bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of repeated Strongylus vulgaris inoculations and concurrent ivermectin treatments on mesenteric arterial lesions in pony foals
Authors: Klei T. R. , Turk M. A. M. , McClure J. R. , Holmes R. A. , Dennis V. A. , Chapman M. R.
Published: January 2024

Eight of 10 pony foals reared under helminth-free conditions were inoculated po with 50 Strongylus vulgaris infective larvae/week for 4 weeks, at which time 1 foal died of acute verminous arteritis. Inoculation of 7 remaining foals continued at 2-week intervals for 20 weeks. Of the 7 foals, 3 were treated with ivermectin (0.2 mg/kg of body weight) in an oral paste formulation at experiment weeks 8, 16, 24; 4 foals were not treated. Two foals were not inoculated or treated and served as controls. After the first ivermectin treatment, ivermectin-treated foals had fewer days (12 ± 2.9) with rectal temperatures > 38.6 C than did nontreated foals (23.3 ± 3.8). Mean baseline rectal temperatures were 38 ± 0.2 C. Adverse clinical reactions to ivermectin treatment were not observed in foals. Foals were euthanatized and necropsied 3 weeks after the last ivermectin treatment (week 24).

Ivermectin was effective in reducing S vulgaris arterial larval and intestinal adult parasite numbers by 100% in 3 treated foals. Strongylus vulgaris arterial larvae and/or adults were recovered from all 4 nontreated inoculated foals. One nontreated inoculated foal lacked arterial larvae or active arterial lesions, indicating that protective resistance had developed in this individual. Marked gross and histopathologic lesions typical of chronic S vulgaris infection were observed in the 3 nontreated inoculated foals with arterial larvae. Repeated killing of intra-arterial S vulgaris fourth-stage larvae in ivermectin-treated foals did not exacerbate lesions associated with verminous arteritis or induce unique lesions associated with repeated destruction of arterial larvae. Arterial lesions in treated inoculated foals were markedly reduced and had resolved, compared with those in nontreated inoculated foals.
An experimental model of chronic renal disease in dogs by infusion of microspheres into the renal arterial circulation
Authors: Dzanis David A. , Krook Lennart , Harvey H. Jay , Kallfelz Francis A.
Published: January 2024

The feasibility of renal arterial infusion of nonbiodegradable microspheres as a model of chronic renal disease in dogs was evaluated. Resin-coated, styrene-divinyl benzene copolymer microspheres were infused into the kidneys of healthy adult Beagles by direct injections of both renal arteries in a single surgical procedure. Injections of 25-μm diameter microspheres had minimal effect on either the clinical status or serum values of the dogs. Histologic examination revealed the majority of the microspheres lodged within the capillary beds of the glomeruli, and little change to the kidneys. However, injections of 50-μm diameter microspheres caused significant increases in serum concentrations of urea nitrogen and creatinine. Histologically, the larger microspheres obstructed afferent arterioles and small arteries, which caused diffuse glomerular necrosis and nephron damage.

With doses ranging from 1 to 3 million microspheres/dog, a correlation between the quantity of microspheres injected and severity of renal damage was observed. The optimal dose for producing a model of moderate renal disease was determined to be 1.8 million microspheres/dog (0.9 million microspheres/kidney).

During long-term studies, microsphere-injected dogs fed a moderately restricted protein ration remained relatively azotemic, compared with control dogs on the identical ration. During the 5-month postsurgical period, the serum urea nitrogen concentration averaged 18.41 ± 1.59 mg/dl (mean ± SE) for the microsphere-injected dogs vs 9.31 ± 0.38 for the control dogs (P < 0.001). Similarly, the mean serum creatinine value was significantly higher (P = 0.020) for the microsphere-injected dogs, compared with the controls (1.28 ± 0.12 mg/dl vs 0.94 ± 0.03). In addition, the difference in mean endogenous creatinine clearance rates was statistically significant (microsphere-injected 1.02 ± 0.05 ml/min/kg, vs control 1.53 ± 0.06, P < 0.001).
Diagnostic complementary DNA probes for genome segments 2 and 3 of epizootic hemorrhagic disease virus serotype 1
Authors: Wilson W. C. , Fukusho A. , Roy P.
Published: January 2024

Potential diagnostic complementary DNA (cDNA) clones of gene segments 2 and 3 from epizootic hemorrhagic disease virus serotype 1 (EHDV-1) have been produced. Individual segments of EHDV-1 were isolated, denatured with methylmercury hydroxide, and polyadenylated. The polyadenylated rna was reverse-transcribed and self-hybridized into duplex structures, and the incomplete ends were repaired. The resulting product was then cloned into the plasmid vector pBR322, using the complementary tailing method. Two clones, 1 from segment 2 (E1-2-10) and 1 from segment 3 (E1-3-16) were isolated, colony-purified, and characterized by cDNA/RNA blot hybridization and endonuclease restriction analysis. The cDNA clones of rna segment 3 of EHDV-1 cross hybridized with the corresponding segment of ehdv serotype 2 by results of cDNA/RNA blot hybridization, but not with rna of bluetongue virus serotypes isolated in the United States. After cDNA/RNA dot-blot hybridization analysis of 17 EHDV field strains, the segment-2 clone was found to be serotype-specific, whereas the segment-3 clone was serogroup-specific.
Distribution of material injected intramuscularly in dogs
Authors: Autefage A. , Fayolle P. , Toutain P-L.
Published: January 2024

A radiopaque marker was injected, using needles of various lengths, into the cervical musculature, the lumbar epaxial musculature, and the cranial and caudal muscular masses of the thighs of anesthetized dogs. After this procedure, the dogs were euthanatized and deep-frozen. The bodies were then sectioned, and the slices were radio-graphed to determine the fate of the injected material.

