bluuebunny/crossref_metadata_2025 huggingface dataset:
Age, geographic, and temporal distribution of fecal shedding of Cryptosporidium parvum oocysts in cow-calf herds
Authors: Atwill Edward R. , Johnson Eileen , Klingborg Donald J. , Veserat Gary M. , Markegard Gary , Jensen Wayne A. , Pratt David W. , Delmas Richard E. , George Holly A. , Forero Larry C. , Philips Ralph L. , Barry Sheila J. , McDougald Neil K. , Gildersleeve Rhonda R. , Frost William E.
Published: January 2024

Objective

To evaluate fecal shedding of Cryptosporidium parvum from California cow-calf herds with respect to age, geographic region, temporal effects, and association with watery feces.

Animals

Cows and calves from 38 beef cow-calf operations.

Procedure

Fecal specimens were collected and examined for C parvum oocysts, using immunofluorescent microscopy. Associations between age, geographic region, month of collection, watery feces, and likelihood of shedding C parvum were evaluated.

Results

3.9% of cattle were shedding C parvum oocysts. Prevalence of shedding among calves ranged from 0 to 13%, and was 0.6% among cattle ≥ 12 months old. The odds of shedding C parvum among 2-month-old calves were 41 times greater than among cattle > 4 months old. The odds of shedding C parvum among cattle tested in May were 8.7 times greater than among cattle tested during June, July, or August. The odds of infected individuals having watery feces were 3 to 4 times greater than for noninfected individuals, but the etiologic fraction was only 8 to 9%.

Conclusions and Clinical Relevance

Substantial fecal shedding of C parvum by cow-calf herds was limited to calves 1 to 4 months old, with low prevalence detected in older animals. Risk of contamination of watersheds with C parvum was limited to those periods when young calves were in the herd. Although the odds of having watery feces were greater for animals infected with C parvum than for noninfected animals, the low etiologic fraction suggests that most calves with watery feces were not infected with C parvum. (Am J Vet Res 1999;60: 420-425)
Nutrient uptake by viscera drained by the portal vein in neonatal calves during intravenous infusion of glutamine
Authors: Nappert Germain , Zello Gordon A. , Ferguson James , Naylor Jonathan M.
Published: January 2024

Objective

To quantify glutamine use by viscera drained by the portal vein in neonatal calves and to determine whether uptake could be stimulated by long-term IV infusion or long-term use of oral supplements.

Animals

4 healthy neonatal calves.

Procedure

A femoral artery, jugular vein, and the portal vein were surgically cannulated in each calf. Blood flow in the portal vein was measured, using an ultrasonic transit-time flow probe. Calves were given an IV infusion of glutamine on days 6, 8, and 10 after surgery. Before the first infusion, calves were fed a diet of milk only. The diet was supplemented with glutamine for the second and third infusions. Glutamine was administered via the jugular vein during a 5-hour period. Venous and arterial blood samples were collected every hour for 5 hours.

Results

During glutamine infusion, uptake of glutamine by viscera drained by the portal vein increased in association with increased production of ammonia. Glutamine supplementation of the diet did not alter glutamine uptake. Glutamine infusion did not increase viscera uptake of indispensable amino acids. Longterm use of glutamine supplements or infusion of glutamine for periods of more than 1 hour increased glutamine uptake by viscera. Arterial leucine concentration and uptake of leucine by the viscera decreased during glutamine infusion, indicating that leucine became the limiting factor.

Conclusion

Glutamine administration (supplements or infusions) to calves may require that a mixture of amino acids be provided to improve effectiveness.

Clinical Relevance

Glutamine may be beneficial in treatments designed to promote intestinal healing in diarrheic calves. (Am J Vet Res 1999;60:446-451)
Disease-specific changes in equine ground reaction force data documented by use of principal component analysis
Authors: Williams G. E. , Silverman B. W. , Wilson A. M. , Goodship A. E.
Published: January 2024

Objective

To assess the force plate as a diagnostic aid in equine locomotor abnormalities, particularly for abnormalities such as navicular disease that do not have specific diagnostic criteria.

Animals

17 Thoroughbreds without observable locomotor abnormalities (group A), 6 Thoroughbreds with superficial digital flexor tendon injury (group B), and 8 Thoroughbreds with navicular disease (group C).

Procedure

Using a force plate, ground reaction force patterns were recorded at the trot. Peak limb vertical force and force/time curve parameters were derived from 4 identifiable points at the beginning and end of vertical and craniocaudal horizontal plots. Principal component analysis (PCA) of group-A data was undertaken on beginning and end of stride data, and the first 2 components were represented graphically. The PCA rotation matrices were applied to equivalent data for horses of groups B and C.

Results

Asymmetry of peak vertical force (PVF) could not be differentiated among groups A, B, and C. Values for group-B horses, however, were significantly outside mean group-A values on the PCA plot for beginning of stride phase variables. Group-B data were within the group-A range for end of stride phase variables. Values for group-C horses were significantly outside the group-A range for beginning of stride phase variables and were outside mean group-A values for end of stride phase variables.

Conclusions

PCA of force/time data provides a sensitive method to evaluate the force/time curve associated with 2 specific injury/disease processes.

Clinical Relevance

Horses alter weight-bearing in biomechanically distinct ways, thus creating potential for the force plate to become an important diagnostic and prognostic tool. (Am J Vet Res 1999;60:549–555)
Immunohistochemical assay for detecting estrogen receptors in canine mammary tumors
Authors: Graham Joanne C. , O'Keefe Deborah A. , Gelberg Howard B.
Published: January 2024

Objective

To determine the estrogen receptor (ER) content of canine mammary gland tumors by use of immunohistochemical (IHC) examination of formalin-fixed sections.

