bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of intracameral injection of viscoelastic solutions on intraocular pressure in dogs
Authors: Gerding Paul A. , McLaughlin Susan A. , Brightman Alan H. , Essex-Sorlie Diane , Helper Lloyd C.
Published: February 2025

Intraocular pressure (iop) was determined in right eyes of 20 healthy dogs after sodium hyaluronate (1%, n = 5), sodium chondroitin sulfate (4%) and sodium hyaluronate (3%, n = 5), hydroxypropyl methylcellulose (2%, n = 5), or balanced salt solution (control, n = 5) was injected into the anterior chamber. Applanation tonometry was used to measure iop in both eyes of each dog for up to 168 hours.

The 3 viscoelastic solutions resulted in an increased mean iop by postinjection hours (pih) 2; from pih 12 until pih 72, the iop was significantly (P < 0.001) lower than baseline. The control group did not have an increase in iop at pih 2; mean iop decreased below baseline measurements within 2 hours and remained lower until pih 72. Mean differences in iop were not found among treated eyes (P = 0.50), and a significant interaction of any treated eyes in a group was not detected (P = 0.21). By pih 168, the iop approached baseline values in all groups.
Isoelectric focusing under dissociating conditions for analysis of muscle protein from clinically normal dogs and Labrador Retrievers with hereditary myopathy
Authors: Mehta Jagjivan R. , Braund Kyle G. , McKerrell Rosemary E. , Toivio-Kinnucan Maria
Published: February 2025

Protein profiles of whole homogenates of anconeus (slow twitch) and biceps femoris (fast twitch) muscles of clinically normal dogs and of Labrador Retrievers with hereditary myopathy (hm) were resolved on flat bed Polyacrylamide isoelectric-focusing gels. Three methods of sample solubilization were performed. The solubilization buffer, with high concentrations of urea, precipitated the zwitterionic detergent, but use of the buffer containing 3% NP-40, 9.2M urea, and 0.1M arginine resulted in better resolution and stability of pH gradient. Gels of anconeus muscle from clinically normal dogs contained 2 protein bands specific to anconeus muscle, whereas gels of biceps femoris muscle from clinically normal dogs contained 3 protein bands amplified in biceps femoris muscle that were barely detectable in anconeus muscle. The staining intensity of protein bands in biceps femoris muscles from Labrador Retrievers with hm was decreased, relative to controls. The quantitative analysis of peak height ratios of biceps femoris muscle revealed significant (P < 0.05) differences between profiles of clinically normal dogs and Labrador Retrievers with hm.
Nuclear scintigraphic assessment of liver size in clinically normal dogs
Authors: Godshalk Cynthia P. , Twardock A. Robert , Kneller Stephen K.
Published: February 2025

Measurement of liver size was made on nuclear scintigraphic images obtained from 16 clinically normal, anesthetized dogs in ventral, dorsal, right and left lateral, and left dorsal oblique positions after administration of technetium 99m-sulfur colloid. Linear measurements of liver length and width were made from each scintiscan, and liver surface area was determined by setting a region of interest manually and by use of a computer count of pixels above a minimal intensity (threshold method). All linear measurements had a statistically significant (P < 0.05) correlation with liver and body weight, with the exception of the measurements of liver width made on dogs in dorsal and left lateral dorsal oblique positions. The highest correlation (r = 0.89) between the scintigraphic measurements and liver weight was the multiplication of measurements of liver width and length from the right lateral view. Although all area determinations were significantly (P < 0.05) correlated with liver and body weight, for most views, the manual method of determining the region of interest had a slightly better correlation with the liver weight than did the threshold method.
Clinical and microbiologic findings in lambs inoculated with Pasteurella haemolytica after infection with ovine adenovirus type 6
Authors: Lehmkuhl Howard D. , Contreras Jose A. , Cutlip Randall C. , Brogden Kim A.
Published: February 2025

Colostrum-deprived lambs (10 to 20 days old) were inoculated with either ovine adenovirus type 6 (oav-6; n = 6), Pasteurella haemolytica type Al (n = 6), or oav-6 followed by P haemolytica 5 days later (n = 10). Another group (n = 3) served as sham-inoculated controls. Lambs inoculated with oav-6 or P haemolytica developed mild and moderate respiratory tract disease of 6 and 3 days' duration, respectively. Lambs inoculated with virus and bacteria developed clinical signs of respiratory tract disease of greater intensity and duration (9 days) than with either agent alone. Within 3 hours of bacterial inoculation, all lambs that received P haemolytica were anorectic, listless, and febrile, and had hyperpnea and dyspnea. Ovine adenovirus type 6 was isolated from all virus-inoculated lambs. Although P haemolytica was not recovered from all bacteria-inoculated lambs, it was recovered for a longer period in the group that received both agents. Antibody to oav-6 was detected in virus-inoculated lambs as early as day 6 after inoculation. The control lambs remained clinically normal and neither virus nor bacteria were recovered at necropsy.
Lesions of transmissible gastroenteritis virus infection in experimentally inoculated pigs suckling immunized sows
Authors: Moxley Rodney A. , Olson LeRoy D.
Published: February 2025