Material that was injected into the neck or caudal region of the thigh was determined to be located in the muscle bellies or dispensed throughout the intermuscular fascial sheaths. In contrast, material injected into the lumbar area and cranial region of the thigh was located entirely in the muscle bellies. It was concluded that the best sites for injection in dogs are the lumbar epaxial musculature or the quadriceps femoris muscle when im administration is imperative.
Muscle responses of Thoroughbreds to conventional race training and detraining
Authors: Foreman Jonathan H. , Bayly Warwick M. , Allen Jennifer R. , Matoba Hideki , Grant Barrie D. , Gollnick Philip D.
Published: January 2024

Ten healthy sedentary Thoroughbreds with previous race training experience were trained conventionally for 9 weeks. Muscle biopsy samples were obtained before and after training and after 6 weeks of detraining pasture rest. Biopsy samples were obtained from the right deltoid, triceps, vastus lateralis, middle gluteal, biceps femoris, and semitendinosus muscles.

The deep-frozen biopsy samples were analyzed for activities of succinate dehydrogenase (sdh), 3-hydroxy-acylcoenzyme A dehydrogenase (had), and phosphorylase (phos) and for glycogen concentration. The triceps and gluteal muscle samples were also serially sectioned and stained for myofibrillar actomyosin adenosine triphosphatase (ATPase) activity after alkaline (pH 10.3) and sequential acidic (pH 4.34) ATPase inactivation. Fiber types I (alkaline preincubation), IIA1, IIA2, and IIA3 (sequential acidic preincubation over 5 minutes) were identified and were evaluated for fiber-type distribution and fiber areas.

Increases in response to training were observed in deltoid and vastus muscle sdh and gluteal muscle had activities, and deltoid muscle glycogen concentration (P < 0.05 to P < 0.01). Changes in phos activity were not observed. Type-IIA1, -IIA2, and -IIA3 fiber areas in triceps muscle were increased in response to training (P < 0.05 to P < 0.01). Changes in fiber-type distribution did not occur in response to training.

Changes in muscle enzyme activities, glycogen concentration, fiber types, and fiber areas were not seen from posttraining to detraining. Further increases were observed when detraining values were compared with pretraining values in deltoid, triceps, vastus, gluteal, and biceps femoris muscle sdh activities and in gluteal muscle glycogen concentration (P < 0.05 to P < 0.01).

It was concluded that the predominant failure to detect training-induced muscle enzyme changes, along with documentation of increases in fast-twitch muscle fiber areas, indicate that conventional Thoroughbred training is principally of a sprinting nature. A greater emphasis on longer, slow endurance work early in training might add greatly to Thoroughbred horses’ abilities to withstand the rigors of sprint training.
In vitro study of the function of adrenocortical cells from pigs of differing in vivo response to adrenocorticotropin
Authors: Zhang Shu-Hua , Hennessy David P. , Cranwell Peter D.
Published: January 2024

A study was conducted to determine whether within-breed differences in adrenocortical response to exogenous adrenocorticotropin (acth) might be accounted for by differences in responsiveness of the adrenocortical cells per se. Large White × Landrace male pigs (n = 20) were used; 10 had high adrenocortical response to acth administration and 10 had low response. Five high and 5 low responders were euthanatized at 15 weeks of age, and the remaining 5 high and 5 low responders were euthanatized at 21 weeks of age. Adrenal glands were removed and weighed, and adrenocortical cells were dispersed by tryptic digestion and incubated for 2 hours with synthetic acth at concentrations ranging from 0.5 to 10,000 pg/ml. Samples were taken at 30-minute intervals, and cortisol concentration was determined by use of a radioimmunoassay. Results indicate that for pigs of both age groups, high responders had heavier adrenal glands, with higher adrenocortical cell density and higher cell yield than did low responders. Synthetic acth had a stimulatory effect on dispersed porcine adrenocortical cells, as indicated by changes in cortisol concentration in vitro. Adrenocortical cells from high responders produced less cortisol, on a per-cell basis, than did those from low responders. However, when corrected for total cell yield, the potential cortisol production by each pair of adrenal glands was significantly (P < 0.05) higher in the high responders than in the low responders. Thus, high-responding pigs have larger adrenal glands and higher adrenocortical cell density, which may result in higher output of cortisol after acth administration or exposure to stressors.

For high- and low-responding groups, 15-week-old pigs had higher adrenal gland weight to body weight ratio, higher adrenocortical cell density, and higher steroidogenic function per adrenocortical cell than did 21-week-old pigs.
Partial pressures of oxygen and carbon dioxide, pH, and concentrations of bicarbonate, lactate, and glucose in pleural fluid from horses
Authors: Brumbaugh Gordon W. , Benson Patricia A.
Published: January 2024

Samples of pleural fluid from 20 horses with effusive pleural diseases of various causes were evaluated; samples from 19 horses were used for the study. There were differences for pH (P = 0.001) and partial pressure of oxygen (Po2) between arterial blood and nonseptic pleural fluid (P = 0.0491), but there were no differences for pH, Po2, partial pressure of carbon dioxide (Pco2), and concentrations of bicarbonate (HCO3-), lactate, and glucose between venous blood and nonseptic pleural fluid. Paired comparisons of venous blood and nonseptic pleural fluid from the same horse indicated no differences.

