bluuebunny/crossref_metadata_2025 huggingface dataset:
Nuclear imaging of the stomach of healthy dogs
Authors: Berardi Cynthia , Twardock A. Robert , Wheaton Lynn G. , Schaeffer David J.
Published: January 2024

To evaluate the use of technetium pertechnetate (99mTcO4) as a means of estimating gastric mucosal integrity, nuclear images of the empty stomach were obtained from 6 dogs at 20, 40, 60, 120, 180, and 240 minutes after iv administration of the radiopharmaceutical. Blood and gastric secretion samples were collected during the same time intervals. The left lateral-view image of the stomach was used to calculate the relative fraction of the dose in the stomach and the count density ratio. Between 20 and 40 minutes and 40 and 60 minutes, significant differences (P < 0.001) were apparent in the amount of 99mTcO4 in the stomach. Blood concentration of 99mTcO4 decreased significantly (P < 0.001), whereas gastric secretion concentration increased significantly (P < 0.001) over time. Qualitative assessment of the gastric nuclear scans and the statistical analytic results indicated that the optimal time for imaging the canine stomach was between 40 and 60 minutes after radiopharmaceutical administration. In a second study, the same dogs were pretreated with the H2-receptor antagonist cimetidine and the cholinergic antagonist glycopyrrolate to block gastric secretions. Over time, changes in the relative dose fraction in the stomach and the density ratio were the same as values obtained during the experiment performed without use of cimetidine and glycopyrrolate. Results of the study indicate that nuclear imaging with 99mTcO4 outlines normal canine gastric mucosa and that pretreatment with cimetidine and glycopyrrolate has no effect on the quality of the gastric image.
Reversibility of furazolidone-induced cardiotoxicosis in ducklings
Authors: Webb Dale M. , Van Vleet John F.
Published: January 2024

Furazolidone cardiotoxicosis was induced in 2 groups (fz and fz-cr groups) of newly hatched male Pekin ducklings (100/group) by feeding a ration containing 650 mg of furazolidone/kg of feed (ppm) for 28 days. A third group (control ration, cr group; n = 100) was fed the same ration without furazolidone. On day 28, the control ration was initiated for the fz-cr group initially given the furazolidone-containing ration, to allow recovery from the effects of the drug, whereas ducklings of the fz group continued to consume the furazolidone-containing ration. Biweekly, beginning with week 4, ducklings were euthanatized to assess severity of gross lesions and to obtain sections of myocardium for histologic and ultrastructural examination. Clinical evidence (increased weight gain, increased feed consumption, decreased mortality, reduced prevalence of palpable ascites) of regression of cardiotoxicosis of ducklings of the fz-cr group was nearly complete by day 56 (28 days after cessation of furazolidone intake). Likewise, regression of gross lesions, as measured by overall prevalence of gross lesions, left ventricular volume, and ascites prevalence and severity, were also essentially complete by day 56. Myofibrillar lysis was not seen in sections from the heart (examined ultrastructurally) obtained from ducklings of the cr group that were euthanatized on day 28, 56, or 98. Myofibrillar lysis was detected in all ducklings (4/4) fed furazolidone (fz and fz-cr groups) and euthanatized on day 28. Myofibrillar lysis was not seen in the heart of ducklings of the fz-cr group that were euthanatized on day 56 or 98. Myofibrillar lysis was detected in the heart from all ducklings of the fz group that were euthanatized on day 56. Leptomeres were observed in cardiac myocytes of ducklings that had been fed furazolidone, but not in those fed only the control ration. Our clinical, gross pathologic, and ultrastructural findings indicate that regression of the cardiac lesions of furazolidone toxicosis may be essentially complete by 28 days after cessation of furazolidone intake. Our ultrastructural findings indicate that furazolidone consumption may result in cardiac dilatation by altering myofibrillar/cytoskeletal attachments of myocytes.
Comparison of methods to determine glucose kinetics and measurement of recycling and lactose formation in lactating cows
Authors: Biedebach M. C. , Anand R. S. , Black A. L. , Jevning R.
Published: January 2024

Several investigators have suggested that the conventional multicompartmental exponential analysis of in vivo glucose metabolism is arbitrary and possibly not the most accurate description of glucose kinetics, especially in the large animal. In support of that hypothesis, we found that in a systematic comparison of 3 methods, blood-specific radioactivity data in single-injection studies of glucose metabolism in lactating cows was better described graphically, or by a hybrid polynomial-biexponential curve fit, than by an exclusively exponential curve fit. We hypothesized that this finding was attributable to partial failure of linearity and steady-state assumptions that underlie the exponential model.

Second, using both an irreversible tracer (3H-labeled glucose) and reversible tracer (14C-labeled glucose), we found that glucose carbon recycling had no effect during the first 2 hours, but became significant in lactating cows 7 hours after injection.

