bluuebunny/crossref_metadata_2025 huggingface dataset:
Eleven-year analysis of changes in the incidence and recurrence of cystic ovarian disease in a herd of dairy cattle in California
Authors: Scholl Daniel T. , BonDurant Robert H. , Farver Thomas B.
Published: January 2024

Individual card records of all cows that began 1 or more lactations between the inclusive dates of Jan 1, 1976 and Dec 31, 1986 were obtained from a California dairy herd. Calving date, lactation number, physical examination date, conception date, and clinical findings pertinent to cystic ovarian disease (cod) were extracted from the records. Lactation-specific data were organized into cohorts by quarter and year in which lactation began, and the following estimates were calculated for each of the 44 cohorts: separate actuarial cumulative incidences for cows in their first lactation, cows in the second or later lactation, and all cows combined; separate proportions of the incident cases that were in their second or greater lactation and that had recurred from any previous lactation; proportions of the incident cases that had recurrence of cod 1 or more times, and recurrence 2 or more times during the lactation; and the mean number of days in lactation at diagnosis of the incident case. Time-series analysis and multiple-regression modeling procedures were used to characterize changes in the overall incidence rate over the study period and to describe the contribution of additional measures to the dynamics of the incidence rates. The quarterly actuarial cumulative incidences of cod increased concurrently with the increased incidence among cows in the second or later lactation. Neither the proportion of incident cases that were diseased during a previous lactation nor the proportion of cases that were in the second or later lactation contributed to the observed changes in the overall incidence rate. The proportions of incident cases that recurred 1 or more times during the lactation did not increase, but the proportions that had 2 or more recurrences increased equivocally.
Urinary indices of renal function in sheep with induced aminoglycoside nephrotoxicosis
Authors: Garry Franklyn , Chew Dennis J. , Hoffsis Glen F.
Published: January 2024

Aminoglycoside nephrotoxicosis (agnt) was induced in ewes by daily sc administration of gentamicin. Changes in urinary indices of renal function during the development of agnt are reported. Measurements from timed, volume-measured urine samples were made on days 0, 7, and 8 and included creatinine clearance, total excretion (te) rates of electrolytes (Na, K, Cl, P) and urine volume. Measurements from free-catch urine samples (without volume measurement) were made daily and included fractional excretion (fe) rate of electrolytes, urine osmolality, and urine-to-serum osmolality and urine-to-serum creatinine ratios. With the onset of agnt, FE rates of Na, K, Cl, and P increased many fold above baseline values (200 ×, 4 to 5 ×, 6 to 9 ×, and 70 to 95 ×, respectively, on days 7 and 8), indicating decreased tubular reabsorption or increased tubular secretion. The increased FE rates were not representative of increases in total electrolyte excretion rates. The total excretion of Na (TENa) was mildly increased, TEK was decreased, TECl was unchanged, and TEP was significantly increased on days 7 and 8. Abnormal urinalysis results, glucosuria, and increased FEP preceded appreciable increase in serum creatinine concentration. Other abnormal urinary indices of renal function coincided with or followed the increase in serum creatinine concentration. Urinary indices may help characterize renal function associated with the disease state, but did not provide early indication of agnt.
Determination of concentration of hyaluronate in equine serum
Authors: Tulamo Riitta-Mari , Saari Herkko , Konttinen Yrjö T.
Published: January 2024

Concentration of hyaluronate (ha) in equine serum was determined by a recently developed specific radioassay. The mean ± SD HA concentration in equine serum was 288 ± 145 μg/L, was age dependent, and varied widely between horses (range, 190 to 760 μg/L).

Light or moderate exercise increased serum ha concentration from baseline values by 1.5- to 3-fold. In all horses, serum ha concentration returned to or below the original resting values 1 and 2 hours after exercise.
Duration of etomidate-induced adrenocortical suppression during surgery in dogs
Authors: Dodam John R. , Kruse-Elliott Kris T. , Aucoin David P. , Swanson Clifford R.
Published: January 2024

Plasma cortisol concentrations were compared in canine surgical patients given etomidate (2 mg/kg of body weight, iv) or thiopental sodium (12 mg/kg, iv) for anesthetic induction. Blood samples to determine plasma concentrations of etomidate were obtained at 0, 5, 10, 15, and 30 minutes and 1, 2, 3, 4, 5, 6, 8, 12, and 24 hours after induction. Adrenocortical function was evaluated before surgery by use of adrenocorticotropic hormone stimulation tests. Dogs in both induction groups had high plasma cortisol concentrations after induction. Dogs given thiopental had a significant increase (P < 0.05) in plasma cortisol concentration from baseline at 2, 3, 4, 5, 6, 8, and 12 hours after induction. Dogs given etomidate had a significant increase (P < 0.05) in plasma cortisol concentration from baseline at 5, 6, and 8 hours after induction. A comparison of plasma cortisol concentrations determined at 2, 3, 4, 5, and 6 hours after induction with thiopental or etomidate revealed a higher (P < 0.05) concentration in dogs given thiopental.

The disposition of etomidate was best described by a 2-compartment model, with a redistribution half-life of 0.12 ± 0.04 minute and a terminal half-life of 1.70 ± 0.27 minute. Plasma cortisol concentrations did not correlate with plasma etomidate concentrations.