There were differences (P = 0.0001, each) for pH, Po2, Pco2, and concentrations of HCO3- between arterial blood and septic pleural fluid. Differences also existed for pH (P = 0.0001), Pco2 (P = 0.0003), and concentrations of HCO3- (P = 0.0001), lactate (P = 0.0051), and glucose (P = 0.0001) between venous blood and septic pleural fluid. Difference was not found for values of Po2 between venous blood and septic pleural fluid, although 4 samples of septic pleural fluid contained virtually no oxygen. Paired comparisons of venous blood and septic pleural fluid from the same horse revealed differences (P < 0.05) for all values, except those for Po2.

These alterations suggested functional and physical compartmentalization that separated septic and healthy tissue. Compartmentalization and microenvironmental factors at the site of infection should be considered when developing therapeutic strategies for horses with septic pleural disease.
Development of wheat-sensitive enteropathy in Irish Setters: Biochemical changes
Authors: Hall Edward J. , Batt Roger M.
Published: January 2024

Biochemical changes in the small intestine during development of naturally acquired wheat-sensitive enteropathy of Irish Setters were investigated. To distinguish primary biochemical abnormalities from secondary effects of intestinal damage, progeny of affected dogs reared on a normal wheat-containing diet were compared with their own littermates reared on a cereal-free diet and with age-matched clinically normal Irish Setters fed the same wheat-containing diet. Peroral jejunal biopsy specimens were sequentially obtained between weaning and 1 year of age; specific activity and reorientating sucrose density-gradient distribution of organelle marker enzymes were determined. Major primary biochemical abnormalities were not detected in affected progeny. In affected dogs fed wheat, there was a selective, but secondary, loss of the brush border alkaline phosphatase and aminopeptidase N activities. This loss was associated with the development of partial villus atrophy, but represented a specific effect of dietary wheat on the brush border, not merely a nonspecific effect of mucosal damage, because other brush border enzymes, including disaccharidases, were not similarly affected. Increased soluble activities of lysosomal and peroxisomal marker enzymes late in the disease process may represent alterations in these 2 organelles as a secondary consequence of mucosal damage.
Failure of pH to predict ionized calcium percentage in healthy horses
Authors: Kohn Catherine W. , Brooks Charles L.
Published: January 2024

Blood, serum, and plasma total calcium concentrations and plasma and serum ionized calcium concentrations were anaerobically determined by use of a calcium-specific electrode for samples obtained from 39 healthy horses. Mean (± sd) serum ionized calcium concentration was 6.6 ± 0.3 mg/dl (1.6 ± 0.1 mmol/L) and the mean serum ionized calcium percentage was 58.2 ± 3.4%. Serum ionized calcium percentage was not significantly correlated with serum pH. Plasma ionized calcium percentage was weakly correlated with plasma pH (r = − 0.480; P ≤ 0.05). Ionized calcium concentration was determined in serum samples manipulated in vitro by additions of 1 to 80 μl of 0.1N hydrochloric acid or sodium hydroxide to yield 6 to 10 pH values between 6.8 and 8.2. In all horses, the relationship between serum ionized calcium percentage and serum pH at these pH values was then examined by use of a repeated-measures multiple regression analysis. Correlations between serum ionized calcium percentage and adjusted serum pH value for each horse were highly significant (P ≤ 0.05); however, analysis of pooled data from all horses indicated that a statistically significant relationship between serum pH and ionized calcium percentage did not exist. Lack of a significant relationship between these variables was most likely attributable to heterogeneity of variance of ionized calcium percentage among horses, reflecting variation in undefined biochemical constituents of serum that affect the equilibrium of calcium binding. When it is essential to evaluate the calcium status of a horse, direct measurement of serum ionized calcium concentration is recommended.
Isolation, characterization, and quantitative analysis of C-reactive protein from horses
Authors: Takiguchi Mitsuyoshi , Fujinaga Toru , Naiki Masaharu , Mizuno Shinya , Otomo Kanjuro
Published: January 2024

C-reactive protein (crp) was isolated from equine serum by use of calcium-dependent affinity chromatography conjugated pneumococcal C-polysaccharide, anion exchange chromatography, and gel filtration. It was identified as genuine crp by its immunochemical cross-reactivity with anti-human crp, its homology with human crp in amino acid composition, and its pentameric structure as revealed by electron microscopy. Purified equine crp had a molecular weight of approximately 118,000 and was composed of 5 identical, nonglycosylated and noncovalently associated subunits with molecular weight of approximately 23,000 each. Equine crp migrated in the region between β- and γ-globulin by results of immunoelectrophoresis, and its isoelectric point was about 7.0.

In horses, increased crp concentration was associated with clinical pneumonitis, enteritis, and arthritis, compared with values obtained in clinically normal horses by use of single radial immunodiffusion method. After im administration of turpentine oil or castration, serum crp concentration increased to 6 times higher than baseline values. Results indicate that crp may be an acute-phase reactant protein in horses.
Changes in coagulation and fibrinolysis in horses during exercise
Authors: McKeever Kenneth H. , Hinchcliff Kenneth W. , Kociba Gary J. , Reed Stephen M. , Muir William W.
Published: January 2024