Sample Population

21 mammary gland tumors from 20 adult dogs.

Procedure

ER were detected in formalin-fixed tissues, using an avidin-biotin alkaline phosphatase IHC assay and were quantified on fresh-frozen tumor samples, using a modified dextran-coated charcoal (DCC) assay.

Results

7 of 21 tumors had visually detectable nuclear ER by use of IHC staining, whereas 8 of 21 tumors were positive for ER by use of the DCC assay. The ER-positive cells in 5 IHC-positive tumors were epithelial cells with histologic criteria of early malignancy. The remaining 2 ER-positive tumors detected by use of IHC had ER-positive mast cells within areas of connective tissue around the tumor.

Conclusions

Immunohistochemistry is an additional method for detection of ER in canine mammary tumors. The major advantage of this type of assay is that it may be performed on formalin-fixed tissues, and individual ER-positive cells may be identified. Discovery of ER-positive mast cells by use of IHC is of concern, particularly if the ER status of a tumor is based on DCC results alone.

Clinical Relevance

Because most canine mammary tumors are fixed in formalin prior to histologic evaluation, an IHC assay that identifies ER-positive cells is desirable. Adjunctive antiestrogen therapy could be administered to dogs with ER-positive tumors. (Am J Vet Res 1999;60:627–630)
Comparison of peripheral and core temperatures in anesthetized horses
Authors: Tomasic Michael , Nann Lawrence E.
Published: January 2024

Objective

To examine temporal patterns of rectal, nasal, groin, and skin temperatures measured in adult horses undergoing general anesthesia and to determine accuracy and precision of temperatures at these sites, compared with core temperature.

Animals

5 healthy adult horses.

Procedure

Induction, maintenance of, and recovery from general anesthesia were performed in an air-conditioned surgical suite. Room temperature and relative humidity were approximately 21 C and 40%, respectively. Anesthesia was maintained for 2.5 hours, and body temperatures were measured and recorded every 5 minutes. Mean values were compared by use of ANOVA for repeated measures. Correlation coefficients for linear regressions of site temperature versus core temperature at 30-minute intervals were used to evaluate precision.

Results

Rectal temperature decreased in a linear manner, similar to core temperature. Nasal, groin, and skin temperatures followed a biphasic pattern; they sharply increased initially, peaked, then decreased at a rate similar to that of core temperatures. Rectal temperature always accurately reflected core temperature. Initial significant differences between core temperature and nasal, groin, or skin temperature disappeared as peripheral site temperatures approached peak values. Precision of core temperature estimation was generally poor for rectal, groin, and skin temperatures but was high (r > 0.90) after the first hour of anesthesia.

Conclusion

Anesthesia-induced core heat redistribution develops with minimal effect on core temperature. Rectal temperature can accurately reflect core temperature. (Am J Vet Res 1999;60:648–651)
Aerosolized albuterol sulfate used as a bronchodilator in horses with recurrent airway obstruction
Authors: Derksen Frederik J. , Olszewski Michal A. , Robinson N. Edward , Berney Cathy , Hakala Joyce E. , Matson Charles J. , Ruth Daniel T.
Published: January 2024

Objective

To determine the dose of aerosolized albuterol sulfate required to cause bronchodilation in horses with recurrent airway obstruction (RAO) and duration of this effect.

Animals

19 horses with RAO (10 in experiment 1; 9 in experiment 2).

Procedure

Horses were moved from pasture to stables, and airway obstruction was induced. Pulmonary function was measured in 10 horses before and 5, 10, and 30 minutes after administration of vehicle or 120, 240, 360, or 720 µg of the drug. Nine horses received vehicle or 360 or 720 µg of albuterol, and pulmonary function was measured at baseline and 5 minutes and 1, 2, 3, 4, 5, 6, and 7 hours later. Horses were evaluated for adverse drug effects.

Results

360 µg of albuterol was required to cause significant bronchodilatation; 720 µg did not enhance bronchodilatation or increase duration of action. Depending on which pulmonary function parameter was evaluated, bronchodilatation achieved by use of albuterol lasted between 30 minutes and 1 hour. Because there was a significant vehicle effect, the combined effect of vehicle and drug lasted up to 3 hours. Adverse effects were not observed.

Conclusions

Aerosolized albuterol, 360 or 720 µg, is a safe and effective bronchodilator in horses with RAO. Onset of action is rapid (5 minutes), and effects last from 30 minutes to 3 hours.

Clinical Relevance

Aerosolized albuterol is useful for treatment of bronchospasm in horses with RAO. (Am J Vet Res 1999;60:689–693)
Biosafety of Brucella abortus strain RB51 for vaccination of mature bulls and pregnant heifers
Authors: Edmonds Matthew D. , Schurig Gerhardt G. , Samartino Luis E. , Hoyt Phillip G. , Walker Joel V. , Hagius Sue D. , Elzer Philip H.
Published: January 2024

Objective

To determine shedding and colonization profiles in mature sexually intact bulls and pregnant heifers after vaccination with a standard calfhood dose of Brucella abortus strain RB51 (SRB51).

Animals

6 sexually mature 3-year-old Jersey bulls and 7 mixed-breed heifers in midgestation.

Procedure

Bulls and pregnant heifers were vaccinated IM with the standard calfhood dose of 3 × 1010 colony-forming units of SRB51. After vaccination, selected body fluids were monitored weekly for vaccine organism shedding. Pathogenesis was monitored in bulls by weekly breeding soundness examination and, in heifers, by delivery status of the calf. Vaccine organism colonization was assessed by obtaining select tissues at necropsy for bacterial culture. Serologic analysis was performed by use of numerous tests, including complement fixation, an SRB51-based ELISA, and immunoblot analysis.

