bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of inactivated Newcastle disease viral vaccines containing different emulsion adjuvants
Authors: Brugh M. , Stone H. D. , Lupton H. W.
Published: February 2025

Chickens inoculated with inactivated-virus Newcastle disease vaccines containing different emulsion adjuvants were challenge exposed with viscerotropic velogenic Newcastle disease virus. Adjuvant activity was evident in all of 9 vaccines containing mineral oil emulsion (oe), but was not evident in 2 vaccines which contained a metabolizable lipid emulsion (le) adjuvant consisting of peanut oil, glycerol, and lecithin. Serologic responses of chickens inoculated with oe vaccines were 10- to 100-fold higher than those of chickens inoculated with le vaccines. One of 106 chickens given oe vaccine, 12 of 24 given le vaccine, and all of 24 nonvaccinated control chickens were clinically affected or died after challenge exposure. Five oe vaccines emulsified only by brief vigorous shaking had adjuvant activity similar to 4 oe vaccines emulsified by conventional homogenization.
Isolation of virus and antibody containing immune complexes from mink with Aleutian disease by affinity chromatography of equine complement Clq
Authors: Burger Dieter , Sriranganathan Nammalwar , McDonald Thomas L. , Gorham John R.
Published: February 2025

Affinity chromatography on immobilized equine complement Clq was used for the isolation of complement-binding immune complexes in sera of mink infected with Aleutian disease virus. Immune complexes were isolated and quantitated from 4 of 5 infected mink, as early as 2 weeks after infection and before hypergammaglobulinemia had appeared. The quantity of immunoglobulin G in these immune complexes ranged from 180 to 370 μg/ml serum. There were no Clq-binding immune complexes found in mink which were negative for Aleutian disease antibody. Using 125I-labeled BSA-anti-BSA complexes, we demonstrated that the affinity columns bound selectively immune complexes which had formed in antibody excess, whereas immune complexes in antigen excess were not bound. By neutralization of sensitized virus with anti-mink IgG serum, non-Clq-binding immune complexes were also detected, which indicates that circulating immune complexes in persistently infected mink are heterogeneous as far as their reactivity with equine Clq is concerned.
Costa as a glycogen store and probable site of energy generation in Tritrichomonas foetus
Authors: LeMoine L. A. , Hart L. T. , Larson A. D. , McCorkle-Shirley S.
Published: February 2025

Costae were isolated from the parasitic protozoan Tritrichomonas foetus and were found to contain 87% of the total cellular glycogen. Radiotracer studies, using [U-14C]glucose, were performed on starved and unstarved whole cells and on costae isolated from starved and unstarved cells. During cell starvation, catabolism of labeled costal glycogen was demonstrated. Preferential utilization by the cell of costal glycogen over other cellular glycogen stores was indicated.
Epizootic bovine abortion: Histogenesis of the fetal lesions
Authors: Kennedy Peter C. , Casaro A. P. , Kimsey P. B. , Bon Durant R. H. , Bushnell R. B. , Mitchell Geoffrey M.
Published: February 2025

The development of the fetal lesions of epizootic bovine abortion (eba) was studied in a series of experiment and field cases of the disease. Thirty-six experimentally infected fetuses were recovered at periods of 29 to 126 days after their dams had been infected by allowing the vector tick Ornithodorus coriaceus to feed on them. The sequential development of the fetal lesions was studied and the lesions compared with those in both naturally occurring and experimentally induced infections of the dams which either aborted or carried to term. The early changes observed in the fetuses consisted of transformation and proliferation of lymphocytes and mononuclear phagocytes. These changes were marked by 50 days after tick exposure of the dams, but fetal lesions specific enough to permit making the diagnosis of the disease did not develop until 100 days after dams were exposed by tick feeding. In the fetuses which were either aborted or carried to term after prolonged infection, acute necrotizing lesions were superimposed on the chronic proliferative fetuses. Acute necrotizing foci developed in several organs, but most commonly in lymph nodes and spleen. These foci frequently formed pyogranulomas. Acute vasculitis developed at the same time as the acute focal-necrotizing lesions. These lesions were similar to immune-mediated lesions that result from the deposition of toxic complexes in the tissues. Immunofluorescent examination demonstrated that immunoglobulins (Ig)G and IgM were present in the vascular lesions.
Isolation of bovine syncytial virus from mesenteric lymph nodes of cattle
Authors: Marshall R. G. , Gillette K. G.
Published: February 2025

Bovine syncytial virus was isolated from mesenteric lymph nodes of young dairy calves, beef cattle, and mature dairy cattle. Isolations were made in cocultures of lymph node specimens and bovine embryonic lung cells or by subpassage of cocultures in which cytopathic effects were not initially detected. The bovine syncytial viral isolates after storage at −65 C for 3 months in either infected cell cultures of supemate fluids from suspensions or sonically treated infected cell monolayers were usually recovered. Bovine syncytial virus also was recovered from cell cultures after storage for 6 months at −25 C.
Using red blood cell creatine concentration to evaluate the equine erythropoietic response
Authors: Wu Ming-Jeong , Feldman Bernard F. , Zinkl Joseph G. , Jain Nemi C.
Published: February 2025

Red blood cell creatine concentration was examined to determine its association with the equine erythropoietic response. Studies were conducted on 9 healthy horses, 4 healthy ponies, 24 anemic horses, and 2 horses in which anemia was experimentally induced. A modified Jaffe reaction was used to measure rbc creatine concentration. The mean rbc creatine concentration of the 9 healthy horses was 5.72 ± 0.42 mg/dl, and that of the 4 healthy ponies was 2.59 ± 0.31 mg/dl. Density-separation of erythrocytes from the healthy horses revealed significantly higher (P < 0.001) creatine content (7.72 ± 0.57 mg/dl) in the young rbc populations than in the old rbc populations (4.03 ± 0.27 mg/dl).