Intestinal lesions of transmissible gastroenteritis (tge) virus infection in conventionally reared pigs suckling either nonvaccinated, vaccinated, or previously infected sows were studied by scanning electron microscopy, light microscopy, and immunofluorescent microscopy for tge viral antigen. Pigs were inoculated with virulent tge virus when they were 5 or 21 days old and were euthanatized shortly after the onset of diarrhea or 96 hours after inoculation if no diarrhea developed. Pigs inoculated when they were either 5 or 21 days old and suckling nonvaccinated sows developed severe lesions, including swelling and necrosis of enterocytes and severe villus atrophy. Pigs inoculated when they were 5 days old and suckling sows vaccinated with attenuated vaccines developed less-severe villus atrophy, and those suckling sows immunized by exposure to nonattenuated tge virus developed moderate or no villus atrophy. Pigs inoculated when they were 21 days old and suckling sows vaccinated with attenuated vaccines had severe villus atrophy, whereas those suckling sows immunized by exposure to nonattenuated virus had more-moderate villus lesions. Villus atrophy was inhibited to various degrees in pigs suckling immunized sows, depending in part on the antibody titer in the colostrum and milk.
Time of appearance of esterase-positive alveolar macrophages in bovine fetal lung
Authors: Hambolu Joseph O. , Klemm Robert D.
Published: February 2025

Bovine fetal lung tissue was examined histochemically, using α-naphthyl butyrate (nonspecific method), to detect the presence of esterase-positive pulmonary alveolar macrophages (pam). Positively stained pam were first seen in the alveolar septa and lumina of the lungs of 4 of 8 fetuses 240 days old. Macrophages (n = 100) in 240-day-old fetuses were 6.74 ± 0.07 µm, and in most cells, esterase-positive granules were sparsely distributed in the cytoplasm. In 10 fetuses 250 days old, the alveolar septa and lumina of lungs contained positively stained macrophages, as did those of all older fetal lungs examined. Compared with macrophages of the 240-day-old fetuses, those (n = 50) of 250-day-old fetuses were significantly larger, 7.32 ± 0.10 µm (P < 0.0001), and esterase-positive granules were heavily distributed throughout the cytoplasm.

In all fetal lungs, T lymphocytes contained a single, small, esterase-positive granule, compared with the numerous diffuse esterase-positive granules in pam. Type-II pneumonocytes with well-developed lamellar bodies had no evidence of positive nonspecific esterase reaction in lungs.
Xylazine and tiletamine-zolazepam anesthesia in horses
Authors: Hubbell J. A. E. , Bednarski R. M. , Muir W. W.
Published: February 2025

The cardiopulmonary and anesthetic effects of xylazine in combination with a 1:1 mixture of tiletamine and zolazepam were determined in 6 horses. Each horse was given xylazine iv or im, as well as tiletamine-zolazepam iv on 4 randomized occasions. Anesthetics were administered at the rate of 1.1 mg of xylazine/kg of body weight, iv, 1.1 mg of tiletamine-zolazepam/kg, iv (treatment 1); 1.1 mg of xylazine/kg, iv, 1.65 mg of tiletamine-zolazepam/kg, iv (treatment 2); 1.1 mg of xylazine/kg, iv, 2.2 mg of tiletamine-zolazepam/kg, iv (treatment 3); and 2.2 mg of xylazine/kg, im, 1.65 mg of tiletamine-zolazepam/kg, iv (treatment 4). Tiletamine-zolazepam doses were the sum of tiletamine plus zolazepam. Xylazine, when given iv, was given 5 minutes before tiletamine-zolazepam. Xylazine, when given im, was given 10 minutes before tiletamine-zolazepam.

Tiletamine-zolazepam induced recumbency in all horses. Duration of recumbency in group 1 was 31.9 ± 7.2 (mean ± 1 sd) minutes. Increasing the dosage of tiletamine-zolazepam (treatments 2 and 3) significantly (P < 0.05) increased the duration of recumbency. Xylazine caused significant (P < 0.05) decreases in heart rate and cardiac output and signifient (P < 0.05) increases in central venous pressure and mean pulmonary artery pressure 5 minutes after administration. Respiratory rate was decreased. Arterial blood pressures increased significantly (P < 0.05) after xylazine was administered iv in treatments 1 and 3, but the increases were not significant in treatment 2. Xylazine administered im caused significant (P < 0.05) increases in central venous pressure and significant (P < 0.05) decreases in cardiac output. Tiletamine-zolazepam administration caused significant (P < 0.05) decreases in arterial partial pressure of oxygen and arterial pH and significant (P < 0.05) increases in arterial partial pressure of carbon dioxide. These changes persisted for the duration of recumbency.

Induction to lateral recumbency was rapid and smooth. Recovery from anesthesia was smooth when xylazine was administered iv. Results of this study indicated that xylazine, in combination with tiletamine-zolazepam, is useful to induce reasonably safe short-term anesthesia in horses.
Effects of phenylbutazone on glucose tolerance and on secretion of insulin in healthy geldings
Authors: Zicker Steven C. , Brumbaugh Gordon W.
Published: February 2025

The effect of phenylbutazone (4.4 mg/kg of body weight, iv, q 24 h, for 5 days) on glucose tolerance and on secretion of insulin in 6 healthy geldings was determined. Phenylbutazone significantly lowered fasting concentrations of glucose in plasma but did not significantly change the concentration of insulin in serum. There was no significant effect of phenylbutazone on glucose tolerance, on secretion of insulin, or on the area under the insulin/glucose ratio vs time curve in healthy geldings, as determined by paired t test analysis.
Eructation of gas through the gastroesophageal sphincter before and after limiting distension of the gastric cardia or infusion of a β-adrenergic amine in dogs
Authors: Strombeck Donald R. , Griffin D. W. , Harrold Doris
Published: February 2025

Gas eructation function of the gastroesophageal sphincter (ges) was investigated in 6 conscious dogs before and after a sleeve was placed around the ges and gastric cardia and during iv infusion of a β-adrenergic amine (epinephrine). To induce eructation, nitrogen gas was insufflated (351.4 ± 2 ml/min; mean ± sem) into the stomach through 1 channel of a 4-lumen catheter. After baseline studies and epinephrine infusion studies were completed in each dog, surgery was done to limit partially gastric distension by intraluminal contents by placing a silicone rubber sleeve around the ges and the first few centimeters of the cardia. Gastroesophageal sphincter pressure was 31.8 ± 2.2 mm of Hg in baseline studies, 17.3 ± 1.3 mm of Hg during epinephrine infusion (P < 0.003), and 30.3 ± 2.2 mm of Hg after the sleeve was placed around the ges and cardia.