Changes in clotting time (ct) and fibrinolytic actvity (fa) were evaluated in 6 mature, female horses during exercise. Two trials were performed on consecutive days, using a randomized crossover design. Each mare was assigned to either an exercise trial or a control trial on the first day, and to the alternate trial 24 hours later. Mares exercised for 20 minutes on a treadmill at an elevation of 2° and a velocity of 5 m/s. Venous blood samples were collected immediately before exercise, at 4, 8, 12, 16, and 20 minutes during exercise, and 15 minutes after cessation of exercise. Blood was placed into plain glass tubes for determination of CT, and into chilled, citrated tubes for determination of FA, plasminogen/plasmin complex activity (plg), one-stage prothrombin time (ospt), activated partial thromboplastin time (aptt), and antithrombin-III (at-III) activity. There were significant differences (P < 0.05) between the control and exercise groups for ct, fa, and plg. During exercise, clotting time decreased from 21.5 ± 1.6 minutes to 9.9 ± 1.6 minutes (mean ± sd; P < 0.05), without significant changes in ospt, aptt, or at-III. Fibrinolytic activity and plg increased (P < 0.05) during exercise. Changes in ct, fa, and plg were significant at 4 minutes of exercise, remained altered until the end of exercise, and returned to baseline values by 45 minutes of recovery. Clotting time, ospt, aptt, fa, at-III, and plg did not change (P > 0.05) during control trials.
Glucose tolerance and insulin response in normal-weight and obese cats
Authors: Nelson R. W. , Himsel C. A. , Feldman E. C. , Bottoms G. D.
Published: January 2024

Glucose tolerance and insulin response were evaluated in 9 normal-weight and 6 obese cats after iv administration of 0.5 g of glucose/kg of body weight. Blood samples for glucose and insulin determinations were collected immediately prior to and 2.5, 5, 7.5, 10, 15, 30, 45, 60, 90, and 120 minutes after glucose infusion.

Baseline glucose concentrations were not significantly different between normal-weight and obese cats; however, mean ± sem glucose tolerance was significantly impaired in obese vs normal-weight cats after glucose infusion (half time for glucose disappearance in serum—77 ± 7 vs 51 ± 4 minutes, P < 0.01; glucose disappearance coefficient—0.95 ± 0.10 vs 1.44 ± 0.10%/min, P < 0.01; insulinogenic index—0.20 ± 0.02 vs 0.12 ± 0.01, P < 0.005, respectively). Baseline serum insulin concentrations were not significantly different between obese and normal-weight cats. Insulin peak response after glucose infusion was significantly (P < 0.005) greater in obese than in normal-weight cats. Insulin secretion during the first 60 minutes (P < 0.02), second 60 minutes (P < 0.001), and total 120 minutes (P < 0.0003) after glucose infusion was also significantly greater in obese than in normal-weight cats. Most insulin was secreted during the first hour after glucose infusion in normal-weight cats and during the second hour in obese cats. The impaired glucose tolerance and altered insulin response to glucose infusion in the obese cats was believed to be attributable to deleterious effects of obesity on insulin action and β-cell responsiveness to stimuli (ie, glucose).
Synovial fluid pH, cytologic characteristics, and gentamicin concentration after intra-articular administration of the drug in an experimental model of infectious arthritis in horses
Authors: Lloyd K. C. Kent , Stover Susan M. , Pascoe John R. , Adams Paul
Published: January 2024

Chemical and cytologic effects and bactericidal activity of gentamicin in septic synovial fluid were evaluated in an experimental model of infectious arthritis in horses. Septic arthritis was induced by inoculation of approximately 7.5 × 106 colony-forming units of Escherichia coli into 1 antebrachiocarpal joint in each of 16 clinically normal adult horses. Clinical signs of septic arthritis were evident 24 hours after inoculation. Horses were allotted to 3 groups: group-1 horses (n = 5) each were given 150 mg of gentamicin (50 mg/ml; 3 ml) intra-articularly (ia); group-2 horses (n = 5) each were given 2.2 mg of gentamicin/kg of body weight, iv, every 6 hours; and group-3 horses (n = 6) each were given buffered gentamicin, consisting of 3 mEq of sodium bicarbonate (1 mEq/ml; 3 ml) and 150 mg of gentamicin (50 mg/ml; 3 ml), ia. Synovial fluid specimens were obtained at posttreatment hour (pth) 0, 0.25, 1, 4, 8, 12, and 24 via an indwelling intra-articular catheter. Synovial fluid pH was evaluated at pth 0, 0.25, and 24. Microbiologic culture and cytologic examination were performed on synovial fluid specimens obtained at pth 0 and 24, and gentamicin concentration was measured in all synovial fluid specimens.

At pth 0, E coli was isolated from synovial fluid specimens obtained from all horses. Synovial fluid pH was lower (range, 7.08 to 7.16) and wbc count was higher (range, 88,000 to 227,200 cells/μl) and predominantly neutrophilic (95 to 99%) at pth 0 than before inoculation. Synovial fluid pH was lowered further (mean, pH 6.63) after ia administration of gentamicin in group-1 horses; mean pH remained unchanged (7.07) after buffered-gentamicin administration in group-3 horses. At pth 0.25, mean peak synovial fluid gentamicin concentration in horses of groups 1 and 3 (4,745 and 6,190 μg/ml, respectively) was 1,000 times greater than that in group-2 horses (5.1 μg/ml) at the same time. Synovial fluid gentamicin concentration in group-1 and group-3 horses was always greater than that in group-2 horses and remained greater than a minimal inhibitory concentration of gentamicin (2 μg/ml) against many common equine bacterial pathogens for at least 24 hours after injection. Further, the calculated apparent half-life and clearance of gentamicin in synovial fluid calculated after ia administration were similar in horses of groups 1 and 3. By pth 24, E coli could not be isolated from synovial fluid specimens obtained from group-1 horses. However, moderate to heavy growth of E coli was isolated from synovial fluid specimens obtained at pth 24 from horses in groups 2 and 3 (80 and 66%, respectively).