The rbc creatine content was assayed in 19 hot-blooded horses which were anemic due to a variety of causes. Of these anemic horses, 12 with pcv between 25% and 30% had a mean rbc creatine concentration of 6.12 ± 0.46 mg/dl. The 7 other anemic horses with pcv < 25% had a mean rbc creatine value of 6.07 ± 0.12 mg/dl.

Bone marrow films were examined from 5 anemic horses and in the 2 horses in which anemia was experimentally induced. The rbc creatine concentration correlated positively (P < 0.001) with the reticulocyte count in the bone marrow and negatively with the myeloiderythroid ratio (P < 0.001).
Natural cell-mediated cytotoxicity in the domestic cat: Properties and specificity of effector cells
Authors: Tompkins M. B. , Huber K. , Tompkins W. A. F.
Published: February 2025

Using a 51Cr-release microcytotoxicity assay, natural cytotoxic cell activity was demonstrated in the peripheral blood of clinically normal, nonimmune cats. Cytotoxicity was enhanced against virus-infected feline cells over that in noninfected cells. Xenogeneic mouse and hamster target cells were also susceptible to lysis. The cytotoxic activity increased as effector-to-target cell ratios were increased and required a 16-hour assay to be expressed. The specificity of the natural cytotoxicity was selective in that some, but not all, target cells tested were susceptible to lysis. Characterization of the cytotoxic cells showed them to be nonadherent and to possess Fc receptors for immunoglobulin G.
Organ blood flow and distribution of cardiac output in hypocapnic ketamine-anesthetized swine
Authors: Tranquilli William J. , Thurmon John C. , Benson G. John
Published: February 2025

Organ blood flow and distribution of cardiac output (co) were determined in 9 awake (control) and ketamine-anesthesized swine (4 mg/kg bolus followed by continuous infusion of 0.3 mg/kg/min, iv), using 15 μ diameter radionuclide-labeled microspheres. Absolute values of blood flow (per 100 g basis) were determined for various organs and peripheral tissues. Internal organs of the swine, which constituted 8.25 ± 0.79% of the total body mass, received 55.83 ± 5.13% of the co. The fraction of co received by brain, heart, kidneys, liver (via hepatic artery), and gastrointestinal tract was 1.10%, 2.67%, 19.84%, 11.81%, and 16.84%, respectively. During ketamine anesthesia, the fraction of co perfusing the kidneys and liver (hepatic artery) increased from control and values for brain, heart, and splanchnic organs remained unchanged. Blood flow (per unit weight) of brain, cardiac, and splanchnic organs decreased; kidney and skeletal muscle blood flow was unaltered; and hepatic arterial blood flow increased from the awake (control) values. The hyperdynamic state often associated with ketamine anesthesia was not evident in these pigs during intermittent positive-pressure ventilation resulting in hypocapnia.
Transmission and control of caprine arthritis-encephalitis virus
Authors: Adams D. S. , Klevjer-Anderson P. , Carlson J. L. , McGuire T. C. , Gorham J. R.
Published: February 2025

Caprine arthritis-encephalitis virus was isolated from goat milk and transmitted most efficiently to kids through both milk and colostrum. In addition, it appeared that transmissions through other secretions of the doe occurred, but were less important than transmission in milk and colostrum. Intrauterine infection may have occurred in 2 of 32 cesarean-derived goats, but postpartum horizontal transmission could not be ruled out. Transmission by the aerosol route was not demonstrated, and even shortterm direct contact between virus-infected bucks and virus-free does during breeding did not result in transmissin. Prolonged direct contact for over 12 months between weaned cesarean-derived goats and virus-infected goats was necessary before horizontal transmission could be demonstrated under nondairy conditions. However, when uninfected does were milked with infected does, a high percentage became infected in less than 10 months. Heat inactivation (56 C) reduced approximately 105 median tissue culture infective doses of caprine arthritis-encephalitis virus to below titratable levels, and virus was not transmitted to kids fed virus-infected colostrum that had been heated at 56 C for 1 hour. A program of eradication is discussed in which kids are removed from their dams at birth, fed safe sources of colostrum and milk, and isolated from other goats until weaning.
Simultaneous cystometry and uroflowmetry (micturition study) for evaluation of the caudal part of the urinary tract in dogs: Reference values for healthy animals sedated with xylazine
Authors: Moreau Philippe M. , Lees George E. , Gross David R.
Published: February 2025

Micturition studies were performed in 12 healthy dogs (6 females and 6 males). The animals were sedated with xylazine given either iv (1.1 mg/kg) or im (2.2 mg/kg). Separate antepubic catheters were used to perform bladder infusions and record intravesical pressures. Instantaneous urine flow measurements were obtained, using an apparatus specially designed and constructed for small animals.

A total of 45 simultaneous cystometric and uroflowmetric recordings were obtained, and numerical values for 16 different micturition variables were tabulated. The variables were analyzed separately on the basis of sex of the animal, route of administration of the sedative, and the fact of having had a previous bladder instrumentation-micturition study performed. Significant differences within individual dogs were not seen in these analyses. Intravesical pressures, urine flow rates, compliances, and urethral resistance were significantly different (P < 0.05) between male and female dogs.

