bluuebunny/crossref_metadata_2025 huggingface dataset:
High-performance liquid chromatography method for determination of fhinixin in bovine plasma and pharmacokinetics after single and repeated doses of the drug
Authors: Odensvik Kristina , Johansson I. Monika
Published: January 2024

A high-performance liquid chromatography method was developed for determination of flunixin in bovine plasma. The extraction procedure was easily performed and made it possible to detect low concentrations of flunixin with high accuracy. The limit of quantitation was 7 ng/ml (relative standard deviation = 18%, n = 10). The analytic method permits processing of 60 samples/d. Flunixin, as well as the internal standard (diclofenac sodium), belong to the group of nonsteroidal anti-inflammatory drugs, which are known to have a high degree of binding to plasma proteins. Therefore, an evaluation of several buffer systems was undertaken to optimize analytic conditions.

Cattle were given 2.2 mg of flunixin meglumine/kg of body weight. In experiment 1, single injections were administered IV to 1 cow and IV and IM to 1 heifer (7 days apart), and pharmacokinetic variables were calculated. The IV data were best described by a two-compartment model. The half-life after single IV or IM administration was around 4.0 hours. In experiment 2, the decreasing flunixin concentration was determined after the last of either 4 IM injections daily (n = 3 cows) or 2 IM injections daily (n = 3 cows) administered during a 14-day postpartum period. The half-life, determined between 48 and 96 hours after the last dose, was approximately 26 hours in both groups, and flunixin could be detected in plasma up to 8 days, on average.

The protein binding of flunixin was studied, using the method of equilibrium dialysis. Flunixin was found to have a high degree of protein binding (ie, 99.4 ± 0.2%) at a flunixin concentration in plasma of 3 to 24 μg/ml. Differences in protein binding between cattle were not found.
Cardiovascular effects of epidurally administered morphine and a xylazine-morphine combination in isoflurane-anesthetized dogs
Authors: Keegan Robert D. , Greene Stephen A. , Weil Ann B.
Published: January 2024

Cardiovascular effects of epidurally administered morphine, a morphine-xylazine combination, and saline solution (control) during isoflurane-maintained anesthesia were assessed in 6 healthy dogs. Anesthesia was induced with isoflurane in O2 and was maintained at 2.0% end-tidal isoflurane concentration. Ventilation was controlled to maintain PaCO2 at 35 to 45 mm of Hg. The dorsal pedal artery was cannulated for measurement of systolic, mean, and diastolic pressures, and for blood sample collection. Arterial blood pH and gas tensions were determined every 30 minutes. Cardiac output was determined by thermodilution. The ecg, heart rate, body temperature, central venous pressure, mean pulmonary artery pressure, pulmonary capillary wedge pressure, end-tidal isoflurane concentration, and CO2 tension were monitored. Systemic and pulmonary vascular resistance, arterial HCO3- concentration, base excess, and cardiac index were calculated. After baseline measurements were taken, morphine (0.1 mg/kg of body weight) in 5 ml of isotonic saline solution, morphine and xylazine (0.1 mg of morphine and 0.02 mg of xylazine/kg) in 5 ml of isotonic saline solution, or 5 ml of isotonic saline solution was injected into the lumbosacral epidural space. Data were recorded at 5, 15, 30, 45, 60, 75, 90, 105, and 120 minutes after epidural injection. Statistical analysis included anova for repeated measures. Significance was set at P < 0.05. None of the measured variables was significantly different among the 3 treatments at any time. Results of the study indicated that epidural administration of morphine or morphine and xylazine is not associated with significant cardiovascular side effects during isoflurane-maintained anesthesia in dogs.
Cytologie evaluation of bronchoalveolar lavage fluid obtained from Standardbred racehorses with inflammatory airway disease
Authors: Moore Bonnie Rush , Krakowka Steven , Robertson James T. , Cummins Joseph M.
Published: January 2024

Cytologic examination of bronchoalveolar lavage fluid (balf), including phenotypic analysis of lymphocytes, was performed on 32 Standardbreds with poor race performance and endoscopic examination findings characteristic of inflammatory airway disease (iad). Nucleated cell counts in balf from iad-affected horses were higher than those in control horses; the cytologic profile of balf in affected horses included mixed inflammation, characterized by mild neutrophilia, lymphocytosis, and monocytosis. Eosinophil and mast cell counts were not higher in the iad-affected group, compared with those in the control group; however, 4 iad-affected horses had marked eosinophilia (24.7 ± 4.8% SEM) in balf. Phenotypic analysis of lymphocytes in balf obtained from IAD-affected horses revealed a low proportion of CD4-positive cells and B cells, compared with those in the control group; these findings may have been representative of a greater proportion of non-B, non-T cells (null cells) in horses with iad. The cytologic profile of balf obtained from horses with iad differed from that in horses affected with chronic obstructive pulmonary disease, suggesting that the pathogenesis of inflammation in horses with iad may differ from that of chronic obstructive pulmonary disease.
Use of technetium-99m sulfur colloid to evaluate changes in reticuloendothelial function in dogs with experimentally induced chronic biliary cirrhosis and portosystemic shunting
Authors: Koblik Philip D. , Homof William J. , Yen Chi-Kwan , Fisher Paul E. , Komtebedde Jan
Published: January 2024

Technetium-99m sulfur colloid scintigraphy was used to study alterations of reticuloendothelial function in 7 dogs with experimentally induced biliary cirrhosis and portosystemic shunting. Scintigraphic studies were performed before and 6 weeks after common bile duct ligation. Radiocolloid plasma clearance rate was determined by measuring activity in plasma samples and by analyzing the rate of liver uptake on dynamic scintigraphic image sequences. Percentage of uptake in the liver, spleen, and lungs, as well as the ratio of hepatic-to-extrahepatic uptake, was determined from static equilibrium images. Relative to preoperative values, there were significant decreases in plasma clearance rate, percentage of fiver uptake, and ratio of hepatic-to-extrahepatic uptake and significant increases in percentage of spleen and lung uptake on postoperative studies.

