bluuebunny/crossref_metadata_2025 huggingface dataset:
Laryngeal paralysis-polyneuropathy complex in young Dalmatians
Authors: Braund Kyle G. , Shores Andy , Cochrane Susan , Forrester Dru , Kwiecien Jack M. , Steiss Janer E.
Published: January 2024

Clinical, morphologic, and morphometric findings are reported in 14 young Dalmatians with laryngeal paralysis. Neurologic signs, including megaesophagus, were observed in 13 of 14 dogs. Electromyographic abnormalities included fibrillation potentials and positive sharp waves in laryngeal, esophageal, facial, and distal appendicular muscles. Neurogenic atrophy was detected in intrinsic laryngeal and appendicular skeletal muscles. A diffuse, generalized polyneuropathy, dominated by axonal degeneration, was observed in recurrent laryngeal and appendicular peripheral nerves. Results of quantitative studies, using single teased fiber and cross-sectional nerve preparations, indicated that changes were more severe in distal parts of peripheral nerves, with preferential loss of medium sized (5.5 to 8 μm) and large-caliber (8.5 to 12 μm) myelinated nerve fibers. Ultrastructural alterations were observed in myelinated and unmyelinated nerve fibers. The term laryngeal paralysis-polyneuropathy complex is proposed for this apparent dying-back disorder, which is clinically, electrophysiologically, and pathologically different from laryngeal paralysis in young Bouvier des Flandres and Siberian Huskies. Prognosis for Dalmatians with laryngeal paralysis-polyneuropathy complex is guarded to poor. The condition is believed to be inherited.
Spectrum analysis of diaphragmatic global electromyograms in cattle, with special regard to appropriate strategy for detection of fatigue
Authors: Desmecht Daniel J-M. , Linden Annick S. , Close Roland P. , Michaux Charles L. , Lekeux Pierre M.
Published: January 2024

Although the respiratory tract of healthy and diseased cattle has been intensively studied during the past few years, only a few attempts to detect dysfunctions of bovine inspiratory muscles have been reported. Such technique would be useful in assessing the possibility of inspiratory muscle fatigue in the context of ventilatory failure. Fatigue in skeletal muscle is associated with characteristic changes in the electromyographic power spectrum. Power spectral analysis was therefore applied to cattle diaphragmatic electromyograms (emgdi) to precisely determine the exact influence of motion and ecg artifacts, describe its basic frequency content, and extract a spectral index capable of providing an accurate warning of fatigue.

The emgdi was recorded via intramuscularly placed fishhook electrodes in 5 healthy young bulls during resting and stimulated respiration. The emgdi and egc signals were analyzed by use of power spectral density analysis after band-pass filtering (20 to 1,800 Hz). The emgdi spectrum was concentrated in the band width 20 to 530 Hz. Electrode motion artifacts were absent, and it was always possible to find an electrode pair giving ecg-free emgdi. Of the 12 power and frequency values used to quantitate the spectrum, the most stable was the centroid frequency. It was reproducible within and between calves and was only minimally altered by changing inspiratory load.

Though the clinical relevance of fatigue in the respiratory musculature in case of ventilatory failure is currently unknown, the method described here constitutes a possible approach to detection of such phenomenon in cattle.
Microvascular thrombosis associated with onset of acute laminitis in ponies
Authors: Weiss Douglas J. , Geor Raymond J. , Johnston Gary , Trent Ava M.
Published: January 2024

The hypothesis that equine laminitis is caused by thrombosis of vessels in the laminar corium (dermis) was investigated. Hemostatic alterations were evaluated by determining platelet count, platelet survival, platelet adhesiveness to vascular subendothelium, activated clotting time, and whole blood recalcification time. Thrombosis of vessels in the hoof wall was evaluated by scintigraphic studies of the hoof wall after administration of indium-111 (111In)-labeled platelets, contrast arteriography, and histologic examination. Platelet count remained constant before and at the onset of lameness; however, survival of 111In-labeled platelets was shortened. Scintigraphy of affected feet revealed accumulation of 111In-labeled platelets distal to the coronary band. Arteriography of disarticulated saline-perfused feet revealed marked reduction in blood supply to affected hooves. Histologic examination of the laminar dermis disclosed variable numbers of microthrombi in dermal veins of affected feet from 3 of 4 ponies with laminitis. Whole blood recalcification time was shortened at 8 hours after administration of carbohydrate and was prolonged at the onset of laminitis. Activated clotting time was prolonged at 32 hours after carbohydrate administration and at the onset of lameness. Plasma endotoxin-like activity was detected in 1 of 4 affected ponies. These data confirm that microvascular thrombosis existed at the onset of lameness in ponies with carbohydrate-induced laminitis and indicate that systemic coagulopathy may have preceded development of thrombosis.
Caudal analgesia induced by epidural or subarachnoid administration of detomidine hydrochloride solution in mares
Authors: Skarda Roman T. , Muir William W.
Published: January 2024

Seven adult mares were used to determine the analgesic, cns, and cardiopulmonary effects of detomidine hydrochloride solution after epidural or subarachnoid administration, using both regimens in random sequence. At least 1 week elapsed between experiments.