The micturition study was a simple and reliable urodynamic testing method that could be clinically useful in dogs. In contrast to urodynamic tests previously described in veterinary medicine, this method provided evaluation of the bladder and urethra as a functional unit during both the filling and the emptying phases of micturition. A micturition study should not be regarded as an absolute measure of the physiologic activity of the caudal part of the urinary tract. However, it can provide important additional information for clinical assessment when the lower part of the urinary tract is affected by disease, injury, or drugs.
Studies of the pathogenesis of anemia of inflammation: Mechanism of impaired erythropoiesis
Authors: Weiss Douglas J. , Krehbiel Janver D. , Lund John E.
Published: February 2025

Cats with induced sterile abscesses developed a hematologic disorder consistent with anemia of inflammation. Serum iron concentrations decreased while the abscess was present, but erythropoietin concentrations did not change significantly.

Cobalt administration to control (healthy) cats resulted in polycythemia, reticulocytosis, and hyperferremia. Cats with abscesses responded to cobalt similarly; however, magnitudes of the polycythemia and reticulocytosis were less.

Constant infusion of ferric citrate (iv) into cats with sterile abscesses maintained serum iron concentration in the normal to high range. The iron infusion did not prevent the anemia, but did enable the bone marrow to respond to the anemia.
Transmission of equine cyathostomes (Strongylidae) in central Texas
Authors: Craig T. M. , Bowen J. M. , Ludwig K. G.
Published: February 2025

After foaling, 6 mares and their foals were placed on equine parasite-free pastures. Observations of fecal nematode eggs and pasture larvae indicated peak cyathostome egg production occurred in late August and early September, with greatest numbers of larvae on the forage appearing during October. Two foals were necropsied for parasitologic evaluations at approximately 155 days of age. Both had approximately 100,000 adult cyathostomes, mostly Cylicostephanus longibursatus, Cylicocyclus nassatus and Cyathostomum catinatum. However, there were nearly 7 times more cyathostome larvae (189,004) in the foal necropsied in October, during the autumn rise in pasture larval populations, than in the foal examined in September (27,354).
Blood-gas tensions and acid-base status in ponies during treadmill exercise
Authors: Parks Christine M. , Manohar Murli
Published: February 2025

Blood-gas tensions and acid-base status were examined in 8 healthy grade ponies at rest (heart rate = 55 ± 3 beats/min) and during moderate (fast trot; heart rate = 155 ± 3 beats/min) and severe (gallop; heart rate = 218 ± 7 beats/min) exercise performed on a treadmill. Arterial oxygen tension and hemoglobin-oxygen saturation of exercising ponies did not change from the resting values. Arterial oxygen content increased markedly during exercise, as a consequence of increased hemoglobin concentration. The total oxygen content, as well as the saturation of hemoglobin with oxygen in the mixed venous blood, decreased at each intensity of exercise. Arterial carbon dioxide tension decreased with moderate (16%) and severe (29%) exercise, indicating hyperventilation. In galloping ponies, during steady-state severe exercise marked metabolic acidosis developed, as indicated by a sharp increase in the arterial concentration of lactic acid (11.6 ± 1.3 mM/L during severe exercise vs 0.6 ± 0.3 mM/L at rest). This increase in lactate was accompanied by a decrease in arterial pH and bicarbonate concentration.
Effects of dietary copper and molybdenum on tansy ragwort (Senecio jacobaea) toxicity in sheep
Authors: White R. D. , Swick R. A. , Cheeke P. R.
Published: February 2025

Dried tansy ragwort (Senecio jacobaea), which contains pyrrolizidine alkaloids (pa), was fed to sheep to determine whether pa consumption influenced liver Cu concentrations. Nine Polypay wether lambs were allotted to 3 groups according to the diets: control diet + 50 μg of Cu/g of feed (control + Cu); tansy ragwort (TR) diet + 50 μg of Cu/g of feed (TR+Cu); and TR diet + 50 μg of Cu/g of feed and 10 μg of Mo/g of feed (TR + Cu + Mo). Liver Cu concentrations were sharply increased (13-fold) after 8 weeks of feeding the diets, and then decreased slightly. There were no significant differences in concentrations of liver Cu among treatment groups. All lambs in the group fed TR + Cu + Mo died by the end of 23 weeks, with the usual signs of pa poisoning, including liver necrosis, hepatic megalocytosis, and biliary hyperplasia. The TR intake was about 2.7 to 3.0 kg/kg of their initial body weight. All lambs in the group fed the control + Cu diet survived. The results indicated that sheep fed TR do not preferentially accumulate liver Cu. There was an indication that dietary Mo increased susceptibility to TR intoxication.
Immunologic studies of progeny of atopic dogs
Authors: Schwartzman Robert M.
Published: February 2025

Atopic dogs were bred to establish a colony of progeny predisposed to develop type I hypersensitivity. In a 2-year period, 72 pups were born and were monitored for clinical evidence and immunologic “markers” of atopic disease. Thirteen dogs in the colony, belonging to the oldest age group, manifested clinical signs compatible with atopic disease. Immunologic variables relative to serum IgE levels, parasitic infection, and duration of severity of clinical signs of disease were studied in this group. Analysis of this data did not identify indicators which could be used to predict the development of the atopic state in dogs.
Acute exposure to hymenoxon: Electron microscopic study of the mouse liver
Authors: Bowers Daniel E. , Jones Daniel H. , Sampson H. Wayne , Dunlap Mary K.
Published: February 2025

Young, male mice (25 to 30 g) were given oral doses of hymenoxon, a sesquiterpene lactone, for 5, 10, or 20 days. Hymenoxon, isolated from Hymenoxys odorata DC, was dissolved in dimethyl sulfoxide (dmso) and water (1:1, v/v) and was administered daily at a dosage level of 100 mg/kg of body weight for 5, 10, or 20 days. Two control groups were maintained; 1 group was given dmso and water, and 1 group was given water only. Twenty-four hours after the last dosing, the mice were euthanatized and their livers were processed for transmission electron microscopy.

