bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Polymerase Chain Reaction and Virus Isolation for Detection of Epizootic Hemorrhagic Disease Virus in Clinical Samples from Naturally Infected Deer
Authors: Aradaib Imadeldin E. , Akita Geoffery Y. , Pearson James E. , Osburn Bennie I.
Published: May 2011

We compared our recently reported reverse transcriptase polymerase chain reaction (PCR)-based assay for detection of epizootic hemorrhagic disease virus (EHDV) in clinical samples with different virus isolation (VI) procedures. Thirty-six blood samples and 1 spleen sample from deer were assessed by the EHDV PCR assay and VI in baby hamster kidney (BHK)-21 cells and embryonated chicken eggs (ECE). The EHDV PCR assay detected EHDV RNA from 6 blood samples obtained from deer during 1988–1989 outbreaks of epizootic hemorrhagic disease and from the spleen and blood samples of a deer with clinical hemorrhagic disease in 1992. The 6 blood samples from the 1988–1989 outbreaks and the spleen sample from the 1992 case were VI positive on BHK-21 cell culture. The blood from the same deer with the PCR- and VI-positive spleen was VI negative in BHK-21 cells and ECE. All EHDV isolates were identified as EHDV serotype 2 by a plaque inhibition test. The results of this study indicate that the sensitivity of the previously described EHDV PCR assay is comparable to or greater than that of the VI method in BHK-21 cell culture or ECE. The EHDV PCR assays could provide a superior diagnostic alternative to the current cumbersome and time-consuming VI procedures.
Evaluation of Laboratory Tests for Confirming the Diagnosis of Encephalitic Listeriosis in Ruminants
Authors: Johnson Gayle C. , Fales William H. , Maddox Carol W. , Ramos-Vara Jose Antonio
Published: May 2011

Retrospective analysis of 93 bovine, ovine, and caprine cases diagnosed as listerial encephalitis revealed positive bacterial isolations in only 63% of 59 cases in which bacterial culture was attempted. Only 42% of 41 attempted bovine brain cultures were successful, compared with 67% from 6 sheep brains and 92% from 12 goat brains. Gram stains and Listeria-specific immunohistochemistry were evaluated as tools for verifying the presence of bacteria or listerial antigens in 38 animals. Sixteen of 17 animals in this group with positive bacterial isolations were immunochemically positive for listerial antigens (including 5/6 cattle), but Gram stains detected only 9/17 positive animals (including 1/6 cattle). Antigen was also detected in 15 of 21 animals (including 5/9 cattle) with unsuccessful or unattempted bacterial isolations. Of all 38 animals, the histologic diagnosis could be verified in 82% by immunohistochemistry, compared to 47% verified by Gram stains. Immunohistochemical testing was especially beneficial in locating antigen in lesions with few bacteria or bacterial antigens and is a rapid method of confirming the diagnosis of encephalitic listeriosis where inappropriate material is submitted for bacterial isolation or in culture-negative cases.
Iatrogenic Compressive Lumbar Myelopathy and Radiculopathy in Adult Cattle following Injection of an Adjuvanted Bacterin into Loin Muscle: Histopathology and Ultrastructure
Authors: O'Toole Donal , McAllister Milton M. , Griggs Kenneth
Published: May 2011

Compressive lumbar myelopathy is a recognized iatrogenic complication of injecting water-in-oil vaccines into paravertebral sites of laboratory animals and chickens. Herein, we report the histologic and ultrastructural features of a similar complication in a herd of cattle. Iatrogenic posterior paresis developed over 34 days in 56 of 610 cows (9.2%) following injection of a commercial bacterin 11–34 days earlier into M. longissimus lumborum. The bacterin was composed of inactivated Escherichia coli and Campylobacter fetus ssp. venerealis in a proprietary adjuvant. Tissues were collected for histopathology from 9 affected cattle that died or were euthanized after clinical signs lasting 6–38 days. A range of tissues, including the injection site lesion and lumbar spinal nerve roots, was obtained for ultrastructural examination from a cow with paresis of 31 days duration. There was locally extensive pyogranulomatous myositis with fibrosis and necrosis in right M. longissimus lumborum. Extension of the lesion into the vertebral canal via spinal nerve foramina resulted in focal pyogranulomatous inflammation in epidural fat and in adjacent dura mater. There was axonal degeneration in dorsal, lateral, and ventral columns and chromatolysis of spinal motor neurons in lumbar spinal cord, secondary to compression. A distinctive histologic and ultrastructural feature of pyogranulomata was the presence of osmiophilic material at the center of inflammatory foci, surrounded by macrophages and giant cells that contained intracytoplasmic lipid droplets. Ultrastructural examination of entrapped spinal nerves revealed axonal degeneration and loss of myelinated and unmyelinated fibers, segmental demyelination with remyelination, axonal spheroid formation, and early axonal regeneration. Two cattle also had bilaterally symmetrical acute myodegeneration with sarcoplasmic mineralization and secondary histiocytic myositis in axial and appendicular muscles, probably due to prolonged recumbency and vascular compromise (downer cow myopathy). Paresis probably developed as the result of the combination of a paravertebral injection site and the florid granulomatous response elicited by a constituent in the vaccine, most likely the water-in-oil adjuvant.
Characterization of the Humoral Immune Response to Porcine Reproductive and Respiratory Syndrome (PRRS) Virus Infection
Authors: Yoon Kyoung-Jin , Zimmerman Jeffrey J. , Swenson Sabrina L. , McGinley Michael J. , Eernisse Ken A. , Brevik Andy , Rhinehart Lydia L. , Frey Merwin L. , Hill Howard T. , Platt Kenneth B.
Published: May 2011