During insufflation, gastric pressures before eructation increased to 5.74 ± 0.41 mm of Hg before and to 15.15 ± 1.63 mm of Hg after cardia sleeve placement (P < 0.001). Eructation occurred at intervals of 1.83 ± 0.41 minutes before cardia sleeve placement, and eructations were not observed with the sleeve in place. Before the sleeve was placed, administration of epinephrine resulted in an eructation interval of 0.84 ± 0.09 minutes, which was significantly different from that in the same dogs given no drugs (P < 0.004).

In vitro comparison of stomachs filled with fluid or filled with fluid and gas revealed that relatively small amounts of gas added to a partially filled stomach caused marked distension of the gastric cardia in comparison with no effects when fluid only was added.

Seemingly, distension of the gastric cardia was the important stimulus for eructation. Limiting this distension prevented eructation and β-adrenergic stimulation increased eructation frequency.
Total and antigen-specific serum immunoglobulin isotype concentrations in hyperimmunized cattle that have undergone plasmapheresis
Authors: McVey D. Scott , Loan Raymond W.
Published: February 2025

The effects of prolonged plasmapheresis of cattle on total and antigen-specific immunoglobulin production were evaluated. Five adult cows were hyperimmunized by repeated iv administration of live, logarithmic-phase Pasteurella haemolytica A1 organisms. Three of the cows underwent plasmapheresis daily for 3 weeks. From 2 cows, serum was only obtained periodically. Anti-P haemolytica antibody was assayed by indirect hemagglutination and a kinetic-augmented, antigen-capture elisa for capsular polysaccharide and lipopolysaccharide/outer membrane protein antigens. Total serum immunoglobulin concentration was determined for IgM, IgG1, and IgG2 by primary radial immunodiffusion. Anti-P haemolytica Al activity increased rapidly after immunization. After beginning plasmapheresis, the antigen-specific antibody activities remained nearly constant. In general, anti-lipopolysaccharide/outer membrane protein activity (in terms of concentration) was higher than anti-capsular polysaccharide activity and was not affected as much by the plasmapheresis. Total serum Ig concentration decreased transiently by a small amount after beginning plasmapheresis.
Antibody complement-dependent bacteriolysis in experimentally induced pasteurellosis in mice
Authors: McVey D. Scott , Loan Raymond W.
Published: February 2025

Affinity-purified bovine immunoglobulin isotypes were bacteriolytic for Pasteurella haemolytica biotype A, serotype 1 (pha-1). This bacteriolysis was specific and complement-dependent. The IgM and IgG1 were the most active isotypes in the classic complement cascade. These isotypes also induced bacteriolysis through the alternative complement cascade. The comparative bacteriolytic activities of IgG1 and IgM were equal within each cascade; however, the bacteriolytic activities of IgG1 and IgM were lower in the alternative cascade than in the classical cascade. The IgG2 was more bacteriolytic than IgA in the classic and alternative complement pathways.

Bovine immunoglobulins passively protected C57BL/6 mice from experimentally induced pasteurellosis. There were no major differences in the protection among hyperimmune sera, purified IgM, or purified IgG. Mice were protected from pha-1 by approximately 1.9 μg of IgG and 1.2 or 0.1 (μg of IgM. Elimination of murine complement with cobra venom factor 3 reduced pha-1 clearance in passively immunized C57BL/6 mice. The protective effect of IgM mediated resistance was highly dependent on an intact complement system. The intact complement cascade was associated with enhanced clearance of pha-1 from the liver. Although pha-1 was susceptible to antibody complement-mediated bacteriolysis in vitro, the dependence on an intact complement cascade was not absolute in experimentally induced murine septicemic pasteurellosis.
Ivermectin plasma concentrations in Collies sensitive to ivermectin-induced toxicosis
Authors: Tranquilli W. J. , Paul A. J. , Seward R. L.
Published: February 2025

Five Collies sensitive to toxic effects of ivermectin and 7 nonsensitive Collies were given 100 μg of ivermectin/ kg of body weight, po. Blood samples were collected from each dog before treatment; at posttreatment hours 1, 2, 3.5, 5, and 8; and at posttreatment days 1, 2, 4, 7, 14, and 21. Each sample was assayed for ivermectin concentration, and statistical analyses were performed on the resulting plasma concentration data to determine differences in absorption and clearance of drugs between the 2 groups. Variables measured were area under the curve (using the trapezoidal rule), peak plasma concentration, and the time to peak concentration. Differences between sensitive and nonsensitive Collies for variables analyzed were not significant (P > 0.05).
Ultrastructure of hepatic and renal lesions in chickens fed aflatoxin
Authors: Mollenhauer Hilton H. , Corrier Donald E. , Huff William E. , Kubena Leon F. , Harvey Roger B. , Droleskey Robert E.
Published: February 2025