We conclude that, compared with thiopental, a single bolus injection of etomidate reduces the adrenocortical response to anesthesia and surgery from 2 to 6 hours after induction. Because cortisol concentrations were significantly higher than baseline, and because cardiopulmonary function is maintained after a single bolus injection of etomidate, it can be considered a safe induction agent in dogs.
Protein requirements of growing pups fed practical dry-type diets containing mixed-protein sources
Authors: Case Linda P. , Czarnecki-Maulden Gail L.
Published: January 2024

The protein requirement of Pointer pups fed practical diets was assessed in 3 experiments. Eight-week-old pups required 25.2% protein when fed a combination of corn gluten meal, soybean meal, and meat and bone meal for 2 weeks. However, when a poor-quality poultry by-product meal was substituted for some of the corn gluten meal and meat and bone meal, the requirement increased to 27.5%. This increased requirement was explained by decreased digestibility of the poultry by-product meal diet. Pups fed each of the diets required 18% digestible protein to maximize growth rate. Sixteen-week-old pups were more efficient at utilizing the experimental diets, requiring only 23% crude protein (17.2% digestible protein) to maximize growth rate.
Serum disposition of exogenous progesterone after intramuscular administration in bitches
Authors: Scott-Moncrieff J. C. , Nelson R. W. , Bill R. L. , Matlock C. L. , Bottoms G. D.
Published: January 2024

Progesterone was administered im to 6 adult anestrous bitches at a dosage of 2 mg/kg of body weight. Serum progesterone concentrations were measured prior to progesterone administration and for 72 hours thereafter. The serum progesterone concentration time data were analyzed by use of a pharmacokinetics modeling computer program. The mean (± sd) peak serum progesterone concentration (34.3 ± 7.8 ng/ml) was reached at 1.8 ± 0.2 hours after progesterone administration. The mean serum progesterone concentration was 6.9 ± 1.4 ng/ml at 24 hours and 2.0 ± 0.4 ng/ml at 48 hours after progesterone administration. By 72 hours after administration, mean serum progesterone concentration was 0.9 ± 0.2 ng/ml, which was comparable to serum progesterone concentrations prior to injection. The mean half-life of the absorption phase was 0.5 hours (range, 0.3 to 0.7 hours). The mean half-life of elimination was 12.1 hours (range, 9.5 to 13.8 hours). By analysis of the data, it was established that a dosage of 3 mg/kg, when the hormone was given im to dogs once a day, would maintain serum progesterone concentration > 10 ng/ml.
Experimental transmission of a granulocytic form of the tribe Ehrlichieae by Dermacentor variabilis and Amblyomma americanum to dogs
Authors: Anziani Oscar S. , Ewing S. A. , Barker R. W.
Published: January 2024

Transstadial transmission of granulocytic Ehrlichieae in dogs was attempted using ticks, Amblyomma americanum and Dermacentor variabilis. Ticks were exposed by feeding as nymphs on acutely infected pups; adult ticks then fed to repletion on susceptible adult dogs that were monitored daily for signs of infection. Evidence of transmission was not observed in control dogs or in those exposed to D variabilis. In contrast, dogs exposed to A americanum developed serologic or clinical evidence of infection, but organisms were not seen in blood smears until corticosteroids were administered, causing recrudescence and accompanying parasitemia. At 12 days after subinoculation of blood obtained from donor adult dogs, before corticosteroids were administered, a febrile response, thrombocytopenia, and appearance of morulae in neutrophilic granulocytes were observed in 2 susceptible recipient dogs.
Effect of age on isoproterenol-induced maximal heart rate in horses
Authors: Goetz Thomas E. , Manohar Murli
Published: January 2024

The effect of age on maximal heart rate induced by iv infusion of isoproterenol was studied in 19 healthy, sedentary, normothermic horses ranging in age from 0.25 to 9.90 years. Isoproterenol was administered iv (1.0 μg/kg of body weight/min) for 3 minutes, and the heart rate attained during the last 30 seconds of the infusion was determined. Linear regression of the maximal heart rate on age suggested that the rate decreased with age in a trend described by the equation: maximal heart rate (beats/min) = 209.63 − 3.28 × age (years). The regression coefficient (r) for this relation was 0.769 (P < 0.001). These data indicate that as healthy horses age, their β-adrenoceptor-mediated maximal chronotropic response is diminished.
Influence of cortisol and different steroidogenic pathways on estrogen synthesis by the bovine placenta
Authors: Hoedemaker Martina , Weston Patricia G. , Wagner William C.
Published: January 2024

The influence of cortisol on estrogen synthesis by the bovine placenta and the importance of the Δ4 and Δ5 pathway for estrogen production were investigated. For experiment 1, portions of fetal villi (200 mg) were incubated for 48 hours with 0, 10, 100, and 1,000 ng of cortisol/ml with [3H]androstenedione (3H-A) or [3H]pregnenolone (3H-P5). Villi were also incubated for 4, 28, and 52 hours with or without cortisol (500 ng/ml) and with 3H-A or 3H-P5 (experiment 2). The conversion of various [3H]steroid metabolites such as A, P5, 17α-OH-pregnenolone (17α-OH-P5), progesterone (P4), 17α-OH-P4, cholesterol (chol), and chol plus lipoprotein (500 μg/ml) into estrogen was measured during a 4-hour incubation (experiment 3). In experiment 1, cortisol increased conversion of 3H-A and 3H-P5 into estrogen by 3 to 41% and 7 to 34%, respectively, in a dose-dependent manner (P < 0.05). In experiment 2, times of incubation did not influence conversion of 3H-A into estrogen, which, however, was increased significantly (P < 0.05) over all times of incubation by administration of 500 ng of cortisol/ml. Conversion of 3H-P5 into estrogen increased over time of incubation and was stimulated by cortisol (P < 0.05). However, there was no interaction between cortisol treatment and time of incubation. In experiment 3, conversion of 3H-A, 3H-P5, and 3H-17α-OH-P5 into estrogen was greater than the conversion of the other precursors tested. Mean conversion of 3H-A, 3H-P5, 3H-17α-OH-P5, 3H-P4, 3H-17α-OH-P4, 3H-chol, and 3H-chol plus lipoprotein was 23%, 10.6%, 11.0%, 1.8%, 1.8%, 0.3% and 0.7%, respectively. Our results suggest that, in cows, the Δ5 pathway is the preferred pathway for placental estrogen synthesis and that cortisol directly stimulates estrogen production, probably by activating enzymes involved in this pathway.
Determination of a sedative dose and influence of midazolam on cardiopulmonary function in Canada geese
Authors: Valverde Alexander , Honeyman Virginia L. , Dyson Doris H. , Valliant Anne E.
Published: January 2024

