bluuebunny/crossref_metadata_2025 huggingface dataset:
Platelet function and antithrombin, plasminogen, and fibrinolytic activities in cats with heart disease
Authors: Welles Elizabeth G. , Boudreaux Mary K. , Crager Cynthia S. , Tyler Jeff W.
Published: January 2024

Platelet function, antithrombin and plasminogen activities, and fibrinolytic capabilities in 11 cats with acquired heart disease were compared with results in 4 healthy cats. Of 11 cats with heart disease, 9 had hyperthyroidism with secondary cardiac dysfunction. One cat with hyperthyroidism had renal disease and heart failure, and of 2 cats with idiopathic hypertrophic cardiomyopathy, 1 also had renal disease. At the time of testing, 3 cats had thromboembolic events associated with the disease. Compared with healthy cats, cats with acquired heart disease had increased activity of antithrombin III, a protein that behaves as an acute-phase reactant. Plasminogen activity was decreased, although not significantly, in cats with acquired heart disease, compared with results in healthy cats. In cats with left ventricular dysfunction, clot retraction was decreased (marginal significance, P = 0.058) and might be attributed, in some cases, to the medications received by the cats. Dilute whole blood clots from all cats failed to lyse in vitro. This observation, at present, lacks adequate explanation. Platelets from cats with acquired heart disease, compared with platelets from healthy cats, had decreased responsiveness (aggregation and [14C]serotonin release) to adenosine diphosphate and increased responsiveness to collagen. Hyperthyroid cats were receiving various drugs (propranolol, atenolol, or diltiazem) to empirically treat clinical signs of disease attributable to cardiac dysfunction. Although numbers of cats in each group were small, definite trends were observed in the results of tests. Platelets from cats receiving atenolol had decreased responsiveness to adenosine diphosphate and unaltered responsiveness to collagen, compared with platelets from healthy cats, and may have decreased risk of thrombus formation. Cats receiving propranolol and diltiazem had platelets with markedly increased responsiveness to collagen; however, these drugs appeared to provide sufficient cardioprotective benefits to counter the prothrombotic effects.
Plasma concentration of atrial natriuretic peptide in relation to severity of mitral regurgitation in Cavalier King Charles Spaniels
Authors: Häggström Jens , Hansson Kerstin , Karlberg Bengt E. , Kvart Clarence , Olsson Kerstin
Published: January 2024

Plasma concentration of immunoreactive atrial natriuretic peptide (ir-anp) was investigated in 83 Cavalier King Charles Spaniels with variable severity of mitral regurgitation caused by chronic valvular disease (cvd). Severity of mitral incompetence was assessed by echocardiography. Significant differences in plasma concentrations of ir-anp were not found between clinically normal dogs (New York Heart Association functional class O), dogs with only cardiac murmur (class I), and dogs with echocardiographic evidence of slight to moderate left atrial and ventricular dilatation (class II). Dogs with severe left atrial and ventricular dilatation and clinical signs of congestion (classes III and IV) were found to have significantly (P < 0.001) increased plasma concentration of ir-anp. Overall, moderate degree of association was found between plasma concentration of ir-anp and left atrial and left ventricular diameters (Pearson's r = 0.65, 0.60, respectively, P < 0.001), as well as heart rate (r = 0.47, P < 0.01). However, left atrial enlargement was found to have the predominant effect on plasma ir-anp concentration. It is concluded that the plasma concentration of ir-anp did not become markedly increased before decompensation of chronic mitral regurgitation associated with severe enlargement of the left atrium and ventricle in Cavalier King Charles Spaniels.
Ground reaction force profiles from force platform gait analyses of clinically normal mesomorphic dogs at the trot
Authors: Rumph Paul F. , Lander Jeffry E. , Kincaid Steven A. , Baird Debra K. , Kammermann John R. , Visco Denise M.
Published: January 2024

Force platform analysis of gait provides ground reaction force information that can be used to study limbs with normal or abnormal function. When combined, the interrelated variables of ground reaction forces give a more thorough description of gait than when used individually.

To describe the pattern of ground reaction forces in clinically normal, conditioned, mesomorphic dogs, we studied the data from platform gait analyses of 43 dogs. Mediolateral (Fx), craniocaudal (Fy), and vertical (Fz) forces were measured and recorded. Torque (Tz) around the vertical axis also was calculated.

Mean stance times for forelimbs and hind limbs were 0.278 and 0.261 second, respectively. Among dogs, ground reaction forces were normalized and expressed as percentage of body weight (%bw). The vertical (Fz) peak, average force during stance phase, and force vs time impulses were 106.68, 60.82, and 17.2 %bw in forelimbs, and were 65.11, 35.3, and 9.33 %bw in hind limbs. The forelimb braking/ propulsive (Fy) peaks were −16.74 and +6.73 %bw. In hind limbs, these peaks were −3.76 and +7.69 %bw. The usual mediolateral force (Fx) pattern found in forelimbs was laterally directed, with average peak magnitude of 6.69 %bw, whereas the hind limb patterns were variable.
Diagnostic test for lymphoproliferative disease virus infection of turkeys, using the polymerase chain reaction
Authors: Sarid Ronit , Chajut Ayelet , Malkinson Martin , Tronick Steven R. , Gazit Arnona , Yaniv Abraham
Published: January 2024