Male broiler chicks were given feed and water ad libitum from hatching through 3 weeks of age. The feed contained 0, 1.25, 2.5, and 5.0 μg of aflatoxin/g of feed. The chicks were killed by cervical dislocation and specimens of liver and kidney were obtained for electron microscopy on days 3, 6, 9, 17, and 21. In chicks fed 5.0 μg of aflatoxin, the primary lesions in liver were hepatocellular lipidosis, enlargement of bile canaliculi, reduction in mitochondrial size, mild lymphocytic infiltration, and hepatocellular degeneration and necrosis. Similar lesions were noticed in some chicks fed 2.5 μg of aflatoxin, but none was observed in chicks fed at 1.25 μg of aflatoxin. At 5 μg of aflatoxin, the most consistent lesion in the kidney was thickening of the glomerular basement membrane. Similar glomerular lesions were observed at 2.5 μg of aflatoxin, but not at 1.25 μg of aflatoxin. Some foot processes of the glomerular epithelial cells were poorly developed. Fusion of foot processes was not observed and fibrous material was not evident in the basement membrane. The pseudopodia of endothelial cells lining the thickened basement membrane were depleted in number or were absent. Degenerative changes also were observed in the cells of the proximal convoluted tubules, but these were less consistent than those of the glomerulus.
Evaluations of buparvaquone as a treatment for equine babesiosis (Babesia equi)
Authors: Zaugg J. L. , Lane V. M.
Published: February 2025

We evaluated the efficacy of buparvaquone in eliminating Babesia equi of European origin in carrier horses and in experimentally infected splenectomized ponies. When administered at the rate of 2.5 mg/kg of body weight, im, 4 times at 96-hour intervals, buparvaquone was effective in eliminating B equi carrier infection in 1 horse. Such results could not be repeated at the same dosage or at 3.5 or 5 mg/kg, im. Buparvaquone given at the rate of 4 to 6 mg/kg iv and/or im was therapeutically effective in 4 of 5 acute B equi infections in splenectomized ponies. The treated ponies became carriers.
Transendoscopic neodymium:yttrium aluminum garnet laser irradiation in horses
Authors: Tate Lloyd P. , Sweeney C. L. , Cullen J. M. , Corbett W. T. , Newman H. C. , Brown T. C. , Ketner M. T.
Published: February 2025

A neodymium:yttrium aluminum garnet (Nd:yag) laser was used to study effects of applying laser irridation transendoscopically to the corniculate process of the asytenoid cartilage in horses. Dosimetry was established initially in vitro in 10 corniculate cartilages that were irridated and examined histologically to determine penetration depths at selected power settings.

Eleven-horses were given xylazine iv and butorphoral tartrate iv, and their left ventricle and corniculate process were irradiated. Six horses had left laryngeal hemiplegia and were euthanatized and necropsied 14 weeks after laser application and evaluation for upper airway stridor. Endoscopy was performed in the 5 other horses; they were euthanatize and necropsied at selected intervals to characterize the healing process.

Healing was by second intention and was complete at 14 weeks. Two horses developed buds of granulation tissue along the laser incision, which resolved after a second laser application. Scar tissue formation resulted in left of midline displacement of the dorsal portion of the right corniculate process. The left ventricle healed without complications and was totally ablated. All horses had inspiratory stridor when exercised 14 weeks after laser irradiation.
Neonatal survival in swine: Effects of low birth weight and clinical disease
Authors: Gardner Ian A. , Hird David W. , Franti Charles E.
Published: February 2025

Data were collected for 3,636 full-term pigs born in a commercial swine herd to determine the effects of birth weight and clinical disease on survival during the first 3 weeks of life. Logistic regression models were constructed for 7-day survival for all live-born pigs, and for 21-day survival for pigs surviving the first week of life. Estimates of birth weight and disease effects were adjusted simultaneously for other risk factors including litter size, parity, and within-litter variation in birth weight. The 7-day survival model indicated that survival odds improved significantly with increasing birth weight. Maximal survival, relative to pigs weighing < 601 g at birth, was evident in pigs weighing > 2 kg at birth (odds ratio [or] = 349). Diarrhea (or = 2.7) and splayed limbs (splay leg; or = 37.3) significantly (P < 0.05) reduced 7-day survival. Models of 21-day survival indicated a smaller, but still significant, effect of birth weight on survival. Acyusted survival odds for pigs in the heaviest weight group ( > 2 kg) were 20.1 times higher than pigs weighing < 801 g. Diarrhea (or = 2.7) and lameness (or = 2.6, 2 limbs) significantly (P < 0.05) decreased 21-day survival.
Antigenic and restriction enzyme analysis of isolates of Campylobacter fetus subsp venerealis recovered from persistently infected cattle
Authors: Wesley Irene V. , Bryner John H.
Published: February 2025

Thirty-two isolates of Campylobacter fetus subsp venerealis were obtained from 1 bull and 4 heifers with experimentally induced infection. When whole-cell antigens of isolates were cross titrated with antisera to the infecting strain, isolates from 3 heifers had limited antigenic variation, whereas whole-cell antigens of isolates from 2 cattle (the bull and a heifer) differed serologically from those of the infecting strain. Changes were detected specifically in 6 heat-labile antigens. Of the 6 heat-labile factors evaluated, all were initially present on the infecting parent strain, but not on early isolates obtained from 4 of the 5 cattle. Restriction enzyme analysis revealed minor variation in the dna fingerprints of isolates obtained from individual cattle, thus implying stability of the Campylobacter genome once persistent infection is established. Isolates with identical restriction enzyme patterns expressed different heat-labile antigens. Correlation could not be found between the dna electrophoretic pattern and the expression of heat-labile antigens.
Transmission of a vaccinal strain of infectious bovine rhinotracheitis virus from intranasally vaccinated steers commingled with nonvaccinated steers
Authors: Baker John C. , Rust Steven R. , Walker Robert D.
Published: February 2025