In selected cases, ia administration of unbuffered gentamicin may be a useful supplement to drainage, lavage, and systemic antibacterial and anti-inflammatory treatment in horses with naturally acquired infectious arthritis.
Ultrasonographic-anatomic correlation and imaging protocol for the spleen in anesthetized dogs
Authors: Wood A. K. W. , McCarthy P. H. , Angles J. M.
Published: January 2024

Sonographic and/or anatomic observations were made of the spleen in 27 dogs. Anatomic studies were used to establish precise correlations between the gross anatomic features of the organ and its ultrasonographic image. In 8 anesthetized dogs, ultrasonographic images of the spleen were made in dorsal, transverse, and sagittal planes. When it was incident to the ultrasonic beam, the splenic capsule was represented by a fine echogenic line that defined the boundaries of the organ. The splenic substance had a uniformly mottled echogenicity apart from the anechoic lumen of the splenic venous rami, which were detected at and near the hilus of the spleen. Less regularly, splenic arterial rami were detected at the hilus, but not within the splenic substance. Dorsal and transverse images were made with the ultrasonic transducer perpendicular to the left thoracic and abdominal wall at the 11th intercostal space and caudoventrad to it. Sagittal images were produced with the transducer's face directed craniad, placed parallel to the left lateral abdominal wall, and pushed under the costal arch. The adoption of such an ultrasonographic imaging protocol ensures that all of the spleen is inspected. A definitive opinion can then be given as to whether the spleen is normal or abnormal. Pathologic changes in the spleen must also be differentiated from changes in adjacent organs or structures.
Pharmacokinetics of flunixin meglumine in lactating cattle after single and multiple intramuscular and intravenous administrations
Authors: Anderson K. L. , Neff-Davis C. A. , Davis L. E. , Bass V. D.
Published: January 2024

The pharmacokinetics of flunixin were studied in 6 adult lactating cattle after administration of single iv and im doses at 1.1 mg/kg of body weight. A crossover design was used, with route of first administration in each cow determined randomly. Plasma and milk concentrations of total flunixin were determined by use of high-pressure liquid chromatography, using an assay with a lower limit of detection of 50 ng of flunixin/ml.

The pharmacokinetics of flunixin were best described by a 2-compartment, open model. After iv administration, mean plasma flunixin concentrations rapidly decreased from initial concentrations of > 10 μg/ml to nondetectable concentrations at 12 hours after administration. The distribution phase was short (t½α, harmonic mean = 0.16 hours) and the elimination phase was more prolonged (t½β, harmonic mean = 3.14 hours). Mean ± sd clearance after iv administration was 2.51 ± 0.96 ml/kg/min. After im administration, the harmonic mean for the elimination phase (t½β) was prolonged at 5.20 hours. Bioavailability after im dosing gave a mean ± sd (n = 5) of 76.0 ± 28.0%.

Adult, lactating cows (n = 6) were challenge inoculated with endotoxin as a model of acute coliform mastitis. After multiple administration (total of 7 doses; first iv, remainder im) of 1.1 mg/kg doses of flunixin at 8-hour intervals, plasma flunixin concentrations were approximately 1 μg/ml at 2 hours after each dosing and 0.5 μg/ml just prior to each dosing. Flunixin was not detected in milk at any sampling during the study.

Flunixin concentrations necessary to induce therapeutic effects in cattle are unknown. Results of our study indicate that administration of 1.1 mg/kg doses of flunixin meglumine at 8-hour intervals would produce plasma concentrations similar to those demonstrated to be effective clinically in treatment of equine musculoskeletal disorders and colic.
Alteration in intestinal morphologic features associated with extensive large-colon resection in horses
Authors: Bertone Alicia L. , Cockerell Gary L. , Lee Robert E. , Stashak Ted S.
Published: January 2024

Light microscopy, morphometry, and scanning electron microscopy were used to examine the mucosal morphologic features of 7 intestinal specimens (3 from the small intestine; 4 from the large intestine) from each of 8 horses 1 year after sham operation (group 1; n = 3) or extensive large-colon resection (group 2; n = 5). Qualitative light microscopic examination did not reveal differences between groups, but morphometry revealed significantly (P < 0.05) greater intercrypt area and distance in horses with colon resection and this was most pronounced in the cecum and remaining right ventral and dorsal colon. Crypt area and depth were similar for horses with colon resection and sham operation (P > 0.05). Qualitative evaluation of the scanning electron micrographs revealed more prominent crypt orifices in the large intestine of horses with colon resection. The larger intercrypt distance in the colon of horses with resection was not an obvious feature of the qualitative evaluation of the surface with scanning electron microscopy. Small intestinal morphologic features were variable and significant differences were not detected between horses with sham operation and colon resection. Horses adapted to extensive large-colon resection within 1 year by increasing the absorptive (intercrypt) surface area of the remaining large intestine.
Ultrasonographic examination of the liver in cows
Authors: Braun U.
Published: January 2024