A 17-gauge Huber point (Tuohy) directional needle was used to place a catheter with stylet into either the epidural space at the first coccygeal interspace or the subarachnoid space at the lumbosacral intervertebral junction. Catheters were advanced so that the tips lay at the caudal sacral (S5 to S4) epidural space or at the midsacral (S3 to S2) subarachnoid space. Position of the catheter was confirmed radiographically. A 1% solution of detomidine HCl was injected into the epidural catheter at a dosage of 60 µg/kg of body weight, and was expanded to a 10-ml volume with sterile water to induce selective caudal epidural analgesia (cea). A dose of 30 µg of detomidine HCl/kg expanded to a 3-ml volume with spinal fluid was injected into the subarachnoid catheter to induce caudal subarachnoid analgesia (csa). Analgesia was determined by lack of sensory perception to electrical stimulation (avoidance threshold > 40 V, 0.5-ms duration) at the perineal dermatomes and no response to superficial and deep muscular pinprick stimulation at the pelvic limb and lumbar and thoracic dermatomes. Maximal cea and csa extended from the coccyx to spinal cord segments T15 and T14 at 10 to 25 minutes after epidural and subarachnoid drug administrations in 2 mares. Analgesia at the perineal area lasted longer after epidural than after subarachnoid administration (142.8 ± 28.8 minutes vs 127.1 ± 27.7 minutes). All mares remained standing. Both cea and csa induced marked sedation, moderate ataxia, minimal cardiopulmonary depression, increased frequency of second-degree atrioventricular heart block, and renal diuresis. All treatments resulted in significantly (P < 0.05) decreased heart rate, respiratory rate, systemic arterial blood pressure, pcv, and plasma total solids concentration. To the contrary, arterial carbon dioxide tension, plasma bicarbonate, and standard base excess concentrations were significantly (P < 0.05) increased. Arterial oxygen tension, pH, and rectal temperature did not change significantly from baseline values.

Results indicate that use of detomidine for cea and csa in mares probably induces local spinal and cns effects, marked sedation, moderate ataxia, mild cardiopulmonary depression, and renal diuresis.
Ultrasonography of the umbilical structures in clinically normal calves
Authors: Watson Elizabeth , Mahaffey Mary B. , Crowell Wayne , Selcer B. A. , Morris Debra D. , Seginak Lucy
Published: January 2024

The umbilical stalk, vein, and arteries, urachal region, and urinary bladder of 9 healthy Holstein calves were scanned ultrasonographically at weekly intervals from 1 day to 3 weeks of age. Four additional calves of representative ages, 1 day, 1 week, 2 weeks, and 3 weeks were euthanatized after ultrasonographic evaluation of the umbilical structures. Umbilical structures from these 4 calves were dissected, photographed, and examined histologically to ensure normalcy. These gross specimens were correlated with the ultrasonographic images and compared with serial ultrasonograms of 9 calves. The ultrasonographic scanning technique and the appearance of normal umbilical stalk, arteries, and vein, and urachus in calves were different from those described for foals. The umbilical vein of calves was scanned from the umbilical stalk to the liver along the right abdominal wall. Two veins, which merged within the body wall, were identified within the stalk. Umbilical arteries were not found within the umbilical stalk; they ended abruptly near the apex of the urinary bladder. A urachal remnant was not identified in any of the calves.

A range of normal values for measurement of the umbilical stalk, umbilical arteries, and umbilical vein at 3 sites was determined. The described ultrasonographic appearance and measurements of the normal Holstein calf umbilicus may be used as a reference for evaluation of calves with internal umbilical abnormalities.
Application of an enzyme-multiplied immunoassay technique for determination of caffeine elimination kinetics as a test of liver function in clinically normal dogs
Authors: Golden Dennis L. , Spano Joseph S. , Wilson Robert C. , DeGraves Fred J. , Whatley Elizabeth M.
Published: January 2024

A commercially available automated enzyme-multiplied immunoassay technique (emit) was used to determine serum caffeine concentration after oral and iv administrations of caffeine at dosage of 5 mg/kg of body weight to 12 clinically normal dogs. Dogs were allotted to 2 groups of 6 dogs each; 1 group initially received caffeine orally and the other received caffeine iv. After 72 hours, caffeine administration was repeated in all dogs in the alternate manner. Serum samples were obtained at multiple intervals over 24 hours to determine distribution and elimination kinetics. Analysis of the drug concentration-time data indicated iv elimination half-life (t½) of 6.39 ± 1.87 hours, volume of distribution at steady state of 685.3 ± 132.2 ml/kg, total body clearance of 1.31 ± 0.38 ml/min/kg, absorption t½ of 1.02 ± 0.68 hour, oral elimination t½ of 6.53 ± 2.72 hours, lag time after oral administration of 0.0614 ± 0.0661 hour, highest measured concentration of 5.29 ± 1.17 μg/ml, time to peak concentration of 2.74 ± 1.30 hours, and bioavailability of 99.4 ± 19.4%. Data from 6 dogs best fit a 1-compartment open model and those from 6 other dogs best fit a 2-compartment open model. On the basis of data from the 6 dogs that best fit a 2-compartment model, t½ of distribution was 0.58 ± 0.72 hour. Data for oral administration best fit a single absorption phase and a single elimination phase.

The increased availability and simplicity of the emit offers an opportunity to study the application of caffeine elimination for clinical evaluation of dogs with liver disease. Data obtained from this study allow determination of t½ and clearance to be simplified by obtaining samples 4 and 8 hours after oral or iv administrations and establishes canine reference values for elimination kinetics of caffeine administered at dosage of 5 mg/kg and assayed by use of the emit.
Cytologic characterization of bronchoalveolar lavage fluid collected through an endotracheal tube in cats
Authors: Hawkins Eleanor C. , Kennedy-Stoskopf Suzanne , Levy Julie , Meuten Donald J. , Cullins Laura , DeNicola Dennis , Tompkins Wayne A. F. , Tompkins Mary B.
Published: January 2024

Bronchoalveolar lavage was performed through an endotracheal tube in 34 specific-pathogen-free cats to determine expected values for bronchoalveolar lavage fluid cytologic analysis, using this method of collection. Saline solution for lavage was instilled in 3 separate aliquots at a volume of 5 ml/kg of body weight each. Analysis of sequential aliquots was performed to investigate the differences in cell counts among the 3 fractions. The effect of combining aliquots, including or omitting the first fraction, was evaluated to determine whether all aliquots could be combined for analysis without substantially affecting results.