Ninety-seven feeder steers, averaging 7 months of age, were allotted to 3 groups. Group I (n = 33) was vaccinated intranasally with an infectious bovine rhinotracheitis virus (ibrv) vaccine on postinoculation day (pid) 0; group II (n = 31) was not vaccinated on pid 0 but was commingled with group I; and group III (n = 33) served as controls housed in the same facility, but was physically separated from groups I and II. On pid 20, all steers were given a modified-live ibrv vaccine im. Virus isolation attempts from nasal swab specimens collected on pid 10 resulted in ibrv isolation from 19 (57.6%) of group I, 4 (12.9%) of group II, and 0 of group III. By pid 20, geometric mean titer for serum antibody to ibrv had increased in group I but had decreased in groups II and III. By pid 40, geometric mean titer for serum antibody to ibrv had increased in the 3 groups in response to im vaccination given on pid 20. Seemingly, transmission of a vaccinal strain of ibrv to nonvaccinated steers did not take place at a frequency that elicited a humoral immune response similar to that of vaccinated steers.
Influence of bovine intestinal fluid on the expression of K99 pili by Escherichia coli
Authors: Francis D. H. , Allen S. D. , White R. D.
Published: February 2025

A study was conducted to determine whether intestinal fluid collected from various portions of bovine intestine differed in its effect on production of K99 pili by Escherichia coli. The small and large intestines of 7 calves, euthanatized 4 hours after a final feeding of milk, were divided into 6 to 9 segments from which intraluminal fluids were collected. Depending on the amount of fluid collected, up to 20 E coli strains that express K99 pili were grown on media prepared from the content of each specimen and then were tested for K99 pilus expression. In general, intestinal fluid from the most proximal small intestinal segments were more suppressive to K99 pilus expression than was fluid from more distal segments of small intestine. Only about 20% of the E coli test strains expressed K99 pili when grown on medium prepared from proximal small intestinal segmental fluid, whereas > 90% did when grown on medium prepared from distal small intestinal segmental fluid. Fluid from the large intestine varied considerably from calf to calf in its effect on K99 pilus expression.

A correlation was found between K99 pilus expression and pH of the intestinal fluid, with the lower pH values (characteristic of proximal intestinal segmental fluid) being suppressive. The correlation between K99 pilus production and the pH of the medium was verified, using defined laboratory media adjusted to various pH values. Strains of E coli grown in medium at or below pH 5.5 failed to express K99 pili, whereas the same strains when grown in medium at or above pH 6.5 expressed K99 pili in abundance.
Serodiagnosis of ovine paratuberculosis, using lipoarabinomannan in an enzyme-linked immunosorbent assay
Authors: Sugden E. A. , Corner A. H. , Samagh B. S. , Brooks B. W. , Turcotte C. , Nielsen K. H. , Stewart R. B. , Duncan J. R.
Published: February 2025

The use of lipoarabinomannan (lam; obtained from Mycobacterium paratuberculosis) in an elisa (lam-elisa) to test 75 sheep sera from a paratuberculosis-infected flock resulted in an approximate threefold increase in sensitivity (from 23.5% to 70.6%), compared with the use of Annau's polysaccharide in a complement fixation test (p-cft). Even after manipulation of the lam-elisa cut-off value to produce a specificity of 100% to match that of the p-cft, the sensitivity still was approximately twofold greater than that of the p-cft. Anti-bovine monoclonal antiglobulin-enzyme conjugates matched commercially available anti-ovine polyclonal antiglobulin-enzyme conjugates with respect to sensitivity and specificity. False-positive results were found to be less frequent after combining 2 serodiagnostic tests, lam-elisa and d antigen-agar gel immunodiffusion, resulting in an increase in specificity from 88.1% to 95.2%. The repeatability of true seropositive and seronegative results was found to be 89.5% and 91.1%, respectively, for sera obtained ≤ 1 month prior to slaughter and 91.7% and 95.5%, respectively, for reanalysis of sera obtained at the time of slaughter.
Study of association between histologic features and echogenicity of architecturally normal cat kidneys
Authors: Yeager Amy E. , Anderson Wayne I.
Published: February 2025

Thirty-eight grossly and histologically normal cat kidneys were examined ultrasonographically. The echogenicity of the renal cortex was subjectively evaluated by scoring it as largely or not largely different from the echogenicity of the renal medulla and as similar or not similar to the echogenicity of the renal sinus. The presence or absence of a medullary hyperechoic band was determined. The length, width, and height of each kidney was measured. Hematoxylin and eosin-stained sections of each kidney were examined microscopically. The amount of fat vacuoles in the tubular epithelium of the renal cortex was scored as plentiful or not plentiful. The presence or absence of a medullary band of mineral deposits within the lumina of renal tubules was determined. A plentiful amount of fat vacuoles in renal cortex was associated positively with a large difference in echogenicity between cortex and medulla (P < 0.01) and with similar echogenicity of cortex and sinus (P < 0.01). The presence of a medullary hyperechoic band was associated positively with a band of mineral deposits within medullary tubular lumen (P 0.01). Kidneys with a large difference in echogenicity between cortex and medulla and kidneys with a plentiful amount of fat vacuoles were not significantly different in size (P = 0.56). These groups were larger (P < 0.01) in length, width, and height than were kidneys without a large difference in echogenicity between cortex and medulla and kidneys that did not have plentiful cortical fat vacuoles.
In situ production of interferon in tissues of chickens exposed as embryos to turkey herpesvirus and Marek's disease virus
Authors: Sharma J. M.
Published: February 2025