Hepatocyte organelles of hymenoxon-treated mice appeared normal although the bile canaliculi contained a fine granular material and membranous structures, including myelin figures. The canaliculi of hymenoxon-treated mice were also markedly dilated, compared with bile canaliculi in the control groups. The mean area of bile canaliculi of the 5-, 10-, and 20-day mice was 14.08 μm2, 15.65 μm2, and 17.56 μm2, respectively, compared with 7.73 μm2 for the canaliculi of dmso + water-treated mice. The P values were < 0.001, 0.02, and 0.05 for the 5-, 10-, and 20-day hymenoxon-treated mice, respectively. Seemingly, the mouse was not a good model for studying hepatic ultrastructural changes produced by hymenoxon, using dosages ≤ 100 mg/kg/day for 20 days.
Toxicity of Kalanchoe spp to chicks
Authors: Williams M. C. , Smith Mary C.
Published: February 2025

Leaves of Kalanchoe daigremontiana, K tubiflora, K fedtschenkoi, K tomentosa, K tomentosa × K beharensis, and 4 cultivars of K blossfeldiana were tested for toxicity to 2-week-old Leghorn chicks. These species were analyzed for percentage of alkaloids, aliphatic nitro compounds, soluble oxalates, and nitrates and were examined qualitatively for cyanogenic glycosides. The solubility of the toxic principle in Κ daigremontiana was determined.

Leaves of Κ daigremontiana, K tubiflora, and K fedtschenkoi were toxic to chicks at dosage levels of 8 to 12 mg/g of body weight. Toxic signs included depression, muscular incoordination, twitching and spiraling of the neck, tremors, convulsions, paralysis, and death, Kalanchoe tomentosa, K tomentosa × K beharensis, and 4 cultivars of K blossfeldiana were nontoxic at the highest dosage levels tested.

Aliphatic nitro compounds and cyanogenic glycosides were not detected in any species. Alkaloids, nitrates, and soluble oxalates were present only in nontoxic concentrations. The toxic principle in K daigremontiana was soluble in 50%, 80%, and 100% ethanol, slightly soluble in water and acetone, and insoluble in benzene, chloroform, and ether.
Abortion in the dog due to Campylobacter species
Authors: Bulgin Marie S. , Ward Alton C.S. , Sriranganathan Nammalwar , Saras Patricia
Published: February 2025

Campylobacter jejuni was isolated from a Wheaten Terrier bitch which had aborted (in southern Idaho). A Campylobacter of undetermined species also was isolated from aborted Poodle pups (in central Washington). It appears that persons may have been the source of infection in the Idaho event, but the source for the other was not speculated.

These findings of perinatal death due to Campylobacter in dogs from widely separated areas indicate that pathologic evaluation of cases involving premature and aborted pups should include bacteriologic tests, using appropriate media and atmospheric conditions necessary for the cultivation of these organisms.
Organophosphate detoxification related to induced hepatic microsomal enzymes of chickens
Authors: Ehrich Marion , Larsen Calvert , Arnold Jesse
Published: February 2025

Detoxification of the organophosphate malathion in its activated form (malaoxon) was increased in livers of chickens given microsomal enzyme inducers (β-naphthoflavone, 3-methylcholanthrene, butylated hydroxytoluene (bht), or polychlorinated biphenyls). Positive correlations between inducer and microsomal enzyme activity were demonstrated for β-naphthoflavone with demethylation of p-nitroanisole and for 3-methylcholanthrene and for bht with cytochrome P450/448 and cytochrome b5. Malaoxon detoxification decreased in correlation with decreases in quantities of cytochrome P450/448 in birds fed a low-protein diet. Prediction of malaoxon detoxification was aided by using enzyme activities as dependent variables in the regression model, although only in birds given bht were all of the 5 enzymes necessary for providing the best predictive model.
Megakaryocytes with intracytoplasmic blood cells
Authors: Chiu Taisan
Published: February 2025

The phenomenon of megakaryocytes containing intracytoplasmic blood cells was frequently observed in the bone marrow of rats. The frequency appeared to increase in inflammatory or neoplastic conditions. The types of blood cells engulfed were mainly neutrophils. For the first time, megakaryocytes also were found to be engulfed.
Sensory nerve conduction velocity of cutaneous afferents of the radial, ulnar, peroneal, and tibial nerves of the cat: Reference values
Authors: Redding R. W. , Ingram J. T.
Published: February 2025

The mean conduction velocities of the compound action potentials of sensory axons of the cutaneous branches of the radial, ulnar, peroneal, and tibial nerves of the healthy cat were determined by cutaneous stimulation and recorded by averaged evoked response technique. Locations for both stimulation and recording electrodes were identified. Mean conduction velocities were: radial nerve, 83.6 ± sd 8.3; ulnar nerve, 89.2 ± 10.3; peroneal nerve, 85.3 ± 6.8; and tibial nerve, 80.2 ± 7.9 m/s.
Effect of flunixin meglumine on prostacyclin accumulation in the equine eye
Authors: Cooley P. L. , Milvae R. , Riis R. C. , Laratta L. J.
Published: February 2025

A study was performed to identify prostacyclin (pgi2) in equine aqueous humor, demonstrate an increase in pgi2 following anterior chamber paracentesis, and determine the effects of subconjunctival injection of flunixin meglumine on pgi2 accumulation.