Lymphoproliferative disease virus, a type-C retrovirus, is the etiologic agent of a naturally acquired lymphoproliferative disorder in turkeys. The disease is characterized by rapid induction of lymphoproliferative lesions with morphologic and histopathologic features resembling those of reticuloendotheliosis. Owing to lack of overt clinical manifestations, early detection of lymphoproliferative disease virus is essential for preventing the rapid horizontal spread of the disease that can decimate flocks. We describe development of a simple, rapid, sensitive, and highly specific assay, using the polymerase chain reaction, capable of providing differential diagnosis of the disease soon after infection.
Hemodynamic and anesthetic effects of etomidate infusion in medetomidine-premedicated dogs
Authors: Ko Jeff C. H. , Thurmon John C. , Benson G. John , Tranquilli William J. , Olson William A. , Vaha-Vahe A. T.
Published: January 2024

Hemodynamic and analgesic effects of medetomidine (15 µg/kg of body weight, im) and etomidate (0.5 mg/kg, iv, loading dose; 50 µg/kg/min. constant infusion) were evaluated in 6 healthy adult Beagles. Instrumentation was performed during isoflurane/oxygen-maintained anesthesia. Before initiation of the study, isoflurane was allowed to reach end-tidal concentration ≤ 0.5%, when baseline measurements were recorded. Medetomidine and atropine (0.044 mg/kg) were given im after recording of baseline values. Ten minutes later, the loading dose of etomidate was given im, and constant infusion was begun and continued for 60 minutes. Oxygen was administered via endotracheal tube throughout the study. Analgesia was evaluated by use of the standard tail clamp technique and a direct-current nerve stimulator.

Sinoatrial and atrial-ventricular blocks occurred in 4 of 6 dogs within 2 minutes after administration of a medetomidine-atropine combination, but disappeared within 8 minutes. Apnea did not occur after administration of the etomidate loading dose. Analgesia was complete and consistent throughout 60 minutes of etomidate infusion. Medetomidine significantly (P < 0.05) increased systemic vascular resistance and decreased cardiac output. Etomidate infusion caused a decrease in respiratory function, but minimal changes in hemodynamic values. Time from termination of etomidate infusion to extubation, sternal recumbency, standing normally, and walking normally were 17.3 ± 9.4, 43.8 ± 14.2, 53.7 ± 11.9, and 61.0 ± 10.9 minutes, respectively. All recoveries were smooth and unremarkable. We concluded that this anesthetic drug combination, at the dosages used, is a safe technique in healthy Beagles.
Effect of body direction on heart rate in trailered horses
Authors: Smith Barbara L. , Jones James H. , Carlson Gary P. , Pascoe John R.
Published: January 2024

To determine whether body direction in a trailer affects the degree to which a horse is excited (and presumably stressed) during transport, heart rates were measured in 8 Thoroughbred geldings transported over a 32-km route of county roads while tethered facing forward or backward in a 4-horse stock trailer. Heart rates also were measured on the horses while they were tethered facing forward or backward in the same trailer while it was parked. Heart rates decreased during the first 10 minutes for both groups, and remained stable after the first 15 minutes. Heart rates were not significantly different between horses facing forward or backward during transport or while parked. Heart rates were significantly (P < 0.05) higher for horses during transport, compared with those of horses in a parked trailer whether facing forward or backward.
Evaluation of a technique for detection of pulmonary hemorrhage in horses, using carbon monoxide uptake
Authors: Aguilera-Tejero E. , Pascoe J. R. , Smith B. L. , Tyler W. S. , Woliner M. J.
Published: January 2024

The diffusing capacity for carbon monoxide (dlco) and the functional residual capacity (frc) of the lung were measured in 5 healthy Thoroughbreds before and after instillation of autologous blood into their lungs, in an attempt to develop a method to quantitate extravascular blood in the lungs of horses with exercise-induced pulmonary hemorrhage. Mean (± SD) baseline values of dlco and frc were 333.8 ± 61.9 ml/min/mm of Hg and 21.464 ± 4.156 L, respectively. Blood instillation resulted in decreases in dlco and frc. The paradoxic decrease in dlco (we were expecting to find an increase owing to blood in the airspaces, as has been reported in people) appears to be associated with the bronchoscopic procedure and with presence of blood in the airways. We concluded that rebreathing dlco measurements were not effective for detecting blood introduced bronchoscopically into the lungs of horses.
Myoelectric activity of the cecum and proximal loop of the ascending colon in cows
Authors: Steiner Adrian , Roussel Allen J. , Brumbaugh Gordon W. , Taylor Tex S.
Published: January 2024

Six Jersey cows were implanted with 8 pairs of bipolar electrodes: 1 in the jejunum, 1 in the ileum, 3 in the cecum, and 3 in the proximal loop of the ascending colon (plac). Myoelectric activity was recorded at 2- to 3-day intervals, 3 times for 8 hours or 4 times for 6 hours, using a computer-based oscillograph and data-acquisition program.

