogenic response. However, there was a marked trend for the cold-stressed calves to have higher lymphocyte-stimulation responses to the mitogens tested, as compared with those in calves maintained in thermoneutral chambers. Also, there was a tendency for an age-related increase in mitogenic responsiveness, because most calves at 3 days of age had higher lymphocyte responses than when they were born. Nutritional and cold stress appeared to primarily influence the mitogenic responses of T lymphocytes.
In Vitro Fermentation of Feces from Normal and Chronically Diarrheal Horses
Authors: Minder H. P. , Merritt A. M. , Chalupa William
Published: February 2025

Feces from 13 healthy horses and 8 horses with chronic diarrhea were subjected to an in vitro fermentation procedure that had been developed for rumen fluid. Fermentations were conducted over 6 hours in a closed system, with and without an essential amino acid (eaa) mixture being added to the basic starch-buffer medium. The addition of eaa caused no significant difference in results of fermentation of feces from healthy horses. For diarrheic animals, there was a significant (P < 0.01) increase in gas and total volatile fatty acids production whether eaa were present or not, and α-amino nitrogen was utilized in significantly (P < 0.01) greater amounts only if eaa was present. Fermentations were repeated on feces from five of the eight diarrheal horses after they had been treated with oral iodochlorhydroxyquin for 1 week, and had shown desirable clinical response. A significant difference was not shown between pre- and posttreatment fermentations, except for decreased butyrate production.

The results are consistent with the hypothesis that chronic equine diarrhea is primarily a colonic disease and indicates that colonic maldigestion may, in part, be responsible for excess fecal water.
Horizontal Transmission of a Pancreas-Passaged Avian Encephalomyelitis Virus in Chicks
Authors: Miyamae T.
Published: February 2025

Pancreas-passaged avian encephalomyelitis (ae) virus was transmitted horizontally in a group of 40 (1-day-old) chicks within 3 weeks after they were intermingled with two orally infected 1-day-old chicks. Viral antigen was detected in the pancreas of these contact-exposed chicks. After 5 weeks, contact-exposed chicks developed high titers against ae virus, but the chicks did not develop clinical signs of ae. The passaged virus could not be recovered from feces of six immunized chicks.
Method for Intermittent Collection of Large Volumes of Lymph by Means of an Exteriorized Visceral Lymphatic Trunk Shunt
Authors: Brown Bobby G. , Klesius Phillip H.
Published: February 2025

A surgical technique involving a cannulation of the visceral lymphatic trunk of the calf was developed to improve the intermittent collection of large volumes of lymph. Catheters were inserted in the visceral lymphatic duct and ligated to form an external loop. Large numbers of pure lymphocytes (2 to 5 × 109) were collected from the lymphatic duct in less than 45 minutes. Drainage from the cannula was maintained on the average for 5 to 7 weeks to periods of up to 14 weeks. Visceral trunk cannulation in calves offers several advantages over the previously described thoracic duct-venous shunt techniques for collection of lymph and entry into the lymphatic circulation.
Influence of Albendazole on Reproductive Function of Bulls
Authors: Berndtson W. E. , Chenoweth P. J. , Olar T. T. , Pickett B. W. , Seidel G. E.
Published: February 2025

Twenty-six Hereford or Angus bulls of breeding age were used to determine whether the anthelmintic albendazole influenced weights of reproductive organs, spermatozoal production, spermatozoal output, quality of freshly ejaculated or frozen semen, serum testosterone values, or libido. Values for most of these measurements in 12 bulls treated with a single oral dose (22.5 mg of albendazole/kg of body weight) were not different from those for 14 nontreated controls, and the few differences that were observed appeared to be spurious and generally were not significant (P > 0.05) when data were adjusted for pretreatment differences among treated and control bulls. The treatment did not alter reproductive function of the bulls.
Serum Concentrations of Immunoglobulins G, A, and Μ in Dogs with Neoplastic Disease
Authors: Madewell B. R. , Hills D. L. , Franti C. E.
Published: February 2025