Midazolam HCl (1.0 or 2.0 mg/kg of body weight) was administered im to 6 Canada geese to determine a sedative dose that would allow positioning for radiologic examination. The effects of both test doses on cardiopulmonary function were evaluated at 5, 10, 15, 20, 30, and 40 minutes after drug administration and were compared with 2 end-tidal isoflurane concentrations (1.5 and 2.5%). The 2.0 mg/kg dosage induced moderate sedation at 15 and 20 minutes; sedation was adequate for positioning the geese. Sedation induced by the 1.0 mg/kg dosage was inadequate. The effects of both test doses on blood pressure, heart rate, and temperature were not significantly different from each other and from baseline data. Respiratory rate increased significantly (P < 0.05) at 10, 15, 20, and 30 minutes with the 2.0 mg/kg dosage, and at 15 and 20 minutes with the 1.0 mg/kg dosage. Blood pressure and respiratory rate were significantly (P < 0.05) decreased with isoflurane when compared with baseline data and the midazolam test doses. The results of this study indicate that midazolam at a dosage of 2.0 mg/kg induces adequate sedation with minimal cardiopulmonary changes, and, as an alternative to general anesthesia with isoflurane, provides a satisfactory level of restraint for radiography.
Morphologic measurements of the external horizontal ear canal of dogs
Authors: Stout-Graham Michele , Kainer Robert A. , Whalen L. Ray , Macy Dennis W.
Published: January 2024

Microscopic anatomy of the horizontal part of the external ear canal was evaluated in 24 dogs. Sixteen dogs were from breeds known to have a predisposition to otitis externa. The remaining 8 dogs were from breeds that do not have a predisposition to otitis externa. Dogs were separated into groups according to predisposition to otitis externa: group 1—predisposed dogs without otic inflammation, group 2—predisposed dogs with otic inflammation, and group 3—nonpredisposed dogs without otic inflammation.

Qualitative microscopic evaluation of distribution of hair follicles revealed hair within proximal, middle, and distal regions of the horizontal ear canal in all breeds. The degree of keratinization was directly proportional to the presence of otic inflammation and was excessive in group-2 dogs.

Quality of sebaceous glands within the horizontal ear canal was similar among dogs with and without otitis externa, whereas the quantity of apocrine tubular glands was significantly increased (P < 0.05) in dogs with otitis. Quantity of apocrine tubular glands was also greater in group-1 dogs than in group-3 dogs.

Thickness of the soft tissue in the external ear canal increased in direct proportion to the progression of disease and was greatest in the proximal region of the affected ear canal. Soft tissue located caudally between nonopposing ends of the annular cartilage, within the proximal region of the horizontal ear canal, contained few glands and hair follicles in dogs without otitis externa. In dogs with otitis externa, this region was infiltrated by distended apocrine tubular glands.
Effect of hypertonic vs isotonic saline solution on responses to sublethal Escherichia coli endotoxemia in horses
Authors: Bertone Joseph J. , Gossett Kent A. , Shoemaker Katherine E. , Bertone Alicia L. , Schneiter Harvey L.
Published: January 2024

Cardiovascular responses to sublethal endotoxin infusion (Escherichia coli, 50 μg/ml in lactated Ringer solution at 100 ml/h until pulmonary arterial pressure increased by 10 mm of Hg) were measured 2 times in 5 standing horses. In a 2-period crossover experimental design, horses were either administered hypertonic (2,400 mosm/kg of body weight, iv) or isotonic (300 mosm/kg, iv) NaCl solution after endotoxin challenges. Each solution was administered at a dose of 5 ml/kg (infusion rate, 80 ml/min). Complete data sets (mean arterial, central venous, and pulmonary arterial pressures, pulmonary arterial blood temperature, cardiac output, total peripheral vascular resistance, heart rate, plasma osmolality, plasma concentration of Na, K, Cl, and total protein, blood lactate concentration, and pcv) were collected at 0 (baseline, before endotoxin infusion), 0.25, 1, 1.5, 2, 2.5, 3, 3.5, 4, and 4.5 hours after initiation of the endotoxin infusion. Blood constituents alone were measured at 0.5 hour and cardiovascular variables alone were evaluated at 0.75 hour. By 0.25 hour, endotoxin infusion was completed, a data set was collected, and saline infusion was initiated. By 0.75 hour, saline solutions had been completely administered.