Finally, we determined that approximately 52 to 55% of the glucose replacement rate was being used to generate lactose.
Comparison of antibody response by use of synthetic adjuvant system and Freund complete adjuvant in rabbits
Authors: Mallon Francine M. , Graichen M. Elizabeth , Conway Bruce R. , Landi Margaret S. , Hughes Howard C.
Published: January 2024

Two commercially available synthetic adjuvant systems, trehalose dimycolate (tdm) and tdm + monophosphoryl lipid A (mpl), were compared with Freund complete adjuvant (fca) for the ability to stimulate antibody production in New Zealand White rabbits (Oryctolagus cuniculus). In addition, each animal was evaluated for adverse reactions. The antigen, rat liver microsomal epoxide hydrolase, was administered sc emulsified with fca, tdm, or tdm + mpl. Serum antibody titers were stimulated with all 3 adjuvant-antigen combinations. The highest titer was produced by use of fca; tdm + mpl produced an intermediate response, and tdm produced the lowest titer. All of the rabbits immunized with fca developed sterile subcutaneous abscesses. Rabbits immunized with tdm or tdm + mpl developed no abscesses, and only slight reactions at the injection sites. The synthetic adjuvant system tdm + mpl is recommended for use in rabbits, considering its adequate stimulation of antibody production with minimal adverse reactions.
Resistance of Pasteurella multocida A:3,4 to phagocytosis by turkey macrophages and heterophils
Authors: Harmon Barry G. , Glisson John R. , Latimer Kenneth S. , Steffens W. L. , Nunnally Jean C.
Published: January 2024

A virulent field isolate and 2 vaccine strains of Pasteurella multocida A:3,4 were compared for resistance to phagocytosis by turkey macrophages and heterophils, using in vitro assays. The least virulent vaccine strain (M-9) was phagocytosed to a greater degree than was the field isolate or the other vaccine strain (Clemson University). All 3 bacteria differed significantly from each other in the amount of capsular material present as measured by polycationic ferritin labeling and electron microscopy. Removal of the capsule with hyaluronidase resulted in a significant increase in phagocytosis of the field isolate.
Comparison of natural transmission of bovine leukemia virus in Holstein cows of two genetic lines selected for high and average milk production
Authors: Detilleux Johann C. , Freeman A. E. , Miller L. D.
Published: January 2024

One hundred and fifty lactating Holstein cows from 2 genetic lines selected for high and average milk production were used in the study. Sera from 6 annual herd tests were analyzed by agar-gel immunodiffusion test for antibodies to bovine leukemia virus. Odds of being seropositive were analyzed by use of stepwise and backward logistic regression procedures. Analysis within birth year revealed that estimated ln odds increased by 0.19/year of age among cows of the high genetic line and by 0.43 among cows of the average genetic line. This was accompanied by a more important cohort effect among high producers than among average producers.
Identification of Mycoplasma gallisepticum by use of monoclonal antibody in a rapid slide agglutination test
Authors: Morsy Mohamad A. , Panangala Victor S. , Gresham Martha M.
Published: January 2024

Monoclonal antibody (MAb) against Mycoplasma gallisepticum strain PG31 was produced in BALB/c mice. The MAb (designated M9) was of IgG3 isotype and reacted with an epitope in M gallisepticum antigens with molecular weights of 35, 90, 95, and 98 kilodaltons (kDa). The M9 reacted with M gallisepticum antigens in the dotblot elisa and in western blot assays. It agglutinated M gallisepticum strains PG31, F, R, S6, A5969, and 9 field isolates from various sources. A coagglutination assay, using Staphylococcus aureus (Cowan strain 1), was developed to enhance the agglutination of some weakly agglutinating M gallisepticum isolates. The M9 did not react with M synoviae, M iowae, M meleagridis, M gallinarum, or M gallinaceum in any of the aforementioned assays. This MAb may be useful in facilitating laboratory diagnosis of M gallisepticum infections.
Use of nonimaging nuclear medicine techniques to assess the effect of flunixin meglumine on effective renal plasma flow and effective renal blood flow in healthy horses
Authors: Held J. P. , Daniel Gregory B.
Published: January 2024

The effect of flunixin meglumine on renal function was studied in 6 healthy horses by use of nonimaging nuclear medicine techniques. Effective renal plasma flow (erpf) and effective renal blood flow (erbf) were determined by plasma clearance of 131I-orthoiodohippuric acid before and after administration of flunixin meglumine. Mean erpf and erbf was 6.03 ml/min/kg and 10.7 ml/min/kg, respectively, before treatment and was 5.7 ml/min/kg and 9.7 ml/min/kg, respectively, after treatment. Although erpf and erbf decreased after flunixin meglumine administration, the difference was not statistically significant.
Pathophysiologic effects of Ostertagia ostertagi in calves and their prevention by strategic anthelmintic treatments
Authors: Xiao L. , Gibbs H. C. , Yang C.
Published: January 2024

Pathophysiologic effects of Ostertagia ostertagi infection and their prevention by strategic anthelmintic treatments were studied in 3 groups each of 6 steer calves. Group-1 calves were noninfected controls. Group-2 calves were inoculated with 100,000 third-stage larvae on the 1st and 28th days of the experiment and grazed on pasture initially free of contamination. Group-3 calves were on a similar regimen as those in group 2, but were also treated with ivermectin 9 days after each larval inoculation. Group-2 calves had increased plasma pepsinogen and gastrin values and decreased weight gains, and total serum protein and albumin concentrations from the 2nd week of infection onward. They were anemic at 10 to 12 weeks and had lower carcass and meat quality at slaughter. Strategic anthelmintic treatments were effective in preventing these effects and calves in groups 1 and 3 had similar performances. On the basis of our findings, high pepsinogen values were related to worm burdens, whereas high gastrin concentrations were related to gastric lesions.
Evaluation of the instantaneous centers of rotation of the stifle before and after repair of torn cruciate ligament by use of the over-the-top technique in dogs
Authors: Mitton Greg R. , Ireland W. P. , Runyon C. L.
Published: January 2024