Chicken eggs at embryonation day (ed) 18 or newly hatched chicks were inoculated with turkey herpesvirus (hvt), Marek's disease virus (mdv), or virus-free diluent and, at intervals after inoculation, tissue homogenates of virus-exposed and virus-free chickens or chicken embryos were examined for interferon (ifn) activity. Homogenates of lung, thymus and spleen specimens from chickens given hvt at ed 18 had ifn activity. Activity of ifn in the lungs was studied further. Homogenates of lung specimens from chickens exposed to hvt at hatching also had ifn activity, although the concentration of ifn was lower than that in chickens given hvt at ed 18. The pathogenic isolates of mdv (JM-mdv), but not the attenuated (Md11/75C-mdv) or nonpathogenic (SB1-mdv) isolates, inoculated at ed 18 also induced high lung ifn activity. Exposure to a combination of hvt and SB1-mdv induced ifn activity comparable with that in chickens given hvt alone. The ifn activity in homogenates of lung specimens from virus-exposed chickens was species specific and heat and pH stable, but was destroyed by trypsin treatment. Occasionally, low ifn activity also was detected in homogenates of tissue specimens from virus-free chickens or chicken embryos. This ifn activity could have been produced constitutively or may have been induced by substances (inducers) in the environment.
Ultrasonographic and biometric evaluation of the eye and orbit of dogs
Authors: Cottrill Nancy B. , Banks William J. , Pechman Robert D.
Published: February 2025

The normal B-scan ultrasonographic anatomic features of the eye and orbit of mesocephalic and dolichocephalic dogs were described. The B-scan appearance of ocular and orbital structures correlated well with the visual morphologic features of the specimens.

The eyes of mesocephalic and dolichocephalic dogs were measured by use of ultrasonographic methods; those measurements were compared with direct measurements of the specimens. The 2-tailed Student t-test was used for all statistical analyses (P = 0.05). Measurements made included mid-cornea to anterior lens surface, lens thickness, vitreous body (posterior lens surface to retina), and axial globe length. The A-scan measurements of all 4 ocular distances were significantly different, compared with direct measurements. The B-scan measurements of mid-cornea to anterior lens surface, lens thickness, and vitreous body were significantly different from direct measurements; however, there was no significant difference between B-scan and direct measurements of axial globe length. There was no significant difference between A- and B-scan measurements. These findings suggest that A- and B-scan measurements are similar and that B-scan measurements are reasonably accurate for axial globe determination.

Several variables were compared by B-scan and direct measurement methods. The axial globe length of dolichocephalic dogs was significantly longer than that of mesocephalic dogs. The axial globe length of made and female dogs was not significantly different in mesocephalic or dolichocephalic dogs. There was no significant difference in the axial globe length of right and left eyes in mesocephalic or dolichocephalic dogs.
Normal blood supply to the canine mandible and mandibular teeth
Authors: Roush James K. , Howard Paul E. , Wilson James W.
Published: February 2025

The normal blood supply to the canine mandible and mandibular teeth was determined by microangiography and correlated histology. Branches of the inferior alveolar artery supplied the cortical bone of the mandibular body. Vessels from the periosteal and endosteal surfaces supplied symphyseal cortical bone. Direct vascular anastomoses were not found to cross the fibrous mandibular symphysis. Blood supply to the mandibular teeth was via dental arteries derived from the inferior alveolar artery, with interdental and interradicular arteries supplying the alveolar bone and periodontal ligament.
Role of leukotriene B4 in the pathogenesis of Klebsiella pneumoniae-induced bovine mastitis
Authors: Rose David M. , Giri Shri N. , Wood S. J. , Cullor J. S.
Published: February 2025

Mastitis was induced in 4 lactating cows by inoculation of Klebsiella pneumoniae (107 organisms/ml) via the teat canal. Sterile isotonic saline solution (1 ml) was instilled into designated control quarters via the teat canal. Changes in milk leukotriene B4 and C4 (ltb4, ltc4) concentrations, milk somatic cell counts, and milk bovine serum albumin concentration were monitored over a 24-hour postinoculation period.

Milk ltb4 concentration before inoculation in control quarters and quarters later to be infected was 376 ± 45 and 326 ± 56 pg/ml of milk, respectively. A significant (P < 0.05) increase in milk ltb4 concentration in the infected quarters was first observed at postinoculation hour 6, and milk ltb4 concentration in infected quarters generally remained significantly high through postinoculation hour 14. Thereafter, milk ltb4 concentration in infected quarters was not significantly different from the concentration in control quarters. Measurable amounts of ltc4 were not detected in the milk of either control or infected quarters. Milk bovine serum albumin concentration in the infected quarters generally was high throughout the study, as were milk somatic cell counts. The results of this study suggested that ltb4 contributes to the pathogenesis of bovine mastitis.
Resistance to gentamicin and amikacin of gram-negative organisms isolated from horses
Authors: Orsini James A. , Benson Charles E. , Spencer Pamela A. , Van Miller E.
Published: February 2025

Resistance of gram-negative bacteria to gentamicin has become an increasingly common problem among clinical isolates from human beings. Susceptibility of isolates from horses to gentamicin and amikacin was evaluated for the period from July, 1983 to June, 1985. All isolates of Escherichia coli, and species of Enterobacter, Klebsiella, Proteus, and Pseudomonas examined were susceptible to amikacin, except 2 of the 46 Pseudomonas isolates. In contrast, 13 to 50% of isolates were resistant to gentamicin. Escherichia coli, and Klebsiella, Proteus, and Enterobacter species isolates were highly significantly more susceptible to amikacin (P < 0.01) than to gentamicin. Pseudomonas spp (P = 0.13) were not significantly different in susceptibility to the 2 drugs. There was significant variation among genera in their susceptibility to gentamicin (P = 0.002), primarily because of the frequency of resistance in isolates of Klebsiella spp and Proteus spp, compared with the other 3 organisms (E coli, Enterobacter spp, and Pseudomonas spp). There was no significant difference of susceptibility to amikacin among the genera studied (P = 0.06).
Critical and controlled tests of activity of a macrocyclic lactone (compound F28249-α) against natural infections of internal parasites of equids
Authors: Lyons E. T. , Drudge J. H. , Tolliver S. C.
Published: February 2025