The mechanism of technetium-99m-labeled sulfur colloid extraction by the liver is different from that of other radiocolloids; it does not require active phagocytosis or pinocytosis. Thus, fiver uptake of this tracer principally reflects effective liver blood flow. Portosystemic shunting was documented in these dogs at the time of the postoperative radiocolloid scans, and we believed was responsible for the decrease in liver reticuloendothelial activity. Possible mechanisms for the increased splenic and pulmonary reticuloendothelial activities are discussed.
Detection of Toxoplasma gondii-specific IgA in the serum of cats
Authors: Burney Derek P. , Lappin Michael R. , Cooper Christi , Spilker Melissa M.
Published: January 2024

An elisa for detection of Toxoplasma gondii-specific IgA in feline serum was developed. A group of cats (n = 7) was inoculated orally with T gondii bradyzoites. Toxoplasma gondii-specific serum IgM, IgG, and IgA responses were followed sequentially by use of the ELISA for 34 weeks. Serum IgA was detected later than IgM or IgG, and was detected in most cats on week 34 after inoculation. None of the cats was seropositive for IgA during the oocyst-shedding period. A group of client-owned cats with suspected clinical toxoplasmosis and a group of healthy cats were tested for Toxoplasma gondii-specific IgA in serum. A trend toward association of T gondii-specific IgA in serum of cats with ocular disease was observed.
Evaluation of marking materials for cutaneous surgical margins
Authors: Seitz Susan E. , Foley George L. , Marretta Sandra Manfra
Published: January 2024

Microscopic evaluation of the margins of excised cutaneous neoplasms is of paramount importance for determining that neoplastic tissue does not extend to the excision borders. Dyes or pigments that indelibly mark the tissue should be more reliable than sectioning techniques or suture markers for identifying the surgical margins before and after tissue processing. We evaluated 5 pigments to select a material that could be rapidly applied by surgeons, and readily identified on histologic section by the pathologists.

Twenty normal canine skin specimens were assigned to each of 5 groups. Each group was treated with artists’ pigments in acetone, India ink in acetone, alcian blue, typists’ correction fluid, or a commercially available marking kit. Ten specimens within each group were marked before formalin fixation, and 10 were marked after fixation. Application properties, fixation and processing properties, and microscopic characteristics were evaluated for each material.

Application properties were acceptable for all marking materials on unfixed specimens, and for alcian blue, India ink in acetone, and correction fluid on fixed specimens. Fixation and processing properties were acceptable for all materials except correction fluid. All marking materials survived fixation and processing, and colors were readily visualized under the microscope. Microscopic characteristics were acceptable for alcian blue, India ink in acetone, and the commercial kit.

Overall, alcian blue was the best marking material, with India ink in acetone and the commercial kit also acceptable. Correction fluid and artist’ pigments in acetone were not acceptable because pigment fragmentation and incomplete tissue coverage hindered microscopic evaluation of resection margins.
Bacterial expression of the caprine arthritis-encephalitis virus gag and env proteins and their use in enzyme-linked immunosorbent assay
Authors: Clavijo Alfonso , Thorsen Jan
Published: January 2024

The core protein and the transmembrane protein, encoded for the structural genes gag and env, respectively, of caprine arthritis-encephalitis virus were amplified by use of polymerase chain reaction, cloned into a pGEX-2T vector, and expressed in Escherichia coli as fusion proteins with the glutathione S-transferase at their C-terminus. The recombinant proteins were purified and evaluated by use of an elisa. Sera from 269 goats were tested, and the results were compared with those obtained by use of immunoblot analysis. When results from both recombinant elisa (r-elisa) were compared, it appeared that the transmembrane glycoprotein was more immunoreactive than the core protein, because it was recognized by a higher percentage of sera from infected goats. When results of the 2 elisa (p28 r-elisa and p40 r-elisa) were combined in parallel, they were comparable to those of the immunoblot test, with sensitivity of 100% and specificity of 98.3%. It was also found that use of both r-elisa makes it possible to compare the variable immunoreactivity against gag and env viral antigens, which may be correlated with the disease state. The r-elisa, using core and transmembrane proteins, appears to be highly sensitive and specific for detection of antibodies against caprine arthritis-encephalitis virus.
Urethral pressure response to smooth and skeletal muscle relaxants in anesthetized, adult male cats with naturally acquired urethral obstruction
Authors: Straeter-Knowlen Ingrid M. , Marks Steven L. , Rishniw Mark , Speth Robert C. , Wirth W. , Knowlen Grant G.
Published: January 2024