Twenty ponies were found to be normal upon ocular examination and were placed under general anesthesia. Anterior chamber paracentesis was performed in both eyes (right and left); immediately afterward, 25 mg of flunixin meglumine was injected (subconjunctivally) in the left eye. Aqueous paracentesis was performed 1.5 hours later (both eyes). Aqueous humor samples were assayed for 6-keto pgf1α, the stable, inactive metabolite of pgi2. Eyes treated with flunixin meglumine contained less 6-keto pgf1α than did control eyes.
Transruminal and transreticular palpation of abdominal viscera of the permanently fistulated dairy cow
Authors: McCarthy P. H.
Published: February 2025

A detailed description is given of the abdominal viscera which are palpated through the walls of the rumen and reticulum of the live dairy cow surgically prepared with a permanent fistula.

Transruminal and transreticular palpation can be complementary to transrectal and transcolonic examination in gaining detailed knowledge of the topography of abdominal viscera in the live dairy cow.
Angiography of the corpus cavernosum penis in the pony stallion during erection and quiescence
Authors: Bartels J. E. , Beckett S. D. , Brown B. G.
Published: February 2025

Serial arteriography was used to determine the vascular pattern and blood flow in the penis of the pony stallion. Ponies were anesthetized with pentobarbital sodium, and catheters were surgically introduced into the internal pudendal and obturator arteries. The vascular anatomy was visualized by angiography via image-intensified fluoroscopy and was recorded on 70-mm film at 3 frames/s or by direct radiography.

Blood flow into the corpus cavernosum penis (ccp) was limited during quiescence because the blood was immediately shunted into the venous system. After vasodilation with mild stimulation from an electro-ejaculator, there was increased filling of the ccp and corpus spongiosum penis. Contrast medium injected into the internal pudendal artery entered the bulb of the penis during peak erection, but medium injected into the obturator artery could not enter the crus penis during peak erection. The contrast medium stopped in the obturator artery at the edge of the ischiocavernous muscles due to the occlusion of the deep arteries of the penis by contraction of these muscles. When contrast medium was injected directly into the ccp near the glans to outline the body of the penis, there was no evidence of venous outlets along the body.
Effects of selenium on polymorphonuclear leukocyte function in goats
Authors: Aziz E. S. , Klesius P. H. , Frandsen J. C.
Published: February 2025

Polymorphonuclear neutrophils (pmn) from goats fed selenium-deficient and selenium-adequate diets were tested for their ability to perform (i) random migration under agarose, (ii) leukotaxis toward serum chemotaxins under agarose, and (iii) phagocytosis of opsonized zymosan by chemiluminescence analysis, Function of pmn from goats fed the selenium-deficient diet was severely depressed, and incubation of these cells with selenium resulted in marked functional enhancement. Also, administration of selenium to goats fed the selenium-deficient diet resulted in increased pmn functions. Increase or decrease in pmn function was associated with corresponding alterations in blood, serum, and intracytoplasmic pmn glutathione peroxidase activities. It was concluded that a selenium-inadequate diet fed to goats results in depressed pmn function which is associated with physiologic changes in glutathione peroxidase levels.
Dexamethasone and prednisolone in the horse: Pharmacokinetics and action on the adrenal gland
Authors: Toutain Pierre L. , Brandon Roslyn A. , Pomyers Harold de , Alvinerie Michel , Baggot J. Desmond
Published: February 2025

Pharmacokinetics of dexamethasone and prednisolone were studied in 6 horses given dexamethasone alcohol (iv or im) or dexamethasone 21-isonicotinate as a solution iv or im (50 μg/kg of body weight), prednisolone 21-sodium succinate iv or im (0.6 mg/kg of body weight), or prednisolone acetate im (0.6 mg/kg of body weight). Plasma concentrations were determined using a high-performance liquid chromatographic method. After dexamethasone alcohol (iv) or dexamethasone 21-isonicotinate (iv), the half-life of elimination was similar (53 minutes) for both formulations. After dexamethasone (alcohol and isonicotin-ate, im), concentrations were low or nondetected. After prednisolone 21-sodium succinate (iv), the half-life of elimination (99.5 minutes) was significantly (P < 0.01) longer than that for dexamethasone. After prednisolone 21-sodium succinate (im), absorption was rapid and bioavailability was high. After prednisolone acetate (im), absorption was slow and prednisolone was present in plasma for about 7 days. Due to the nonlinearity of prednisolone kinetics, a bioavailability higher than 100% was obtained.

The basal plasma hydrocortisone concentration was approximately 70 ng/ml. After dexamethasone (iv or im), plasma hydrocortisone values decreased after a 2-hour delay and returned to base line after a 3 to 4 day delay. After prednisolone 21-sodium succinate (iv or im), plasma hydrocortisone decreased immediately (iv) or rapidly (im) and returned to base line after a 24-hour delay. After prednisolone acetate (im), plasma hydrocortisone decreased for up to 21 days.
Interactions of cold stress and Pasteurella haemolytica in the pathogenesis of pneumonic pasteurellosis in calves: Method of induction and hematologic and pathologic changes
Authors: Slocombe R. F. , Derksen F. J. , Robinson N. E. , Trapp A. , Gupta A. , Newman J. P.
Published: February 2025