Seven dogs with torn cruciate ligament were used to evaluate the “over-the-top” repair procedure, using instantaneous center of rotation (icr). Normal and cruciate-torn stifles of dogs were radiographed before surgery, using an image intensifier videotape system. The injured stifle was reradiographed 6 weeks after surgery. Images of the stifles were photographed from video monitor. Photographs were analyzed by a digitizer hooked to a computer to find the icr at various angles. Data were analyzed, using multivariate analysis of variance. Relative to those of normal stifles, icr of the damaged stifles were located significantly (P < 0.05) proximal and caudal. After surgery, the icr were still proximal and caudal, but not significantly so. We conclude that the cruciate-torn stifle deviates significantly from normal and that such deviation is restored to normal limits by use of the over-the-top procedure.
Market stress-associated changes in serum complement activity in feeder calves
Authors: Purdy Charles W. , Richards Alan B. , Foster Gene S.
Published: January 2024

Classical hemolytic complement (C) of calves was analyzed during a protocol designed to imitate the usual market handling of feeder calves from the southeastern United States. Serum C concentrations of the calves (n = 100 × 4 years) were evaluated on their farm of origin, on arrival at an auction market, on arrival at a feedyard, and during their first 4 weeks in the feedyard. Complement concentrations (measured in ch50 units) were typically lowest at the farm of origin and highest when the calves entered the auction market 28 to 133 days later. Serum C concentrations decreased after the calves encountered the severe stresses of being in the auction market for 7 days, 24-hour truck transport (1,932 km) to the feedyard, and the first 7 days in the feedyard. The C concentrations recovered after 21 to 28 days in the feedyard. Steers had significantly (P ≤ 0.05) lower C concentrations than did heifers in 3 of 4 years at the farm of origin, and in 2 of 4 years at the auction market. Morbid calves had significantly (P ≤ 0.05) lower C values than did healthy calves on day 7 in the feedyard in 3 of 4 years. There were significant differences in C concentrations of calves from different farms of origin in each of the 4 years. There was no significant difference in C concentrations of calves that were vaccinated vs those not vaccinated with Pasteurella haemolytica.
Effect of stage of gestation on efficacy of Brucella abortus strain-19 vaccination in cattle
Authors: Crawford Richard P. , Adams L. Garry , Ficht Thomas A. , Templeton Joe W. , Williams John D.
Published: January 2024

Seventy-nine cattle in all stages of gestation were inoculated with a low dose (2.5 × 108 colony-forming units) of Brucella abortus strain 19, then challenge exposed with pathogenic B abortus strain 2308 during the subsequent gestation. A brucellosis case was defined by isolation of strain 2308 from dam or calf samples. Cumulative incidence of brucellosis cases was 48, 33, 25, or 47% for cattle that were, respectively, not pregnant, or 19 to 87, 100 to 167, or 190 to 253 days in gestation at vaccination. The cumulative incidence was 56% in 27 nonvaccinated controls. The 95% confidence intervals for risk ratios included 1 in all cattle, except those that were 100 to 167 days in gestation at vaccination (ie, second trimester); the confidence interval for this group was 0.21 to 0.97. The prevented fraction (1-risk ratio) attributed to strain 19, in ascending order, was 0.14, 0.16, 0.4, or 0.55, respectively, for cattle that were not pregnant, or were 190 to 253, 19 to 87, or 100 to 167 days in gestation at vaccination.

Potential confounders of breed, pen effect, and gestation days at challenge exposure did not significantly affect results. Results supported the hypothesis that stage of gestation at vaccination will affect the prevented fraction of brucellosis, or efficacy of strain 19, in cattle vaccinated with a low dose and, therefore, is one factor that may explain variation in strain 19-induced protection.
Morphologie and morphometric study of the facial nerve in clinically normal adult dogs
Authors: Braund Kyle G. , Mehta Jagjivan R. , Amling Karen A. , Toivio-Kinnucan Maria
Published: January 2024

A morphologic and morphometric study was carried out on the facial nerve: to determine normal histologic data in myelinated fibers of clinically normal young adult dogs; to establish reference values for mean fiber diameter, and to delineate the relative diameter frequency distribution curve. Few degenerative changes were observed in single teased-nerve fibers and semithin cross-sectional nerve preparations. Statistical difference was not observed between left and right facial nerves. The distribution of fiber diameters in the facial nerve was unimodal. Mean ( ± sd) fiber diameter of the facial nerve was 3.92 ± 1.18 μm. Approximately 89% of fibers in the facial nerve had diameter between 3 and 6 μm. Fiber diameter ranged from 2 to 12 μm; however, < 1% of fibers had diameter > 8 μm.
Variable suppression of feline bone marrow fibroblast colony-forming units by two isolates of feline leukemia virus
Authors: Wellman Maxey L. , Kociba Gary J. , Mathes Larry E.
Published: January 2024

Bone marrow fibroblast colony-forming units (cfu-f) were evaluated in cats experimentally infected with different isolates of FeLV. Cats infected with the Kawa-kami-Theilen isolate of FeLV (FeLV-KT) had progressive decrease in the number of cfu-f at 2, 4, and 6 weeks after infection. The number of cfu-f in FeLV-KT-infected cats ranged from 38 to 70% of the preinoculation cfu-f value. Of 3 cats with FeLV-KT-induced suppression of cfu-f, 2 developed fatal nonregenerative anemia. Cats infected with the Rickard isolate of FeLV (FeLV-R) had more moderate decrease in the number of cfu-f at 2, 4, and 6 weeks after infection. The number of cfu-f in FeLV-R-infected cats ranged from 62 to 82% of the preinoculation cfu-f value. The FeLV-R-infected cats did not become anemic.
In vitro assay of nuclear uptake of doxorubicin hydrochloride in osteosarcoma cells of dogs
Authors: Weinstein M. Joy , Berg John , Kusuzaki Katsuyuki , Springfield Dempsey S. , Gebhardt Mark C. , Mankin Henry J.
Published: January 2024