The development of the humoral immune response against porcine reproductive and respiratory syndrome (PRRS) virus was monitored by an indirect fluorescent antibody (IFA) test, immunoperoxidase monolayer assay (IPMA), enzyme-linked immunosorbent assay (ELISA), and serum virus neutralization (SVN) test over a 105-day period in 8 pigs experimentally infected with ATCC strain VR-2402. Specific antibodies against PRRS virus were first detected by the IFA test, IPMA, ELISA, and the SVN test 9-11, 5-9, 9-13, and 9-28 days postinoculation (PI), respectively, and reached their maximum values by 4-5, 5-6, 4-6, and 10-11 weeks PI, respectively, thereafter. After reaching maximum value, all assays showed a decline in antibody levels. Assuming a constant rate of antibody decay, it was estimated by regression analysis that the ELISA, IFA, IPMA, and SVN antibody titers would approach the lower limits of detection by approximately days 137, 158, 324, and 356 PI, respectively. In this study, the immunoperoxidase monolayer assay appeared to offer slightly better performance relative to the IFA test, ELISA, and SVN test in terms of earlier detection and slower rate of decline in antibody titers. Western immunoblot analysis revealed that antibody specific for the 15-kD viral protein was present in all pigs by 7 days PI and persisted throughout the 105-day observation period. Initial detection of antibodies to the 19-, 23-, and 26-kD proteins varied among pigs, ranging from 9 to 35 days PI. Thereafter, the antibody responses to these 3 viral proteins of PRRS virus continued to be detected throughout the 105-day study period. These results clearly indicate that the 15-kD protein is the most immunogenic of the 4 viral proteins identified and may provide the antigenic basis for the development of improved diagnostic tests for the detection of PRRS virus antibodies.
Porcine Reproductive and Respiratory Syndrome: NEB-1 PRRSV Infection did not Potentiate Bacterial Pathogens
Authors: Cooper V. L. , Doster A. R. , Hesse R. A. , Harris N. B.
Published: May 2011

A 2-phase study was conducted to evaluate the ability of the NEB-1 strain of porcine reproductive and respiratory syndrome virus (PRRSV) to potentiate common bacterial pathogens of swine. In phase I, 25 of 50 4-5-week-old specific-pathogen-free (SPF) pigs were exposed to NEB-1 PRRSV (day 0). Seven days after virus inoculation, 8 groups received 1 of 4 bacterial pathogens: Haemophihs parasuis, Streptococcus suis, Salmonella cholerasuis, and Pasteurella multocida. The ability of NEB-1 PRRSV to produce clinical disease, viremia, neutralizing antibody, gross and microscopic lesions and to potentiate bacterial pathogens was assessed. Response to NEB-1 PRRSV was similar among inoculated pigs; prolonged hyperthermia, lethargy, mild to moderate dyspnea, and cutaneous erythema were consistent clinical signs. No clinical differences were observed in groups after bacterial challenge. Virus was isolated from serum at weekly intervals through the end of the study, and all PRRSV-inoculated pigs had seroconverted by study termination. Two of 5 pigs died in non-PRRSV-inoculated groups challenged with H. parasuis and Streptococcus suis. Mortality in PRRSV-infected pigs was limited to 1 of 5 pigs from the Salmonella cholerasuis-challenged group. Gross lesions were seen in pigs dying after inoculation in H. parasuis- and Streptococcus suis-inoculated groups, in Salmonella cholerasuis-and P. multocida-challenged pigs, and in 1 non-PRRSV-inoculated control pig. Microscopic lesions consisted of mild to moderate proliferative interstitial pneumonia, nonsuppurative myocarditis, lymphoid hyperplasia, and nonsuppurative encephalitis in PRRSV-inoculated pigs. Findings in phase I indicated that NEB-1 PRRSV does not potentiate bacterial disease while inducing consistent clinical signs, viremia, seroconversion, and microscopic lesions. Based upon initial findings in phase I, in phase II, 18 of 36 4-6-week-old SPF pigs were exposed to NEB-1 PRRSV (day 0). Two days after virus inoculation, 2 of 4 groups were exposed to either Streptococcus suis or P. multocida. Clinical findings were similar to those of phase I. One of 6 pigs died in each of the Streptococcus suis-challenged groups. Animals succumbed 3 and 5 days after bacterial challenge in the non-PRRSV-inoculated and PRRSV-inoculated groups, respectively. Mild gross and microscopic pulmonary lesions were observed. Phase II findings support the conclusions of phase I that NEB-1 PRRSV does not potentiate certain bacterial infections of swine.
Application of Antibody Titers against Bovine Viral Diarrhea Virus (BVDV) as a Measure to Detect Herds with Cattle Persistently Infected with BVDV
Authors: Houe H. , Baker J. C. , Maes R. K. , Ruegg P. L. , Lloyd J. W.
Published: May 2011