Six healthy neonatal calves were chilled with cold water and had focal tracheitis induced by spraying 5% acetic acid into the tracheal lumen. Subsequently, 20 ml of sterile saline solution was injected intratracheally. The effects of these interventions on total and differential white cell counts, plasma Cortisol, histamine, and bradykinin, hematocrit, total plasma solids, and indices of the erythrocyte size and hemoglobin content were determined over the subsequent 12 hours. Cold stress increased plasma Cortisol levels for less than 1 hour, but did not alter any other variable. This group of calves served as a control group for a second series of neonatal calves which were given 2 × 109 organisms ofPasteurella haemolytica intratracheally immediately following an identical period of chilling and acetic acid exposure. Calves given P haemolytica became neutropenic. There were increased numbers of circulating band neutrophils by 12 hours after exposure, and serum cortisol values were maintained at the same or greater than cold stress concentrations for all measurement periods subsequent to exposure. Infected calves had acute fibrinous pneumonia from which P haemolytica was isolated. Contrary to previous reports, these data may indicate a role for the neutrophil in the pathogenesis of early lesions of pasteurellosis. Although the association of circulating corticosteroids with stress and subsequent infection is clear, our data provide no evidence to indicate that circulating histamine or bradykinin are involved in the pathogenesis of the acute lesions of Pasteurella pneumonia.
Effect of levamisole on lymphocyte blastogenesis and neutrophil function in dexamethasone-treated cattle
Authors: Roth James A. , Kaeberle Merlin L.
Published: February 2025

Levamisole was evaluated at 6 dose levels for its ability to prevent the dexamethasone-induced suppression of in vitro lymphocyte blastogenesis or neutrophil function in cattle. Dexamethasone (0.4 mg/kg of body weight, im) and levamisole hydrochloride (0.5, 1.0, 2.0, 4.0, or 8.0 mg/kg orally) were administered to groups of 4 cattle daily for 3 days. Another group of 4 cattle were given the 3-day dexamethasone treatment and 6.0 mg/kg of levamisole (the recommended anthelmintic dose) was given only once on the 1st day that dexamethasone was given. Results obtained from the dexamethasone-levamisole-treated cattle were compared with results obtained from cattle that were given only dexamethasone. Levamisole had no apparent consistent ability to enhance lymphocyte blastogenic responsiveness (to the mitogens phytohemagglutinin, concanavalin A, or pokeweed mitogen or in a 1-way mixed lymphocyte reaction) or to enhance neutrophil function (random migration, nitroblue tetrazolium reduction, iodination, or antibody-dependent cell-mediated cytotoxicity) in dexamethasone-treated cattle.
Caprine arthritis-encephalitis virus isolated from Michigan goats
Authors: Pawlisch Ray A. , Maes Roger K.
Published: February 2025

A syncytium-forming agent with reverse transcriptase activity was isolated in cell culture from materials collected from 19 Michigan goats and 1 goat recently imported from California. Syncytia formation could be maintained by subpassaging cells or filtered supernate from infected cultures with caprine fetal synovial membrane indicator cells. Electron microscopy by negative staining with ammonium molybdate revealed 100-nm retrovirus-like particles morphologically identified as caprine arthritis-encephalitis virus. The agent was recovered from synovial membrane explants, synovial fluid, colostrum cells, and peripheral blood mononuclear cells of clinically arthritic goats. Samples were collected from 9 Michigan goat herds, and virus was isolated from 7 of these herds.
Role of canine parainfluenza virus and Bordetella bronchiseptica in kennel cough
Authors: Wagener Jeffrey S. , Sobonya Richard , Minnich Linda , Taussig Lynn M.
Published: February 2025

The effect of Bordetella bronchiseptica upper airway colonization on the clinical, radiographic, serologic, pathologic, and pulmonary function changes caused by canine parainfluenzal virus (cpiv-2) infection was studied in 24 purebred Beagle pups (10.5 ± 1.4 weeks old). Eight control dogs (group I) were not colonized or inoculated with cpiv-2. Of the 12 noncolonized dogs inoculated with cpiv-2 (group II), 9 developed antibody titers to cpiv-2 and 10 had clinical signs of infectious canine tracheobronchitis (kennel cough). Group I and group II dogs did not differ in radiographic findings or pulmonary function. Four group II dogs necropsied 1 to 5 days after clinical signs developed had laryn-gotracheobronchitis and bronchiolar inflammation not present at necropsy on 2 group I dogs. Four dogs had B bronchiseptica upper airway colonization and were inoculated with cpiv-2 (group III). All 4 group III dogs developed positive antibody titers, had clinical signs of kennel cough, and had radiographic changes. Pulmonary dynamic compliance was lower in group III than in group I or group II animals. Respiratory rate and tidal volume did not differ among the 3 groups. The 1 group III dog that was necropsied had changes similar to group II dogs with the addition of lobar bronchopneumonia. The present study indicates that asymptomatic B bronchiseptica colonization may effect the clinical, radiographic, and pulmonary function changes produced by cpiv-2 respiratory tract infections.
Inflammation induced by subcutaneous turpentine inoculation of young American alligators (Alligator mississippiensis)
Authors: Mateo M. R. , Roberts E. D. , Enright F. M.
Published: February 2025

Turpentine-induced skin lesions in young American alligators (Alligator mississippiensis) kept at 25 C were used to study inflammatory response in a reptile. Skin harvested at intervals between 4 hours and 30 days after inoculations were done had no gross changes until days 24 to 26, when superficial skin necrosis was evident. Early responses of congestion and dermal edema (4 to 8 hours) were seen by light microscopy, and these were followed by necrosis and granulocyte migration (1 to 3 days). Later, there was predominance of monocytic cells, including vacuolated macrophages (7 to 30 days). Evident at 14 days and prominent by day 30 were central dermal zones of necrotic debris surrounded by orderly palisades of vacuolated multinucleated giant cells and capillary-laden immature fibrous connective tissue. Systemic illness or visceral lesions were not observed. Controls, given inoculations of sterile saline solution, had no gross or microscopic changes.
Electron microscopy of equine respiratory viruses in organ cultures of equine fetal respiratory tract epithelium
Authors: O'Niell Fielding D. , Issel Charles J. , Henk William G.
Published: February 2025