The effects of the skeletal muscle-relaxing drug dantrolene sodium alone, and in combination with the α1-adrenergic antagonist prazosin, on the urethral pressure profile were investigated in male cats with obstructive lower urinary tract disease. Decreases in mean segmental intraurethral pressure induced by dantrolene (n = 3) or dantrolene in combination with prazosin (n = 3) were evaluated statistically, using a paired design. Statistical analysis was applied to absolute (mm of Hg) pressure values. Intravenous administration of dantrolene alone (1 mg/ kg of body weight, n = 3) significantly decreased pressure in the postprostatic/penile urethral segment, but did not decrease prostatic urethral pressures. Dantrolene in combination with prazosin (0.03 mg/kg, iv) caused a 20% pressure decrease in the prostatic segment (P = 0.060). Preprostatic urethral pressure was not significantly affected by either treatment regimen in the small pool of cats studied. There was no difference in baseline pressures (mm of Hg) in the 3 intraurethral segments of these 6 recently obstructed male cats, compared with historic baseline pressures (mm of Hg) in the 3 intraurethral segments of 28 healthy male cats.

These results indicate that dantrolene and prazosin may be effective in relaxing intraurethral skeletal and smooth musculature in male cats clinically afflicted with obstructive lower urinary tract disease. However, it is not certain that administration of muscle relaxants would facilitate urethral catheterization and removal of the obstruction in male cats with blockage of the lower urinary tract. Strikingly, results of this study suggest that urethral muscle spasm had a minor role in these cats.
Sensitivity and specificity of various serologic tests for detection of Toxoplasma gondii infection in naturally infected sows
Authors: Dubey J. P. , Thulliez P. , Weigel R. M. , Andrews C. D. , Lind P. , Powell E. C.
Published: January 2024

The sensitivity and specificity of various serologic tests for antibodies to Toxoplasma gondii were compared in 1,000 naturally exposed sows, using isolation of viable T gondii as the definitive test. Serum samples obtained from heart blood of 1,000 sows from Iowa were examined for T gondii antibodies by use of the modified agglutination test (mat), latex agglutination test (lat), indirect hemagglutination test (ihat), and elisa. Toxoplasma gondii was isolated from 170 hearts of 1,000 sows by bioassays in mice and cats. The percentage of samples diagnosed as positive for each of the serologic tests was: mat = 22.2% (titer ≥ 1:20), ihat = 6.4% (titer ≥ 1:64), lat = 10.4% (titer ≥ 1: 64), and elisa = 24.1% (OD > 0.360). The sensitivity and specificity of these tests were calculated respectively to be: 82.9 and 90.29% for mat, 29.4 and 98.3% for ihat, 45.9 and 96.9% for lat, and 72.9 and 85.9% for elisa. The dye test was run at 1:20 dilution on only 893 sera because of bacterial contamination and presence of anticomplement substances. Dye test antibodies were found in 17.8% of the sera, and sensitivity and specificity were 54.4 and 90.8%, respectively. Thus, the mat had the highest sensitivity among all serologic tests used.
Jejunal microvasculature of the llama and alpaca
Authors: Yarbrough Tom B. , Snyder Jack R. , Harmon Faye A.
Published: January 2024

The vasculature of the jejunum was studied in 6 llamas and 1 alpaca, using a combination of microangiography, standard light microscopy, and vascular cast imaging. The casts were examined by use of scanning electron microscopy and low-power dissecting microscopy. After administration of 40,000 IU of heparin, all animals were euthanatized by administration of an overdose of sodium pentobarbital. Three sections of jejunum and their respective arcuate vessels were isolated from each animal. One section was immediately placed in formalin for later H&E staining. The second and third sections were placed in warm saline solution, and the vasculature was flushed free of all blood by repeated infusions of the solution. Once flushed of all blood, one section was infused with a radio-opaque medium and subsequently evaluated by microangiography, and the remaining section was perfused with a methylmethacrylate polymer for creation of vascular casts.

The arcuate vessels branched into extensive primary and secondary arcades prior to giving rise to the marginal rete. Muscular arteries and small veins left the marginal rete and penetrated the tunica serosa and tunica muscularis to provide nutrients or drain the mesenteric angle, respectively, or entered into the circumferential submucosal network. The primary penetrating vessels in the submucosa formed an extensive submucosal plexus that supplied the tunica serosa, tunica muscularis, and tunica mucosa. The primary penetrating vessels anastomosed with vessels from oral and aboral sections and with their counterparts from the opposite side at the antimesenteric border. Vessels supplied the tunica serosa and tunia muscularis by branching centrifugally from the submucosal plexus supplying the inner circular and outer longitudinal muscle layers parallel to their respective muscle layers. The arterioles supplying the tunica mucosa branched at right angles, penetrated the muscularis mucosa, and gave rise to clusters of arterioles supplying either the villi or the intervening crypts; anastomosis occurred between these 2 systerns toward the base of the villus. The arterioles gradually developed a discontinuous smooth muscle layer as they approached the base of the villus. Each villus was supplied by a single centrally placed metarteriole that spiraled to the tip of the villus, divided, and descended in a fountaining capillary network. The individual capillaries in the cascade coalesced to drain via 2 to 4 venules at the base of the villus. Branches from the venules entered into an anastomosing network in the lamina propria to drain the crypts. Venules drained in the submucosal plexus and continued paralleling the arterial supply toward the mesenteric border and the arcuate veins. The jejunal vasculature of South American camelids contains an extensive set of anastomotic connections at all levels after formation of the arcuate vessels. Within the scope of this examination into the microvasculature of llamas and alpacas, differences were not detected between the individual species.
Passive immune status at postpartum hour 24 and long-term health and performance of calves
Authors: Wittum Thomas E. , Perino Louis J.
Published: January 2024