Results

After vaccination, none of the vaccinated bulls or heifers shed SRB51 in their secretions. Results of breeding soundness examination for bulls were normal as was delivery status of the pregnant heifers (6 live births, 1 dystocia). At necropsy, SRB51 was not recovered from any of the selected tissues obtained from bulls, heifers, or calves; however, serologic analysis did detect SRB51-specific antibodies in all cattle.

Conclusions and Clinical Relevance

Vaccination with the standard calfhood dose of SRB51 administered IM was not associated with shedding or colonization in sexually mature bulls or pregnant heifers. Also, under conditions of this study with small numbers of animals, IM vaccination with SRB51 does not appear to cause any reproductive problems when administered to sexually mature cattle. (Am J Vet Res 1999;60:722–725)
Persistence of maternal antibodies against Mycoplasma agassizii in desert tortoise hatchlings
Authors: Schumacher Isabella M. , Rostal David C. , Yates Rebecca A. , Brown Daniel R. , Jacobson Elliott R. , Klein Paul A.
Published: January 2024

Objective

To investigate Mycoplasma agassizii-specific maternal antibodies in desert tortoise (Gopherus agassizii) hatchlings.

Sample Population

Plasma from 43 captive-reared desert tortoise hatchlings.

Procedure

ELISA for M agassizii-specific antibodies was performed. Four hatchlings from 4 clutches of 3 M agassizii-seropositive females with chronic upper respiratory tract disease (URTD) were tested on the day of hatching (set 1), and 20 hatchlings from 4 clutches of 4 M agassizii-seropositive females with URTD and 19 hatchlings from 4 M agassizii-seronegative healthy females were tested at 4, 8, 12, and 29 months old (set 2). Immunoblot analysis was performed to determine immunoglobulin classes in yolk and plasma of hatchlings. To determine infection status of hatchlings, yolk, egg shell membranes (set 1), and nasal lavage fluid (sets 1 and 2) were examined for M agassizii by use of polymerase chain reaction.

Results

Yolk and hatchling plasma had significantly lower amounts of specific antibodies than did plasma from adult females. The IgG and IgM antibodies were transferred, but M agassizii-specific antibodies were of the IgG class. Hatchlings were not infected with mycoplasmas. Offspring of sick females had significantly higher specific antibody titers than did offspring of healthy females. Titers were still significantly different in 1-year-old hatchlings.

Conclusions

Desert tortoise females transfer specific IgG and IgM antibodies to their offspring that are still detectable after 1 year.

Clinical Relevance

Infection with M agassizii may be misdiagnosed in hatchlings with persistent maternal antibodies. Passively acquired antibodies may have a role in pathogenesis of mycoplasma-induced respiratory tract disease and other diseases. (Am J Vet Res 1999;60:826–831)
Effects of orally administered enteric-coated omeprazole on gastric acid secretion in horses
Authors: Andrews Frank M. , Doherty Thomas J. , Blackford James T. , Nadeau Jenifer A. , Saxton Arnold M.
Published: January 2024

Objectives

To determine the effects of orally administered omeprazole, as enteric-coated capsules, on baseline and stimulated gastric acid secretion in horses.

Animals

5 healthy 8-year-old mixed-breed horses fitted with gastric cannulas.

Procedure

Enteric-coated granules of omeprazole were mixed with corn syrup and administered orally once daily for 5 consecutive days. On days 1 and 5 beginning 5 hours after omeprazole administration, 4 gastric fluid samples were collected, each for 15 minutes, via the gastric cannula (baseline samples). Pentagastrin was administered IV as a constant infusion for the subsequent 2 hours, and 15-minute gastric fluid samples were again collected (stimulated samples). Fluid volume, acidity (mmol H+/L), and pH and gastric acid production (mmol H+) were determined for all baseline samples and for stimulated samples collected during the second hour of pentagastrin infusion. Control experiments were done in a similar manner after giving corn syrup alone to the same horses.

Results

Compared with values obtained during control experiments, baseline and stimulated gastric fluid acidity and gastric acid production significantly decreased, and the mean pH of gastric fluid samples significantly increased, after horses were given 5 daily doses of omeprazole.

Conclusions and Clinical Relevance

Enteric-coated omeprazole (1.0 mg/kg of body weight; PO) administered once daily for 5 days significantly inhibited unstimulated and pentagastrin-stimulated gastric acid secretion in horses. This commercially available formulation of omeprazole may be efficacious in the treatment of gastroduodenal ulcers in horses. (Am J Vet Res 1999;60:929–931)
Plasma and urine nitric oxide concentrations in horses given a low dose of endotoxin
Authors: Bueno Aloisio C. , Seahorn Thomas L. , Cornick-Seahorn Janyce , Horohov David W. , Moore Rustin M.
Published: January 2024

Objective

To quantify plasma and urine nitric oxide (NO) concentrations before and after low-dose endotoxin infusion in horses.

Animals

11 healthy adult female horses.

Procedure

Eight horses were given endotoxin (35 ng/kg of body weight, IV) over 30 minutes. Three sentinel horses received an equivalent volume of saline (0.9% NaCl) solution over the same time. Clinical signs of disease and hemodynamic variables were recorded, and urine and plasma samples were obtained to measure NO concentrations prior to endotoxin infusion (t = 0) and every hour until postinfusion hour (PIH) 6, then every 2 hours until PIH 24. Blood for hematologic and metabolic analyses and for serum cytokine bioassays were collected at 0 hour, every hour until PIH 6, every 2 hours through PIH 12, and finally, every 6 hours until PIH 24.