A rapid, simple chemosensitivity assay, assessing tumor cell nuclear uptake of doxorubicin hydrochloride, was evaluated in 16 dogs with appendicular osteosarcoma. Doxorubicin was administered to dogs in 5 biweekly treatments, and surgical resection was performed after the second or third treatment. The chemosensitivity assay was performed on biopsy specimens from all dogs before chemotherapy. It was repeated on tissue from resected tumors, and tumors were evaluated histologically to determine the degree of necrosis resulting from chemotherapy. Disease-free and total survival time correlated significantly (P < 0.05 in both cases) with the degree of postchemotherapy necrosis of the primary tumors. Significant correlation was not apparent between the percentage of tumor cells with nuclear uptake of doxorubicin (in either biopsy or resection samples) and disease-free or total survival time. The percentage of cells with nuclear uptake of doxorubicin in surgically resected tumors correlated significantly (P < 0.05) with percentage of necrosis.
Effects of human recombinant interleukin 2 on in vitro tumor cytotoxicity in dogs
Authors: Raskin Rose E. , Holcomb Carolyn S. , Maxwell Anna K.
Published: January 2024

In these studies, the effects of recombinant human interleukin 2 (rHuil-2) were examined on in vitro tumor cytotoxicity by canine blood lymphocytes obtained from peripheral vessels through use of a chromium release microcytotoxicity assay. Cytotoxic activity by lymphokine-activated killer cells was significantly increased, compared with that by untreated lymphocytes in a dose-dependent manner. The maximal effect was attained with 300,000 IU of rHuil-2/ml. Lymphokine-activated killing also was dependent on the duration of incubation with rHuil-2. After 1 day of rHuil-2 incubation, cytotoxicity was significantly increased, compared with that of untreated lymphocytes. Of the 3 times examined, cytotoxicity peaked after 3 days of rHuil-2 incubation. High levels of cytotoxic activity were still present at 7 days of incubation. Numbers of granular lymphocytes increased over the times examined. These results demonstrate functional and morphologic changes in canine peripheral blood lymphocytes obtained from peripheral vessels after incubation with rHuil-2 in a dose- and time-dependent manner.
Effects of the fungal endophyte Acremonium coenophialum in fescue on pregnant mares and foal viability
Authors: Putnam Marshall R. , Bransby David I. , Schumacher John , Boosinger Timothy R. , Bush Lowell , Shelby Richard A. , Vaughan John T. , Ball Don , Brendemuehl James P.
Published: January 2024

Effects of the endophyte Acremonium coenophialum in tall fescue on pregnant mares and foal viability were evaluated. Twenty-two mature pregnant mares were randomly chosen to graze either Kentucky-31 tall fescue that was free from A coenophialum (endophyte-free, ef) or tall fescue infected with A coenophialum (endophyte-present, ep) after the first 90 days of pregnancy through parturition. Concentrations of pyrrolizidine and ergopeptine alkaloids were significantly greater in ep grass, compared with ef pasture. Ten of 11 mares grazing ep pasture had obvious dystocia. Mean duration of gestation was significantly greater for the ep group, compared with the ef group. Foal survivability was severely reduced among mares grazing ep fescue with only 1 foal surviving the natal period. Udder development and lactation were low in mares grazing ep grass. The absence of clinical problems in mares grazing ef grass implicated the endophyte as the causative agent of reproductive problems and perinatal foal mortality in pregnant mares grazing endophyte-infected fescue grass. Caution should be exercised in allowing pregnant mares to graze pastures infected with the endophyte A coenophialum.
Evaluation of total protein content in tears of dogs by polyacrylamide gel disk electrophoresis
Authors: Barrera Rafael , Jiménez Antonio , López Rocío , Ma ñé María C. , Rodríguez Jesús F. , Molleda José M.
Published: January 2024

Concentration of total proteins was measured and sodium dodecyl sulfate-polyacrylamide gel disk electrophoresis was performed on tear and plasma samples obtained from 26 healthy dogs, and the results were compared. Mean ± sem concentration of total proteins in tears was 0.63 ± 0.04 g/dl, and significant effects of age or gender were not found. The protein composition of tears in dogs was complex, and bands from light and heavy chains of immunoglobulins were identified by electrophoresis.
Efficacy of milbemycin oxime against naturally acquired or experimentally induced Ancylostoma spp and Trichuris vulpis infections in dogs
Authors: Blagburn Byron L. , Hendrix Charles M. , Lindsay David S. , Vaughan Joy L. , Hepler Douglas I. , Wright James C.
Published: January 2024

The efficacy of milbemycin oxime was evaluated at dosages of 0.25, 0.50 and 0.75 mg/kg of body weight in dogs naturally infected with mature Ancylostoma spp, at a dosage of 0.50 mg/kg in dogs with experimentally induced immature and mature A caninum, and at dosages of 0.55 to 0.86 mg/kg in dogs naturally infected with mature Trichuris vulpis. Milbemycin oxime was 95 and 99% effective against mature Ancylostoma spp at dosages of 0.50 and 0.75 mg/kg, respectively, but only 49% effective at a dosage of 0.25 mg/kg. Efficacy was 49% against pulmonary L3-L4 stages of A caninum (36 hours after inoculation), > 80% against L4 (120 hours after inoculation) and early L5 stages (216 hours after inoculation), and > 90% against experimentally induced mature stages (360 hours after inoculation). Milbemycin oxime was also 97% effective in the removal of mature Tr vulpis from naturally infected dogs. Adverse reactions were not observed following treatment in any of the dogs.
Efficacy of ivermectin and pyrantel pamoate combined in a chewable formulation against heartworm, hookworm, and ascarid infections in dogs
Authors: Clark J. N. , Daurio C. P. , Plue R. E. , Wallace D. H. , Longhofer S. L.
Published: January 2024