Mean (± sd) duration of the migrating myoelectric complex (mmc) in the ileum was 84.52 ± 4.87 minutes. Phases I and II of the mmc lasted significantly (P < 0.05) longer than phase III. Two types (A and B) of cyclic activity were found in the cecum and plac. Cyclic activity type A was observed predominantly in the cecum, and type B was observed exclusively in the plac. Phase III of the mmc in the ileum was accompanied by hyperactivity type A at the level of the ileocecocolic junction in 60.90 ± 12.65% of the mmc. Twenty-seven types of orally and aborally propagated spike sequences, involving the cecum and plac, were found. They were most frequent when an mmc phase III was observed in the ileum, and least frequent when an mmc phase I was observed in the ileum (P < 0.05). All electrode sites of the cecum and plac served as pacemaker areas. Propagated and nonpropagated spikes were found at all electrode sites of the cecum and plac. Although propagated spikes lasted significantly (P < 0.05) longer than nonpropagated spikes, a clear distinction on the basis of duration could not be defined between the 2 spike types because broad overlapping of duration existed. Duration of cecocolic spiking activity per electrode (expressed as percentage of time) was significantly (P < 0.05) greater during mmc phase III in the ileum than during mmc phase I.

It can be concluded that myoelectric activity of the cecum is well coordinated with the ileum and the plac. Phases of reduced and increased myoelectric activity in the cecum and plac are simultaneous with phases I and III of the mmc in the ileum.
Measurement of upper airway resistance in awake untrained dolichocephalic and mesaticephalic dogs
Authors: Rozanski Elizabeth A. , Greenfield Cathy L. , Alsup Joel C. , McKiernan Brendan C. , Hungerford Laura L.
Published: January 2024

A technique for measuring upper airway resistance was developed in awake untrained dolichocephalic and mesaticephalic dogs. Twenty healthy dogs, 10 Collies (group A—dolichocephalic) and 10 mixed-breed dogs (group B—mesaticephalic), were studied. All dogs tolerated the procedure well, and adverse effects were not observed. Mean (± sem) value for upper airway resistance was 7.1 ± 0.50 cm of H2O/L/s. There was a trend toward lower upper airway resistance (Ruaw) values in group-A dogs, compared with those in group-B dogs. Values of Ruaw were reproducible for an individual dog. The mean individual dog coefficient of variation for Ruaw was 7.5%. The overall Ruaw coefficient of variation for all 20 dogs was 31.4%. This technique for measuring upper airway resistance in dogs is clinically applicable for objectively assessing response to treatment of obstructive upper airway disorders.
Composition of cerebrospinal fluid in healthy adult llamas
Authors: Welles Elizabeth G. , Pugh David G. , Wenzel James G. W. , Sorjonen Donald C.
Published: January 2024

Cerebrospinal fluid and serum were obtained from 17 adult, healthy llamas (9 males, 1 castrated male, and 7 females). Osmolality; activities of lactate dehydrogenase and creatine kinase; and concentrations of glucose, sodium, chloride, potassium, total protein, and albumin were determined in serum and CSF. Total and differential cell counts were determined in CSF, and electrophoresis of CSF proteins was performed.

Total nucleated cell count was low, 0 to 3/μl, which is lower than that reported for other domestic species and is similar to values in healthy people. Differential leukocyte percentages were disparate depending on the degree of blood contamination. Blood contamination influenced the percentage of neutrophils and eosinophils in CSF. Samples with few erythrocytes had differential leukocyte distribution similar to that of other species: mostly lymphocytes, fewer monocytoid cells, and scant neutrophils. Older llamas had a few eosinophils in the CSF.

Total protein, albumin, and γ-globulin concentrations in llamas were similar to values in cattle and were higher than values in most domestic species. Glucose concentration in CSF was approximately 40% of the value in serum (nonruminant animals and peoply typically have CSF glucose concentration that is approximately 60 to 80% of the serum glucose concentration). Sodium and Cl concentrations in CSF were higher than those in serum, whereas K concentration was lower in CSF, compared with serum. Activities of creatine kinase and lactate dehydrogenase in CSF were markedly lower than those in serum, and the ranges of values in this group of healthy llamas were narrow.
Comparison of serum responses in swine after vaccination and challenge exposure with Actinobacillus pleuropneumoniae serotype 1
Authors: Stine Douglas L. , Fedorka-Cray Paula J. , Huether Michael J. , Gentry Martha J. , Anderson G. A.
Published: January 2024

Clinical trials have shown that currently available commercial vaccines against porcine pleuropneumonia provide inconsistent, serotype-specific protection from the disease. Recovery from naturally acquired infection, however, provides solid, serotype cross-protective immunity. We examined various serum responses of pigs receiving 1 of 4 commercial vaccines or a cell extract, and compared the serologic responses of these pigs after challenge exposure with virulent Actinobacillus pleuropneumoniae serotype 1. Evaluation of serum included complement-mediated killing, opsonizing capacity, IgG titers to whole organisms, and cytotoxin neutralization titers. Pigs that received the cell extract had fewer clinical signs of pleuropneumonia than pigs in other vaccinated groups, and also were significantly (P< 0.05) better protected from development of lung lesions and death. Such vaccinates were the only pigs that developed significant (P< 0.05) serum antibody titers (ie, protective immune response) to whole-cell antigens and to cytotoxin.
Pulmonary histopathologic findings, acid-base status, and absorption of colostral immunoglobulins in newborn calves
Authors: LóPez Alfonso , Löfstedt Jeanne , Bildfell Robert , Horney Barbara , Burton Shelley
Published: January 2024