Organ cultures of equine fetal tracheal and nasal turbinate epithelium were inoculated with equine influenza virus-A1 (eiv-A1), equine herpesvirus-1 (ehv-1), or equine rhinovirus-1 (erv-1). Infected organ cultures were processed for scanning and transmission electron microscopy at various intervals and were compared with non-infected controls. Organ cultures inoculated with erv-1 appeared normal with the exception of rare island-like lesions in infected nasal turbinate. Virus particles were not seen in thin sections of organ cultures infected with erv-1. The ehv-1 caused extensive loss of the epithelial layer in tracheal and nasal turbinate organ cultures. The classic stages of herpesvirus morphogenesis were seen in thin sections of organ cultures infected with ehv-1. The eiv-A1 caused a scattered loss of cilia that was only apparent in infected tracheal organ cultures. Cilia were also seen bound in bundles. In thin sections, eiv-A1 particles were seen budding from the bases of microvilli.
Functional and ultrastructural changes in neutrophils from mares and foals experimentally inoculated with a respiratory tract strain of equine herpesvirus-1
Authors: Coignoul F. L. , Bertram T. A. , Cheville N. F.
Published: February 2025

Neutrophils isolated from venous blood of adult and foal ponies inoculated with equine herpesvirus-1 were evaluated by in vitro function tests and by electron microscopy. Foals had fever and severe neutropenia 24 hours after inoculation; increased neutrophil random migration under agarose and decreased antibody-dependent cell-mediated cytotoxicity were significant at 24 hours, but values had returned to preinoculation levels by 72 hours. Mares had fever and leukopenia of less severity, increases in neutrophil migration, and longer persistence of primary granule release than were seen in foals. Reduced migration and degranulation, and a decrease in antibody-dependent cell-mediated cytotoxicity seen with neutrophils from foals, as compared with mares, may relate to the high susceptibility of foals to equine herpesvirus-1 infection.
Ultrastructure of canine, feline, and bovine mast cell neoplasms
Authors: Madewell B. R. , Munn R. J. , Phillips L. K.
Published: February 2025

Biopsy specimens were collected from skin or spleen from 8 dogs, 7 cats, and 1 cow with mast cell neoplasms. Following histopathologic grading, the neoplasms were examined by transmission electron microscopy with the intention of reviewing their fine structure and recording new findings. For 2 feline specimens, short-term cell cultures were established, and adherent cells were fixed in situ and examined with the electron microscope.

In addition to the usual array of mast cell organelles, including Golgi apparatus, secretory granules, mitochodria, vesicles, tubules, microfilaments, and ribosomes, important findings included coarse interdigitation of cytoplasmic projections between adjacent mast cells; intracytoplasmic parallel stacks of 10 nm diameter filaments as well as parallel arrays of coarse, 120 to 150 nm diameter tubules; the appearance of coated vesicles and caveolae on cell surfaces; the appearance of endocytosed erythrocytes; and the formation of giant secretory granules.
Staphylococcus sciuri subsp lentus associated with goat mastitis
Authors: Poutrel B.
Published: February 2025

An organism recovered from mastitic milks of goats was identified as Staphylococcus sciuri subsp lentus. Isolation of this organism in pure cultures from individual half-udder samples of 5 goats of 18 affected, confirms that it possesses pathogenic potential.
Radial immunodiffusion enzyme assay for detection of antibodies to pseudorabies virus in swine serum
Authors: Joo H. S. , Molitor T. W. , Leman A. D.
Published: February 2025

A radial immunodiffusion enzyme assay for the detection and quantitation of antibodies to pseudorabies virus in swine sera was developed and the methods were standardized. The assay combined the principle of radial immunodiffusion with enzyme-linked immunosorbent assay. Quantitation of pseudorabies virus antibody titers was determined by measuring the diameter of a colored circular zone after overnight incubation of antibody with antigen. The specificity and sensitivity of the radial immunodiffusion enzyme assay were compared with that of the standard virus-neutralization test, and the results were determined to be correlated highly (r = 0.694, P < 0.0001). The assay also appeared to be highly reproducible and simple to perform.
Controlled tests of activity of ivermectin against natural infections of migratory large strongyles and other internal parasites of equids
Authors: Drudge J. H. , Lyons E. T. , Tolliver S. C.
Published: February 2025

Four controlled tests (experiments A, B, C, and D) were conducted in naturally infected yearling equids to evaluate activity of ivermectin (0.2 mg/kg im) against migrating Strongylus vulgaris and S edentatus in mesenteric arteries and ventral abdominal wall, respectively. Data were also obtained on activity against other internal parasites of the gastrointestinal tract and eyeworms. The type and number of equids in the experiments were as follows: experiment A—3 ponies, 2 treated and 1 nontreated; experiment B—4 mixed-bred horses, 2 treated and 2 nontreated; experiment C—5 mixed-bred horses, 3 treated and 2 nontreated; experiment D—4 mixed-bred horses, 2 treated and 2 nontreated Intervals between treatment and necropsy were 35 days in experiment A, 52 to 53 days in experiment B, 38 to 41 days in experiment C, and 45 days in experiment D.

Efficacious killing of retroperitoneal forms of S edentatus in the ventral abdominal wall was obtained in the 4 experiments. Only dead worms or fragments were recovered from treated animals, while living 4th-stage and/ or 5th-stage S edentatus was present in nontreated equids in each test. A similar killing effect on S vulgaris in cranial mesenteric arteries was recorded in 2 experiments (B and D); only 1 dead 5th-stage worm was found in 1 of the treated yearlings in experiment B, whereas living 4th- and 5th-stages of S vulgaris were found in the nontreated controls in both experiments. These migrating forms of S vulgaris were not present in the nontreated pony in experiment A or in the horses in experiment C.