Mean (± sem) cardiac output decreased (99.76 ± 3.66 to 72.7 ± 2.35 ml/min/kg) and total peripheral resistance (1.0 ± 0.047 to 1.37 ± 0.049 mm of Hg/ml/min/kg) and pulmonary arterial pressure (33.4 ± 0.86 to 58.3 ± 1.18 mm of Hg) increased for both trials by 0.25 hour after initiation of the endotoxin infusion and prior to fluid administration. For the remainder of the protocol, cardiac output was increased and total peripheral resistance was decreased during the hypertonic, compared with the isotonic, saline trial. Cardiac output was decreased and total peripheral resistance was increased during the isotonic saline trial, compared with baseline values. Both trials were associated with increased blood lactate concentration, but lactate values during the isotonic saline trial were greater and remained increased above baseline values for a longer period (4 hours) than during the hypertonic saline trial (2.5 hours). It was concluded for this model of endotoxemia, that iv administered hypertonic saline solution was associated with more-desirable cardiovascular and metabolic responses than was an equal volume of isotonic saline solution.
Development of brachytherapy technique for nasal tumors in dogs
Authors: White Richard , Walker Michael , Legendre Alfred M. , Hoopes Jack , Smith Joey , Horton Sandra B.
Published: January 2024

Two groups of 4 dogs underwent nasal and ethmoidal turbinectomies followed by irradiation (mean minimal doses of 5,390 and 6,550 cGy of radiation, respectively) from implanted intracavitary sources of iridium 192. Two dogs from each group were euthanatized for histologic evaluation at 3 months after irradiation. The remaining 2 dogs from each group were euthanatized for similar evaluation at 6 months after irradiation. During the course of the study, few clinical complications were encountered. Histologic evaluation of the tissues forming the nasal passages revealed loss of epithelial lining and fibrous tissue replacement of surrounding bone. A direct correlation of pathologic changes could not be associated with the amount of radiation received, but there seemed to be a tendency for greater change in those dogs given higher doses and those kept alive for 6 months.
Effect of acute acidemia on blood biochemical variables in healthy ponies
Authors: Gossett K. A. , French D. D. , Cleghorn B. , Church G. E.
Published: January 2024

l-Lactic acid and d, l-lactic acid infusion in ponies resulted in metabolic acidosis with high anion gap (ag). Increased ag was explained entirely by increased blood l- and d-lactate concentrations. Hydrochloric acid infusion caused metabolic acidosis with decreased ag. Saline (NaCl) infusion caused mild metabolic acidosis, with no significant change in ag.

Plasma K+ concentration was decreased by all types of infusions, with a maximum of 0.50, 0.25, 0.40, 0.50 mmol/L below baseline at the end of infusion in the l-lactic acid-, d,l-lactic acid-, HC1-, and NaCl-infused ponies, respectively. Only hydrochloric acid had a tendency to increase plasma K+ concentration.

Hypophosphatemia developed in NaCl- and HCl-infused ponies, but not in the d, l-lactic acid-infused ponies. Serum inorganic phosphate concentration in l-lactic acid-infused ponies increased initially, but was significantly (P < 0.05) lower than values in the other ponies at 4 hours after onset of infusion.

In ponies, the effect of acidemia on plasma K+ and serum inorganic phosphate concentrations was similar to that reported for other species. Changes were small in magnitude and depended on the nature of the acid anion. Results indicate that large changes in plasma K+ and serum inorganic phosphate concentrations during acidosis are probably not a direct result of acidemia.
Characterization of a panel of monoclonal antibodies and their use in the study of the antigenic diversity of bovine viral diarrhea virus
Authors: Corapi Wayne V. , Donis Ruben O. , Dubovi Edward J.
Published: January 2024

A panel of 40 monoclonal antibodies (MAb) specific for bovine viral diarrhea virus (bvdv) was produced, and each MAb was characterized and grouped according to its viral protein specificity, immunoglobulin subclass, virus-neutralizing activity, and immunoreactivity with a large collection of bvdv isolates. The MAb were found to be specific for 1 of 3 sets of related viral-induced proteins found in cells infected with the Singer strain of bvdv. Group-1 MAb were specific for the 80- and 118-kilodalton (kD) proteins of bvdv. Group-2 MAb recognized 3 proteins with molecular sizes of 54, 56, and 58 kD. Group-3 MAb recognized a 43- and a 65-kD protein. The MAb belonged to either the IgGl, IgG2a, IgG2b, IgG3 subclasses or the IgE class of mouse immunoglobulin. All MAb in group 2 were able to neutralize bvdv and had neutralization titers that ranged from 24 to 1,600,000. The reactivity of the MAb with numerous field isolates of bvdv was highly variable. Both cytopathic and noncytopathic biotypes of bvdv were examined and had the same degree of antigenic variation. The greatest degree of variation was detected with group-2 MAb. The data demonstrate that bvdv isolates have a high degree of antigenic variation that is largely confined to the envelope glycoproteins associated with virus neutralization. The results also suggest that antigenic variability of this virus is important in the development and severity of the disease it causes.
Quantitative microanalysis of equine synovial fluid glycosaminoglycan concentration
Authors: Little C. B. , Hilbert B. J. , Wickstrom S. , Hedlund B. E.
Published: January 2024

An alcian blue precipitation method for quantifying the hyaluronic acid (ha) and sulphated glycosaminoglycan concentration (sgag) in solutions containing both compounds was assessed. The assay was found to be rapid and reliable in solutions containing 0 to 200 mg of ha/dl and 50 to 1,000 μg of sgag/dl, and was not affected by the presence of protein, hemoglobin, or methemoglobin in concentrations normally found in synovial fluid. The ha and sgag concentrations in intercarpal synovial fluid from 13 clinically normal and 11 arthritic horses were evaluated. A relationship was not found between the concentration of ha and sgag and any other synovial fluid variable. The sgag concentration was found to be markedly high in several of the synovial fluid samples from arthritic horses, but did not correlate with the degree of articular cartilage erosion.
Systemic and secretory antibody responses to sequential bovine respiratory syncytial virus infections in vaccinated and nonvaccinated calves
Authors: Stewart R. S. , Gershwin L. J.
Published: January 2024