The total number of nucleated cells retrieved from each cat ranged from 0.9 to 31.1 × 106. Most of these cells were macrophages (78 ± 15%, mean ± sd) and eosinophils (16 ± 14%). The first aliquot had the greatest number of epithelial cells, and the lowest total nucleated cell count and relative and absolute eosinophil counts. Differences among aliquots also were identified for relative and absolute macrophage counts, relative and absolute neutrophil counts, and absolute lymphocyte count. Statistically significant differences were found for many of the cell counts when values from the combination of the second and third aliquots were compared with values from the combination of all 3 aliquots. Magnitude of the differences was small, and these differences were not believed to be of practical consequence.
Influence of estrous cycle stage on adhesion of Streptococcus zooepidemicus to equine endometrium
Authors: Ferreira-Dias Graça , Nequin Lynn G. , King Sheryl S.
Published: January 2024

Equine endometria representative of Kenney's categories I, II, and III were incubated in vitro with phosphate buffer, Streptococcus pneumoniae, or S zooepidemicus. Endometrial tissues from mares in estrus and diestrus were first categorized according to Kenney's classification, then were tested for adherence of S pneumoniae and S zooepidemicus to the epithelia. Bacteria were not observed when the endometrial tissue was incubated with phosphate buffer or S pneumoniae. There was no statistical difference in attachment of S zooepidemicus to endometrial tissue from mares in estrus or diestrus if endometrial classification was ignored. However, bacterial attachment was significantly (P ≤ 0.05) higher in category III endometrium during estrus.
Sensory nerve conduction velocity of the caudal cutaneous sural and medial cutaneous antebrachial nerves of adult horses
Authors: Whalen L. R. , Wheeler D. W. , LeCouteur R. A. , Yovich J. V. , Boggie L. C. , Grandy J. L. , Kainer R. A.
Published: January 2024

Maximal conduction velocities of compound action potentials evoked by stimuli of 2 times threshold in the caudal cutaneous sural (ccsn) and medial cutaneous antebrachial (mcan) nerves were determined by averaging potentials evoked and recorded through percutaneous needle electrodes. Mean maximal conduction velocities of compound action potentials were: ccsn = 61.3 ± 2.0 meters/second (m/s) and mcan = 56.4 ± 2.8 m/s. To confirm accuracy of our percutaneous recordings, compound action potentials were recorded through bipolar chlorided silver electrodes from the exposed surfaces of fascicles of the ccsn and the mcan. The maximal conduction velocities of these potentials were in agreement with the conduction velocities of compound action potentials that were evoked and recorded through percutaneous needle electrodes. The specificity of stimulating and recording sites was verified by recording before and after section of the nerves. Stimuli from 3 to 5 times threshold evoked a second, longer latency, compound action potential that consisted of a variable number of components in the ccsn and mcan. The configurations and conduction velocities of the shorter latency potentials were the same as those of the single compound action potentials evoked by stimuli of 2 times threshold. Mean conduction velocities of the longer latency potentials were: ccsn = 24.4 ± 2.6 m/s and mcan = 24.5 ± 2.2 m/s. Needle electrode and direct stimulation of either the ccsn or the mcan at 3 to 5 times threshold failed to evoke contractions of limb muscles. Therefore, action potentials that contributed to the evoked compound potentials recorded in these horses arose, most likely, from afferent nerve fibers.
Sensory nerve conduction velocity of the dorsal penile nerves of bulls
Authors: Mysinger P. W. , Wolfe D. F. , Redding R. W. , Hudson R. S. , Purohit R. C. , Steiss J. E. , Wright J. C.
Published: January 2024

Mean conduction velocity of sensory axons of the dorsal penile nerves of clinically normal bulls was determined by recording action potentials evoked by cutaneous stimulation. Locations of stimulating and recording electrodes were standardized. Overall mean ± sd conduction velocity was 55.1 ± 5.1 m/s. Mean ± sd velocity recorded from the distal electrode was 53.3 ± 4.9 m/s; velocity recorded from the middle electrode was 55.3 ± 5.0 m/s; and velocity recorded from the proximal electrode was 56.7 ± 5.1 m/s. Differences among means were not significant Four bulls had mean conduction velocities of 54.0 m/s and 48.4 m/s before and 3 weeks after castration, respectively.
Comparison of measured and calculated values for colloid osmotic pressure in hospitalized animals
Authors: Brown Scott Alan , Dusza Kimberly , Boehmer Jennifer
Published: January 2024