We quantified the effect of passive immune status on pre- and postweaning health and growth performance of calves raised in a beef production environment. Blood samples were collected at postpartum hour 24 from 263 crossbred calves for determination of plasma protein (pp) and serum IgG concentrations. Serum IgG concentration was classified as adequate (> 1,600 mg/dl), marginal (800 to 1,600 mg/dl), or inadequate (< 800 mg/dl). Plasma protein concentration was classified as adequate (≥ 4.8 g/dl) or inadequate (< 4.8 g/dl). Morbidity and mortality events in the study population were monitored from birth to weaning, and after weaning throughout the feeding period. The lowest concentrations of serum IgG and pp were observed among calves that experienced morbidity or mortality prior to weaning. Calves that experienced morbidity in the feedlot had lower 24-hour pp values, but had IgG concentration similar to that in calves that were not observed to be ill during the feeding period. Calves classified as having inadequate IgG concentration were at greater risk of preweaning mortality (odds ratio [or] = 5.4), neonatal morbidity (or = 6.4), and preweaning morbidity (or = 3.2), compared with calves classified as having adequate IgG concentration at 24 hours. Calves classified as having inadequate pp concentration at 24 hours had a greater risk of morbidity (or = 3.0) and respiratory tract morbidity (or = 3.1) while in the feedlot, compared with calves classified as having adequate pp concentration. The effects of 24-hour passive immune status on calf growth were indirect through effects on morbidity outcomes. Morbidity during the first 28 days of life was associated with a 16-kg lower expected weaning weight. Respiratory morbidity in the feedlot resulted in a 0.04-kg lower expected mean daily gain. Thus, passive immune status at postpartum hour 24 was an important determinant of health before and after weaning, and was indirectly associated with calf growth during the same periods.
Necropsy survey of metacarpal fusion in the horse
Authors: Les C. M. , Stover S. M. , Willits N. H.
Published: January 2024

Paired metacarpi obtained at necropsy from 100 horses ranging in age from term fetus to 35 years were examined to estimate the prevalence and sites of metacarpal fusion. Metacarpal fusion was seen in 192 of 200 metacarpi, and 78% of all horses 2 years or older had 2 or more fusions. Fusion of the second metacarpal bone to the third metacarpal bone was significantly (P < 0.001) more common than was fusion of the fourth to the third metacarpal bone. Fusions appeared for the most part in pairs and were bilaterally symmetric. Rooney-Prickett type-A carpometacarpal joint configurations (in which there is no measurable articulation between the third carpal and second metacarpal bones) were rare in this population, and Rooney-Prickett type-B configurations (in which there is a measurable articulation between the third carpal and second metacarpal bones) were observed in 98.5% of metacarpi. Medial metacarpal fusion was positively correlated with age, occupation, and proportion of the proximal projection of the carpometacarpal distal joint surface that was taken by the second metacarpal bone. Lateral metacarpal fusion was positively correlated with age and the proportion of the proximal projection of the carpometacarpal distal joint surface taken by the fourth metacarpal bone.

Horses in performance careers (racing, race training, or show ring occupations) had an earlier development of the first 2 fusions than did horses in other or unknown occupations; development of the third and fourth fusions were not significantly different between occupation groups. The rate of metacarpal fusion per horse-year appeared to be at least 10 times higher than a clinically evident rate.

A variety of gross morphologic features was observed in the fusions from this sample, some of which were small, subtle, and possibly difficult to detect in vivo. It is hypothesized that many instances of metacarpal fusion may be a result of functional adaptation of the metacarpus to increased or changed loading conditions, rather than a response to isolated traumatic events.
Evaluation of a porous bovine collagen membrane bandage for management of wounds in horses
Authors: Yvorchuk-St. Jean Kathleen , Gaughan Earl , St. Jean Guy , Frank Rodney
Published: January 2024

Objective

To evaluate the effect of a porous bovine-derived collagen membrane (pbcm) on the rates of wound healing, cellular events, presence of granulation tissue, and appearance at termination of the study in surgically created full-thickness cutaneous wounds of the distal portion of the extremities of horses.

Design

Treated wounds (n = 12) received a pbcm dressing and control wounds were covered with a nonadherent dressing. Forelimbs and hind limbs were cross paired; the right forelimb and left hind limb always received the same dressing application, as did the left forelimb and right hind limb. Limbs pairs were then randomly assigned to 1 of the 2 dressings.

Animals

Six healthy male horses (3 sexually intact, 3 geldings) ranging from 2 to 10 (mean, 6.5) years and weighing between 278 and 568 (mean, 408.5) kg were studied.

Procedure

Full-thickness skin wounds (6.25 cm2) were created on the dorsal metatarsi and metacarpi of the experimental animals. A preformed pbcm dressing was evaluated in half the wounds (n = 12). Control wounds (n = 12) were dressed with a nonadherent gauze dressing. At each bandage change, wounds were subjectively assessed and were photographed, and measurements of horizontal and vertical wound dimensions were documented. Wound biopsy specimens obtained on days 2, 5, 7, 10, 21, and 31 were evaluated for presence of collagen, fibrin, inflammation, epithelium, and cellular elements of healing. Planar morphometry was used to determine total wound area and granulation area from the wound photographs. Percentage of contraction and epithelialization were calculated from these values. Linear regression analysis of the square root of the total wound area and the granulation area was performed. Wound area measurements were analyzed, using anova for repeated measures. Regressions were compared, using covariance analysis and anova. Significance was considered at P < 0.05.