Thirteen critical tests (n = 11 horses and 2 ponies) and 4 controlled tests (n = 4 donkeys and 6 horses) were performed to evaluate the activity of the experimental macrocyclic lactone compound F28249-α against internal parasites of equids. In the critical tests, activity was determined mainly against the large parasites, but 1 critical test also included benzimidazole-resistant small strongyles. In the controlled tests, evaluation of drug activity included large parasites and stomach worms in all 4 tests, and lungworms in 2 tests. The period between treatment and euthanasia was 6 to 9 days for the critical tests and 14, 17, or 52 days for the controlled tests. The compound was administered by stomach tube at dose rates of 1, 2, 3, 3.5, or 4 mg/kg of body weight.

In the critical tests, removal at all 5 dose rates was 100% for Gasterophilus nasalis (2nd and 3rd instars), Parascaris equorum (mature), Strongylus vulgaris, and Strongulus edentatus from the gastrointestinal tract. For Gasterophilus intestinalis in the stomach, mean removals of 2nd instars were 88% at the rate of 2 mg/kg and 93% to 100% at rates ≥ 3 mg/kg. For 3rd instars, mean removals were 7% at 1 mg/kg, 77% at 2 mg/kg, 90% at 3 mg/kg, and 98% at 3.5 mg/kg. Discharge of G intestinalis in feces was typically a slow, prolonged process and probably higher removal values, especially at lower dose rates, would have attended a longer interval after treatment before necropsy examination. There was 100% removal of population B, benzimidazole-resistant small strongyles in the single critical test.

Controlled tests at the 4 dose rates between 2 and 4 mg/kg resulted in variable activity against G intestinalis and Oxyuris equi, but efficacious removals were recorded for S vulgaris, S edentatus, Draschia megastoma, Habro-nema muscae, Trichostrongylus axei, and Dictyocaulus arnfieldi.

In critical and controlled tests, there was some indication of drug activity against parenteral stages of S edentatus and S vulgaris; activity was best in the control test equids euthanatized 52 days after treatment. There did not appear to be drug activity on eyeworms (Thelazia lacrymalis) or tapeworms (Anoplocephala spp).

Toxicosis of transient nature was observed in 1 horsei treated at 4 mg/kg.
DNA polymorphism analysis of hereditary multiple exostoses in horses
Authors: Li Joseph K. K. , Moloney Brian K. , Shupe James L. , Gardner Eldon J. , Leone Nicole C. , Elsner Yoko
Published: February 2025

Genomic dna polymorphisms obtained by restriction fragment-length polymorphism from healthy horses and horses with hereditary multiple exostoses were analyzed. These dna were digested by 12 restriction enzymes and were hybridized against 6 isotopically labeled oncogene probes. Hybridization was not detected with the viral oncogene, v-ras, which indicated this oncogene was absent in the equine genome. Oncogenes (c-raf-1, c-fes, c-myb, c-myc, and c-sis) were present and had similar hybridization patterns and signal intensities in dna from healthy horses and horses with hereditary multiple exostoses. Unique and distinct restriction fragment-length polymorphisms were detected with the c-raf-1 probe only in BamHI- and PstI-digested equine dna.
Trypsin treatment of bovine ova after in vitro exposure to vesicular stomatitis virus
Authors: Stringfellow D. A. , Lauerman L. H. , Thomson M. S.
Published: February 2025

Preimplantation bovine ova were exposed in vitro to vesicular stomatitis virus, Indiana serotype, to document adherence of the virus to the zona pellucida. To determine the efficacy of this treatment, some of the ova were treated with trypsin after exposure to the virus. Vesicular stomatitis virus was isolated from 5 of 10 groups of zona pellucida-intact ova after 12 sequential washes without trypsin treatment. Vesicular stomatitis virus was also isolated from 4 of 11 groups of zona pellucida-intact ova after trypsin treatment.
Distribution of persistent Salmonella typhimurium infection in internal organs of swine
Authors: Wood Richard L. , Pospischil Andreas , Rose Rebecca
Published: February 2025

Experiments were conducted to establish a persistent Salmonella typhimurium infection in convalescent swine, and to determine rate of shedding and distribution of the organism in internal organs. Naturally farrowed Salmonella-free pigs (n = 37) were orally exposed to S typhimurium when 7 to 8 weeks old. Fecal samples, tonsillar scrapings, and rectal swab specimens were examined bacteriologically for S typhimurium at weekly intervals after exposure until necropsy (maximum of 28 weeks after exposure). Necropsies of 1 to 4 randomly selected pigs were conducted at 2, 4, and 7 days and at 2, 4, 6, 8, 12, 16, 20, 24, and 28 weeks after exposure. The following internal organs were examined bacteriologically for S typhimurium: liver, spleen, kidney, gallbladder, heart, lung, and stomach; segments of the intestinal tract with corresponding lymph nodes; lymph nodes from lymphocenters of the head and neck, thoracic and abdominal cavities, pelvic wall, and thoracic and pelvic limbs. Fecal samples were 83 to 100% culture-positive up to postexposure (pe) week 22, then varied from 14 to 67% positive until pe week 28. At least 60% of tonsillar swab specimens and 50% of rectal swab specimens were culture-positive up to pe week 20, after which they varied from 0 to 70% positive until pe week 28. At necropsy, S typhimurium was recovered most frequently from tonsils (93.5% positive), followed by segments of the intestinal tract from caudal portion of jejunum to rectum (71% recovery from cecum), and mandibular (54.8%) and ileocolic (45.2%) lymph nodes. The organism generally did not persist beyond pe week 2 in other lymph nodes of the head and neck, lymph nodes of the abdominal wall, thoracic cavity, or limbs, or in heart, liver, or spleen. The gallbladder, kidney, and lungs of all pigs were culture-negative.
Differences in virulence between two strains of Streptococcus suis type II after experimentally induced infection of newborn germ-free pigs
Authors: Vecht U. , Arends J. P. , van der Molen E. J. , van Leengoed L. A. M. G.
Published: February 2025