Based on the distribution of antibody titers against bovine viral diarrhea virus (BVDV) in 10 Michigan dairy herds, it was calculated that screening of 5 young stock for BVDV antibody titer could be used to distinguish herds with persistently infected (PI) animals from herds without such animals. The herds were selected to represent 3 different herd categories: A, herds without use of vaccination and without PI animals (5 herds); B, herds with use of killed vaccine but no PI animals (2 herds); C, herds with use of killed vaccine and presence of PI animals (3 herds). The animals were described as having high antibody titers (≥ 128) or low antibody titers (≤ 64). For animals from 9 to 18 months of age, the probability of obtaining at least 3 animals with high titers among a screening sample of 5 animals was calculated as < 0.001 for all herds in category A, < 0.01 for the 2 herds in category B, and > 0.99 for all herds in category C. Thus, among herds in this study, by categorizing 9-1 &month-old animals as having high titers (> 128) or low titers (< 64), herds with PI cattle could be distinguished from other herds by testing only 5 animals.
Apparent Outbreaks of Clostridium Difficile-Associated Diarrhea in Horses in a Veterinary Medical Teaching Hospital
Authors: Madewell Bruce R. , Tang Yajarayma J. , Jang Spencer , Madigan John E. , Hirsh Dwight C. , Gumerlock Paul H. , Silva Joseph
Published: May 2011

Intestinal colonization with toxigenic strains of Clostridium difficile was documented in 9 of 10 horses with acute onset diarrhea in a veterinary medical teaching hospital, whereas a similar isolate was detected in only 1 of 23 other horses without diarrhea in the hospital. One horse with diarrhea was infected simultaneously with both C. difficile and Salmonella krefeld. Clostridium difficile was detected by fecal culture on selective medium, confirmed with a latex particle agglutination test, and identified as toxigenic by polymerase chain reaction amplification of toxin A and toxin B gene sequences. Using an arbitrarily-primed polymerase chain reaction, 6 distinct C. difficile isolates were detected in the feces of the 9 affected horses at the time of the outbreak of diarrhea.
An Enzyme-Linked Immunosorbent Assay (ELISA) for Serological Diagnosis of Neospora Sp. Infection in Cattle
Authors: Paré Julie , Hietala Sharon K. , Thurmond Mark C.
Published: May 2011

A kinetic enzyme-linked immunosorbent assay (ELISA) was developed and optimized for detection of antibodies to Neospora sp. in cattle. Sonicated tachyzoites of Neospora sp. isolated from an aborted bovine fetus were used as antigen. Variability in immunoblot patterns among positive sera, and the fact that all life stages of the parasites are unknown, justified use of a multiple-antigen ELISA to allow for maximum sensitivity. Immunoblot analysis revealed negligible cross-reactions between Toxoplasma gondii antigen and Neospora sp. antisera and between Neospora sp. antigen and antisera from various apicomplexan parasites. The maximum positive-to-negative Vmax (average maximum slope of the optical density over time) ratio was obtained using 200 ng/well of sonicated tachyzoite antigen and a 1:200 serum dilution. Using logistic regression to determine the optimal cutoff point between known infected and noninfected cattle, a sample-to-positive control Vmax ratio of 0.45 was found to maximize the percent correct classification, with an estimated sensitivity of 88.6% and specificity of 96.5%. Use of Neospora caninum antigen following the same protocol demonstrated no difference in ELISA interpretation. Comparison with an existing indirect immunofluorescent antibody (IFA) test showed the ELISA to be the more sensitive and specific test for serodiagnosis of Neospora infection in cattle.
Influence of the Antibiotics Lincomycin and Tylosin on Aflatoxicosis when Added to Aflatoxin-Contaminated Diets of Growing Swine
Authors: Harvey Roger B. , Edrington Thomas S. , Kubena Leon F. , Corrier Donald E. , Elissalde Marcel H.
Published: May 2011