Results

Fibrin score, neutrophil score, and degree of inflammation were significantly greater in the pbcm-treated wounds. No significant differences in the total wound, epithelialized, or contraction areas were detected between the pbcm-treated and control (nonadherent-treated) wounds. Rates of wound healing were not statistically different between the 2 treatment groups, though they were significantly slower in the hind limbs, compared with the forelimbs. Scabs were formed more frequently in the pbcm-treated wounds.

Conclusions

Application of a porous collagen bandage was not detrimental to full-thickness cutaneous wound healing in horses.
Serum haptoglobin concentrations in a population of feedlot cattle
Authors: Young C. R. , Wittum T. E. , Stanker L. H. , Perino L. J. , Griffin D. D. , Littledike E. T.
Published: January 2024

Objective

To determine serum haptoglobin concentrations in a population of feedlot cattle and evaluate their usefulness in predicting subsequent clinical respiratory tract disease.

Design

Prospective longitudinal study.

Animals

366 beef calves.

Procedure

Serum samples were obtained at feedlot entry and 40 and 65 days on feed (DOF). Calves were observed daily for clinical signs of respiratory tract disease. The lungs of 144 of the calves were evaluated at slaughter for the presence of gross lesions of pneumonia.

Results

58% of the calves had detectable serum haptoglobin concentration in at least 1 sample. The proportion of calves with detectable haptoglobin were similar at each sample collection time. A higher proportion of the calves had values > 10 mg/dl at 40 DOF. The prcportion of calves observed with clinical disease during the 10-day period after the 40 DOF sample increased (P < 0.10) as serum haptoglobin concentration increased. At 65 DOF, calves with serum haptoglobin value > 10 mg/dl had a higher (P < 0.05) rate of subsequent clinical respiratory tract disease than did calves with lower values. The proportion of calves with gross pulmonary lesions slaughter increased (P < 0.05) from 39% among calves without detectable serum haptoglobin concentration in any of the 3 samples to 63% among calves with at least 1 observed value > 10 mg/dl.

Conclusions

We observed associations between serum haptoglobin concentration and subsequent clinical respiratory tract disease and pulmonary lesions at slaughter. However, serum haptoglobin concentration alone is not adequate for prediction of clinical disease.

Clinical Relevance

The usefulness for cross-sectional sampling of serum haptoglobin concentration as a diagnostic tool for clinical respiratory tract disease in feedlot cattle appears to be limited.
Effect of oral administration of flunixin meglumine on the inflammatory response to endotoxin in heifers
Authors: Odensvik Kristina , Magnusson Ulf
Published: January 2024

Objective

To compare the effect of oral and IV administrations of flunixin meglumine on the endotoxin-induced inflammatory response in heifers.

Design

The study was conducted in 2 experimental sets in which heifers were exposed to low IV doses of Escherichia coli endotoxin. Within each set, heifers were allocated to 3 treatment groups; pretreatment with flunixin meglumine orally and IV prior to endotoxin administration, or endotoxin administration only. The dose of flunixin used was the recommended therapeutic dose in cattle.

Animals

11 clinically normal heifers weighing from 400 to 640 kg.

Procedure

A permanent cannula was inserted into the jugular vein on the day prior to the experiment. Blood samples were collected regularly during the experiment and analyzed for the content of prostaglandin F2α metabolite, Cortisol, blood mononuclear cells, and polymorphonuclear neutrophilic leukocytes and rectal temperature was measured.

Results

Endotoxin administration caused clinical signs and hematologic changes characteristic of endotoxemia in cattle. Flunixin administered orally prior to experimentally induced endotoxemia exerted an effect equal to that after its IV administration. Significant increases in rectal temperature and prostaglandin F2α metabolite concentrations after administration of endotoxin were abrogated when the heifers were pretreated with flunixin, irrespective of route of administration. Cortisol concentrations were lower after pretreatment with flunixin. However, flunixin did not prevent the decrease in blood mononuclear cells and polymorphonuclear neutrophilic leukocytes seen after endotoxin administration.

Conclusion

Owing to no major difference in the inflammatory response between oral and IV flunixin dosing, flunixin granules may be an alternative to parenteral use in bovine practice.
Effect of a mask and pneumotachograph on tracheal and nasopharyngeal pressures, respiratory frequency, and ventilation in horses
Authors: Holcombe Susan J. , Beard Warren L. , Hinchcliff Kenneth W.
Published: January 2024

Objective

To investigate the effect of a mask and pneumotachograph on ventilation, respiratory frequency, and tracheal and nasopharyngeal pressures in horses running on a treadmill.

Design

Six horses ran at 50, 75, and 100% of the speed that resulted in maximum oxygen consumption, with and without a mask and pneumotachograph. Tracheal and pharyngeal inspiratory and expiratory pressures, respiratory frequency, and arterial blood gases were measured.

Animals

Six Standardbred horses.