Eight trials were conducted in dogs to document the efficacy of ivermectin (6 μg/kg of body weight) and pyrantel pamoate (5 mg of active pyrantel/kg) in a beef-based chewable formulation against Dirofilaria immitis, Ancylostoma caninum, Uncinaria stenocephala, Toxocara canis, and Toxascaris leonina. Three studies involved induced infection with D immitis, and 5 studies involved induced or natural infection with hookworms and ascarids. In 3 intestinal parasite trials, the efficacy of the combination chewable tablet was compared with each of its components. Results indicated that 1 component did not interfere with the activity of the other. In 1 heartworm and 2 intestinal parasite trials, the efficacy of pyrantel, ivermectin/pyrantel combination, or ivermectin with pyrantel dosage of 10 mg/kg was evaluated.

The ivermectin/pyrantel combination was 100% effective in preventing development of D immitis larvae. Efficacy of the combined product against T canis, Toxascaris leonina, A caninum, and U stenocephala was 90.1, 99.2, 98.5, and 98.7%, respectively. In the intestinal parasite trials, each individual component was found not to interfere with the anthelmintic action of the other. Increasing the dosage of pyrantel to 10 mg/kg (2 × that in the combination) did not interfere with the efficacy of ivermectin against heartworm or increase the activity of pyrantel against intestinal parasites.
Blood biochemical characteristics of cattle at sea level and at moderately high altitude (3,000 m)
Authors: Ramirez German , Bittle Polly A. , Colice Gene L. , Santacruz Rafael , Hidalgo Alvaro , Noguera Ivan , Agosti Steven J. , Foulis Philip R.
Published: January 2024

We investigated the biochemical composition of blood from Holstein cows, native breed (criollas), and cows descended from fighting bulls (Vacas de lidia) raised at an altitude of 3,000 m (moderately high altitude, mha), and compared the results with those from Holsteins and cows of similar genetic ancestry as the criollas (scrub cows), both raised at sea level (sl), to determine blood biochemical values characteristic of adaptation to high altitude. Only potassium and calcium concentrations were similar among groups. Glucose concentration was lower in mha cows, with the exception of Vacas de lidia. Serum bicarbonate concentration was lower in mha cows; this finding can be explained by hyperventilation in the hypoxic environment. Serum magnesium concentration was lower in sl and mha Holsteins than in other groups. Serum phosphate concentration was lower in scrub cows, mha Holsteins, and criollas than in other groups. Cholesterol concentrations were lower in sl Holsteins, whereas triglycerides were higher in scrub cows and mha Vacas de lidia. Concentration of high-density lipoprotein was significantly greater in Vacas de lidia and less in mha criollas than in the other groups. Uric acid and total protein were higher in mha groups. Using radioimmunoassay for human proteins, thyroxine-binding globulin was undetectable. Total and free thyroxine and free triiodothyronine were higher in scrub cows, followed by Vacas de lidia; lower values were detected in sl and mha Holsteins and mha criollas.
Respiratory muscle perfusion in ponies during prolonged submaximal exercise in thermoneutral environment
Authors: Manohar Murli , Duren Stephen E. , Sikkes Bridget , Day Jennifer , Baker John P.
Published: January 2024

Distribution of blood flow among various respiratory muscles was examined in 8 healthy ponies during submaximal exercise lasting 30 minutes, using radionuclide labeled 15-μm diameter microspheres injected into the left ventricle. From the resting values (40 ± 2 beats/min; 37.3 ± 0.2 C), heart rate and pulmonary arterial blood temperature increased significantly at 5 (152 ± 8 beats/min; 38.6 ± 0.2 C), 15 (169 ± 6 beats/min; 39.8 ± 0.2 C), and 26 (186 ± 8 beats/min; 40.8 ± 0.2 C) minutes of exertion, and the ponies sweated profusely. Mean aortic pressure also increased progressively as exercise duration increased. Blood flow increased significantly with exercise in all respiratory muscles. Among inspiratory muscles, perfusion was greatest in the diaphragm and ventral serratus, compared with external intercostal, dorsal serratas, and scalenus muscles. Among expiratory muscles, blood flow in the internal abdominal oblique muscle was greatest, followed by that in internal intercostal and transverse throacic muscles, in which the flow values remained similar. The remaining 3 abdominal muscles had similar blood flow, but these values were less than that in the internal intercostal, transverse thoracic, and internal abdominal oblique muscles. Blood flow values for all inspiratory and expiratory muscles remained similar for the 5 and 15 minutes of exertion. However, at 26 minutes, blood flow had increased further in the diaphragm, external intercostal, internal intercostal, transverse thoracic, and the external abdominal oblique muscle as vascular resistance decreased. On the basis of our findings, all respiratory muscles were activated during submaximal exercise and their perfusion had marked heterogeneity. Also, blood flow in respiratory muscles was well maintained as exercise duration progressed; in fact, several muscles had a further increase in perfusion late during exercise.
Characterization of the renal response to protein ingestion in dogs with experimentally induced renal failure
Authors: Brown Scott A. , Finco Delmar R.
Published: January 2024

Effects of a protein meal (2.7 g of casein/kg of body weight) on glomerular filtration rate (gfr) and renal plasma flow (rpf) were assessed in dogs after 15/16 nephrectomy (n = 10), and were compared with observations in dogs with intact kidneys (n = 5). Increase in gfr and rpf was observed in both groups of dogs between 1.5 and 8 hours after protein ingestion. A maximal value for gfr was observed between 4 and 5 hours after protein ingestion in dogs of both groups. Enhancement of urinary protein excretion was evident in partially nephrectomized dogs after protein ingestion (P < 0.05), a result that was confirmed by 24-hour total urine collection from partially nephrectomized dogs fed a balanced ration.