The size of the liver, as well as the situation and diameter of vessels in cattle were determined by use of ultrasonography. Ultrasonographic examinations of the liver were performed on 10 cows 10 times within 2 weeks, using a 3.5-MHz linear transducer on the right side in the 12th, 11th, and 10th intercostal spaces. Dorsal and ventral margin of the liver as well as localization and diameter of the caudal vena cava and the portal vein were determined in each intercostal space. Furthermore, the angle of the liver in the ventral area between the visceral surface and the diaphragmatic surface, the dorsal margin, and the circumference of the gall bladder were determined. The ultrasonographic values of liver size and localization in healthy cows can be used as reference values for the diagnosis of changes in liver size attributable to illness.
Effect of transport loading or noise on blood biochemical variables in calves
Authors: Agnes Francesco , Sartorelli Paola , Abdi Borrow Hagi , Locatelli Alberto
Published: January 2024

The influence of 2 transport stressors (loading and noise) on several serum and plasma biochemical variables was studied in 4 calves. When calves were loaded and kept for 30 minutes on a motionless transport simulator or were exposed to the noise of the working simulator, increases in plasma epinephrine and serum cortisol and nonesterified fatty acids concentrations were similar to changes observed in calves subjected to simulated transport for 30 minutes. Results indicate that loading and noise have an important role in transport stress.
Renal net acid and electrolyte excretion in an experimental model of hypochloremic metabolic alkalosis in sheep
Authors: Lunn D. Paul , McGuirk Sheila M. , Smith Donald F. , MacWilliams Peter S.
Published: January 2024

Renal electrolyte and net acid excretion were characterized during generation and maintenance of hypochloremic metabolic alkalosis in a ruminant model. Two phases of renal response with regard to sodium and net acid excretion were documented. An initial decrease in net acid excretion was attributable to increase in bicarbonate excretion with associated increase in sodium excretion. As the metabolic disturbance became more advanced, a second phase of renal excretion was observed in which sodium and bicarbonate excretion were markedly decreased, leading to increase in net acid excretion and development of aciduria. Throughout the metabolic disturbance, chloride excretion was markedly decreased; potassium excretion also decreased. These changes were accompanied by increase in plasma renin and aldosterone concentrations. There was apparent failure to concentrate the urine optimally during the course of the metabolic disturbance, despite increasing plasma concentration of antidiuretic hormone.
Maturational development of drug-metabolizing enzymes in dogs
Authors: Kawalek J. C. , El Said K. R.
Published: January 2024

A qualitative and quantitative assessment was made of the development of hepatic drug-metabolizing enzymes (dme) in dogs as part of a study of the ability of animal test species to metabolize drugs. The following dme variables were measured in this study: amount of cytochromes P-450 and b5 activity of the nadph and nadh- dependent reductases associated with each of these cytochromes; activity of cytochrome P-450-mediated enzymes, including aniline and coumarin hydroxylases, aminopyrine N-demethylase, and 7-ethoxycoumarin O-deethylase; activity of a uridine diphosphoglucuronic acid glucuronyl transferase with 4-methylumbelliferone as substrate; and glutathione-S-transferase activities, with dinitrochlorobenzene and dichloronitrobenzene as substrates. Most enzyme components had achieved maximal amount or activity by the fifth to eighth week after birth; they tended to decrease after weaning, although the activity of dichloronitrobenzene-glutathione transferase in geriatric dogs (312 to 525 weeks old) was approximately twofold greater than that of 8-week-old pups. There were no gender-related differences in any of the enzyme amounts or activities determined. Individual variation was pronounced even in the homogeneous colony from which these dogs were obtained.
Effects of a specific thromboxane synthetase inhibitor on thromboxane generation and excretion in healthy dogs
Authors: Longhofer Susan L. , Johnson Heidi C. , Culham Cynthia A. , Schultz Kevin T. , Grauer Gregory F.
Published: January 2024

A specific thromboxane synthetase inhibitor, 3-methyl- 2 (3-pyridyl)-l-indoleoctanoic acid (CGS 12970) was administered orally to 6 healthy adult Beagles at a dosage of 30 mg/kg of body weight. Blood generation of thromboxane B2 and urinary excretion of thromboxane B2 were measured before and after administration of CGS 12970. Although 97 ± 0.4% inhibition of thromboxane B2 generation was observed within 2 hours after a single dose of CGS 12970 was administered orally, an effect on urinary excretion of thromboxane B2 was not observed. Additionally, oral administration of 30 mg/kg every 12 hours resulted in 80 ± 14% inhibition of thromboxane B2 generation but had no effect on urinary thromboxane B2 excretion.
Clinical and pathologic studies of experimentally induced Pasteurella haemolytica pneumonia in calves
Authors: Vestweber J. G. , Klemm R. D. , Leipold H. W. , Johnson D. E. , Bailie W. E.
Published: January 2024

Pasteurella haemolytica pneumonia of the right caudal lung lobe was experimentally induced in 2-week-old Holstein calves (n = 11) by endobronchial inoculation of 7.9 × 1010 colony-forming units of 6-hour log-phase bacteria. Calves were studied for 72 hours after inoculation. The challenge procedure consistently induced a lesion in the right caudal lung lobe, which was consistent radiographically with results of pathologic examination and a similar volume of bronchography contrast medium. Clinically, the calves developed a significant increase in rectal temperature within 24 hours after inoculation. Seventy-two hours after inoculation, the total wbc counts, absolute band neutrophil counts, monocyte counts, and blood fibrinogen concentrations were significantly higher than normal and albumin concentration was significantly decreased. Necropsy revealed a circular to oblong lesion that was congested, edematous, and firm and occupied 20 to 40% of the right caudal lung lobe. Histologic examination revealed a severe acute inflammatory reaction characterized by cellular exudate and proteinaceous fluid in the alveoli, interlobular septa, and pleura.
Hematologic values and plasma and tissue folate concentrations in dogs given phenytoin on a long-term basis
Authors: Bunch Susan E. , Easley J. Roger , Cullen John M.
Published: January 2024