Procedure

Oxygen consumption was measured during an incremental exercise test to determine the speed that resulted in maximal oxygen consumption for each horse. Tracheal and pharyngeal pressures were measured, using transnasal tracheal and pharyngeal side-hole catheters connected to differential pressure transducers. Carotid arterial blood samples were collected and PaO2, PaCO2, and pH were measured with a blood gas analyzer.

Results

Peak tracheal and pharyngeal inspiratory pressures were significantly more negative, peak tracheal and pharyngeal expiratory pressures were significantly more positive and respiratory frequency was significantly lower (all P < 0.05) at all speeds when horses wore a mask The PaCO2, was higher and arterial pH and PaO2, were lower (P < 0.05) when horses wore a mask.

Conclusions

The mask and pneumotachograph altered upper airway pressures, respiratory frequency, and ventilation in horses running on a treadmill.(Am J Vet Res 1996; 57: 250-253)
Effect of prepuberal and postpuberal gonadectomy on heat production measured by indirect calorimetry in male and female domestic cats
Authors: Root Margaret V. , Johnston Shirley D. , Olson Patricia N.
Published: January 2024

Objective

To use indirect calorimetry to compare heat production between gonadectomized and sexually intact male and female cats.

Design

Male (n = 6) and female (n = 6) kittens were gonadectomized at 7 weeks or 7 months of age, or left sexually intact. Body heat production was measured by indirect calorimetry in all cats at 12, 18, and 24 months of age.

Animals

18 male and 18 female clinically normal domestic shorthair cats.

Procedure

Heat production was measured, using an open-circuit, respiratory, indirect calorimeter. All cats underwent calorimetry at 12, 18, and 24 months of age. The heat coefficient, a measure of resting metabolic rate, was calculated for each cat at each test; heat coefficient is defined as logarithm of heat (kcal/h) divided by logarithm of body weight (kg).

Results

Heat production did not vary with age in male or female cats. Heat coefficient was higher in sexually intact male and female cats than in gonadectomized male and female cats at 12, 18, and 24 months of age (12 months, females, P < 0.01, males, P = 0.04; 18 months, females, P < 0.01, males, P = 0.02; and 24 months, females and males, P < 0.01).

Conclusions

These data suggest that resting metabolic rate in cats decreases after gonadectomy.

Clinical Relevance

A decrease in metabolic rate is synonymous with a decrease in caloric requirements. Gonadectomized animals fed in a manner similar to sexually intact animals may be predisposed to obesity and its sequelae.(Am J Vet Res 1996;57:371-374)
Use of force-plate analysis of gait to compare two surgical techniques for treatment of cranial cruciate ligament rupture in dogs
Authors: Jevens Dermot J. , DeCamp Charles E. , Hauptman Joe , Braden Terrance D. , Richter Marlee , Robinson Rachel
Published: January 2024

Objective

To use ground reaction forces and related impulses as an objective measurement of limb function in the comparison of 1 extracapsular and 1 intracapsular surgical technique for repair of cranial cruciate ligament rupture in dogs.

Animals

18 healthy dogs.

Design

All dogs underwent force-plate analysis of gait prior to transection of the left cranial cruciate ligament. The dogs were randomly allotted to 3 groups. The ligamentous instability was corrected, using a modified retinacular imbrication technique (MRIT) in 1 group and an under-and-over technique in another group. No attempt was made to correct the ligamentous instability in a control group. Clinical grading of lameness and force-plate analysis of gait were performed at 4, 8, 12, 16, and 20 weeks after surgery.

Procedure

Peak vertical force and vertical, braking, and propulsion impulses were recorded for each limb at each time. The degree of clinical lameness was graded at each time.

Results

Left hind limb peak vertical forces and vertical impulses were significantly decreased at all times after surgery in the control and under-and-over technique group, compared with values before surgery. Dogs of the MRIT group had improved by 20 weeks, with no significant differences between left hind limb peak vertical forces or vertical impulses recorded before surgery and at 20 weeks.

Conclusion

Peak vertical forces and vertical impulses in dogs undergoing MRIT repair after experimentally created cranial cruciate ligament rupture are not significantly different when values recorded for the operated limb at 20 weeks after surgery are compared with those recorded prior to surgery.(Am J Vet Res 1996;57:389-393)
Rate of keratinization of the wall segment of the hoof and its relation to width and structure of the zona alba (white line) with respect to claw disease in cattle
Authors: Budras K.-D. , Mülling Ch. , Horowitz A.
Published: January 2024

Objectives

To determine contribution of the wall segment of bovine cattle hoof to horn production, and relevance of structural differences of the wall segment and its horn production rate to claw disease.

Design

Epidermis and papillary body of the wall segment were examined by mesoscopy, light microscopy, and transmission and scanning electron microscopy. Morphometry of the entire length of the zona alba was examined, and the horn production rate of the wall segment was calculated.

Animals

Mixed-breed, dual purpose (beef and dairy) cattle of either sex, and young (20 months) Holstein-Friesian beef bulls.

Procedure

Blocks of a strip of the hoof from the coronary segment to the sole margin, including epidermis and dermis, were prepared for light and transmission electon microscopy. Prepared specimens of the wall-sole border were examined by scanning electron microscopy. Morphometry was performed on the outer, middle, and inner parts of the zona alba structures on unfixed horn specimens of beef bull claws. After removal of the zona alba specimens, the claw was removed and the proximodistal extent of the epidermal leaflets was measured and analyzed statistically.