A qualitatively similar vasodilatory response was observed in partially nephrectomized dogs and in dogs with intact kidneys, and the mean maximal increase of gfr and rpf expressed as a percentage of baseline values in the latter dogs (47.0 ± 8.1 and 43.6 ± 10.3%, respectively) exceeded that observed in partially nephrectomized dogs (20.8 ± 2.2 and 22.7 ± 6.3%, respectively; P < 0.01). The incremental response of the kidneys to protein ingestion was directly related to the degree of renal function, as reflected in the linear regression relationship between the incremental increase in gfr and the baseline value for gfr (P < 0.01, R2 = 0.721).
Arthrotomy versus arthroscopy and partial synovectomy for treatment of experimentally induced infectious arthritis in horses
Authors: Bertone Alicia L. , Davis D. Michael , Cox Hollis U. , Kamerling Steven S. , Roberts Edward D. , Caprile Kelli A. , Gossett Kent A.
Published: January 2024

To evaluate the clinical, laboratory, and histologic effects of 2 methods of treatment for infectious arthritis in horses, Staphylococcus aureus (3.4 to 3.9 × 103 colony-forming units) was inoculated into the tarsocrural joints of 8 horses on day 0. Each horse was treated with phenylbutazone (2 g, po, q 24 h) and gentamicin sulfate (2.2 mg/kg of body weight, iv, q 8 h) for 14 days. On day 2, general anesthesia was induced, and each horse had 1 tarsocrural joint treated by arthrotomy, with removal of accessible fibrin and lavage with 3 L of sterile balanced electrolyte solution. An indwelling plastic drain was placed in the standing horse to provide a means for lavage with 3 L of balanced electrolyte solution twice daily for 72 hours. The contralateral tarsocrural joint was treated via arthroscopic debridement, synovectomy, and lavage with 3 L of balanced electrolyte solution. Arthrotomy and arthroscopic portals were allowed to heal by second intention. Lameness and thermographic examinations, analysis and bacteriologic culture of synovia, cbc, and wbc differential count were performed prior to inoculation and on days 1, 3, 6, 8, and 13. On day 14, each horse was euthanatized, and the joints were measured, opened, and photographed. Synovium and articular cartilage were obtained for semiquantitative histologic (H&E stain) and histochemical (safranin O fast green stain) evaluation. Lameness and joint circumference were significantly (P < 0.05) greater in limbs treated by arthroscopy, synovectomy, and lavage. Arthrotomy with lavage eliminated the S aureus infection significantly (P < 0.05) earlier than arthroscopy, synovectomy, and lavage; however, both treatments eliminated the infection in all but a single joint. Contamination with other organisms (Streptococcus spp and Enterobacter spp) developed significantly (P < 0.05) more often in joints treated by arthrotomy. These results suggested that arthrotomy with lavage was more effective in eliminating joint infection by providing better drainage than arthroscopy, synovectomy, and lavage; however, arthrotomy had a higher risk of ascending bacterial contamination of the joint.
Histologic evaluation of nerve muscle pedicle graft used as a treatment for left laryngeal hemiplegia in Standardbreds
Authors: Fulton Ian C. , Derksen Frederik J. , Stick John A. , Robinson N. Edward , Duncan Ian D.
Published: January 2024

A nerve muscle pedicle (nmp) graft was placed in the cricoarytenoideus dorsalis (cad) muscle of 6 horses with induced left laryngeal hemiplegia. The nmp graft was created by use of the first cervical nerve and omohyoideus muscle. In 1 horse (control), the first cervical nerve was transected after placement of the nmp graft. One year after the surgical procedure, horses were examined endoscopically and then anesthetized. While the larynx was observed endoscopically, the first cervical nerve was stimulated. Horses were subsequently euthanatized, and the larynx was harvested.

Prior to anesthesia, the endoscopic appearance of the larynx of all horses was typical of laryngeal hemiplegia. During anesthesia, stimulation of the first cervical nerve produced vigorous abduction of the left aiytenoid in principal horses but not in the control horse. The right cricoarytenoideus lateralis and cad muscles were grossly and histologically normal. Also, the left cricoarytenoideus lateralis was atrophic in all horses as was the left cad muscle of the control horse. In contrast, the left cad muscle harvested from principal horses had evidence of reinnervation with type 1 or type 2 fiber grouping. One year after the nmp graft procedure, horses with left laryngeal hemiplegia had reinnervation of the left cad muscle. In another study, reinnervation was sufficient to allow normal laryngeal function during exercise. Combined, these data suggest that the nmp graft procedure is a viable technique for the treatment of left laryngeal hemiplegia in horses.
Accuracy of ultrasonography in the detection of severe hepatic lipidosis in cats
Authors: Yeager Amy E. , Mohammed Hussni
Published: January 2024

The accuracy of ultrasonography in detection of feline hepatic lipidosis was studied retrospectively. The following ultrasonographic criteria were associated positively with severe hepatic lipidosis: the liver hyperechoic, compared with falciform fat; the liver isoechoic or hyperechoic, compared with omental fat; poor visualization of intrahepatic vessel borders; and increased attenuation of sound by the liver. In a group of 36 cats with clinically apparent hepatobiliary disease and in which liver biopsy was done, liver hyperechoic, compared with falciform fat, was the best criterion for diagnosis of severe hepatic lipidosis with 91% sensitivity, 100% specificity, and 100% positive predictive value.
Relation among body condition score, serum urea nitrogen and cholesterol concentrations, and reproductive performance in high-producing Holstein dairy cows in early lactation
Authors: Ruegg Pamela L. , Goodger William J. , Holmberg Charles A. , Weaver Leon D. , Huffman E. Michael
Published: January 2024

Body condition scoring (using a 5-point scale with quarterpoint divisions) was performed on 66 Holstein dairy cows that began their second or later lactation in August, September, or October 1988. Cows’ body condition was scored beginning on postpartum day 4 (± 1) and subsequently at postpartum days (± 1) 18, 32, 46, 60, 73 and 87. Blood samples were obtained on the same dates. Reproductive health examinations were conducted by 1 of 2 veterinarians beginning at postpartum day 21. Reproductive performance was evaluated in relation to body condition score and serum urea nitrogen and cholesterol concentrations.