To investigate the influence of humoral immunity on the severity of disease caused by infection with bovine respiratory syncytial virus (brsv), an experimentally induced infection study was performed on vaccinated and nonvaccinated calves. Fifteen weanling calves were allotted to 3 groups: 1 group of 6 calves was exposed to 2 live virus aerosols, 35 days apart; another group of 6 calves was vaccinated prior to the same aerosol exposures; and the remaining 3 calves served as controls. Clinical signs of infection were converted to a numerical score for evaluating disease severity. For 14 days after each virus exposure, brsv-specific IgG and IgM concentrations in serum and BRSV-specific IgA concentration in nasopharyngeal exudate and lung lavage fluid were measured by elisa. Serum brsv-specific IgG and IgM and secretory brsv- specific IgA concentrations did not correlate with disease sign expression. There was a strong correlation between viral isolation and disease scores. Vaccination prior to virus exposure appeared to have little or no effect on severity of the disease, but it did appear to affect disease persistence. Findings indicate that the immunoglobulins evaluated may be primarily protective in nature and do not contribute to disease severity.
Effectiveness of arprinocid in the reduction of cryptosporidial activity in immunosuppressed rats
Authors: Rehg Jerold E. , Hancock Michael L.
Published: January 2024

Immunosuppressed rats inoculated with Cryptosporidium oocysts isolated from calves' feces were treated with arprinocid, 50 mg/kg of body weight/d. As determined from differences in the mean number of cryptosporidial developmental stages per villus in treated vs control rats, arprinocid had a substantial effect on cryptosporidial activity, which was parasitistatic instead of parasiticidal. Drug-ranging experiments indicated that arprinocid was effective at 50 and 25 mg/kg/d, but not at 12.5 mg/kg/d. These results suggest that further testing of arprinocid in different animal models, or in phase-I clinical trials, is warranted.
Pharmacokinetics of single doses of digoxin administered intravenously to ducks, roosters, and turkeys
Authors: Pedersoli W. M. , Ravis W. R. , Lee H. S. , Krista L. M. , Spano J. S.
Published: January 2024

A single dose of digoxin was injected, iv, into 5 mature male turkeys (0.066 mg/kg of body weight), 8 male ducks (0.066 mg/kg), and 6 roosters (0.33 mg/kg). Twenty-three serial venous blood samples were collected before (baseline) and after the administration of digoxin to turkeys, ducks, and roosters. Plasma concentrations of digoxin were determined in duplicate by a radioimmunoassay that was validated for avian species. The plasma concentrations were best fitted by a 3 (turkeys, ducks)- and 2 (roosters)- compartment open model, with first-order elimination from the central compartment. Significant (P < 0.05) kinetic differences were determined among species. Mean half-life (t½) for ducks, roosters, and turkeys were 8.30 ± 2.70 (mean ± SD), 6.67 ± 3.50, and 23.7 ± 4.8 hours, respectively. The volume of distribution at steady state (Vss) was 14.7 ± 2.9, 3.13 ± 0.49, and 2.27 ± 0.36 L/kg, and total body clearance (cl) of drug was 1.54 ± 0.43, 0.461 ± 0.187, and 0.136 ± 0.022 L/h/kg for ducks, roosters, and turkeys, respectively. The mean residence time was 10.3 ± 3.9, 8.37 ± 4.97, and 16.8 ± 2.2 hours, respectively. Volume of distribution at steady state and cl in ducks were several fold higher than that in turkeys. The terminal half-life of digoxin determined for ducks and roosters in this study was considerably shorter than those previously reported for several mammalian species.
Recombinant DNA probe detecting Eperythrozoon suis in swine blood
Authors: Oberst R. D. , Hall S. M. , Jasso R. A. , Arndt T. , Wen L.
Published: January 2024

A genomic library to Eperythrozoon suis dnawas constructed in λ gt11, and from this library, E suis clone KSU-2 was identified as a potential diagnostic probe. In hybridization experiments that used 100-μl samples of blood collected in chaotropic salt solutions, the KSU-2 probe hybridized strongly with purified E suis organisms and blood samples from splenectomized swine that were parasitized with E suis. However, the probe under stringent conditions did not give radiographic indications of hybridizing with equine blood dna, bovine blood dna infected with Anaplasma marginale, canine blood dna infected with Ehrlichia canis, feline blood dna infected with Haemobartonella felis, or uninfected swine blood dna.
Pneumonic pasteurellosis induced experimentally in gnotobiotic and conventional calves inoculated with Pasteurella haemolytica
Authors: Vestweber J. G. , Klemm R. D. , Leipold H. W. , Johnson D. E.
Published: January 2024

Experimental pneumonia caused by Pasteurella haemolytica was induced in 2-week-old gnotobiotic (n = 4) and conventional (n = 6) calves by endobronchial inoculation into the right caudal lung lobe of 7.9 × 1010 ± 0.6 × 1010 (mean ± sd) colony-forming units of P haemolytica in the 6-hour log phase of growth. The calves were studied for 24 hours or less. Regression lines for the relationship between clinical index and time for the gnotobiotic group and conventional group of calves were compared, and the clinical index was found to be significantly (P ≤ 0.005) more rapid in the gnotobiotic group. There was also a significant difference in the preinoculation, absolute segmented neutrophil count (P ≤ 0.05), and in the total serum protein, albumin, and globulin values (P ≤ 0.05). Comparison of the preinoculation and post inoculation blood cell and blood chemical values revealed a significant increase (P ≤ 0.05) in the numbers of band neutrophils and fibrinogen in conventional calves, and a significant decrease (P ≤ 0.05) in the total wbc count in gnotobiotic calves. Necropsy of both groups of calves revealed a circular to oblong lesion that was congested, edematous, and firm, and which occupied 20% to 100% of the right caudal lung lobe and involved the remaining lung lobes to a more minor degree. When mean lesion scores of the 2 groups of calves were compared, no significant difference (P ≤ 0.05) was found. Microscopic examination of the lungs revealed edema of the perivascular and interlobular septa and hemorrhage in the alveoli of both groups, although the conventional group had more fibrinopurulent inflammation.
Pulmonary lesions induced by 3-methylindole and bovine respiratory syncytial virus in calves
Authors: Castleman W. L. , Lacy S. , Slauson D. O. , Atz J.
Published: January 2024