Results

Horn production increased in the distal half of the wall segment, was greatest at the wall-sole border, and highest above the abaxial end of the zona alba. High horn production resulted in an incompletely keratinized, softer horn.

Conclusions and Clinical Relevance

High horn production at the zona alba increases susceptibility to vascular disturbance. Claw dyskeratoses appear first in areas of high horn production, areas which are also subject to a greater frequency of claw lesions. (Am J Vet Res 1996;57:444–455)
Use of enzyme-linked immunosorbent assay to measure thrombin-antithrombin III complexes in horses with colic
Authors: Topper Michael J. , Prasse Keith W.
Published: January 2024

Objectives

To evaluate new ELISA for measurement of thrombin-antithrombin III (TAT) concentration, and to correlate the values to other tests of hemostasis in horses with colic.

Design

Plasma TAT concentration and 8 other hemostasis analytes were measured in horses with colic at hospital admission and during the next 4 days. Retrospectively, data were analyzed by outcome, broad-category diagnosis, and clinical management, and for correlation between TAT and other assays.

Animals

100 horses with colic.

Procedure

Plasma samples were evaluated for TAT, fibrinogen, and fibrin degradation products concentrations; antithrombin III (ATIII), protein C, α2-antiplasmin, and plasminogen activities; prothrombin time (PT); and activated partial thromboplastin time.

Results

Changes were indicative of a hypercoagulable state, most severe in nonsurviving horses, characterized by increased TAT concentration; decreased ATIII, protein C, and plasminogen activities; and increased PT. Nonsurvivors had significantly increased TAT concentration compared with that in survivors, without regard to sample collection time; however, compared over time, TAT was significantly increased only at admission. Highest TAT concentration was in nonsurvivors with inflammatory intestinal lesions. There was significant negative correlation between TAT and ATIII, protein C, α2-antiplasmin, and plasminogen values, and significant positive correlation between TAT and PT, and fibrin degradation products values.

Conclusions

Plasma TAT reflects the current state of coagulation system activation and is a good assay for early diagnosis of the hypercoagulable state in horses with the most severe forms of colic.

Clinical Relevance

Measurement of equine TAT provides further information to characterize the hypercoagulable state in horses to aid in case management. (Am J Vet Res 1996;57:456–462)
Event-time analysis of the effect of 60-day milk production on the parturition-to-conception interval in dairy cows
Authors: Harman J. L. , Gröhn Y. T. , Erb H. N. , Casella G.
Published: January 2024

Objective

To quantify the effect of early-lactation milk and milk fat production on time to conception.

Design

Event-time analysis (survival analysis).

Sample Population

44,450 cows delivering calves between September 1985 and September 1986, from 6,227 Ayrshire dairy herds in 80 Finnish communities.

Procedure

Primiparous and multiparous cows were analyzed in separate Cox proportional hazards models. 60-day milk and milk fat production were categorized and regressed against days from parturition to conception for the period 56 to 120 postpartum days, controlling for season of parturition, parity, herd production, occurrence of 43 diseases, and community.

Results

Multiparous cows producing above the 80th percentile for 60-day milk, but with milk fat production below the 75th percentile, were significantly more likely to conceive, compared with cows with lower production and compared with cows with similar milk production but with milk fat between the 75th and 97th percentiles. They were slightly more likely to conceive than cows with highest milk fat production, although not significantly so. Primiparous cows producing above the 80th percentile for 60-day milk with milk fat below the 75th percentile also had the highest conception probability. The highest producing primiparae had significantly lower conception probability than all others.

Conclusions

Controlling for disease occurrence, calving season, parity, herd production level, and community, there appeared to be an inverted U-shaped relation between 60-day production and conception probability.

Clinical Relevance

Primiparous cows that are high producers may not be receiving the same careful management that high-producing multiparous cows receive. (Am J Vet Res 1996; 57:634–639)
Identification of neutrophil NADPH oxidase proteins gp91-phox, p22-phox, p67-phox, and p47-phox in mammalian species
Authors: Hitt Nancy D. , Kleinberg Michael E.
Published: January 2024

Objective

To identify and characterize 4 components of the NADPH oxidase complex, gp91-phox, p22-phox, p67-phox, and p47-phox, in common laboratory animal species.

Animals

2 clinically normal animals from each of the following species: rabbit, sheep, cow, pig, and macaque (Macaca nemistrina). A pool of 8 rats.

Procedure

Neutrophils were harvested from blood. Membrane and cytosol fractions were isolated and separated by sodium dodecyl sulfate-polyacrylamide gels. Gels were transferred, and immunoblots were probed with antibodies directed against individual human NADPH oxidase proteins. Human neutrophil membrane and cytosol fractions served as controls.

Results

Immunoreactive bands were observed in all species for gp91-phox, p67-phox, and p47-phox proteins. Immunoreactive bands for p22-phox protein were observed in cells from rats, rabbits, pigs, and macaques.

Conclusions

The NADPH oxidase and its component proteins have been highly conserved across mammalian species. Lack of immunoreactivity to p22-phox in sheep and cows can be explained by sequence divergence and epitope variability at the p22-phox C-terminus.

Clinical Relevance

The high degree of NADPH oxidase protein conservation may allow the existing knowledge of the human neutrophil NADPH oxidase to be applied to the study of animal disease. Am J Vet Res 1996; 57:672–676
Differential distribution of von Willebrand factor in canine vascular endothelium
Authors: Smith Jennifer M. , Meinkoth James H. , Hochstatter Tressa , Meyers Kenneth M.
Published: January 2024

Objective

To determine whether endothelial cell (EC) von Willebrand factor (vWf) is uniformly distributed in canine blood vessels.