The concentrations of the three major classes of immunoglobulins (Ig) were determined in canine serum by single radial immunodiffusion against calibrated standards. Serum samples were collected from 121 dogs categorized into 3 groups: normal dogs (n = 34), those with lymphosarcoma (n = 41), and those with malignant, solid neoplasms other than lymphosarcoma (n = 46). The mean value for serum IgM concentration in the group of dogs with lymphosarcoma was significantly (P ≤ 0.02) higher than was the mean IgM concentration of the normal dogs. Dogs with neoplasms other than lymphosarcoma had significantly increased serum concentrations of IgG and IgM antibodies. There was no significant difference in serum IgA concentration among the three groups. A wide range of Ig concentrations was in the serum of clinically normal dogs, as well as in dogs with neoplastic diseases. Although individual dogs with neoplasms had low serum Ig concentrations, the 81 dogs with neoplastic disease were generally able to synthesize Ig.
Semen Changes in Boars After Experimental Infection with Pseudorabies Virus
Authors: Larsen R. E. , Shope R. E. , Leman A. D. , Kurtz H. J.
Published: February 2025

Two groups of adult boars were inoculated with a field strain of pseudorabies virus (prv) by intranasal droplet; one group was given 5 × 105 median tissue culture infective doses (tcid50), and the other, 5 × 106 tcid50. (A third group was maintained as controls.) Ejaculates were examined twice a week for volume, sperm numbers, sperm morphology, and presence of prv.

Severe clinical disease with fever followed administration of the larger virus dose. Death (one boar), testicular degeneration, and transient elevation in spermatozoa with proximal cytoplasmic droplets were seen in different members of this group. The smaller dose resulted in seroconversion, but did not produce signs of disease. In this group, volume, sperm numbers, and sperm morphology did not decline when compared with base-line values or data of control animals. The virus was not isolated from semen. Effects of prv infection on semen quality in boars seem to be related to the associated clinical signs of systemic disease.
Immunologic Relationship Between Page's and Sawata's Serotype Strains of Haemophilus paragallinarum
Authors: Kume Katsumi , Sawata Akira , Nakase Yasukiyo
Published: February 2025

Immunologic relationship among Page's A, B, and C and Sawata's 1 and 2 serotype strains of Haemophilus paragallinarum was investigated. In cross-protection tests, two distinct type-specific immunities existed among the strains used. All Page's serotype A strains (083, W, Georgia, and Germany) were immunologically similar to Sawata's serotype 1 strain 221, although serotype C strain Modesto was similar to serotype 2 strain H-18. Cross-protection was not observed between these two serotypes. However, strains Spross and 0222 of serotype B lacked pathogenicity and protective antigenicity.
Serum Proteins in Normal Cats and Cats Infected with Aelurostrongylus abstrusus
Authors: Barsanti J. A. , Hubbell J.
Published: February 2025

Serum proteins were evaluated by cellulose acetate electrophoresis in cats prior to and every 2 weeks for 24 weeks after oral infection with third stage larvae of Aelurostrongylus abstrusus. Evaluation of electrophoretograms was standardized by determination of electrophoretic migration ratios. Six fractions of serum proteins were consistently identified: albumin and α1, α2, β1, β2, and γ globulin. Relative and absolute concentrations of each serum protein fraction were determined. The only changes found were a decrease in concentration of α globulins and an increase in concentration of β1 globulins. These changes were mild, however, so that the concentrations for infected cats were still within 1 sd of the control concentrations. Apparently serum electrophoresis is not a useful diagnostic test for aelurostrongylosis.
Humoral Regulation of Erythropoiesis in Cats: Preliminary Report
Authors: Dunn C. D. R. , Legendre A.
Published: February 2025

Cats were subjected to acute or subacute phlebotomy regimens in a study to investigate the humoral regulation of erythropoiesis as mediated by erythropoietin. The erythropoietic effects of the acute phlebotomy regimen were similar to those effects of the subacute regimen. Serum erythropoietin in cats was increased for at least 10 days after initiating the phlebotomies.
Electron Microscopic Identification and Subsequent Isolation of a Rotavirus from a Dog with Fatal Neonatal Diarrhea
Authors: England James J. , Poston Robert P.
Published: February 2025

Negative contrast electron microscopic examination of intestinal contents from a 3-day-old pup with fatal diarrhea exhibited numerous rotavirus-like particles. Rotavirus was subsequently recovered, using MDCK cells, and was carried through 11 sub-passages; rotavirus-like particles were identified in each passage by negative contrast electron microscopic examination. Experimental inoculation of two 6-month-old Beagle dogs with purified intestinal contents did not result in clinical signs or virus shedding.
Prolonged Excretion of Toxoplasma gondii in Semen of Goats
Authors: Dubey J. P. , Sharma S. P.
Published: February 2025