Our objectives were to describe the ultrastructural morphogenesis of pulmonary lesions induced by 3-methylindole in 30- to 45-day-old Holstein calves and to determine whether toxic exposure to 3-methylindole exacerbates pulmonary lesions induced by bovine respiratory syncytial virus. Administration of 3-methylindole (0.25 g/kg) to calves resulted in interstitial edema and ultrastructural swelling of type-I alveolar epithelial cells and nonciliated bronchiolar epithelial cells as early as 4 to 6 hours after intraruminal administration. More severe alveolar edema containing protein was associated with swelling of capillary endothelial cells at 2 days after administration. Proliferation of type-II alveolar epithelial cells was first observed at 2 days after 3-methylindole administration, and marked hyperplasia of type-II epithelial cells and nonciliated bronchiolar epithelial cells was evident by 4 days after administration. Pulmonary cytochrome P-450 monooxygenase concentrations decreased significantly (P < 0.001) by 12 hours after administration and did not increase significantly again by 8 days after administration. Calves were inoculated with bovine respiratory syncytial virus 3 days after administration of 3-methylindole, and pulmonary lesions were assessed 5 days after viral inoculation. Viral replication was demonstrated by fluorescence microscopy for viral antigen or by transmission electron microscropy in ciliated and nonciliated airway epithelial cells. Viral antigen was identified infrequently in alveolar macrophages and in type-II alveolar epithelial cells. 3-Methylindole exposure in calves did not result in more widespread distribution of viral antigen in alveolar tissue of respiratory syncytial virus-inoculated calves or in significant enhancement of viral pneumonia. The results indicated that young calves are susceptible to 3-methylindole-induced pulmonary injury and that nonciliated bronchiolar epithelial cells, type-I alveolar epithelial cells, and pulmonary endothelial cells are most susceptible to injury. The results failed to indicate that 3-methylindole pulmonary toxicosis significantly enhances respiratory disease induced by bovine respiratory syncytial virus.
Effect of dose of Brucella abortus strain 19 in yearling heifers on the relative risk of developing brucellosis from challenge exposure with strain 2308
Authors: Crawford Richard P. , Adams L. Garry , Richardson Barbara E.
Published: January 2024

Yearling heifers were given SC injections of 108 (n = 40), 109 (n = 44), or 1010 (n = 44) colony-forming units of Brucella abortus strain 19 (S19). The proportion of heifers with positive serologic test results at 1 month following vaccination increased as the dose of S19 increased. These proportions decreased with time, and all heifers had negative card, rivanol, and complement fixation test results within 4 months. Positive elisa results persisted beyond 4 months in all three S19 dose groups; however, all heifers were elisa-negative within 9 months after vaccination. Comparable lymphocyte transformation activity was stimulated by S19 doss of 109 or 1010 and approximately half of the heifers in both groups had a positive stimulation index at 9 months.

Immunity of the pregnant heifers was challenged 9 months after vaccination with 107 B abortus strain 2308 as follows: diluent controls (n = 69); 108 B abortus S19 (n = 40); 109 B abortus S19 (n = 39); and 1010 B abortus S19 (n = 39). Tissue specimens from heifers were obtained at parturition and necropsy for culturing of B abortus. The proportion of heifers that developed brucellosis, ie, had positive culture results, increased as gestation days at challenge exposure increased. The effect of gestational age was controlled in the analysis using logisic regression. The relative risk of brucellosis was reduced to 0.38, 0.15, and 0.06 for B abortus S19 doses of 108, 109, and 1010, respectively, compared with diluent controls at 1. Risk of brucellosis in heifers vaccinated with 108, 109, or 1010 S19 was, respectively, one-third, one-seventh, or one-seventeenth that of diluent controls or nonvaccinated heifers.
Frequency of association of noncytopathic bovine viral diarrhea virus with bovine neutrophils and mononuclear leukocytes before and after treatment with trypsin
Authors: Bolin Steven R. , Ridpath Julia F.
Published: January 2024

Enriched populations of neutrophils and mononuclear leukocytes from 9 cattle persistently infected with non-cytopathic bovine viral diarrhea virus were analyzed for frequency of association with virus, using flow cytometric procedures. Trypsinization of neutrophils decreased the frequency of viral association from 0.82% to 0.49%. Similar treatment of mononuclear leukocytes decreased the frequency of viral association from 5.53% to 4.81%. Results of immunocytochemical procedures to locate viral antigen were inconclusive for neutrophils, but viral antigen was found in the cytoplasm of mononuclear leukocytes. A distinct and highly pure population of eosinophils was identified during flow cytometric analysis of neutrophil populations from 2 of 9 cattle.
Cultivation of tissue from the matrix of the stratum medium of the equine and bovine hoof walls
Authors: Ekfalck Anders , Rodriguez-Martinez Heriberto , Obel Nils
Published: January 2024