Design

Content of EC vWf from vascular segments was evaluated in Haütchen preparations, using immunohistochemistry. EC from femoral arteries and veins and jugular veins were grown in culture, and the intracellular content and constitutive release of vWf from these cells were measured. The amount of vWf mRNA in the cultured EC was determined.

Animals

Vascular segments for Hautchen preparations and EC for culture were obtained from 5 and 10 clinically normal, mixed-breed dogs, respectively.

Procedures

Appropriate vascular segments were removed, fixed, processed for immunohistochemistry, using a monospecific polyclonal antibody to canine vWf, and Haütchen preparations were made. Intracellular and constitutive released vWf was measured, using an ELISA, and vWf mRNA was measured by Northern blot analysis.

Results

Intact endothelial linings from femoral veins, jugular veins, vena cava, and pulmonary veins stained more intensely than femoral arteries, carotid arteries, aorta, and pulmonary veins. Constitutive release and intracellular content of vWf in cultured EC from femoral veins was about 30 times higher than that from femoral arterial EC, which was barely detectable. Similar differences were seen in amounts of mRNA.

Conclusions

There is marked diversity in EC vWf in canine vasculature that may result from differences in vWf mRNA.

Clinical Relevance

Low amounts of vWf in canine systemic arterial EC may contribute to thromboresistance of canine arteries. (Am J Vet Res 1996; 57:750–755)
Prevalence of Serpulina species in relation to diarrhea and feed medication in pig-rearing herds in Sweden
Authors: Fellström Claes , Pettersson Bertil , Johansson Karl-Erik , Lundeheim Nils , Gunnarsson Anders
Published: January 2024

Objective

To determine prevalence of various pheno- and genotypes of Serpulina sp in young pigs in relation to diarrhea and feed medication in Swedish pig-rearing herds.

Design

Isolation of spirochetes. Phenotypical and genotypical classification.

Sample Population

Young pigs (n = 358) in 19 pig-rearing herds.

Procedure

Serpulina isolates were classified according to a biochemical scheme based on hemolysis, indole production, hippurate hydrolysis, and α-galactosidase, α-glucosidase, and β-glucosidase activities. The 16S rRNA sequences for 10 of the field strains and 2 type strains of Serpulina spp were aligned and compared. Minimum inhibitory concentrations of olaquindox for 9 of the strains were determined.

Results

Weakly β-hemolytic intestinal spirochetes (WBHIS) were isolated from 17 of the herds and 65% of the samples. More than 1 phenotype of WBHIS was found in 12 of the 19 herds. S hyodysenteriae was not isolated in any of the herds. Hippurate-positive WBHIS were isolated in 6 of 7 herds affected by diarrhea, but in only 1 of 8 herds without diarrhea. Hippurate-positive strains were closely related to the pathogenic strain P43 if judged from sequence comparisons. Strains with the same biochemical profile isolated within a herd had identical sequences, but when isolated from different herds, sequence differences were observed. The prevalence of WBHIS was reduced in herds medicated with olaquindox. Investigated field strains had minimum inhibitory concentration values ≤ 1 μg/ml for olaquindox.

Conclusion

The presence of WBHIS, with the ability to hydrolyze hippurate, was related to diarrhea in pig herds.

Clinical Relevance

Potentially pathogenic WBHIS can be distinguished from nonpathogenic strains by the hippurate hydrolysis test. (Am J Vet Res 1996;57:807–811)
Effects of furosemide on hemorheologic alterations induced by incremental treadmill exercise in Thoroughbreds
Authors: Weiss Douglas J. , Geor Raymond J. , Burger Katherina
Published: January 2024

Objective

To determine whether furosemide treatment altered the blood flow properties and serum and RBC electrolyte concentrations of Thoroughbreds during submaximal treadmill exercise.

Design

Thoroughbreds were subjected to submaximal treadmill exercise with and without treatment with furosemide (1 mg/kg of body weight, IV).

Animals

5 healthy Thoroughbreds that had raced within the past year and had no history of exercise-induced pulmonary hemorrhage.

Procedure

Venous blood samples were obtained before exercise, at treadmill speeds of 9 and 13 m/s, and 10 minutes after exercise, and hemorheologic and electrolyte test results were determined.

Results

Hemorheologic changes 60 minutes after furosemide administration included increased PCV, plasma total protein concentration, whole blood viscosity, mean RBC volume, and RBC potassium concentration, and decreased serum potassium concentration, serum chloride concentration, and RBC chloride concentration. Furosemide treatment attenuated the exercise-associated changes in RBC size, serum sodium concentration, serum potassium concentration, RBC potassium and chloride concentrations, and RBC density; exacerbated exercise-associated increases in whole blood viscosity; and had no effect on RBC filterability.

Conclusions

The hemorheologic effects of furosemide probably occurred secondary to total body and transmembrane fluid and electrolyte fluxes and would not improve blood flow properties.

Clinical Relevance

The beneficial effects of furosemide treatment in reducing the severity of bleeding in horses with exercise-induced pulmonary hemorrhage cannot be explained by improved blood flow properties. (Am J Vet Res 1996;57:891–895)