Toxoplasma gondii was demonstrated by mouse inoculation in semen of three of three goats orally inoculated with 104 oocysts of the GT-1 strain of T gondii. From goats 1 and 3, T gondii was first detected in semen 7 days after inoculation (dai) and 12 dai from goat 2. Excretion continued over a period of 52 days from goat 1 and 16 days from goat 2. Goat 3 had excreted T gondii for 5 days when it was killed 14 dai.
In Vitro Antimicrobial Susceptibility of Salmonellae from Animals in Louisiana
Authors: Cox Hollis Utah
Published: February 2025

A total of 56 Salmonella isolates from animals were tested for susceptibility to 12 antimicrobial agents by the standard disk diffusion and microdilution methods. All isolates were susceptible to gentamicin, tobramycin, amikacin, chloramphenicol, trimethoprim and sulfonamide, colistin, and nitrofurantoin. Isolates were most frequently resistant to tetracycline (50%) and kanamycin (36%). A low prevalence of resistance to ampicillin (16%), carbenicillin (16%), and cephalothin (4%) was found. The differences in susceptibility results between the two methods were minor.
Surgical Implantation of Cardiovascular Devices in the Thorax of the Horse
Authors: Waugh S. L. , Campbell K. B. , Klavano P. A. , Grant B. D.
Published: February 2025

A surgical thoracotomy and implantation of an electromagnetic flow probe around the ascending aorta and catheters in the left ventricular (lv) apex of the horse were evaluated. Sixteen operations were done: 4 horses were used for acute experiments, 4 horses died from surgical manipulation, and 8 horses were studied chronically for 18 to 57 days.

The electromagnetic flow probe allowed continuous measurement of stroke volume and heart rate. The lv apical catheters, in conjunction with thermal dilution techniques and pressure-sensitive devices, allowed measurement and calculation of mean arterial blood pressure, total peripheral vascular resistance, lv residual fraction, lv and diastolic volume, and lv end systolic volume.
Comparison of Circulatory and Respiratory Effects of Isoflurane and Halothane Anesthesia in Horses
Authors: Steffey E. P. , Howland D.
Published: February 2025

Circulatory and respiratory effects of alveolar concentrations of 1.31, 1.97, and 2.62 vol % of isoflurane in oxygen were studied in eight young, healthy horses during spontaneous and controlled ventilation. These isoflurane concentrations were equivalent, respectively, to 1.0, 1.5, and 2.0 times the minimal alveolar concentration of isoflurane, which prevents movement in horses in response to a standard pain stimulus. Results of the isoflurane studies were compared with similarly derived findings in these same horses during equipotent halothane in oxygen anesthesia. Isoflurane, similar to halothane, produced a dose-related depression of cardiovascular function which was less severe during spontaneous ventilation and associated hypercapnia. The two anesthetic agents produced similar circulatory effects during controlled ventilation and constant arterial carbon dioxide tension except for a significantly (P < 0.05) less depressed cardiac output/kg of body weight and stroke volume that occurred with minimal alveolar concentration 1.5 and 2.0 isoflurane. Total peripheral resistance was greatest when these horses were anesthetized with halothane regardless of the alveolar dose. In horses, isoflurane was, in general, no more depressing than was halothane to circulatory and respiratory function.
Total Plasma Corticosteroid Concentrations in Horses with Combined Immunodeficiency
Authors: Magnuson Nancy S. , Perryman Lance E. , Grant Barrie , Estergreen V. L.
Published: February 2025

Plasma corticosteroid concentrations of seven Arabian foals with combined immunodeficiency (cid) and five non-cid Arabian foals were measured. Plasma corticosteroid concentrations were quantitated throughout gestation for ten mares heterozygous for the cid trait and pregnant with cid foals, as well as for 20 mares heterozygous for the cid trait and pregnant with non-cid foals. Five nonpregnant mares heterozygous for the cid trait also were tested during the same period. Concentrations of plasma corticosteroids in foals with cid (34.4 ± 5.2 ng/ml) were not different from those of non-cid foals (37.6 ± 8.4 ng/ml). Significant differences in corticosteroid concentrations were not detected between mares pregnant with cid foals (61.5 ± 16.4 ng/ml) and mares pregnant with non-cid foals (61.5 ± 12.7 ng/ml) or between pregnant mares and nonpregnant mares (77.9 ± 10.7 ng/ml).
Effects of Intravenous and Aerosol Administration of Crude Shigella Toxin to Rhesus Macaques: Preliminary Study
Authors: Liu C. T. , Sanders R. P. , Dominik J. W. , Formal S. B.
Published: February 2025