A study was conducted to investigate whether aspiration of amniotic fluid is associated with a deleterious effect on absorption of colostral immunoglobulins or on blood gas and acid-base values of healthy newborn calves. Fourteen calves purchased from commercial sources were transported to a research facility immediately after birth and fed colostrum with known concentrations of immunoglobulins. Blood samples for gas analyses were collected within 5 hours of birth, 24 hours later, and prior to euthanasia. Between 3 and 5 days of age, calves were euthanatized by an overdose of barbiturates. Eleven calves had evidence of bronchoaspiration of amniotic fluid, as determined by presence of meconium, squamous epithelium, or keratin in histologic sections of fixed lung or by cytologic analysis of bronchoalveolar lavage fluid. Blood gas tensions and pH were within reference ranges in 11 of 14 calves. Aspiration of amniotic fluid could not be linked to any specific changes in blood gas tensions, add-base status, or absorption of colostral immunoglobulins. Presence of keratin and meconium in the lungs often was accompanied by mild exudative alveolitis and focal atelectasis. It was concluded that aspiration of small amounts of amniotic fluid with or without meconium is common in calves and is not associated with hypoxemia, respiratory acidosis, or failure of passive transfer.
Effect of sample handling on measurement of plasma glucose and blood lactate concentrations in horses before and after exercise
Authors: Ferrante Pamela L. , Kronfeld David S.
Published: January 2024

Collection of a satisfactory blood sample requires special procedures to prevent changes in glucose and lactate content after the sample has been obtained. Changes in measured plasma glucose and blood lactate concentrations attributable to anticoagulants and storage procedures, respectively, were examined in blood samples obtained from horses at rest and after exercise.

To evaluate the effect of anticoagulants on measured plasma glucose concentration, blood was preserved with either sodium fluoride/potassium oxalate or lithium heparin. Measured plasma glucose concentration in blood obtained at rest and after exercise was 6 and 10 % lower (P = 0.0038), respectively, when blood was preserved with fluoride/oxalate, compared with heparin. The erythrocyte volume in the blood sample was 15% smaller (P = 0.0001) in samples preserved with fluoride/oxalate, indicating a movement of water out of erythrocytes in the blood sample mixed with that anticoagulant.

To evaluate the effect of storage procedure on measured blood lactate concentration, part of the blood sample was immediately deproteinized for blood lactate analysis, and the remaining blood was maintained for 30 and 60 minutes at either 0 or 22 C before deproteinization. When blood samples were maintained at 0 C prior to deproteinization, there was no difference in blood lactate concentration, regardless of the incubation time, compared with that in samples immediately deproteinized. Blood lactate concentration was greater (P < 0.01) in samples maintained at 22 C, compared with that in samples immediately deproteinized, and with that in equivalent samples maintained at 0 C.

Blood preserved with fluoride/oxalate had lower measured plasma glucose concentration, compared with blood preserved with heparin, which was probably attributable to shrinkage of erythrocytes and dilution of the plasma with intracellular water. Minimal changes in blood lactate concentration were observed in samples maintained at 0 C up to 60 minutes.
Three-dimensional sonographic imaging of the equine superficial digital flexor tendon
Authors: Wood A. K. W. , Sehgal C. M. , Reef V. B.
Published: January 2024

In a feasability study, a technique for constructing 3-dimensional sonographic images of the superficial digital flexor tendon (sdft) was established in 6 clinically normal horses and applied to 7 horses with injured sdft. Two-dimensional B-mode sonographic images were recorded on videotape as the sonographic transducer was manually moved along the palmar aspect of the metacarpal region. Selected videofields were digitized, and 3-dimensional images were constructed, using a computer work station and dedicated software program. The 3- dimensional images were of high quality and presented qualitative clinical information in unique fashion. Indication of the extent of sdft injuries was excellent. Such 3-dimensional images would be especially useful in explaining to owners and trainers the importance of the injury to their horse and would have a role in monitoring tendon healing and in the assessment of various treatments.
Clinical, hematologic, and biochemical findings in dogs after induction of shock by injection of heartworm extract
Authors: Kitoh K. , Watoh K. , Chaya K. , Kitagawa H. , Sasaki Y.
Published: January 2024

A crude, whole-body extract of female or male heartworms was injected iv into 28 dogs with and 22 dogs without heartworm (hw) infection. The female hw extract caused shock in 22 of 24 dogs with and 12 of 20 dogs without hw infection. The male hw extract induced shock in 4 of 4 dogs with and 1 of 2 dogs without hw infection. Prevalence of shock caused by female hw extract was significantly (P < 0.05) higher in dogs with than without hw infection; shock developed 5 to 30 minutes after hw injection. These signs were observed: marked decrease in blood pressure; collapse (initial collapse); paleness of mucous membranes; weak heart sounds; dyspnea; skin coldness; intestinal hyperperistalsis, and defecation; increases in rbc count, serum total protein concentration, serum osmolality, serum Na and blood glucose concentrations; and decreases in neutrophil, eosinophil, and platelet counts. Alanine transaminase, alkaline phosphatase, and lactate dehydrogenase activities increased substantially from the time of initial collapse to 24 hours after hw injection. Of 39 dogs with shock, 29 recovered from initial collapse, but 5 of the 29 subsequently collapsed again (secondary collapse), with bloody diarrhea followed by death. Of these 39 dogs, 6 died during initial collapse without bloody diarrhea, and 4 were euthanatized during initial collapse. It was confirmed that hw extract had, in fact, induced shock. These clinical, hematologic, and biochemical findings were fundamentally similar to those associated with shock resulting from administration of drugs, such as diethylcarbamazine and milbemycin D, in microfilaremic dogs with hw infection.
Comparison of maturation of drug-metabolizing enzymes in calves with functioning or nonfunctioning rumen
Authors: Kawalek Joseph C. , Said Kathleen R. El
Published: January 2024