Number of days to first recorded signs of estrus and first breeding were not related to body condition score at calving, amount of condition loss, cumulative 80-day milk yield, or 305-day fat corrected milk yield. Cows that calved with body condition score ≥ 3.50 required more days to conceive. Cows losing > 0.75 points of condition had longer days of conception. Body condition score at calving and amount of condition lost were not related to services per conception or diagnosis of follicular cyst.

Cumulative 80-day milk yield was not related to days to conception or services per conception. Cows that produced = the mean 305-day milk yield required more services and had longer days to conception than cows that produced < the mean 305-day milk yield. Cows with diagnosis of ovarian follicular cysts had greater cumulative 80- and 305-day milk yields than did cows that were not diagnosed with follicular cysts.

Cows conceiving with ≤ 2 services did not differ in average daily milk production, body condition score, or serum urea nitrogen concentration from cows conceiving with > 2 services, but cows that conceived with ≤ 2 services had higher serum cholesterol values than did cows requiring more services.
Direct cutaneous arterial supply to the tail in dogs
Authors: Smith Mark M. , Carrig Colin B. , Waldron Don R. , Trevor Peter B.
Published: January 2024

Cutaneous arterial blood supply to the tail was evaluated in 12 dogs. Subtraction radiography of internal iliac artery and distal aorta angiography in 3 of these dogs was used to determine arterial blood supply to the tail from the median sacral and lateral caudal arteries. Dissection of the tail in 8 canine cadavers revealed bilateral subcutaneous location of lateral caudal arteries following tail amputation. An axial pattern flap based on the lateral caudal arteries contributed to the reconstruction of a large caudodorsal cutaneous defect in a dog. An axial pattern flap based on the lateral caudal arteries following tail amputation may be indicated to aid reconstruction of large caudodorsal cutaneous defects of the trunk in dogs.
Exercise-induced pulmonary hemorrhage in horses with experimentally induced allergic lung disease
Authors: Derksen Frederik J. , Slocombe Ronald F. , Gray Peter R. , Robinson N. Edward
Published: January 2024

The lungs of sensitized horses were exposed to aerosolized ovalbumin. Some horses (n = 4) were given ovalbumin in 1 lung only, whereas in others (n = 7), ovalbumin or vehicle were inoculated in the cranial, ventral, and caudal regions of the caudal lung lobe. Horses were exercised 5 hours after ovalbumin exposure. Immediately before exercise, endoscopy failed to reveal any abnormality. After exercise, endoscopic examination of horses subjected to unilateral ovalbumin exposure revealed extensive blood in airways leading to the exposed lung in all horses. Blood was not observed in the airways leading to the control lung. Mean (± sem) minimum volume of the exposed and control lungs was 9.5 ± 1.5 and 5.5 ± 1.6 L, respectively; this difference was statistically significant (P< 0.05). Bronchoscopy of horses subjected to regional ovalbumin or vehicle exposure and exercise revealed a small amount of blood-tinged fluid in the bronchi serving the regions of the lung inoculated with ovalbumin. Minimum volumes of such regions were not significantly different from one another. However, their minimum volume was significantly (P<0.05) larger than that of vehicle-inoculated regions. Gross and histologic examination confirmed inflammation and hemorrhage in the ovalbumin-exposed, but not the control lungs or lung regions. Thus, exercise can cause blood from an injured region of lung to appear in the larger airways. Regional differences in lung structure and function do not influence the appearance of blood in the airways.
Transplacental infection of porcine fetuses following experimental challenge inoculation with encephalomyocarditis virus
Authors: Christianson W. T. , Kim H. S. , Yoon I. J. , Joo H. S.
Published: January 2024

Ten multiparous sows were inoculated between 46 and 50 days of gestation with a fetal swine isolate of encephalomyocarditis virus (emcv) to investigate the ability of the virus to cause transplacental infection and fetal death. Four sows (group 1) were inoculated im with emcv MN-25 that had been passaged 4 times on baby hamster kidney-21 line cell monolayers. Two sows were euthanatized at postinoculation (pi) day 23, and the other 2 sows at pi day 44. An additional 6 sows (group 2) were inoculated IM with the same virus that had been passaged 5 additional times in pigs. Two sows were euthanatized at 14 days, and the remaining 4 sows at PI day 28. Clinical signs were not observed in any of the sows, whereas all sows seroconverted to emcv. In group 1, only 2 of 50 fetuses were mummified. Virus was not recovered, although emcv antibodies were detected in the 2 mummified fetuses. In group 2, the 2 sows that were euthanatized at PI day 14 had 26 normal fetuses and there was no evidence of fetal infection. However, in the 4 sows euthanatized at Pi day 28, 20 of 48 fetuses were mummified, hemorrhagic, or edematous. Encephalomyocarditis virus was recovered from 21 of 48 fetuses. Transplacental infection and fetal deaths in pregnant sows was achieved following infection with emcv passaged in pigs.
Evaluation of colostral IgGl absorption in newborn calves after treatment with alkalinizing agents
Authors: Ayers M. Wayne , Besser Thomas E.
Published: January 2024