A relation exists between colloid osmotic pressure (π) and serum total protein concentration; equations describing this relation have been used to determine a calculated value for π. However, the relation between total protein concentration and π is altered by the method used to measure protein and by changes in the ratio of concentrations of albumin (A) to globulin (G). We developed nomograms for estimating π from A and G concentrations, using samples obtained from clinically normal animals and compared the accuracy of these nomograms with that of previously described equations relating π to total protein concentration. For comparison, serum samples from canine (n = 106), equine (n = 79), feline (n = 24), and bovine (n = 27) patients admitted to the University of Georgia Veterinary Medical Teaching Hospital were used. Results indicated that nomograms based on protein concentration estimated by a refractometer generally were the least reliable. Although predictive nomograms, using total protein concentration determined by the biuret method, provided better results for serum samples, there was considerable variation between measured and calculated values for π in all species studied. Calculated values for π derived from A and G concentrations were most closely related to measured values for π dogs, horses, and cats. However, calculated values for π differed from measured values by as much as 5 mm of Hg for some samples by each of the methods of estimation. These results indicate that, although calculated values for π may be most accurate when variations in the A-to-G ratio are accounted for in the nomogram, none of the calculation methods provided a consistently accurate estimate of π. For clinical patients, π based on these nomograms cannot replace direct measurement.
Host factors affecting seroprevalence of bluetongue virus infections of cattle
Authors: Ward Michael P. , Carpenter Tim E. , Osburn Bennie I.
Published: January 2024

Results of testing of 19,731 samples from a serologic survey of cattle with bluetongue virus (btv) infections in Australia were analyzed for association between age, species, or sex and test result. Bivariate analysis indicated that all 3 host factors were associated with test result. After adjusting for confounding caused by the location of each animal in the study (high, moderate, and low btv prevalence regions), cattle ≥ 4 years old had an odds ratio of 4.33 (95% confidence interval, 3.99, 4.71) for a positive test result, compared with that for cattle < 2 years old. Cattle 2 to 4 years had an odds ratio of 2.28 (2.14, 2.54), compared with cattle < 2 years old. Bos taurus cattle had an odds ratio of 1.76 (1.63, 2.05) of a positive test result, compared with crossbred cattle, and B indicus cattle had an odds ratio of 1.20 (1.09, 1.33), compared with crossbred cattle. Sexually intact (+) male cattle were found to have an odds ratio of 3.13 (2.66, 3.49) for a positive test result, compared with castrated male (−) cattle, and female cattle were found to have an odds ratio of 1.38 (1.29, 1.48), compared with male (−) cattle.

Multivariate analysis of btv testing results was performed, using stepwise logistic regression. The most parsimonious model selected included age, species, and sex factors, and first-order interaction terms between these factors. This model was only able to be fit to data from cattle restricted to the high (> 25%) btv prevalence region. Odds ratios were found to increase with age for male (−) cattle of all species. Odds ratios were found to be greatest at 2 to 4 years of age for female cattle of all species and for B taurus and crossbred male (+) cattle.
Conjunctival microbial flora of clinically normal pigs
Authors: Davidson Harriet J. , Rogers Donna P. , Yeary Teresa J. , Stone Greg G. , Schoneweis David A. , Chengappa M. M.
Published: January 2024

Conjunctival swab specimens from healthy pigs were cultured to determine normal microbial population. Four commercial swine operations were selected for study. Pigs of 4 age groups were tested: nursing pigs, nursery pigs, feeder pigs, and sows. Swab specimens were taken from the conjunctival sac of each pig. Bacterial, fungal, and mycoplasmal growth was determined separately. Chlamydia sp was detected by use of an elisa. Bacteria were recovered from 98% of specimens evaluated. α-Streptococcus sp (89%) was the most commonly recovered organism, followed by Staphylococcus epidermidis (39%) and Staphylococcus sp (39%). Mycoplasma sp was not detected in any of the specimens. Chlamydia sp was identified in 28% of all specimens evaluated. These results are similar to reports of normal conjunctival flora in other domestic animals.
Evaluation of an enzyme-linked immunosorbent assay that uses the 41-kd flagellin as the antigen for detection of antibodies to Borrelia burgdorferi in cattle
Authors: Ji Benxiu , Thomas Chester B. , Collins Michael T.
Published: January 2024

An elisa was developed to detect antibodies to the 41-kd flagellin (P41) of Borrelia burgdorferi in serum obtained from cattle. Absorption studies, immunoblot analysis, immunoelectron microscopy, and correlation of results of the P41 -elisa and the P39- elisa as well as measurement of the antibody to P41 in calves challenge-exposed with Borrelia theileri were used to assess the specificity of the P41-elisa. Antigens derived from Escherichia coli, Leptospira interrogans serovar hardjo, and B burgdorferi were used for absorption studies and immunoblot analysis. Antibodies to P41 of B burgdorferi cross-reacted with antigens of E coli, but were not cross-reactive with L hardjo. A value 3 SD higher than the mean of the negative-control population of cattle was defined as the minimum value (cutoff value) for a positive result by the P41-elisa. Use of this value for classification of test results reduced the predicted rate of false-positive results attributable to E coli cross-reactivity to 1%. Immunoblot analysis revealed that test-positive serum from cattle reacted mainly with 41-, 39-, 34-, and 31-kd proteins of B burgdorferi, as well as several smaller proteins. Immunoelectron microscopy revealed that serum from cattle that was test-positive by the P41-elisa bound to the flagellin and outer membrane of B burgdorferi. Results of absorption studies, immunoblot analysis, and immunoelectron microscopy were correlated and indicated that serum from cattle that was test-positive by P41-elisa had stronger reactivity to B burgdorferi antigens than to antigens of E coli or L hardjo. The concentrations of antibodies measured by P41-elisa and P39-elisa testing were highly correlated (R2 = 0.78). Calves challenge-exposed with B theileri also had test-positive results by the P41-elisa as early as 2 weeks after exposure, but serum antibody concentrations decreased to prechallenge-exposure concentrations by 9 weeks after exposure. We concluded that the P41- elisa was useful as a screening method to detect B burgdorferi infections in cattle.
Placental transfer of enrofloxacin and ciprofloxacin in rabbits
Authors: Aramayona Jose J. , Garcia Maria A. , Fraile Lorenzo J. , Abadía Ana R. , Bregante Miguel A.
Published: January 2024

Placental transfer of enrofloxacin and ciprofloxacin was evaluated, using a rabbit in situ perfusion model. A two-step infusion program was carried out to obtain steady-state maternal plasma concentrations of these drugs. For each compound, the placenta in 5 rabbits was perfused for 200 minutes with Earle's enriched bicarbonate buffer at flow rate of 1.5 ml/min. To assess reliability of the model, most of the determinants of placental transfer (maternal and fetal pH, gas balance, heart status, rectal temperature, and protein binding) were controlled. In addition, the infusion program included administration of antipyrine, a commonly used indicator of placental exchange.