Explants from the matrix of the stratum medium of the wall of the equine and bovine hoof each were cultured on a microporous membrane, using a standard culture medium. After incubation at 37 C, the outgrowth was a mixture of keratinocytes and fibroblasts, with predominance of the latter. After incubation at 34 C, the keratinocytes dominated, covering the lateral surfaces of the explant as well as the basal surface. Lateral outgrowth of keratinocytes was observed at the borderline of the original epidermis and at the borderline of the explant’s contact with the membrane. Epithelial outgrowth from the former consisted of rounded aggregates protruding into the medium, whereas outgrowth from the latter formed a pluristratified carpet occupying a considerable part of the membrane. In the outer layers, keratinocytes covering the cut surfaces of the dermis of the explant had a differentiation pattern of the kind that characterizes the keratinocytes of the hoof; differentiation was not observed in the lateral outgrowth.
Plasma glucocorticoid concentrations in calves as an indicator of stress during parturition
Authors: Hoyer C. , Grunert E. , Jöchle W.
Published: January 2024

Plasma glucocorticoid concentrations and blood gas values were determined for 6 days in 47 newborn calves that had been subjected to various obstetrical procedures at term. Concentrations of glucocorticoids were uniformly high at birth (70 to 103 ng/ml). Increasing degrees of acidosis were accompanied by increasing glucocorticoid concentrations in plasma. Plasma glucocorticoid concentrations decreased sharply during the first 6 hours after delivery and reached a plateau at 48 hours after birth (14 to 21 ng/ml). The latter was taken as an indication that adaptation had been achieved. Calves subjected to severe pulling had higher glucocorticoid concentrations at birth (110.4 ng/ml) than calves requiring no assistance (88.3 ng/ml), calves requiring only slight assistance (83.8 ng/ml), or calves that had been delivered by cesarean section (82.9 ng/ml).
Use of a multiple logistic regression model to determine prognosis of dairy cows with right displacement of the abomasum or abomasal volvulus
Authors: Gröhn Y. T. , Fubini S. L. , Smith D. F.
Published: January 2024

Data at admission and at surgery were collected on 458 cows with right displacement of the abomasum or abomasal volvulus, to derive multiple logistic regression models for predicting postsurgical outcome (productive, salvaged, or terminal). The derived models contained few and easily obtained variables. The weight associated with each variable was determined objectively. Three admission variables (heart rate, base excess, and plasma chloride concentration), and 5 surgical variables (heart rate, base excess, diagnosis, method of decompression used, and appearance of abomasal serosa) were used in the final models. Predicted outcomes that used the admission and surgical models were closely related with actual outcomes. Total correct classification for satisfactory (productive) versus unsatisfactory outcome (salvaged and terminal) was 78.2% for the admission model and 82.7% for the surgical model. Combining data on cows with productive and salvaged outcomes as satisfactory outcome, and terminal as unsatisfactory outcome, total correct classification was 90.7% for the admission model and 93.2% for the surgical model. Using predicted probabilities, the market value of productive and salvaged cows, and the medical and surgical costs, one can calculate the expected economic value of each outcome. Treatment can be justified if the sum of the expected value of productive and salvaged outcome exceeds the sum of the medical and surgical costs and the expected salvaged value of the cow that was not treated surgically.
Use of ELISA for detection of immunoglobulins G and M that recognize Salmonella dublin lipopolysaccharide for prediction of carrier status in cattle
Authors: Spier Sharon J. , Smith Bradford P. , Tyler Jeff W. , Cullor James S. , Dilling George W. , Pfaff Lin Da
Published: January 2024

Immunoglobulin reactions to Salmonella dublin in serum and milk from 4 groups of lactating cows were measured by an indirect elisa. The groups consisted of (1) cows that were natural carriers of S dublin in the mammary gland, (2) experimentally infected cows that did not become carriers, (3) cows inoculated with a commercial S dublin bacterin, and (4) cows used as S dublin-negative controls. Milk and serum samples were obtained at monthly intervals. Models for predicting carrier status were developed by use of stepwise logistic regression. Independent variables consisted of serum and milk IgG and IgM titers to S dublin lipopolysaccharide and a ratio of IgG to IgM. The utility of a single sample vs multiple samples obtained at 1-month or 2-month intervals was tested by comparison of goodness-of-fit χ2 P values for 8 models predicting carrier status.

Immunoglobulin reactions specific to S dublin were a significant predictor of carrier status (P < 0.001). Serum IgG titers specific for S dublin were the most important variable for predicting carrier status. Two serum IgG titers to S dublin obtained 2 months apart was a better predictor of carrier status than measurement of the IgG:IgM ratio from a single serum sample. Immunoglobulin recognizing S dublin epitopes also were detected in milk samples. In milk, performing 2 ELISA 60 days apart to determine IgG and IgM reactions to S dublin appeared to be useful for the prediction of carrier status, but was not as accurate as models for serum immunoglobulin reactions.
Correlation of clinical and laboratory data with serum tumor necrosis factor activity in horses with experimentally induced endotoxemia
Authors: Morris Debra Deem , Crowe Natalie , Moore James N.
Published: January 2024