During earlier investigations of the hepatic effects in dogs of long-term administration of phenytoin alone or in combination with primidone, erythrocytic macrocytosis, neutropenia, neutrophilic hypersegmentation, and thrombocytopenia were observed. Such abnormalities were observed most often in dogs given phenytoin and resembled those known to be attributable to folate deficiency in human beings with epilepsy treated with phenytoin. To pursue the theory that these hematologic aberrations were caused by drug-induced folate deficiency, 12 dogs were given a diet specifically formulated to contain a minimally adequate concentration of folate. After 2 weeks, phenytoin was administered daily (400 mg, po, q 8 h) to 8 of the 12 dogs for 54 weeks. A cbc, bone marrow aspiration biopsy, and measurement of plasma and rbc folate concentrations were done every 3 weeks. Bone marrow aspirates were examined by transmission electron microscopy after 24 and 36 weeks, and at the end of the treatment period. Hepatic folate concentration was also determined in all dogs before and after treatment. Excretion of formiminoglutamic acid, as a marker of folate deficiency, was measured in all dogs at the end of the study.

All dogs remained healthy throughout the treatment phase. Consistent abnormalities were not observed in the blood or bone marrow of treated dogs. Plasma and RBC folate concentrations decreased in control and treated dogs as a result of dietary restriction (P < 0.02), and remained stable until the end of the study. The rbc folate content decreased further in treated dogs (P < 0.02), although the hepatic folate content was similar in control and treated dogs. Treated dogs did not excrete formiminoglutamic acid more rapidly than did control dogs. Gross necropsy or histologic abnormalities were not identified in control or treated dogs. We concluded that long-term administration of phenytoin was not associated with clinical, hematologic, or biochemical evidence of folate deficiency in dogs.
Temporal relationships of viremia, interferon activity, and antibody responses of sheep infected with several bluetongue virus strains
Authors: Foster Neil M. , Luedke Albert J. , Parsonson Ian M. , Walton Thomas E.
Published: January 2024

Sheep had viremias that were first detected on day 3 (± 1) after infection with several strains of bluetongue virus (btv) representing United States serotypes 10, 11, 13, and 17. Diphasic peaks of infectivity were attained on days 6 and 10 (± 2). Interferon (ifn) was first detected in serum samples on day 5 (± 1), and reached greatest concentrations on day 6 (± 2), which coincided with the first viremic peak; ifn concentrations then decreased toward zero by day 10 (± 2). Interferon peak concentrations induced approximately a 90% decrease in virus titer. The decrease in ifn concentrations by day 9 (± 2) corresponded with the second viremic peak on day 10 (± 2). Onset of the decrease in detectable concentrations of virus after the second peak of viremia corresponded to the initial detection of serum antibody to btv by day 10 (± 2). Virus titer decreased and antibody production increased until approximately days 21 to 28, when the titers plateaued and virus was not detected. Febrile responses peaked on day 7 (± 1) during the peak viremic period. The wbc count was depressed at the time the virus titer increased, but returned to normal values while the sheep were still viremic. Diphasic viremias in btv-infected sheep were attributed to induction of high concentrations of ifn concurrent with the first virus titer peak, followed by production of antibody to specific btv strains and a subsequent reduction in viremia at the second virus titer peak.
Activation of rainbow trout complement by C-reactive protein
Authors: Nakanishi Yuki , Kodama Hiroshi , Murai Takashi , Mikami Takeshi , Izawa Hisao
Published: January 2024

The activation of the complement system of rainbow trout by trout C-reactive protein (crp) was investigated. Complement fixation tests were performed by using rabbit hemolysin-sensitized sheep erythrocytes and rainbow trout complement. Purified crp increased the consumption of complement in the presence of Streptococcus pneumoniae C-polysaccharide (cps), indicating the activation of the complement system. In contrast to this, acute phase serum activated the complement in the absence of cps. Consumption of the complement by acute-phase serum was depressed when crp was removed from acute-phase serum by cps-sepharose 4B affinity chromatography. The acute-phase serum, as well as crp plus cps, suppressed in vitro growth of Vibrio anguillarum in the presence of complement, and enhanced the phagocytosis of the bacteria by glass-adherent peritoneal exudate cells. These results indicated that crp has a role in host defense during acute-phase response through the activation of the complement system, enhancement of phagocytosis, and suppression of bacterial growth.
Postnatal development of the brain stem auditory-evoked potential in dogs
Authors: Strain George M. , Tedford Bruce L. , Jackson Rose M.
Published: January 2024

Recordings of averaged brain stem auditory-evoked potentials were obtained from 13 Beagle pups of both genders to document the postnatal development of the response from age 1 to 76 days. Responses were recorded between needle electrodes placed on the vertex and the ipsilateral ear, with ground at the interorbital line. Recordings were performed without sedation. Low-amplitude responses to high-intensity stimuli could be recorded from animals prior to opening of the ear canals. Peak latencies did not change after day 20 for peak I, day 30 for peaks II and III, and day 40 for peak V. As a result, the interpeak latencies between peaks I and III did not change after day 30, but continued to decrease until day 40 for peaks III-V and IV. Peak amplitudes reached plateau values by day 20 (peak I) or day 30 (peaks II, III, and V). All of the measured latency and amplitude values had significant (P < 0.001) linear regression lines of latency vs age and amplitude vs age. The brain stem auditory-evoked potential thresholds were mature by day 20.
Antigen expression in cultured oral keratinocytes from dogs
Authors: Wilkinson J. Erby , Smith C. A. , Suter Maja M. , Lewis Robert M.
Published: January 2024