Drug concentrations were measured in maternal plasma and perfusate by use of a high-performance liquid chromatographic assay. Plasma protein-binding estimation indicated no differences between the drugs. Placental clearance of the drugs was significantly (P< 0.01) different (0.88 ± 0.13 ml/min for enrofloxacin and 0.06 ± 0.02 ml/min for ciprofloxacin). These values accounted for 81 and 5%, respectively, of the placental clearance found for antipyrine.

These results indicate that caution must be taken when enrofloxacin is to be used during pregnancy, and suggest the need to extend this type of experiment to species that can be exposed to these drugs used for therapeutic or prophylactic purposes.
Decrease in the α1-proteinase inhibitor Spi3 in equine bronchoalveolar lavage fluid
Authors: Milne E. M. , Pemberton A. D. , Dixon P. M. , McGorum B. C. , Scudamore C. L. , Miller H. K P.
Published: January 2024

The α1-proteinase inhibitors of trypsin, Spi1, Spi3A, and Spi3B, in bronchoalveolar lavage fluid (balf) and serum of horses were separated by electrophoresis, and their proportions were quantified in 12 control horses and 12 with chronic obstructive pulmonary disease (cofd). A significantly lower proportion of Spi3B (P < 0.05) and higher proportion of Spi1 (P < 0.02 to P < 0.01) were detected in balf, compared with serum, in control and copd-affected horses and appeared to be attributable to reduced Spi3 activity in balf. There was no significant difference between the control and copd groups in this respect, indicating that the decrease in Spi3 may be a physiologic phenomenon. The differences observed may be associated with proteolytic damage to or preferential complex formation by Spi3.
Pharmacokinetics and pharmacodynamics of acepromazine in horses
Authors: Marroum P. J. , Webb A. I. , Aeschbacher Gina , Curry S. H.
Published: January 2024

A specific, sensitive, reverse-phase high-performance liquid chromatographic assay for acepromazine, with analytic sensitivity as low as 5 ng/ml of plasma, and electrochemical detection with an oxidation potential of 0.7 V, was used to study the pharmacokinetics of acepromazine given at a dosage of 0.15 mg/kg of body weight in horses. The relation between effect and pharmacokinetics of the drug was examined. The effects studied included those on blood pressure, pulse, pcv, measures of respiration function, and sedation. Intravenously administered doses led to a biphasic concentration decay pattern with an α-phase distribution half-life of < 3 minutes. The β-phase half-life was in the range of 50 to 150 minutes. The cns effects peaked at 20 minutes after administration, and the hemodynamic effects peaked at 100 minutes. In all horses, the most sensitive variable was the pcv, which decreased by up to 20% (P < 0.0001). Systolic, diastolic, and mean blood pressures decreased (P < 0.0001); heart rate was unchanged (P > 0.05). Neither blood gas tensions nor blood pH changed noticeably (P > 0.05). In all horses studied, acepromazine had a significant (P < 0.0001) sedative effect, as observed by posture and alertness. None of the observed pharmacodynamic effects correlated well with plasma acepromazine concentration. These effects persisted beyond the time of detectable acepromazine concentration, indicating that they might be caused by active metabolites, or that their timing could result from complex pharmacokinetic compartment influences.
Evaluation of a single-injection method for estimating glomerular filtration rate in dogs with reduced renal function
Authors: Brown Scott Alan
Published: January 2024

Two methods for evaluating glomerular filtration rate (gfr), after single iv administration of inulin, were assessed in dogs after partial nephrectomy. The first method, determination of plasma clearance of inulin (PCIn), was taken as the quotient of the administered dose of inulin (1,000 mg) divided by the area under the plasma inulin concentration vs time curve. The second estimate of renal function was obtained from the plasma concentration of inulin 75 minutes after iv administration of 1,000 mg: C(75). The values for PCIn and C(75) were related (R2 = 0.955, P < 0.0001 and R2 = 0.867, P < 0.0001, respectively) to a previously validated method for measurement of GFR in dogs, urinary clearance of exogenous creatinine (CCr). Results of this study support use of PCIn and C(75) values to estimate GFR in dogs with reduced renal function. In particular, PCIn and C(75) were closely related to CCr in partially nephrectomized dogs with plasma creatinine concentration within the reference range for clinically normal dogs.
Ferula communis variety brevifolia intoxication of sheep
Authors: Tligui Noursaid , Ruth George R.
Published: January 2024

Sheep given powdered Ferula communis variety brevifolia at dosage of 2.5 g/kg of body weight/d for 15 days developed classical clinical signs of intoxication: anorexia, somnolence, apparent weakness, and hemorrhage. Marked reduction of vitamin K-dependent coagulation factors and prolongation of prothrombin time and activated partial thromboplastin time were consistent with presence of ferulenol, a toxic coumarinic factor in the plant. Changes induced in the coagulation system developed by the second day of plant administration and were normal within 4 days after dosing was stopped. There was no evidence of primary liver damage or platelet malfunction. Of 6 intoxicated sheep, 2 died with only minimal evidence of hemorrhage.
Coat color darkening in a dog in response to a potent melanotropic peptide
Authors: Johnson Paula D. , Dawson Brenda V. , Dorr Robert T. , Hadley Mac E. , Levine Norman , Hruby Victor J.
Published: January 2024