Experiments were conducted to determine the dose response, survival time, blood biochemical changes, and cardiohepatic responses to a single iv injection of crude Shigella toxin in rhesus macaques (Macaca mulatta). Circulatory shock, hepatic failure, respiratory depression, dyspnea, convulsions, and coma were observed before death. The survival time was inversely related to the administered toxic dose, which ranged from 20 to 200 μg/kg of body weight. However, the severity of lesions in the heart and gastrointestinal tract was directly correlated with the amount of the injected dose. Macaques exposed to aerosols of crude Shigella toxin did not show any signs of toxicosis within 7 days after exposure and were considered permanent survivors. Seemingly, an iv crude preparation of Shigella toxin is lethal to rhesus macaques, but an aerosol crude preparation of Shigella toxin is not.
Bovine Mycoplasmal Mastitis from Intramammary Inoculations of Small Numbers of Mycoplasma bovis: Local and Systemic Antibody Response
Authors: Bennett R. H. , Jasper D. E.
Published: February 2025

Typical mycoplasma mastitis spread to all four quarters in each of four cows after each cow was inoculated in one quarter with 70 colony-forming units of Mycoplasma bovis. Up to 50 days after inoculation, immunoglobulin (Ig) M was the predominant Ig responsible for serum indirect hemagglutination titers. After 57 days, IgG was predominant.

Milk whey indirect hemagglutination titers did not distinguish between quarters resolving the infection and those that did not.

Milk whey IgG and IgA concentrations increased in quarters that resolved the infection and in quarters that did not. In the initially inoculated quarters, total daily production of IgG was greater in the quarter resolving the infection than in the three quarters not resolving the infection. Total IgA production was also higher at and after the peak of infection in the quarter resolving the infection than in the quarters that did not.
Fecal Occult Blood Tests in Cattle
Authors: Payton Alice J. , Glickman Lawrence T.
Published: February 2025

Three methods for fecal occult blood detection were evaluated in mature cows. Bovine blood (heparinized) was infused directly into the abomasum of mature nonlactating rumen-fistulated cows. After administration of the blood, feces from the cows were periodically collected, tested, stored, and retested. Sensitivity for two of the three methods was optimal at 2 days of storage, regardless of temperature at storage. A dilute alcoholic solution of guaiac was the most sensitive and reproducible method. In vitro tests demonstrated that guaiac solution could detect a quantity of blood comparable with a daily blood loss of 69 to 75 ml. In addition, the minimal transit time of blood from abomasum to rectum was measured and ranged from 7 to 19 hours.
Plasma Concentrations of Iditol Dehydrogenase (Sorbitol Dehydrogenase) in Ponies Treated with Aflatoxin B1
Authors: Asquith R. L. , Edds G. T. , Aller W. W. , Bortell R.
Published: February 2025

Twelve clinically normal Shetland ponies were allocated to one of four treatment groups. Aflatoxin B1 was administered at the dosage level of 2 mg/kg of body weight to group A, 1 mg/kg to group B, and 0.5 mg/kg to group C; a placebo was given to group D (controls). Plasma samples were assayed at 4-hour intervals for iditol dehydrogenase (id) (sorbitol dehydrogenase) concentrations as an indicator of hepatic damage.

One of the ponies in group A died 68 hours after dosing; another pony in group A died 76 hours after dosing. All other animals survived the experiment. The means of peak id values were as follows: group A, 1514.0 IU/L (P < 0.05); group B, 192.6 IU/L (P < 0.05); group C, 8.5 IU/L (P < 0.05); and group D (controls), 2.7 IU/L.