Oral keratinocytes from dogs were cultured on either collagen gels or artificial matrices at the air-liquid interface, and the expression of keratinocyte antigens and basement membrane components was determined, using various monoclonal and polyclonal antibodies. Keratinocytes grown on collagen gels expressed pemphigus vulgaris, pemphigus foliaceous, and bullous pemphigoid antigens. Diffuse, suprabasal, and superficial keratinocyte membrane differentiation antigens identified by various monoclonal antibodies also were expressed in a pattern identical to that observed in the native tissue. Laminin and type-IV collagen were deposited at the keratinocyte-collagen interface in a patchy distribution. When synthetic matrices were used, the oral keratinocytes differentiated, but to a lesser extent than cells grown on collagen gels. Antigen expression for cells grown on synthetic matrices was similar to that for cells on collagen, except for failure of the keratinocytes on synthetic membranes to express superficial cell antigens and pemphigus foliaceous antigens.
Variance of indirect blood pressure measurements and prevalence of hypertension in clinically normal dogs
Authors: Remillard Rebecca L. , Ross James N. , Eddy Jean B.
Published: January 2024

In a series of 3 studies, indirect blood pressure measurements were obtained to define normal variance, identify hypertension, and estimate the prevalence of hypertension in apparently healthy dogs. In part 1, we measured values in 5 clinically normal dogs twice weekly for 5 weeks in a home setting. Mean ± SD systolic arterial pressure (sap) and diastolic arterial pressure (dap) was 150 ± 16 and 86 ± 13 mm of Hg, respectively. The dap significantly (P < 0.01) decreased with repeated measurements over the 5-week period. In part 2, we assessed the variation between blood pressures measured in a clinic vs those measured in the home. Within a 2-week period, measurements were obtained from 10 clinically normal dogs in a private veterinary clinic and again in their home. Significant differences were not observed between clinic and home measurements of sap and dap; however, heart rate was significantly (P < 0.05) higher in the clinic. In part 3, SD about the sap and dap mean values were determined in 102 clinically normal dogs. Canine hypertensive status was determined, using statistical methods and data from 102 clinically normal dogs. Values of sap > 202 mm of Hg and dap > 116 mm of Hg were determined to be 2 SD beyond the mean and, therefore, were interpreted to be hypertensive. Approximately 10% of the 102 apparently healthy dogs measured in this study were considered hypertensive on the basis of these criteria. In addition, a border zone of suspected hypertension was estimated, using the mean + 1.282 SD. The sap border zone was between 183 and 202 mm of Hg, whereas the dap border zone was between 102 and 113 mm of Hg. Of the 102 dogs, 12 had values within these zones of suspected hypertension.
Evaluation of age, breed, and gender as risk factors for umbilical hernia in horses of a hospital population
Authors: Freeman David. E. , Spencer Pamela A.
Published: January 2024

Age, breed, and gender distributions of 168 horses with umbilical hernia treated at the University of Pennsylvania School of Veterinary Medicine were analyzed to determine risk factors for this disease. For the 3 breeds that constituted the largest proportion of hospital and case populations, Thoroughbred, Standardbred, and Quarter Horse, the overall ratio of females to males was 1.63. In a hospital population of the same age group, 0 to 48 months, the female to male ratio was 0.93. Compared with males, females were at significantly higher risk for umbilical hernia after adjustment for breed and age (odds ratio, 2.01; 99% confidence interval, 1.31 to 3.10; P = 0.00002). Of the 2 major breeds, Thoroughbreds were at greater risk than Standardbreds for umbilical hernia, after adjustment for gender and age (odds ratio, 1.80; 99% confidence interval, 1.10 to 2.95; P = 0.0020). The results provide information about a common congenital defect in horses that can be used for future genetic research.
Comparison of effects of cimetidine and omeprazole on mechanically created gastric ulceration and on aspirininduced gastritis in dogs
Authors: Jenkins C. C. , DeNovo R. C. , Patton C. S. , Bright R. M. , Rohrbach B. W.
Published: January 2024

A double-blind study was conducted to compare gastri ulcer healing time in nontreated dogs with that in dogs treated with either cimetidine or omeprazole. Single ulcers were created in the gastric antrum by use of a suction biopsy capsule. Each dog was given 25 mg of aspirin/kg of body weight orally for 20 days after ulcer induction. Five control dogs were given aspirin only (no anti-ulcer medication) during the 20-day study. Six dogs were given cimetidine at dosage of 10 mg/kg orally every 8 hours, and 6 dogs were given omeprazole orally at dosage of 2 μmol/kg (0.7 mg/kg) once daily. All dogs were examined endoscopically on days 5, 10, 15, and 20 and were given a score for the size of the mechanically created ulcer and a score for the degree of aspirin-induced gastritis. All dogs were euthanatized on day 21, and gastric lesions were examined histologically. Significant differences were not evident in ulcer healing scores or degree of aspirin-induced gastritis among treated and nontreated dogs on days 5, 10, 15, and 20. However, aspirin-induced gastritis was less severe in dogs of the omeprazole group than in dogs of the cimetidine or control group on each day observations were made. The effect of omeprazole given once daily was comparable with that of cimetidine given every 8 hours in lessening aspirin-induced gastritis.