Analogues of a melanocyte-stimulating hormone (α-msh) have been documented to be effective in inducing integumental melanogenesis in several species. These melanotropin analogues are more potent than the natural hormone and have prolonged biological activity, without apparent teratogenic or other toxic effects, at least in rodents. In a pilot study, a cyclic α-msh analogue, α-msh4-10-NH2, was administered sc to a dog at a dose of 1 mg of analogue in 1 ml of 0.9 % NaCl for 3 weeks, without noticeable adverse effects. There was gradual and extensive darkening of the coat, which originally was predominantly tan, with tips of black. Initially, the darkening involved face and extremities, then gradually expanded to include the trunk and tail hair. Visual pigmentation peaked approximately 2 months after injections were completed. As new hair growth continued subsequent to the injections, the original tan color appeared at the proximal end of the hair shaft, leaving a dark terminal band on all affected hairs. These observations clearly indicated that follicular melanogenesis can be induced in dogs by treatment with a melanotropic peptide.
Pharmacokinetics and short-term clinicopathologic changes after intravenous administration of a high dose of methimazole in dogs
Authors: Vail David M. , Elfarra Adnan A. , Panciera D. L. , Hutson Paul R.
Published: January 2024

A bolus dose of methimazole (mmi) was administered iv over 1 minute to 5 healthy adult dogs at a dosage (40 mg/kg of body weight) known to impart protection against cisplatin-induced renal disease. Blood and urine samples for pharmacokinetic analysis were collected over a 24-hour period. Physical examination, CBC, determination of serum thyroid hormone concentrations, and serum biochemistry analysis were performed over a 10-day period to evaluate short-term toxicoses. At this dosage, mmi appears to be safe and well tolerated in dogs; only 1 of the 5 dogs had mild and transient increases in serum activity of hepatic enzymes. In addition, mmi did not alter serum thyroid hormone concentrations. Half-life of 8.82 hours and mean residence time of 12.18 hours were determined for mmi. Renal clearance of native mmi, along with sulfate and glucuronide conjugates, represented only 20 % of total systemic clearance. Results of this study provide further information concerning clinical use of mmi in dogs and may contribute to better understanding of the mechanism of mmi protection against chemically induced nephrotoxicosis.
Comparison of peritoneal fluid analysis before and after exploratory celiotomy and omentopexy in cattle
Authors: Anderson David E. , Cornwell Dean , St.-Jean Guy , Desrochers André , Anderson Lane S.
Published: January 2024

The effect of right paralumbar fossa exploratory celiotomy and omentopexy on peritoneal fluid constituents was studied in 22 adult dairy cows. Six cows were eliminated on the basis of physical examination findings (n = 2), surgical findings (n = 2), or inability to obtain a sufficient volume of peritoneal fluid (n = 2). Sixteen cattle had normal results of cbc and serum biochemical analysis, and a minimum of 1 ml of peritoneal fluid was obtained by abdominocentesis. Abdominocentesis was repeated on days 1, 2, and 6 after surgery. Statistical analysis for repeated measures was performed, using a significance level of P < 0.05. Stage of gestation was evaluated for interaction with time.

Mean total nucleated cell count was 3,200 cells/μl before surgery, was significantly increased 2 days after surgery (16,336 cells/μl), and continued to increase through day 6 (20,542 cells/μl). Mean polymorphonuclear cell count was 1,312 cells/μl before surgery and was significantly higher at 2 (11,043 cells/μl) and 6 (10,619 cells/μl) days after surgery. Mean lymphocyte count was 254 cells/μl before surgery and was significantly increased 2 days (1,911 cells/μl) after surgery. By day 6, lymphocyte numbers were similar to preoperative values. Mean mononuclear cell count was 770 cells/μl before surgery and was significantly increased on days 1 (3,084 cells/μl), 2 (3,285 cells/μl), and 6 (2,349 cells/μl) after surgery. Mean eosinophil numbers were 1,388 cells/μl before surgery and were significantly increased on day 6 (6,347 cells/μl) only. Interaction between time and stage of gestation was found only for specific gravity and total protein concentration. In general, specific gravity and total protein concentration increased after surgery (mean before surgery, 1.016 and 3.6 g/dl; mean after surgery, 1.021 and 5.6 g/dl). Left paralumbar fossa celiotomy performed 7 days after surgery did not reveal complications of repeated abdominocentesis, and pregnancy status was unchanged.