Drug-metabolizing enzyme activities were measured in livers from calves fed commercial milk replacer (nonfunctioning rumen [veal]), and those fed milk replacer supplemented with whole grain and hay from the first week of age (functioning rumen [ruminating calves ]). After birth, cytochrome P450 and its nadph-dependent reductase activities remained unchanged in veal calves; in ruminating calves they increased almost 50%. Cytochrome P450- mediated reactions, such as aniline hydroxylase activity, tripled in ruminating calves, but remained unchanged in veal calves. In both groups of calves, coumarin hydroxylase and 7- ethoxycoumarin 0 -deethylase activities increased after birth, but maturation rates and activity values in ruminating calves were considerably greater than those of veal calves. The aminopyrine N-demethylase activity for veal calves was equal to that of calves with functioning rumen. Uridine diphosphoglucuronic acid glucuronyl transferase and glutathione - S-transferase activities also were higher in calves with functioning rumen than in veal calves. This increased activity in calves with functioning rumen probably represents a response to environmental exposure to xenobiotics. Compared with rumen-functional calves, bob veal (0 to 3 weeks old) and fancy veal (15 to 19 weeks old) calves fed commercial milk replacer have a significantly (P = 0.05) diminished capacity for metabolizing drugs and other xenobiotics. From a regulatory perspective, the variance in drug-metabolizing enzyme activities within these different market classes of calves suggests that specific studies designed to determine drug residue-depletion times in veal calves may be needed.
Characterization of an Actinobacillus pleuropneumoniae seeder pig challenge-exposure model
Authors: Lechtenberg Kelly F. , Shryock Thomas R. , Moore Gregory
Published: January 2024

Five strains of Actinobacillus pleuropneumoniae serotype 1 were used to intranasally infect 5 groups of pigs. Using each bacterial strain, infected pigs (termed seeder pigs) were commingled for 48 hours with 5 groups of noninfected test pigs, then were removed. Seeder and test pigs were maintained in isolation and were observed for 14 days. Seeder pigs had mortality that was threefold greater than that of test pigs (24% vs 8%). Rectal temperature in excess of 40.3 C was achieved for 84% of test pigs and 88% of seeder pigs. Neither of these 2 variables was statistically different between the 2 groups of pigs. Clinical impression scores ≥ 2 (on a 0 to 3 scale) were threefold (64% vs 20%) greater for seeder than for test pigs (P < 0.05). The total number of bacterial isolations or nonrecoverable isolates was tabulated for test and seeder pigs’ lungs at necropsy, irrespective of the amount of lesions. The number of A pleuropneumoniae isolations was not statistically different between test and seeder pig populations. Recovery of Pasteurella multocida or other bacteria was greater from the seeder pigs (P < 0.05), whereas the number of non-recoverable isolates was greater from test pigs than from seeder pigs (P < 0.05). Assessment of lung lesions at necropsy by either visual estimation or on a weight basis were in agreement. Fewer test pigs had lung lesions in excess of 5% of total lung volume than did seeder pigs (40% vs 84%) and, according to the odds ratio estimation, seeder pigs were 7 times more likely than test pigs to have such lesions. These results indicate a predictable, moderate intensity, natural exposure model for use in the study of Actinobacillus pleuropneumoniae-induced pneumonia. The seeder pig model appears to mimic field infection in development of clinical illness, febrile response, lung lesions, mortality, and low potential for secondary pneumonic bacterial involvement, thus providing a useful tool for preliminary evaluation of anti-infective modalities.
Isolation of thyroid peroxidase and lack of autoantibodies to the enzyme in dogs with autoimmune thyroid disease
Authors: Thacker Eileen L. , Davis John M. , Refsal Kent R. , Bull Robert W.
Published: January 2024

Fifty serum samples from dogs with clinical signs of hypothyroidism and autoantibodies (aa) to thyroglobulin (Tg), thyroxine, or triiodothyronine were screened for aa to thyroid peroxidase (tpo). Thyroid peroxidase is the antigen against which microsomal aa are formed in human beings with lymphocytic thyroiditis. The tpo was isolated from canine thyroid tissue, using a modification of the procedure for purifying porcine tpo. The enzyme was solubilized from the membrane, using a deoxycholate-trypsin solution, followed by ammonium sulfate precipitation and diethylaminoethyl Sephadex chromatography. Activity of tpo was determined, using an iodide oxidation assay and a guaiacol assay. A monoclonal antibody to canine Tg, coupled to an immunoaffinity column, was used to eliminate the contaminating Tg from the tpo preparation. Using the tpo preparation as an antigen, an elisa was performed on 10 serum samples and immunoblot assays were performed on 50 canine sera. Autoantibodies to tpo were not found in any of the sera. Assays also were performed, using purified porcine and human tpo and evidence of cross-reactivity with canine tpo was not identified. The absence of aa to tpo in dogs suggests a different pathogenesis for autoimmune thyroid disease in dogs than that hypothesized for lymphocytic thyroiditis in human beings.
Immunologic, histologic, and virologic features of herpesvirus-induced stromal keratitis in cats
Authors: Nasisse Mark P. , English Robert V. , Tompkins Mary B. , Guy James S. , Sussman Wendy
Published: January 2024