Results

Differences in plasma NO concentrations across time were not apparent, but urine NO concentrations significantly decreased at 4 and 20 to 24 hours in endotoxin-treated horses. Also in endotoxin-treated horses, alterations in clinical signs of disease, and hemodymanic, metabolic, and hematologic variables were significant and characteristic of endotoxemia. Serum interleukin-6 (IL-6) activity and tumor necrosis factor (TNF) concentrations were increased above baseline values from 1 to 8 hours and 1 to 2 hours, respectively.

Conclusions and Clinical Relevance

Plasma and urine NO concentrations did not increase in horses after administration of a low dose of endotoxin, despite induction of an inflammatory response, which was confirmed by increased TNF and IL-6 values characteristic alterations in clinical signs of disease, and hematologic, hemodynamic and metabolic variables. (Am J Vet Res 1999:60:969-976)
Pharmacokinetic variables of mivacurium chloride after intravenous administration in dogs
Authors: Smith Lesley J. , Schwark Wayne S. , Cook D. Ryan , Moon Paula F. , Looney Andrea L.
Published: January 2024

Objective

To determine pharmacokinetic variables of mivacurium chloride after IV administration in dogs.

Animals

5 healthy Labrador Retrievers.

Procedure

Anesthesia was induced with thiopental and maintained with halothane in oxygen. Dogs were ventilated mechanically to an end-tidal PCO2 value between 35 and 40 mm Hg. Heart rate, direct blood pressure, and arterial pH were recorded throughout the experiment. Core temperature, end-tidal PCO2, and halothane concentration were kept constant throughout the experiment. Paired blood samples for determination of plasma cholinesterase activity were collected prior to administration of a bolus of mivacurium (0.05 mg/kg of body weight), which was administered IV during a 2-second period. Arterial blood samples were obtained for determination of plasma mivacurium concentration 0, 1, 3, 5, 10, 30, 60, 120, 150, and 180 minutes after administration of mivacurium. Blood was collected into tubes containing EDTA and 0.25% echothiophate. Mivacurium concentration was determined, using reversed-phase high-performance liquid chromatography.

Results

For the trans-trans isomer, mean ± SEM volume of distribution was 0.18 ± 0.024 L/kg, median half-life was 34.9 minutes (range, 26.7 to 53.5 minutes), and clearance was 12 ± 2 ml/min/kg. For the cis-trans isomer, values were 0.31 ± 0.05 L/kg, 43.4 minutes (range, 31.5 to 69.3 minutes), and 15 ± 2 ml/min/kg, respectively. Values for the cis-cis isomer were not calculated, because it was not detectable in plasma 60 minutes after mivacurium administration in all 5 dogs.

Conclusions and Clinical Relevance

The trans-trans and cis-trans isomers of mivacurium have a long half-life and slow clearance in healthy dogs anesthetized with halothane. (Am J Vet Res 1999;60:1051-1054)
Comparative pharmacokinetics of enrofloxacin in mice, rats, rabbits, sheep, and cows
Authors: Bregante Miguel A. , Saez Pilar , Aramayona Jose J. , Fraile Lorenzo , Garcia Maria A. , Solans Carlos
Published: January 2024

Objective

To compare pharmacokinetic variables of enrofloxacin (ENR) after IV administration in mice, rats, rabbits, sheep, and cows and to perform allometric analysis of ENR.

Animals

47 mice, 5 rats, 5 rabbits, 5 sheep, and 5 cows.

Procedure

Serially obtained plasma samples were assayed for enr concentration, using high-performance liquid chromatography. In vitro plasma protein binding was determined by ultrafiltration. Plasma enr concentration versus time curves were fitted by use of nonlinear least-squared regression analysis. Pharmacokinetic variables were correlated further with body weight.

Results

In all species studied, the best fit was obtained for a two-compartment open model; ENR half-life ranged from 89 minutes in mice to 169 minutes in cows. Volume of distribution was large in all species studied, with values ranging from 10.5 L/kg in mice to 1.5 L/kg in sheep. Body clearance ranged from 68.1 ml/min/kg for mice to 4.6 ml/min/kg for sheep. Unbound ENR was found to be (mean ± SD) 58 ± 2, 50 ± 6, 50 ± 2, 31 ± 2, and 40 ± 3% in plasma of mice, rats, rabbits, sheep, and cows, respectively. The only pharmacokinetic variables that could be correlated with body weight were elimination half-life, clearance, and volume of distribution. Allometric exponents denoting proportionality of half-life, body clearance, and volume of distribution with body weight were 0.06, 0.82, and 0.90, respectively.

Conclusions and Clinical Relevance

An allometric approach could provide a suitable method for determining a scale for ENR pharmacokinetics among various mammalian species. This would faciliatate the administration of appropriate doses of ENR to all animals. [Am J Vet Res 1999;60:1111–1116)
Colostral immunoglobulin concentrations in Holstein and Guernsey cows
Authors: Tyler Jeff W. , Steevens Barry J. , Hostetler Douglas E. , Holle Julie M. , Denbigh John L.
Published: January 2024

Objective

To compare the concentration of IgG in colostrum between Holstein and Guernsey cows and among cows of various lactations.

Design

Cross-sectional cohort study.

Sample Population

Colostrum samples from 77 Holstein and 24 Guernsey cows.

Procedure

Colostrum samples were obtained from 101 cows. Colostral IgG concentration was determined, using a radial immunodiffusion assay. Regression analysis was used to determine the effect of breed and lactation number on colostral IgG concentration. Survival analysis and t-tests were used to compare the proportion of colostrum samples that would provide 100 g of IgG for various volumes of colostral intake.