A square root transformation analysis of the postdosing response of id values in relation to time demonstrated that the mean of group A became significantly higher (P < 0.05) than did the mean of the control group at 5 to 6 hours. The mean of group B at 12 to 16 hours and the mean of group C at 20 to 24 hours also were significantly higher (P < 0.05) than was the mean of the control group.
Evaluation of an Analytical Method for the Diagnosis of Cantharidin Toxicosis Due to Ingestion of Blister Beetles (Epicauta lemniscata) by Horses and Sheep
Authors: Ray Allen C. , Post Lynn O. , Hurst J. Monty , Edwards William C. , Reagor John C.
Published: February 2025

An analytical method for cantharidin, using high performance liquid chromatography, was applied to field specimens from horses and sheep with blister beetle (Epicauta lemniscata) poisoning. Stomach content and urine proved to be valuable aids in diagnosis. One incident of cantharidin toxicosis in ruminants (sheep) was confirmed.
Persistent Hog Cholera Infection Detected During Virulence Typing of 135 Field Isolates
Authors: Carbrey E. A. , Stewart W. C. , Kresse J. I. , Snyder M. L.
Published: February 2025

During the hog cholera (hc) eradication program in the United States, 135 field isolates were characterized by inoculation into specific-pathogen-free pigs. This gave origin to the classification of 61 (45%) as high virulent, 37 (27%) as low virulent, 29 (22%) as avirulent or immunizing, and 8 (6%) as capable of causing persistent infection.

The persistent infections caused by the eight isolates were of long duration, lasting in one instance to 152 days. The persistently infected pigs remained relatively free of clinical signs of hc but had high concentrations of hc virus (hcv) in their blood. When 6 of these pigs were given a second inoculation (with the virulent Ames strain of hcv), 2 died while the health status of 4 remained unchanged.
Rotavirus Antibody in Chickens as Measured by Enzyme-Linked Immunosorbent Blocking Assay
Authors: Bartz Curtis R. , Conklin Richard , Steele James H. , Glass S. E.
Published: February 2025

The antibody titer of 202 chickens to SA-11 rotavirus was determined by enzyme-linked immunosorbent blocking assay. The chickens were from 15 separate flocks on six farms. The titer was detectable (1:18 or greater dilution) in 43% of the chickens. The wide variation in infection rate between flocks on individual farms (0% to 90%) indicated there is probably not significant transmission of the virus between flocks on the farm. Significant differences in numbers of serotest-positive birds were found between separate farms, possibly reflecting different management practices.
Enzyme-Linked Immunosorbent Assay, Using Staphylococcal Protein A for Detecting Virus Antibodies
Authors: Potgieter L. N. D. , Rouse B. T. , Webb-Martin T. A.
Published: February 2025

A modification of the indirect enzyme-linked immunosorbent assay (elisa) was developed which used staphylococcal protein A linked to horseradish peroxidase. Virus antibodies in equine, bovine, porcine, feline, canine, lagomorphic (rabbit), and human sera were detected, using the indirect elisa in which the antiglobulin enzyme conjugate was replaced by protein A linked to horseradish peroxidase. Results of the elisa were compared with the results of the serum-virus neutralization test. The application of the test in laboratories performing serologic assays with sera from diverse animal species is discussed.
Immunologie Responses in Colostrum-Fed and Colostrum-Deprived Calves
Authors: Clover C. K. , Zarkower A.
Published: February 2025

The influence of colostrum on several aspects of the neonatal immune response, including lymphocyte reactivity in vitro, was examined in the calf from birth through 96 hours after delivery. Using a whole blood microculture assay, the blastogenic response of peripheral blood lymphocytes (pbl) incubated with phytohemagglutinin (pha), pokeweed mitogen (pwm), or Escherichia coli lipopolysaccharide (lps) were examined for colostrum-fed (cf) and colostrum-deprived (cd) calves. The pha and pwm stimulated significant levels of [3H]thymidine incorporation in both calf groups, although lps was only marginally mitogenic. However, pbl from cd calves during the first 24 hours after delivery had significantly greater amounts of total label incorporation in response to the three mitogens as compared with the label in pbl from cf calves.

Differential and total wbc counts differed markedly between cf and cd calves during the first 48 hours after delivery; cf animals had significantly increased leukocyte counts at 6, 12, and 24 hours, due primarily to transient neutrophilia. Blood sera collected from calves before ingesting colostrum contained trace amounts of immunoglobulin (Ig) M and IgG; all three classes of Ig (M, G, and A) were present in significant amounts in sera of calves after colostrum feeding. The observed effects of colostrum on various components of the immune system are discussed.