Sequential histologic, immunologic, and virologic features of herpesvirus-induced keratitis were studied in 18 experimentally infected cats. Histologic changes were assessed by use of light microscopy, and the presence of viral antigen, B lymphocytes, and T lymphocytes was verified immunohistochemically. Flow cytometry was used to monitor changes in blood T lymphocytes (CD4 and CD8 homologues) and B lymphocytes. Cellular immunity was assessed by use of the lymphocyte proliferation assay. Development of stromal keratitis was preceded by prolonged absence of corneal epithelium, decreased numbers of circulating lymphocyte subsets, decreased mitogen responses, and acquisition of viral antigen by the corneal stroma. Return to normal of circulating lymphocyte numbers and function was temporally associated with the arrival of neutrophils and B and T lymphocytes in the corneal stroma. Sequelae to stromal inflammation were fibrosis and scarring. Findings suggest that suppression of local immune responses allows virus access to the corneal stroma, and that subsequent keratitis is mediated by an immune response to viral antigen.
Effects of increasing velocity on braking and propulsion times during force plate gait analysis in Greyhounds
Authors: McLaughlin Ron , Roush James K.
Published: January 2024

The percentage of limb contact time spent in braking and propulsion was determined for the forelimbs and hind limbs of Greyhounds at 2 walk speeds and 3 trot speeds. Limb contact times decreased significantly (P < 0.05) as velocity increased between each velocity range. At a slow walk (0.92 to 1.03 m/s), braking and propulsion were 56.1 and 43.6% of contact time in the forelimbs and 41.6 and 58.1% of contact time in the hind limbs, respectively. At a fast walk (1.06 to 1.17 m/s), braking and propulsion were 56.7 and 43.5% of contact time in the forelimbs and 41.5 and 58.4% of contact time in the hind limbs, respectively. There was no significant difference in the percentage of contact time that the forelimbs and hind limbs spent in braking and propulsion between the 2 walk velocities. At the slow trot (1.5 to 1.8 m/s), braking and propulsion were 56.8 and 43% of contact time in the forelimbs and 30.1 and 67.6% of contact time in the hind limbs, respectively. At the medium trot (2.1 to 2.4 m/s), braking and propulsion were 55.9 and 43.5% of contact time in the forelimbs and 33.8 and 63.2% of contact time in the hind limbs, respectively. At the fast trot (2.7 to 3.0 m/s), braking and propulsion were 57.2 and 43% of contact time in the forelimbs and 37.5 and 61.1% of contact time in the hind limbs, respectively. Braking percentage increased and propulsive percentage decreased significantly (P < 0.05) in the hind limbs between the slow and fast trot speeds. There was no significant difference in the percentage of forelimb contact time spent in braking and propulsion between the walk and the trot gaits or among the 3 trot velocities.
Diethylcarbamazine-induced Dirofilaria immitis larval death, as indicated by immunoglobulin E concentration, in dogs with concurrent Ancylostoma caninum infection
Authors: Yamagata G. Richard , Gershwin Laurel J. , Wong Ming M.
Published: January 2024

Immunoglobulin E is produced in response to parasitic nematodes that undergo blood and tissue migrations. Results of our previous studies indicated that IgE and IgG respond to Dirofilaria immitis in experimentally infected dogs. To determine the association between treatment with the larvicide, diethyl-carbamazine (dec), and antibody responses and to examine the potential influence of infection with a nonfilarid intestinal nematode on isotype-specific immune responses, we monitored, by use of isotype-specific elisa, separate IgE and IgG responses against D immitis in 4 groups (A-D) of 8 dogs experimentally coinfected with D immitis and Ancylostoma caninum. All dogs were monitored from 2 weeks before inoculation with D immitis, through postinoculation (pi) week 20. Group-B dogs received a daily regimen of 6.6 mg of dec/kg of body weight. Group-C dogs received 4.95 mg of oxibendazole/kg daily. Group-D dogs received dec and oxibendazole, equivalent to the daily doses given to dogs of groups B and C. All dogs given oxibendazole had no A caninum at necropsy. Of the groups receiving dec, 3 group-B dogs each had 1 to 2 D immitis at necropsy. When results of chronologic IgE determination for all groups were statistically compared, only groups B and C had significant (P = 0.0148 and P ≪0.00005, respectively) increases in IgE values. Group-C dogs had the highest IgE values from pi week 10 until the end of the study, whereas IgG values were statistically identical to those of group-A dogs. Group-B dogs given only dec and having the least number of D immitis of all groups, had IgE values that peaked at pi week 6; values were significantly (P = 0.0002) higher than those for all other groups. In Group-B dogs, IgG values increased significantly (P ≪ 0.00005) only at pi week 20 and were significantly (P ≪ 0.00005) decreased after pi week 6, compared with values for all other groups. Group D containing 6 dogs infected with 1 to 18 D immitis found at necropsy had IgE values between those of group-B dogs and those of nondec-treated groups at pi week 6. There was no difference in IgG values between 3 groups at pi week 6, and IgE values were found to be a better correlator than were IgG values to the number of D immitis larvae killed in the tissues during this period. All differences in IgG and IgE values not only correlated with treatment status and number of D immitis adults found at necropsy, but also with the developmental stage of D immitis commonly present in the groups at each time point and the number of adult D immitis found at necropsy.
Development of methods for analyzing plasma lipoprotein concentrations and associated enzyme activities and their use to measure the effects of pregnancy and lactation in cats
Authors: Watson T. D. G. , Butterwick R. F. , McConnell M. , Markwell P. J.
Published: January 2024