Fifteen newborn germ-free pigs were inoculated with 2 strains, D-282 and T-15, of Streptococcus suis type II. Some pigs also were preinoculated with Bordetella bronchiseptica, which successfully predisposed them to S suis infection. The 2 streptococcal strains were differentiated by muramidase treatment, which released certain high molecular-weight proteins, termed muramidase-released proteins (mrp), from the cell wall of strain D-282, but not from the cell wall of strain T-15. Only strain D-282 (mrp-positive) induced clinical signs of disease and markedly increased neutrophil numbers in pigs. Streptococci were more frequently isolated from fecal swab specimens obtained from pigs inoculated with strain D-282 (mrp-positive) than from specimens obtained from pigs inoculated with strain T-15 (mrp-negative). Both strains were isolated from nasal swab specimens obtained from all infected pigs. Postmortem examination revealed fibrinopurulent meningitis, polyserositis, and polyarthritis in pigs inoculated with strain D-282; this strain was isolated from the cns, serosae, visceral organs, heart, and joints. Whereas strains D-282 caused several pathologic changes, strain T-15, isolated from the lungs, caused only pneumonia. Both strains were isolated from the tonsils of all pigs. Virulence differed distinctly between the mrp-positive and the mrp-negative strains.
Effect of prostaglandin F2α on adrenal-produced steroid hormones in cows
Authors: Watson Elaine D. , Hinrichs K.
Published: February 2025

Ovariectomized, nonlactating cows were treated with im injections of either physiologic saline solution or prostaglandin f2α. Plasma concentrations of cortisol increased significantly by 30 to 60 minutes after injection of prostaglandin f2α, but there were no significant increases in plasma concentrations of estradiol, progesterone, or testosterone. After saline solution treatment, there were no increases in any of the hormones measured.
Application of a Hall-effect transducer for measurement of tendon strains in horses
Authors: Stephens Paul R. , Nunamaker David M. , Butterweck Diane M.
Published: February 2025

Custom-designed Hall-effect strain sensors (hes) were implanted surgically onto the superficial digital flexor tendons of the forelimbs of 4 adult Thoroughbreds. Strains were recorded at various gaits, using a portable amplifer and fm cassette recorder. Strain calculations used the original length (l) as the hes position with the forelimb in the relaxed neutral position during anesthesia. A characteristic deflection in the strain cycle recording was confirmed to correspond to initial hoof contact with the ground (heel strike) by simultaneous recording of weight bearing via a footswitch. Heel strike was used as the reference point to determine the magnitude of strain change during weight bearing and nonweight bearing under various conditions. The weight-bearing strains (heel strike to maximal strain) recorded in 2 horses (with a rider) were 3.1% and 7.6% at the walk, 6.5% and 10.1% at the trot, and 11.5% and 16.6% at the gallop. Strain rate during tendon loading at the gallop was approximately 200%/s. The magnitude of strain change during nonweight bearing (minimal strain to heel strike) was smaller than during weight bearing, but also increased with faster gaits. In 3 horses led at the walk and trot, modest increases in hoof angle (baseline, 52°) resulted in small increases in the magnitude of strain change during weight bearing at the trot, but the magnitude of strain change at the walk was not affected. Results of the study indicated that the hes can be successfully adapted to provide continuous strain measurement without subjective signs of discomfort or lameness in horses during or after instrumentation.
Effects of xylazine and/or butorphanol or neostigmine on myoelectric activity of the cecum and right ventral colon in female ponies
Authors: Rutkowski Judith A. , Ross Michael W. , Cullen Kenneth
Published: February 2025

Effects of xylazine HCl (0.5 mg/kg of body weight, iv) and/or butorphanol tartrate (0.04 mg/kg, iv) or neostigmine methylsulfate (0.022 mg/kg, iv) on myoelectric activity of the cecum and right ventral colon were studied in 4 conscious female ponies. Eight bipolar Ag/AgCl electrodes were sequentially placed on the seromuscular layer of the cecum (6 electrodes) and right ventral colon (2 electrodes). Recordings began 30 minutes before and continued for 90 minutes after drug administration. Each drug or drug combination was studied on 2 occasions in each pony. Two major patterns of coordinated spike bursts were identified. A series of coordinated spike bursts began at the cecal base and was conducted to the cecal apex (pattern I). A series of coordinated spike bursts began at the cecal apex, traversed the cecum, cecocolic orifice, and right ventral colon and was termed a progressive pattern (pattern II).

Xylazine administration caused a significant decrease in patterns I and II for 20 minutes (P < 0.05). Butorphanol tartrate administration caused a significant decrease in the progressive pattern for 10 minutes (P < 0.05) without affecting the orally directed pattern. Administration of the combination of xylazine/butorphanol significantly decreased the frequency of pattern I for 40 minutes (P < 0.05) and pattern II for 30 minutes (P < 0.05). Neostigmine administration caused a significant increase in the frequency of pattern II for 30 minutes (P < 0.05) without affecting pattern I (P > 0.05). Changes in conduction velocity of pattern I or II or the duration of spiking activity were not significantly different because of any treatment.