Results

Guernsey cows produced 36.4 g of IgG/L of colostrum more than that of Holstein cows. Cows in the third or greater lactation produced 19.5 g of IgG/L of colostrum more than that of first-lactation cows. The IgG concentration of colostrum produced by second-lactation cows did not differ significantly from that produced by first-lactation cows. The colostral IgG concentration of these Holstein and Guernsey cows was higher than values that have been reported elsewhere.

Conclusions and Clinical Relevance

Volume of colostrum needed to meet IgG intake goals is probably lower for Guernsey cows than Holstein cows. Colostrum from first-lactation cows was adequate in IgG content. The practice of discarding colostrum from first-lactation cows on the basis of inadequate IgG content was not justified in this study. (Am J Vet Res 1999;60:1136–1139)
Effect of transportation and feed withdrawal on shedding of Salmonella Typhimurium among experimentally infected pigs
Authors: Isaacson Richard E. , Firkins Lawrence D. , Weigel Ronald M. , Zuckermann Federico A. , DiPietro Joseph A.
Published: January 2024

Objective

To determine whether stress associated with transportation or feed withdrawal increased fecal shedding of Salmonella Typhimurium among pigs experimentally infected with the organism.

Animals

86 healthy pigs.

Procedure

Pigs were challenge exposed with Salmonella Typhimurium at 4 weeks old and reared conventionally. When pigs reached market weight, they were assigned to groups and subjected to various combinations of transportation and feed withdrawal. Ileocecal contents were collected after slaughter and tested for Salmonella Typhimurium.

Results

Salmonella Typhimurium was not detected in feces collected from pigs just prior to slaughter. When feed was withheld for 24 hours prior to slaughter, the proportion of transported pigs with Salmonella Typhimurium in ileocecal contents at the time of slaughter was not significantly different from the proportion of nontransported pigs. However, when feed was not withheld prior to slaughter, the proportion of transported pigs with Salmonella Typhimurium in ileocecal contents at the time of slaughter was significantly higher than the proportion of nontransported pigs.

Conclusions and Clinical Relevance

When carrier pigs remained on feed, transportation stress increased the proportion positive for Salmonella sp. On the basis of results reported here, it is suggested that producers withhold feed from pigs for 24 hours prior to transportation to a slaughter plant. (Am J Vet Res 1999;60:1155–1158)
Comparison of clinical signs and hemodynamic variables used to monitor rabbits during halothane- and isoflurane-induced anesthesia
Authors: Imai Ayako , Steffey Eugene P. , Ilkiw Jan E. , Farver Thomas B.
Published: January 2024

Objective

To characterize variables used to monitor rabbits during inhalation anesthesia.

Animals

8 male New Zealand White rabbits.

Procedure

Rabbits were similarly anesthetized with halothane (HAL) or isoflurane (ISO) in a crossover study; half received HAL followed by ISO, and the protocol was reversed for the remaining rabbits. After induction, minimum alveolar concentration (MAC) was determined for each agent, using the tail-clamp method, and variables were recorded at 0.8, 1.0, 1.5, and 2.0 MAC (order randomized).

Results

Mean ± sem mac was 1.42 ± 0.05 and 2.07 ± 0.09% for hal and iso, respectively. Directly measured auricular mean arterial blood pressure was 52.8 ± 5.6 and 54.8 ± 6.1 mm Hg at 0.8 mac for hal and iso, respectively, and decreased from these values in a parallel dose-dependent manner. Respiratory frequency remained constant (range, 69 to 78 breaths/min) over the range of hal doses but incrementally decreased from a mean of 53 (at 0.8 mac) to 32 breaths/min (at 2.0 mac) for iso. The Paco2 was similar at 0.8 mac for hal and iso and progressively increased with increasing doses of both agents; Paco2 at 2.0 mac for iso was significantly greater than that at 2.0 mac for hal (79.8 ± 13.7 vs 54.9 ± 4.0 mm Hg, respectively). Eyelid aperture consistently increased in a dose-dependent manner for both anesthetics.

Conclusions

Arterial blood pressure, Paco2, and eyelid aperture consistently and predictably changed in rabbits in response to changes in anesthetic doses. The magnitude of respiratory depression was greater for iso than for hal. (Am J Vet Res 1999;60:1189–1195)
A technique for evaluating analgesia in conscious perching birds
Authors: Paul-Murphy Joanne R. , Brunson David B. , Miletic Vjekoslav
Published: January 2024

Objective

To develop a technique for objective assessment of modulation of nociperception in conscious perching birds.

Animals

31 adult African grey parrots.

Procedure

Birds were randomly assigned to receive saline (0.9% NaCl) solution (n = 10), butorphanol tartrate (11), or buprenorphine hydrochloride (10), IM. Birds were fitted with a surface electrode on the medial metatarsus of 1 leg. An electrical stimulus was delivered to the bird’s foot through an aluminum surface on half of the perch. The alternate side of the perch delivered a noxious thermal stimulus. A withdrawal response to either stimulus was recorded when the bird lifted its foot or vigorously flinched its wings.

Results

Responses to thermal stimuli were extremely variable during baseline testing and after administration of drugs. Thus, significant differences were not detected after drug injection. In contrast, responses to an electrical stimulus were predictable with much less variation.

Conclusions and Clinical Relevance

This method and device allowed for the reliable determination of withdrawal threshold in perching birds. Use of this technique for objective assessment of modulation of nociperception in conscious perching birds will enable assessment of analgesic drugs. (Am J Vet Res 1999;60:1213–1217)
Pharmacologic effects of epidural versus intramuscular administration of detomidine in cattle
Authors: Prado Maria E. , Streeter Robert N. , Mandsager Ronald E. , Shawley Richard V. , Claypool P. L.
Published: January 2024

Objectives

To determine whether epidural administration of detomidine hydrochloride to cattle induced analgesia of the perineum and to compare analgesic and systemic effects of epidural versus IM administration of detomidine at a dose of 40 μg/kg in cattle.