Methods available for measurement of plasma lipoprotein-cholesterol concentrations and activities of lipoprotein lipase, hepatic lipase, lecithinxholesterol acyl transferase (lcat), and cholesteryl ester transfer protein were adapted for use in cats. A combined ultracentrifugation/precipitation procedure was used to isolate very low-density lipoproteins (vldl), then to separate low-density lipoproteins (ldl) from high-density lipoproteins (hdl). The reagent used, 92 mM heparin-manganese chloride, provided complete precipitation of ldl with only trace and insignificant contamination by hdl. Efforts to selectively measure lipoprotein lipase activity in plasma, collected after IV injection of heparin, by inhibiting hepatic lipase with sodium dodecyl sulfate were unsuccessful, and the activity of this enzyme was calculated as the difference between total and hepatic lipase activities. The latter was measured in the presence of high salt concentration to inhibit lipoprotein lipase. Cholesterol esterifying activity was identified in feline plasma and was typical of lcat, in that it was dependent on apolipoprotein A-I as a cofactor. The intra-assay and interassay coefficients of variation for measurement of lipoprotein lipase, hepatic lipase, and lcat activities were 18.4, 4.6, and 7.2%, and 20.4, 10.7, and 5.3%, respectively. Appreciable cholesteryl ester transfer protein activity was not detected in either undiluted or diluted plasma. These methods were subsequently used to investigate the effects of pregnancy and lactation on lipoprotein metabolism in a group of 10 queens. Plasma concentrations of cholesterol and triglycerides were unaltered during pregnancy, but the concentrations of vldl-cholesterol increased and those of hdl-cholesterol decreased. During lactation, the concentrations of cholesterol and triglycerides decreased owing to reductions in vldl-cholesterol and ldl-cholesterol concentrations and continued suppression of hdl-cholesterol. These changes were associated with alterations in the activities of lipoprotein lipase, which increased after parturition, and hepatic lipase, which increased during pregnancy and lactation, that may help explain their metabolic origins. The activity of lcat remained unchanged.
Effects of storage on serum ionized calcium and pH values in clinically normal dogs
Authors: Schenck Patricia A. , Chew Dennis J. , Brooks Charles L.
Published: January 2024

The stability of ionized calcium (CaI) concentration and pH in sera (n = 14) stored at 23 or 4 C for 6, 9, 12, 24, 48, or 72 hours, or −10 C for 1, 3, 7, 14, or 30 days was evaluated. Also studied were the effects of oxygen exposure, cold handling, and feeding on CaI and pH values. Results indicated that serum CaI concentration was stable throughout 72 hours of storage at 23 or 4 C, and for 7 days at −10 C. Serum CaI concentration significantly (P < 0.05) decreased by 14 days of storage at −10 C. Serum pH was stable for 6 hours at 23 or 4 C, and for 24 hours at −10 C, but significantly (P < 0.05) increased by 9 hours of storage at 23 or 4 C and by 3 days at −10 C. Exposure of the surface of the serum to air immediately before measurement had no effect on CaI or pH values, but mixing serum with air resulted in significantly (P < 0.05) decreased CaI concentration and increased pH. Handling of blood on ice resulted in significantly (P < 0.05) higher serum pH, compared with blood handled at 23 C, but serum CaI concentration was unaffected. Serum obtained at 2 hours after feeding did not have any significant changes in CaI total calcium, or pH values. It appears that if canine serum is obtained, handled, and stored anaerobically, CaI concentration can be accurately measured after 72 hours at 23 or 4 C, or after 7 days at −10 C.
Application of pulsed-field gel electrophoresis for differentiation of vaccine strain RB51 from field isolates of Brucella abortus from cattle, bison, and elk
Authors: Jensen A. E. , Cheville N. F. , Ewalt D. R. , Payeur J. B. , Thoen C. O.
Published: January 2024

Restriction endonuclease patterns of genomic fragments separated by use of pulsed-field gel electrophoresis were used to differentiate Brucella abortus strain RB51, a rifampin-resistant mutant of the standard virulent strain 2308, from other brucellae. Results were compared with results obtained by use of standard methods for characterizing brucellae. Electrophoretic patterns of the ATCC type strains allowed identification of the strains to the level of species. Genomic profiles of B abortus biovars 1, 2, and 4 were similar, as were those of biovars 5, 6, and 9. The profile of biovar 3 was similar to that of biovars 5, 6, and 9, except for a missing band at 93 kb and additional bands at 65 and 67 kb. A different fingerprint was detected in B abortus strain RB51, using the pulsed-field gel electrophoresis patterns of genomic dna digested with restrictive endonuclease Xba I. The profile of B abortus strain RB51 contained a band at 104 kb, as opposed to a 109-kb fragment within profiles of B abortus isolates from naturally infected cattle, bison, and elk. Despite known biochemical and biological differences between RB51 and its parent strain (2308), restriction endonuclease analysis results were similar.
Impact of age-related alteration of plasma α1-acid glycoprotein concentration on erythromycin pharmacokinetics in pigs
Authors: Kinoshita Tomohide , Son Deok-Soo , Shimoda Minoru , Kokue Eiichi
Published: January 2024