The effects of alkalinizing agents, administered prior to feeding colostrum, on blood-gas and acid-base values and on absorption of IgGl were determined in 40 newborn Holstein calves. Two treatments, sodium bicarbonate (3 mEq/kg of body weight, IV) and doxapram HCl (2 mg/kg, IV), were evaluated, using a randomized complete-block experimental design. These treatments resulted in significant (P< 0.01) alteration of blood-gas and acid-base values, generally in the direction of normal values for adult cattle. Significant least squares mean effects were detected for sodium bicarbonate treatment on blood pH ( + 0.04 units, P < 0.01), Pco2( + 4.1 mm of Hg, P <0.01), and HCO3 concentration ( + 4.4 mEq/L, P < 0.01). Significant least squares mean effects were detected for doxapram HC1 treatment on blood pH ( + 0.06 pH units, P <0.01) and Pco2(–5.2 mm of Hg, P <0.01). Absorption of colostral IgGl was not affected by the treatments given or by the altered blood-gas and/or acid-base status.
Prevalence of bovine group A rotavirus shedding among dairy calves in Ohio
Authors: Lucchelli A. , Lance S. E. , Bartlett P. B. , Miller G. Y. , Saif L. J.
Published: January 2024

Fecal samples were collected from 450 neonatal calves ranging from 1 to 30 days old, between May, 1988 and May, 1989 to estimate the prevalence of bovine group A rotavirus in a stratified random sample of Ohio daily herds. Calves were from 47 dairy herds chosen to be representative of Ohio herds. Bovine group A rotavirus was detected in fecal samples by a cell culture immunofluorescence test (ccif) and elisa. Of 450 samples tested, 46 (10%) were positive by ccif and 67 (15%) were positive by elisa. The agreement beyond chance between the 2 assays was good (kappa = 0.65). The overall prevalence rate of rotavirus shedding was 16.4% (74/450). Forty-three percent (29/67) of the samples positive by elisa were subgroup 1, none were subgroup 2, and the remaining 57% (38/67) could not be assigned to either subgroups 1 or 2. Thirty herds (62.5%) had at least 1 group A rotavirus-positive calf (mean number of samples per positive herd = 12.4), and 17 herds (37.5%) had no rotavirus-positive calves (mean number of samples per negative herd = 6.0). A live oral rotacoronavirus vaccine was used in neonatal calves of only 1 herd and 3 of 17 (17.6%) calves from this herd were positive for group A rotavirus. The percentage of the rotavirus-positive fecal samples from all calves (n = 450) when stratified by fecal consistency was as follows: 28.3% (13/46) had liquid feces; 25.6% (10/39) had semiliquid feces; 23.4% (22/94) had pasty feces; and 10.7% (29/271) had firm feces. Of the rotavirus-positive calves (n = 74), 17.6% (13/74) had liquid feces; 13.5% (10/74) had semiliquid feces; 29.7% (22/74) had pasty feces; and 39.2% (29/74) had firm feces. The average age of calves shedding rotavirus was 14 days (range, 1 to 30 days). Double-stranded (ds) rna extracted from 36 samples positive by 1 or both tests was examined by polyacrylamide gel electrophoresis. All samples positive by this technique (30/36) had long dsrna migration patterns, typical of group A rotaviruses, including samples from calves in the herd in which the oral vaccine was used. Moreover, the electrophoretic migration pattern of group A rotavirus dsrna in these vaccinated calves differed from that of the rotavirus vaccine strain, suggesting the rotavirus strain circulating in this herd was not the vaccine strain. All samples negative by ccif or elisa that had volumes > 5 ml (n = 323) were also subjected to dsrna extraction and polyacrylamide gel electrophoresis for detection of additional group A or nongroup A rotaviruses; none of them were positive by this technique.
Ultrasonographic appearance of the ovaries of dogs during the follicular and luteal phases of the estrous cycle
Authors: Wallace Shellie S. , Mahaffey Mary B. , Miller Doris M. , Thompson Fred N. , Chakraborty Prabir K.
Published: January 2024

Ultrasonography of the ovaries of 10 bitches was performed daily, using a 7.5-Mhz transducer with a built-in stand-off pad, from the onset of proestrus until the onset of metestrus. Ovarian size, shape, location, echogenicity, follicular development, and apparent ovulation were monitored. Blood samples were collected twice daily for luteinizing hormone determination and daily for progesterone determination. Vaginal smears were made daily for cytologic evaluation. Ultrasonograms were evaluated independent of hormonal and cytologic data, and the day of ovulation was noted. Initially, the ovaries were uniform and had an echogenicity that was equal to or slightly greater than that of the renal cortex. Follicles appeared as focal hypoechoic to anechoic rounded structures. Ovaries were easier to identify as follicular development progressed. Ovarian size increased with time. Apparent ovulation was characterized by a decrease in number of follicles seen from 1 day to the next, but 1 or more follicles remained in at least 1 ovary of 7 of 10 bitches. The ovaries had an oval shape that became rounded after ovulation. At some time after ovulation, all bitches had cystic (anechoic) structures indistinguishable from follicles. These structures increased in echogenicity and decreased in size with time and may have been follicles that did not ovulate, corpora hemorrhagica, fluid-filled corpora lutea, or cyctic luteinized follicles. Time of ovulation determined by ultrasonography paralleled that predicted on the basis of hormonal data in 9 of 10 bitches and with cytologic findings in all bitches.