Animals

18 healthy adult cows.

Procedure

6 cows were given detomidine by epidural administration, 6 were given detomidine IM, and 6 (control group) were not given detomidine. Analgesia was assessed by determining responses to needle pinpricks in the perineum and flank and by applying electrical stimuli to the perineum and flank and determining the voltage that induced an avoidance response. Degree of sedation and ataxia were scored, and mean arterial pressure, heart rate, respiratory rate, and frequency of ruminal contractions were measured.

Results

Epidural and IM administration of detomidine induced comparable degrees of analgesia of the perineum and flank, accompanied by moderate sedation and ataxia, hypertension, cardiorespiratory depression, and rumen hypomotility.

Conclusions and Clinical Relevance

Epidural and IM administration of detomidine at a dose of 40 µg/kg induced similar analgesic and systemic effects in cattle. Epidural administration of detomidine did not appear to be advantageous over IM administration. (Am J Vet Res 1999;60:1242–1247)
Susceptibility of equine erythrocytes to oxidant-induced rheologic alterations
Authors: Baskurt Oguz K. , Meiselman Herbert J.
Published: January 2024

Objective

To evaluate the rheologic responses of equine versus human RBC to oxidant stress induced by superoxide anions.

Sample Population

Equine blood samples were obtained from 8 healthy, 3- to 6-year-old various breed horses of either sex; human blood samples were obtained from 8 healthy adults.

Procedure

Washed RBC were exposed to superoxide anions generated by the xanthine oxidase (XO)-hypoxanthine system (XO activity of 0 to 0.1 U/ml). Deformability of RBC was assessed by ektacytometry, and RBC aggregation was measured in autologous plasma or 3% solution of dextran 70 via a defined-shear photometric technique.

Results

Equine RBC had XO dose-dependent increases in methemoglobin concentration that were greater by 60 to 110% than in human RBC and an enhanced tendency for echinocyte formation (ie, 40% echinocyte formation at highest activity of XO). Oxidant stress reduced deformability (ie, increased rigidity) for equine and human RBC with the effect more prominent for equine RBC. Equine RBC aggregation had a biphasic response with a significant increase in plasma and dextran 70 at low XO activities and inhibition at high activities; echinocytes were incorporated into equine, but not human, RBC aggregates.

Conclusions and Clinical Relevance

Compared with human RBC, equine RBC are more sensitive to oxidant damage as judged by the extent of methemoglobin formation, alteration of aggregation, and reduction of cellular deformability. The high susceptibility of equine RBC to oxidant damage, and the resulting hemorheologic alterations, may have important consequences for tissue perfusion and cardiovascular adequacy in horses; they may be of particular relevance in physiologic or pathophysiologic changes associated with increased oxidant stress. (Am J Vet Res 1999;60:1301–1306)
Characterization of swimming motility and identification of flagellar proteins in Salmonella pullorum isolates
Authors: Chaubal Lisa H. , Holt Peter S.
Published: January 2024

Objective

To identify swimming motility in Salmonella pullorum isolates and to characterize the flagellar proteins produced by motile isolates.

Sample population

30 S pullorum isolates and isolates of 7 other Salmonella sp.

Procedure

Salmonella pullorum isolates were inoculated into high motility medium to evaluate swimming motility. Putative flagellar proteins were purified from the organisms and analyzed by means of gel electrophoresis and western blotting procedures, using various antisera specific for flagellar proteins. Antisera shown to be reactive with putative flagellar proteins were incorporated into the growth medium to examine their effects on motility of the isolates.

Results

All S pullorum isolates had evidence of swimming motility. Two putative flagellar proteins were purified from 2 of the S pullorum isolates: a 60 to 62 kd protein shown to react with antiserum specific for type y flagellar protein, and a 58 to 59 kd protein shown to react with antiserum specific for type d flagellar protein and with antibody reactive to a highly conserved flagellar epitope found on various Enterobacteriaceae. Antiserum specific for type d flagellar protein inhibited swimming motility of S pullorum isolates, but antiserum specific for type y flagellar protein did not.

Conclusions

Results suggest that S pullorum isolates can be induced to manifest swimming motility when grown on medium with a low agar concentration and possess a 58 to 59 kd protein of d serotype and a second protein of 60 to 62 kd that also may be a flagellar protein. (Am J Vet Res 1999;60:1322–1327)
Pharmacokinetic variables and tissue residues of enrofloxacin and ciprofloxacin in healthy pigs
Authors: Anadón Arturo , Martínez-Larrañaga Maria R. , Díaz Maria J. , Fernández-Cruz Maria L. , Martínez Maria A. , Frejo Maria T. , Martínez Marta , Iturbe Javier , Tafur Mcallister
Published: January 2024

Objectives

To determine pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin after a single IV and IM administration of enrofloxacin and tissue residues after serial daily IM administration of enrofloxacin in pigs.

Animals

20 healthy male pigs.

Procedure

8 pigs were used in a crossover design to investigate pharmacokinetics of enrofloxacin after a single IV and IM administration (2.5 mg/kg of body weight). Twelve pigs were used to study tissue residues; they were given daily doses of enrofloxacin (2.5 mg/kg, IM for 3 days). Plasma and tissue concentrations of enrofloxacin and ciprofloxacin were determined. Residues of enrofloxacin and ciprofloxacin were measured in fat, kidney, liver, and muscle.