Erythromycin (em) pharmacokinetic variables were studied after IV administration of the drug (10 mg/kg of body weight) to 1-, 6-, and 15-day-old pigs. With advancing age, from 1 day to 15 days after birth, half-life of em became shorter (3.0 hours to 1.4 hour), whereas apparent volume of distribution, total body clearance (CLt), and intrinsic clearance became greater: 0.68 to 3.28 (L/kg), 0.15 to 1.42 (L/h/kg), and 1.81 to 3.56 (L/h/kg), respectively. The percentage of plasma protein binding of em decreased from 91 to 56%, correlating well with volume of distribution and CLt values. The altered binding percentage depended on plasma α1-acid glycoprotein (agp) concentration, but not on albumin concentration. With advancing age, plasma agp concentration was markedly decreased from approximately 6,000 μg/ml to 700 μg/ml. Despite a twofold increase in intrinsic clearance with advancing age, CLt increased ninefold, implying that the decreased protein binding contributed to the increase of CLt more preferentially than did maturational development of elimination capacity. Therefore, the altered protein binding of em attributable to the change in plasma agp concentration could be a major causal factor of the age-related pharmacokinetic variables of em in pigs.
Regulation of respiratory muscle activities during chemoreceptor stimulation in adult horses
Authors: Ainsworth Dorothy M. , Ducharme Normand G. , Hackett Richard P. , Eicker Steven W. , Snedden Kim
Published: January 2024

We examined the electromyographic activity of the costal portion of the diaphragm and the transverse abdominal and external oblique muscles in 6 chronically instrumented awake adult horses during eupneic breathing, during 2 levels of hypercapnia (fractional concentration of inspired CO2; FICO2 = 0.4 and 0.6), and during 2 levels of hypocapnic hypoxia (FICO2 = 0.15 and 0.12). Using the inert gas technique, we also measured the end-expiratory lung volumes of the 6 horses during eupnea, 6% CO2 challenge, and 12% O2 breathing. During eupneic breathing, phasic electrical activity of these 3 muscles was always present and was preceded by the onset of mechanical flow. At progressive levels of hypercapnia, the magnitude of inspiratory and expiratory electrical activity increased, and for the expiratory muscles, this recruitment coincided with significant (P < 0.05) increases in peak expiratory gastric pressure. However, during hypocapnic hypoxia, differential recruitment patterns of the respiratory muscles were found. The electrical activity of the diaphragm increased in magnitude and occurred sooner relative to the onset of mechanical flow. The magnitude and onset of abdominal expiratory activity failed to increase significantly during these episodes of hyperpnea and this pattern of activity coincided with decrements in peak expiratory gastric pressure. Despite alterations in muscle recruitment patterns during these hyperpneic episodes, end-expiratory lung volume remained unchanged. Thus, we conclude that adult horses respond similarly to awake dogs during peripheral and central chemoreceptor stimulation.
Complement component C3b and immunoglobulin Fc receptors on neutrophils from calves with leukocyte adhesion deficiency
Authors: Worku Mulumebet , Paape Max J. , Carlo Andrea Di , Kehrli Marcus E. , Marquardt Warren W.
Published: January 2024

Receptors for opsonins, such as complement component C3b (CR1) and immunoglobulins, Fc receptors, interact with adhesion glycoproteins in mediating immune functions. Defects in expression of the adhesion glycoproteins CD11/CD18 results in severely hampered in vitro and in vivo adherence- related functions of leukocytes. Little is known regarding the effect of leukocyte adhesion deficiency (lad) on ligand binding and receptor expression.

We investigated the binding and expression of CR1 and Fc receptors by bovine neutrophils isolated from dairy calves suffering from lad, compared with clinically normal (hereafter referred to as normal) age-matched calves. Neutrophils were also assayed for endogenously bound IgG and IgM and for exogenous binding of C3b, IgG1, IgG2, IgM, and aggregated IgG (aIgG), using flow cytometry. Luminol-enhanced chemiluminescence (cl) production in response to IgG2 opsonized zymosan was studied, and specific inhibition of cl was used to determine the specificity of IgG2 binding. Activation of protein kinase C with phorbol myristate acetate was used to determine the effect of cellular activation on expression of CR1.

A greater percentage of neutrophils from normal calves bound C3b than did neutrophils from lad- affected calves. Receptor expression was similar. Activation with phorbol myristate acetate resulted in increased expression of CR1 on neutrophils from normal and lad-affected calves, but expression was almost twofold greater on neutrophils from normal calves. There was no difference between lad-affected and normal calves in percentage of neutrophils that bound endogenous IgG and IgM. A greater percentage of neutrophils from normal calves bound exogenous IgM than did neutrophils from lad-affected calves. Receptor expression for aIgG was greater on neutrophils from lad-affected calves than on those from normal calves. Luminol-enhanced cl of neutrophils in response to IgG2 opsonized zymosan was not different between lad-affected and normal calves.

Results indicate increased binding and expression of Fc receptors for aIgG and decreased binding and expression for C3b and IgM on neutrophils from calves with lad. Leukocyte adhesion deficiency may be compounded by added defects in the expression and binding of receptors for opsonins, such as C3b and IgM.