Serum tumor necrosis factor (tnf) activity was quantitated in 8 horses given an iv infusion of endotoxin (0.03 μg of lipopolysaccharide/kg of body weight, from Escherichia coli 055:B5) in 0.9% NaCl solution over 1 hour. Serum tnf activity was likewise measured in 6 horses given only 0.9% sterile NaCl solution at the same rate. The duration of serum tnf activity was determined, and serum tnf activity was correlated with clinical and laboratory changes during the induced endotoxemia. Horses had no serum tnf activity prior to endotoxin administration, but geometric mean serum tnf activity was significantly higher from 1 to 4 hours after the start of the infusion. In response to endotoxin, horses seemed depressed, had signs of mild to moderate abdominal pain, developed tachycardia and fever, and had leukopenia followed by leukocytosis. Association between serum tnf activity and temperature, heart rate, attitude abnormality score, and wbc count of horses given endotoxin was significant. Serum tnf activity had a significant positive linear correlation with attitude abnormality and heart rate and a negative linear correlation with the wbc count during endotoxemia. Geometric mean serum tnf activity peaked approximately 1.5 hours prior to mean peak fever, and these data were significantly correlated. Results of this study suggest that tnf is an important mediator of endotoxemia in horses.
Immunoperoxidase evaluation of the relationship between necrotic lesions and causative bacteria in lungs of calves with naturally acquired pneumonia
Authors: Haritani M. , Nakazawa M. , Hashimoto K. , Narita M. , Tagawa Y. , Nakagawa M.
Published: January 2024

An immunoperoxidase technique was used to study the relationship between the necrotic lesions and causative bacteria found in lungs of 53 calves that had naturally acquired pneumonia. Four types of necrotic lesions were identified on the basis of morphologic characteristics as follows: type 1 had coagulation necrosis surrounded by a dense zone of numerous degenerated leukocytes; type 2 was similar to type 1, but the central area of the lesions was severely affected, had no alveolar architecture remaining, and was surrounded by a thin, sparse layer of degenerated leukocytes; type 3 had small swirling accumulation of degenerated leukocytes; and type 4 had necropurulent lesions resembling abscesses. By use of the immunoperoxidase technique, Pasteurella haemolytica serovar 1 antigen was confirmed to be associated with the necrotic lesions in many cases of type 1 and in some cases of types 2 and 3. Although some lesions were induced by other bacteria (Haemophilus somnus or Actinomyces pyogenes), the pneumonic lesions associated with P haemolytica could be differentiated from other pneumonic lesions in calves by use of the immunoperoxidase technique.
Effects of human alpha interferon on experimentally induced equine herpesvirus-1 infection in horses
Authors: Seahorn Thomas L. , Carter G. Kent , Martens Judy G. , Crandell Robert A. , Martin Michael T. , Scrutchfield Wilbur L. , Cummins Joseph M. , Martens Ronald J.
Published: January 2024

The immunotherapeutic effect of low-dose human alpha interferon on viral shedding and clinical disease was evaluated in horses inoculated with equine herpesvirus- 1 (ehv-1). Eighteen clinically healthy weanling horses, 5 to 7 months old, were allotted to 3 equal groups. Two groups were treated orally with human α-2a interferon (0.22 or 2.2 U/kg of body weight), on days 2 and 1 before inoculation with ehv-1, the day of inoculation, and again on postinoculation day 1. The horses of the remaining group were given a placebo orally on the same days. The horses were monitored daily for changes in body temperature and for clinical signs of respiratory tract disease. Blood and nasal swab specimens were collected daily for virus isolation. Blood was also collected at intervals throughout the monitoring period for evaluation of cbc, serum IgG and IgM concentrations, and antibody titers to ehv-1. Febrile responses, nasal discharge, viral shedding, changes in cbc, and an increase in antibody titers to ehv-1 were noticed in all horses after inoculation. There was no significant difference (P > 0.05) in mean values of the factors measured between treatment and control groups.
Genetic comparison of ovine and bovine pestiviruses
Authors: Kelling Clayton L. , Kennedy Jane E. , Stine Lisa C. , Rump Kristine K. , Paul Prem S. , Partridge James E.
Published: January 2024

Viral rna oligonucleotide fingerprinting was used to compare genetic relationships among pestiviruses originating from ovine or bovine host species. Ovine pestiviruses, including reference border disease virus and 2 border disease isolates originating from natural pestivirus infections of sheep, appeared to have a more distant genetic relationship among themselves than with certain bovine pestiviruses. A closer genetic relatedness was evident between border disease virus and 3 noncytopathic bovine pestiviruses, including Draper bovine viral diarrhea virus (bvdv), a bvdv isolate that originated from aborted bovine fetuses, and a virus that was isolated from the serum of a calf that had a chronic bvdv infection. Four noncytopathic bovine viruses, including Draper bvdv and 3 field isolates, were closely related. Reference Oregon C24V bvdv, a cytopathic virus, was closely related to only 1 of the 7 noncytopathic viruses in this study.
Gastric cannulation of pregnant sows
Authors: Matzat Paul D. , Ames N. Kent , Hogberg M. G.
Published: January 2024

The purpose of this project was to study the effect of superalimentation in lactating sows through permanent, surgically placed, gastric cannulas. A surgical technique was developed to install gastric cannulas into pregnant sows to allow superalimentation by introducing feed through the cannula. After induction of general anesthesia, a flexible, T-shaped cannula (22 mm outside diameter) was surgically placed in the dorsal portion of the greater curvature of the stomach and exteriorized through the tenth intercostal space approximately 30 cm left of the dorsal midline. Cannulas were installed on day 85 ± 5 days of gestation.

Anesthesia, surgical procedures, and the subsequent presence of the cannula did not affect the size or number of live pigs at birth. In addition, the prevalence of still births and mummified fetuses was not significantly different than that of noncannulated sows. The gastric cannulas did not affect lactation performance, as litter size and weight were unaffected when compared with that in noncannulated controls. Postmortem examination of euthanatized sows revealed adhesions of the gastric wall to the abdominal wall, thus eliminating the possibility of leakage of the gastric contents into the peritoneum. Detrimental effects of the cannulas on gastric function or capacity were not detected, and cannulas could be maintained through multiple parities.