Results

Mean (± SD) elimination half-life and mean residence time of enrofloxacin in plasma were 9.64 ± 1.49 and 12.77 ±2.15 hours, respectively, after IV administration and 12.06 ± 0.68 and 17.15 ± 1.04 hours, respectively, after IM administration. Half-life at α phase of enrofloxacin was 0.23 ± 0.05 and 1.94 ± 0.70 hours for IV and IM administration, respectively. Maximal plasma concentration was 1.17 ± 0.23 µg/ml, and interval from injection until maximum concentration was 1.81 ± 0.23 hours. Renal and hepatic concentrations of enrofloxacin (0.012 to 0.017 µg/g) persisted for 10 days; however, at that time, ciprofloxacin residues were not detected in other tissues.

Conclusions and Clinical Relevance

Enrofloxacin administered IM at a dosage of 2.5 mg/kg for 3 successive days, with a withdrawal time of 10 days, resulted in a sum of concentrations of enrofloxacin and ciprofloxacin that were less than the European Union maximal residue limit of 30 ng/g in edible tissues. (Am J Vet Res 1999;60:1377–1382)
Behavior of stabled horses provided continuous or intermittent access to drinking water
Authors: McDonnell Sue M. , Freeman Douglas A. , Cymbaluk Nadia F. , Schott Harold C. , Hinchcliff Kenneth , Kyle Beth
Published: January 2024

Objective

To compare quantitative measures and clinical assessments of behavior as an indication of psychologic well-being of stabled horses provided drinking water continuously or via 1 of 3 intermittent delivery systems.

Animals

22 Quarter Horse (QH) or QH-crossbred mares and 17 Belgian or Belgian-crossbred mares (study 1) and 24 QH or QH-crossbred mares and 18 Belgian or Belgian-crossbred mares (study 2).

Procedure

Stabled horses were provided water continuously or via 1 of 3 intermittent water delivery systems in 2 study periods during a 2-year period. Continuous 24-hour videotaped samples were used to compare quantitative measures and clinical assessments of behavior among groups provided water by the various water delivery systems.

Results

All horses had clinically normal behavior. Significant differences in well being were not detected among groups provided water by the various delivery systems.

Conclusions and Clinical Relevance

Various continuous and intermittent water delivery systems can provide adequately for the psychologic well-being of stabled horses. (Am J Vet Res 1999;60:1451–1456)
Quantification of left ventricular diastolic wall motion by Doppler tissue imaging in healthy cats and cats with cardiomyopathy
Authors: Gavaghan Brad J. , Kittleson Mark D. , Fisher Kristian J. , Kass Philip H. , Gavaghan Michelle A.
Published: January 2024

Objective

To assess Doppler tissue imaging (DTI) for evaluating left ventricular diastolic wall motion in healthy cats and cats with cardiomyopathy.

Animals

20 healthy cats, 9 cats with hypertrophic cardiomyopathy (HCM), and 9 cats with unclassified cardiomyopathy (UCM).

Procedure

A pulsed wave DTI sample gate was positioned at a subendocardial region of the left ventricular free wall in the short axis view and at the lateral mitral annulus in the apical 4-chamber view. Indices of diastolic wall motion were measured, including peak diastolic velocity (PDV), mean rate of acceleration and deceleration of the maximal diastolic waveform (MDWaccel and MDWdecel, respectively), and isovolumetric relaxation time (IVRT).

Results

The PDV of cats with HCM and 6 of 9 cats with UCM was significantly decreased, compared with that of healthy cats. In the 3 cats with UCM that had a PDV that was not different from healthy cats, MDWaccel and MDWdecel were greater, and IVRT was shorter than those of healthy cats. The IVRT in cats with HCM was longer than that of other cats.

Conclusions and Clinical Relevance

Indices of diastolic function in cats with HCM, and in many cats with UCM, differed from those of healthy cats and were similar to those reported in humans with HCM and restrictive cardiomyopathy, respectively. However, the hemodynamic abnormality was not the same for all cats with UCM; some cats with an enlarged left atrium and a normal left ventricle (ie, UCM) had abnormal left ventricular wall motion consistent with restrictive cardiomyopathy while others did not. (Am J Vet Res 1999;60:1478–1486)
Effect of enalapril on blood pressure, renal function, and the renin-angiotensin-aldosterone system in cats with autosomal dominant polycystic kidney disease
Authors: Miller Rita H. , Lehmkuhl Linda B. , Smeak Daniel D. , DiBartola Stephen P. , Radin Judith
Published: January 2024

Objective

To evaluate blood pressure, renal function, and the renin-angiotensin-aldosterone system (RAAS) in cats with autosomal dominant polycystic kidney disease (ADPKD) and to assess the effect of enalapril on these variables.

Animals

6 cats with ADPKD and 6 age-matched healthy cats.

Procedure

To measure blood pressure and heart rate, a radiotelemetry catheter was placed in the left femoral artery of each cat. Baseline data collection included 24-hour blood pressure, heart rate, and motor activity. Blood was then collected for analysis of RAAS status and renal function. Enalapril (0.5 mg/kg of body weight, PO, q 24 h) was administered for 1 week, and data collection was repeated.

Results

Differences in baseline blood pressure, heart rate, motor activity, RAAS status, and renal function were not detected between cats with ADPKD and control cats. Hypertension was not documented in cats with ADPKD. Blood pressure was significantly reduced for 15 to 17 hours after treatment with enalapril in both groups. Administration of enalapril also resulted in significant increases in plasma renin activity and significant decreases in angiotensin converting enzyme activity and atrial natriuretic peptide concentration but only minimal changes in glomerular filtration rate and effective renal plasma flow in both groups of cats.