Peritoneal fluid constituents are highly variable after exploratory celiotomy and omentopexy in cattle. However, results of this study may provide a reference for interpretation of postoperative peritoneal fluid sample findings in cattle.
Prospective randomized comparison of intravenous versus subcutaneous administration of radioiodine for treatment of hyperthyroidism in cats
Authors: Théon Alain P. , Van Vechten Melinda K. , Feldman Edward
Published: January 2024

One hundred twenty cats with hyperthyroidism were treated with radioiodine (131I); 60 cats were administered radioiodine sc, and 60 cats were administered radioiodine iv. Before treatment, radioactive tracer studies were performed on each cat to determine peak radioactive iodine uptake and effective half-life. These data were used to calculate the dose of radioiodine that would have to be given to each cat to deliver 150 Gy to the thyroid tissue. The 2 groups of cats were similar with regard to age, tracer study results, and radioiodine dose. Mean estimated thyroid mass was larger for cats treated iv, but mean serum thyroxine concentration was higher for cats treated sc. Route of administration did not affect thyroidal uptake of radioiodine. However, radiation exposure of personnel was significantly lower with sc administration than with iv administration, even when iv catheterization was performed Eighty-five percent of cats treated iv and 84% of cats treated sc were euthyroid 4 years after treatment. Six percent of the cats became hypothyroid after treatment. When compared with iv administration, sc administration of radioiodine appeared to be as effective for treatment of hyperthyroidism, safer to personnel, and less stressful to the cats.
Cyproheptadine-induced attenuation of type-I immediate-hypersensitivity reactions of airway smooth muscle from immune-sensitized cats
Authors: Padrid Philip A. , Mitchell Richard W. , Ndukwu I. M. , Spaethe Stephen , Shiou Peter , Cozzi Phillip , Leff Alan R.
Published: January 2024

We assessed the effect of serotonergic inhibition by cyproheptadine on the responsiveness of tracheal smooth muscle (tsm) strips and epithelium-intact third-generation bronchial rings from immune-sensitized (Ascaris suum) cats after exposure to antigen. Cats were sensitized by im administration of antigen and adjuvant twice over a 4-week period. Sensitization was confirmed in vivo by skin testing with antigen and by physiologic airway responses after exposure to nebulized antigen. Tissues were tethered isometrically to force transducers and were actively equilibrated by exposures to KCl-substituted perfusate. Maximal response after exposure to antigen (expressed as percentage of maximal contraction of each tissue to 63 mM KCl (%KCl) was 169 ± 18% KCl for sensitized tsm and 43 ± 18% KCl for sensitized tsm pretreated with cyproheptadine (P < 0.001). Similarly, maximal response to antigen was 81 ± 27% KCl for sensitized bronchial rings, compared with 16 ± 14% KCl for sensitized bronchial rings pretreated with cyproheptadine (P = 0.05 vs control). Blockade of leukotriene synthesis by 10−6 to 10−4M A-64077, a selective 5-lipoxygenase inhibitor, had no significant effect on peak response for either tsm (193 ± 13% KCl vs 169 ± 18% KCl for sensitized untreated tsm) or bronchial rings (79 ± 20% KCl vs 81 ± 27% KCl for sensitized untreated bronchial rings). Release of serotonin from airway tissues was confirmed by the presence of serotonin in the perfusate of 8 sensitized tsm preparations after, but not before, antigen challenge. Our data indicate that airways from immune-sensitized cats have typical immediate-type hypersensitivity responses when exposed to antigen and that these responses are inhibited by serotonin-receptor blockade, but not by blockade of 5-lipoxygenase. These data implicate serotonin as an important mediator in the immediate-type hypersensitivity reaction in the immune-sensitized airways of cats and suggest a potential role for serotonin antagonists in the clinical treatment of asthma in this species.
Safety, efficacy, and duration of immunity induced in swine by use of an avirulent live Salmonella choleraesuis-containing vaccine
Authors: Roof Michael B. , Doitchinoff D. Dean
Published: January 2024

An avirulent live Salmonella choleraesuis culture (SC-54) was evaluated for use as an effective vaccine in preventing salmonellosis caused by S choleraesuis in pigs. Eighty-two pigs, 3 to 4 weeks old, were randomly assigned to 1 of 2 treatment groups, which were designated as either vaccinates or controls. After vaccination, all pigs were examined for fecal shedding of S choleraesuis, rectal temperature, and 10 clinical variables. Significant difference was not detected between vaccinated and nonvaccinated pigs for 14 days (phase I) after intranasal administration of the vaccine. Efficacy and duration of immunity were examined by intranasally challenge exposing respective pigs from either treatment group with a virulent field isolate of S choleraesuis at 2, 8, or 20 weeks after vaccination (phases II-IV). Pigs were again evaluated for 14 days after challenge exposure, and 10 clinical variables and rectal temperature were monitored. Surviving pigs were euthanatized and evaluated for gross lesions, and samples of 7 organs were collected. These organ samples were homogenized, and level of S choleraesuisS choleraesuis infection was determined. After virulent challenge exposure during phases II-IV, the clinical status of the SC-54 vaccinates was significantly (P < 0.05) superior to that of nonvaccinates for rectal temperature, feces consistency, behavior, appetite, body condition, and mean score for the 10 clinical variables. Quantitative bacteriologic culture of the tonsil, lung, liver, spleen, mesenteric lymph nodes, ileum, and colon samples indicated consistent reduction of organ colonization in vaccinates; bacteria numbers in the mesenteric lymph nodes, lungs, and ileum were significantly (P < 0.05) reduced. Gross lesions in pigs indicated reduction of penumonia in vaccinates. Pigs also had consistent weight gain throughout phases of the study after challenge exposure although the differences were not significant conclusion single intranasally administered dose SC-54 given to 3- to 4- week old pigs proved be safe and efficacious and to provide protection to pigs least 20 weeks after initial vaccination.
Effect of enalapril in dogs with pacing-induced heart failure
Authors: Allworth Matthew S. , Church David B. , Maddison Jill E. , Einstein Rosemarie , Brennan Peter , Hussein Nassar Abdul , Matthews Ross
Published: January 2024