Data on parasites of the gastrointestinal tract indicated overall effective removals of S vulgaris, S edentatus, Gasterophilus intestinalis, G nasalis, Habronema muscae, Draschia megastoma, Oxyuris equi, and Parascaris equorum. In contrast, a lack of activity against the tapeworms, Anoplocephala perfoliata and Anoplocephala magna, was indicated by the limited data. Likewise, limited data indicated that the eyeworm Thelazia lacrymalis was not effectively removed. Untoward effects were not observed in any of the treated animals in these tests.
Pathogenesis of feline gastric chlamydial infection
Authors: Gaillard Elias T. , Hargis Ann M. , Prieur David J. , Evermann James F. , Dhillon Aviar S.
Published: February 2025

Studies were conducted to determine whether the gastric chlamydiae that have been observed recently in cats are of pathologic significance. Chlamydiae were isolated in mouse L cell cultures from the homogenized pooled gastric mucosa of 3 cats that had been identified, by histopathologic examination, to have gastric chlamydiosis. Ten specific-pathogen-free kittens were exposed by aerosol and oral inoculation to the harvested feline gastric chlamydiae cell-culture media. In general, the clinical signs and lesions were conjunctivitis, rhinitis, and mild gastritis. The clinical signs and lesions were most severe in 2 chlamydia-infected kittens that had received methylprednisolone acetate (50 mg/kg of body weight). Chlamydiae were demonstrated in epithelial cells of conjunctival and nasal smears in 10 of 10 infected kittens from postexposure days 7 through 35. In addition, chlamydiae were isolated in L cell cultures from a variety of antemortem and postmortem specimens from infected kittens. The present study provided evidence that feline gastric chlamydiae, under appropriate conditions, were capable of inducing, in cats, clinical signs and lesions similar to those induced by the feline pneumonitis agent.
Efficacy of ethylenediamine dihydriodide in the prevention of naturally occurring foot rot in cattle
Authors: Maas J. , Davis L. E. , Hempstead C. , Berg J. N. , Hoffman K. A.
Published: February 2025

The efficacy of an ethylenediamine dihydriodide containing salt mixture was evaluated with regard to the prevention of naturally occurring foot rot in pastured cattle. Ninety-six cattle were assigned to the treatment group and 96 were assigned to the control group. The groups were allowed consumption of salt-mineral mixtures, ad libitum, that were identical, except with respect to iodine concentration. The control group's mixture contained 0.0025% iodine and the treatment group's mixture contained 0.125% iodine (0.156% ethylenediamine dihydriodide).

The incidence of foot rot was measured, as was the severity of the lesions and accompanying lameness. The incidence of foot rot in the control group (20.8%) was significantly (P < 0.05) greater than the incidence in the treatment group (8.3%). The severity of foot rot was greater (P = 0.024) in the control calves vs the treatment calves.

Total serum iodine concentrations were measured in the 2 groups on days 0, 46, and 130 of the experiment. The serum iodine values of the treatment group on day 46 (46 ± 19.8 g/dl) and day 130 (23 ± 12.3 g/dl) were significantly different (P < 0.01) than the serum iodine concentrations of the control animals and the pretreatment values (day 0) of both groups.

Production was measured via calf weaning weights. There were no detectable differences between the 205-day adjusted weaning weights of the calves in the control group vs the calves in the treatment group. Clinical signs of iodism were not observed in the cattle involved in this study.
Comparison of protection induced in lambs by Corynebacterium pseudotuberculosis whole cell and cell wall vaccines
Authors: Brogden K. A. , Cutlip R. C. , Lehmkuhl H. D.
Published: February 2025

Colostrum-deprived lambs were vaccinated im with 10 mg (dry weight) of Corynebacterium pseudotuberculosis whole cells (wc) or cell walls (cw) and their immunity was challenged by iv injection of 3.1 × 104 colony-forming units of C pseudotuberculosis. Before challenge exposure, the logarithmic mean antibody titers were 2.0837 in lambs that were vaccinated with wc, 2.6858 in lambs that were vaccinated with cw, and 1.4214 in control lambs. Significant protection was demonstrated by fewer abscesses and organisms in the lungs of lambs vaccinated with wc or cw (P < 0.05) than in control lambs. By the same criteria, more protection was provided to lambs vaccinated with cw than to lambs vaccinated with wc.
Biological assay of attenuated strain NADL-2 and virulent strain NADL-8 of porcine parvovirus
Authors: Mengeling William L. , Pejsak Zygmunt , Paul Prem S.
Published: February 2025

Attenuated strain NADL-2 and virulent strain NADL-8 of porcine parvovirus (ppv) were titrated in vivo and in vitro under similar conditions to provide a better understanding of some of the factors involved in virulence of ppv in causing maternal reproductive failure of swine. Both strains cause fetal death when they are injected directly into fetal fluids, but only strain NADL-8 does so when administered to pregnant swine. The strains were tested for their hemagglutinating activity (ha), median cell culture infective dose (ccid50), median fetal infective dose (fid50), and median fetal lethal dose (fld50), The fid50 and fld50 were determined by injecting virus directly into the amniotic fluid of fetuses in utero at 44 ± 2 days of gestation and collecting the fetuses 15 ± 1 days later.

Both strains had an ha titer of 64, suggesting that there is a similar number of virions in stock preparations. However, other measurements differed markedly. The ccid50, fid50, and fld50 were 105.5, 103.5, and 100.5, respectively, for strain NADL-2, and 104.5, 107.7, and 106.3, respectively for strain NADL-8. Collectively, the values indicate that more than 10,000 times as much strain NADL-2 would need to reach the conceptus transplacentally to establish infection. These observations may help to explain the different consequences of oronasal exposure of pregnant swine to these strains of ppv.