Conclusions and Clinical Relevance

Although hypertension is common in humans with ADPKD, cats with ADPKD were normotensive. Treatment with enalapril (0.5 mg/kg, PO, q 24 h) significantly reduced blood pressure in normotensive healthy cats and cats with ADPKD, and resulted in predictable changes in RAAS enzyme activities and hormone concentrations. Enalapril had minimal effects on renal function. (Am J Vet Res 1999;60:1516–1525)
Acute Pulmonary Embolism and Immunity in Animal Models
Authors: Imiela Anna M. , Mikołajczyk Tomasz P. , Guzik Tomasz J. , Pruszczyk Piotr
Published: January 2024

Venous thromboembolism, encompassing acute pulmonary embolism (APE) and deep vein thrombosis (DVT), is a potentially fatal disease with complex pathophysiology. Traditionally, the Virchow triad provided a framework for understanding the pathogenic contributors to thrombus formation, which include endothelial dysfunction, alterations in blood flow and blood hypercoagulability. In the last years, it has become apparent that immunity plays a central role in thrombosis, interacting with classical prothrombotic mechanisms, oxidative stress and vascular factors. Thrombosis amplifies inflammation, and exaggerated inflammatory processes can trigger thrombosis mainly due to the activation of leukocytes, platelets, and endothelial cells. APE-related endothelium injury is a major trigger for immune system activation. Endothelium is also a key component mediating inflammatory reaction and it is relevant to maintain vascular permeability. Exaggerated right ventricular wall stress and overload, with coexisting systemic hypotension and hypoxemia, result in myocardial injury and necrosis. Hypoxia, tissue factor activation and cytokine storm are engaged in the thrombo-inflammatory processes. Thrombus development is characterized by inflammatory state vascular wall caused mainly by an early extravasation of leukocytes and intense selectins and cytokines production. Nevertheless, immunity of DVT is well described, little is known about potential chemokine and cellular differences between thrombus that develops in the vein and thrombus that detaches and lodges in the pulmonary circulation being a cause of APE. There is a paucity of data considering inflammatory state in the pulmonary artery wall during an acute episode of pulmonary embolism. The main aim of this review is to summarize the knowledge of immunity in acute phase of pulmonary embolism in experimental models.
Determination of microbiological quality of boiled crayfish (Astacus leptodactylus) samples treated with chitosan
Authors: Ceylan Zafer , İnanlı Ayşe Gürel , Basahel Abdulrahman , Karaboga Dervis , TahsinYilmaz Mustafa
Published: January 2024

Coating crayfish (Astacus leptodactylus) meat samples with chitosan solution could be an effective approach to limit microbiological spoilage. During the 18-day cold storage period at 2°C±1, mesophilic aerobic bacteria (MABc), psychrophilic bacteria (PBc), yeast mold count (YMc), anaerobic bacteria (AnBc), and Enterobacteriaceae growth in the samples coated with chitosan (0.5% and 1%) and also control group samples were tested. Crayfish samples coated with chitosan (0.5% and 1%) had a lower TMABc (6.58 to 4.60 log CFU/g: up to 30.09%), TPBc (3.77 to 1.99 log CFU/g: up to 47.21%), TYMc (1.84 to 1.27 log CFU/g: up to 30.97%), TAnBc (3.69 to 1.88 log CFU/g: up to 49.05%), and Enterobacteriaceae (3.49 to 2.60 log CFU/g: up to 25.50%) counts as compared with control group samples at 2°C±1. The results particularly based on mesophilic anaerobic bacteria suggested that the application would be a promising approach to limit microbial growth and provide food safety for boiled crayfish meat samples.
Ameliorating effects of dietary parsley (Petroselinum crispum) on ammonia toxicity in the rainbow trout, Oncorhynchus mykiss: growth, digestive enzymes, immunity, and stress resistance
Authors: Hajirezaee Saeed , Sharifi Sara , Momeninejad Ali , Ahani Saman , Anzabi Mojtaba Pourahad , Taheri Somayeh
Published: January 2024

Use of phytobiotics as immunostimulant is increasing in aquaculture. In this study, the immune and growth promoting effects of parsley extract (PUE) were examined in the rainbow trout. In this regard, the various dietary levels of parsley extract (PUE), Petroselinum crispum (0, 0.5, 1.5, 3, and 4.5%) was added to the diet of rainbow trout to assay its potentials on immunity, growth, digestive enzymes, and mitigating ammonia-induced stress. A total of 450 fish (15.43±0.06 g; mean ± SE) were distributed into fifteen 300-L fiberglass tanks (30 fish per tank) and fed PUE for 60 days and then challenged with unionized ammonia (0.3 mg/l). According to results, PUE mainly at 3−4.5% levels increased the growth, lipase and protease activities, humoral and mucosal immune components and liver antioxidant enzymes activities. These effects were kept even after ammonia stress, where the immune components were higher in PUE-treated fish than the control group. Furthermore, the dietary PUE reduced ammonia-related oxidative stress, as malondialdehyde (MDA) values (as the indicator of lipid peroxidation) decreased in fish fed PUE. The concentrations of liver metabolic enzymes in blood, both before and after ammonia stress declined in the fish fed PUE. Our findings demonstrated the growth and immune boosting and ammonia-stress mitigating properties of PUE in rainbow trout.
The effect of extra-oral traction : a review
Authors: Howell Susan
Published: January 2024

The application of force to bone has been shown to produce a change in its shape or morphology. This paper reviews the literature relating to the principles of such force application by extra-oral appliances to the maxilla and mandible both in animals and humans. The significance of direction of force, amount of force, and timing of force application is stressed. Studies of craniofacial changes associated with the use of face-bows and cervical straps in orthodontic treatment are closely examined. The post-treatment changes, after the extra-oral forces have been discontinued, are also discussed.