A repeated-measures study was conducted on 5 dogs to clinically, radiographically, and echocardiographically characterize the actions of the angiotensin-converting enzyme inhibitor, enalapril, before and after development of experimentally induced heart failure. Heart failure was artificially induced, using a surgically implanted programmable ventricular pacemaker, which stimulated the heart at a rate of 245 beats/min until a low-output cardiomyopathic state developed. This condition was then stabilized by decreasing the pacing rate to 190 beats/min. Pacing-induced heart failure was successfully induced in a mean ± sd 4.2 ± 1.95 weeks. The condition closely resembled the clinical, radiographic, and echocardiographic features of naturally acquired idiopathic dilated cardiomyopathy in dogs. Enalapril was well tolerated by dogs, and clinical adverse reactions did not develop. Results of echocardiographic studies indicated that enalapril treatment during the control period resulted in a significant (P < 0.05) increase in velocity of circumferential fiber shortening and a significant (P < 0.05) decrease in left ventricular ejection time. Therapeutic responses to enalapril were evident after development of heart failure. These included reduced severity of clinical signs of disease, evidence of decreased radiographically determined cardiac size (2 of 5 dogs), radiographic evidence of a reduction in pulmonary edema and congestion (4 of 5 dogs), significant (P < 0.05) reductions in left atrial and ventricular chamber dimensions (left atrial dimension, diastolic left ventricular internal dimension as determined echocardiographically), and improvement in some echocardiographic indices of left ventricular performance (velocity of circumferential fiber shortening and left ventricular ejection time).
Morphologic observation of neutrophil diapedesis across bovine mammary gland epithelium in vitro
Authors: Lin Y. , Xia L. , Turner J. D. , Zhao X.
Published: January 2024

Neutrophils are present in milk of cows as a means of suppressing invading pathogens during mastitis. However, the manner by which neutrophils traverse the secretory epithelia is still not clear: do they diapedese between epithelial cells or do they kill epithelial cells to gain entry into milk? We investigated the process of bovine neutrophil diapedesis across bovine mammary gland epithelium in vitro. The bovine mammary epithelial cell line mac-t, grown on collagen-coated filters, formed a confluent monolayer with characteristic tight junctions, basal-apical polarity, and functional barriers to the dye trypan blue. Neutrophils added on the apical surface of the monolayer were stimulated to diapedese across the epithelium by the addition of Staphylococcus aureus (107 colony-forming units/ml) to the basal compartment. Light and transmission electron microscopy revealed the series of events for neutrophil transmigration: accumulation of neutrophils on the surface of epithelial monolayer; projection of pseudopods into intercellular junctions and movement of neutrophils between adjacent epithelial cells; and reapproximation of the lateral epithelial cell membranes and reformation of the apical tight junctions after neutrophils crossed the epithelium. Morphologically, epithelial cell damage caused by neutrophil diapedesis was not evident. This in vitro model provides a two-dimensional epithelial sheet by which neutrophil diapedesis can be qualitatively studied under defined conditions. Results of the study suggest a major mode by which bovine neutrophils diapedese across the alveolar epithelia into milk during mastitis.
Enrofloxacin concentrations in dogs with normal prostate and dogs with chronic bacterial prostatitis
Authors: Dorfman Mark , Barsanti Jeanne , Budsberg Steven C.
Published: January 2024

Chronic Escherichia coli-associated prostatitis was induced in 16 dogs; 9 noninfected dogs served as controls; and all dogs were vasectomized. Two to 3 weeks after instillation of bacteria directly into the prostate, the urine or prostatic fluid or both from 13 of 16 dogs were culture positive. Enrofloxacin, a fluoroquinolone antimicrobial agent, was administered orally to all dogs during the third or fourth week after surgery, at a dosage of approximately 5 mg/kg of body weight, every 12 hours for 7 days. Serum and prostatic fluid concentrations of enrofloxacin were concurrently measured in all dogs on days 2, 4, and 6 at 2 hours after dosing. Serum and prostatic tissue concentrations of enrofloxacin were concurrently measured in all dogs on day 7, at 1.5, 3, 4.5, and 6 hours after dosing. When values for these samples were compared, using a two-factor anova, significant differences were not found. Use of this dosing regimen of enrofloxacin resulted in prostatic fluid and prostatic tissue concentrations exceeding the minimum inhibitory concentration of most pathogens that cause bacterial prostatitis. In addition, prostatic fluid-to-serum and prostatic tissue-to-serum concentration ratios were greater than 1.0.
Use of predictive modeling to evaluate the manipulation of milking frequency, temperature, and oxygen tension on growth of Escherichia coli in an artificial intramammary environment
Authors: Goldberg John J. , Bramley A. John , Chen Hongda , Pankey J. Woodrow
Published: January 2024

A method was developed to evaluate frequent milking as a means of controlling intramammary infection. An artificial intramammary environment was used to determine growth responses of Escherichia coli (P4) to natural changes in the mammary gland resulting from bacterial invasion. Physical conditions manipulated in this model were growth medium, temperature, and oxygen tension. Mathematical modeling was then incorporated to generate predictions concerning growth dynamics of the organism when milking frequency was changed. To test accuracy of the model, initial predictions were derived from bacterial growth data in which E coli was incubated in tryptose soy broth for 12 hours at 37 C and Po2 equal to 23.3 mm of Hg. These predictions matched closely with experimental data in which 12-, 4-, and 2-hour milking intervals were simulated in the artificial intramammary environment. The mathematical model was then used to characterize growth rate data from in vitro experiments in ultra-high temperature- treated milk and in vivo experimental infection data generated with E coli (P4). Predictions generated from this model suggested that increasing milking frequency to 4 or 6 times daily controls growth of E coli for a prolonged period and that 12 times daily milking may lead to elimination of the bacterium.