Effects of dietary aflatoxin (AF) and the antibiotics lincomycin (L) and tylosin (T) were evaluated in growing crossbred pigs. Six barrows (3 replicates of 2 each, mean body weight 14.0 kg) per group were assigned to 1 of 6 treatment groups (for a total of 36): 0 mg L, 0 mg T, and 0 mg AF/kg of feed (control); 220 mg L/kg of feed (200 g/ton); 110 mg T/kg of feed (100 g/ton); 2.5 mg AF/kg of feed; 2.5 mg AF plus 220 mg L/kg of feed; 2.5 mg AF plus 110 mg T/kg of feed. Barrows were administered their respective diets for 28 days. Body weight, body weight gain, and feed consumption were reduced by the AF alone, the AF plus L, and the AF plus T treatments, compared with control, L, and T treatments. Altered serum biochemical or hematologic mea surements induced by AF treatments included increased serum activities of alkaline phosphatase and γ-gluta myltransferase, increased hematocrit, hemoglobin, RBC count, WBC count, and mean cell hemoglobin, decreased serum concentrations of albumin, cholesterol, inorganic phosphorus, unsaturated iron binding capacity, total protein, and urea nitrogen, and decreased lymphoblastogenic response. Liver weight was increased, and microscopic lesions were consistent with those observed in cases of aflatoxicosis. With some other minor exceptions for hematologic and immunologic variables, these data indicate that the feed antibiotics lincomycin and tylosin, when added to aflatoxin-contaminated diets, do not have beneficial or detrimental effects on aflatoxicosis in growing swine.
Hemostatic Indices in Healthy Foals from Birth to One Month of Age
Authors: Barton Michelle Henry , Morris Debra Deem , Crowe Natalie , Collatos Chrysann , Prasse Keith W.
Published: May 2011

Hemostatic indices were determined in 45 healthy light breed foals, from birth to 1 month of age, and in 20 healthy adult (>2 years of age) light breed horses. Blood samples were obtained from each foal at 4 ages: 1) < 24 hours, 2) 4-7 days, 3) 10-14 days, and 4) 25-30 days. The following hemostatic indices were determined: platelet count; prothrombin and activated partial thromboplastin times; activity concentrations of protein C, antithrombin III, plasminogen, alpha-2 antiplasmin, tissue plasminogen activator, and plasminogen activator inhibitor- 1; plasma protein C antigen and fibrinogen concentrations; and serum fibrin degradation products concentration. Prothrombin and activated partial thromboplastin times were significantly longer at birth than in older foals. The plasma concentrations of the following were significantly lower at birth than in older foals: antithrombin III, plasminogen and tissue plasminogen activator activities, protein C antigen, and fibrinogen. Concentrations of the following were significantly higher at birth than in older foals: protein C and plasminogen activator inhibitor-1 activities and fibrin degradation products. These results indicate that hemostatic indices of neonatal foals differ significantly from those of older foals and adults. With the exceptions of antithrombin III and tissue plasminogen activator activities, all hemostatic indices measured in foals at 1 month of age were equivalent to adult values.
Comparison of Detection Methods for Bovine Viral Diarrhea Virus in Bovine Abortions and Neonatal Death
Authors: Ellis John A. , Martin Karen , Robert Norman G. , Haines Deborah M.
Published: May 2011

The objective of this study was to examine a monoclonal antibody-based immunohistochemical staining method for its efficacy in diagnosis of bovine virus diarrhea virus (BVDV)-induced abortion and neonatal calf death. This method was compared to viral isolation and immunofluorescence staining of frozen tissue sections. Tissues from 105 cases, 53 fetuses and 52 neonates, were tested by the 3 methods. There were significant numbers of both false negatives and false positives with the immunofluorescence method and significant numbers of false negatives with the viral isolation method. Of the methods tested, immunohistochemical staining using monoclonal antibody 15C5 performed best, differentiating 97% of positive and negative cases. These results indicated that immunohistochemical staining can be applied to improve the accuracy of BVDV diagnosis in cases of abortion and perinatal death.
Gastrointestinal and Skin Lesions in Piglets Naturally Infected with Pseudorabies Virus
Authors: Ezura Kazuhiko , Usami Yoshihide , Tajima Kazuhiko , Komaniwa Hideo , Nagai Satomi , Narita Minoru , Kawashima Kenji
Published: May 2011

Pseudorabies virus (PRV) infection was diagnosed in 4 piglets from a litter by immunohistopathologic examination and virus isolation. Three piglets had moderate to severe neuronal degeneration, and PRV antigen was detected in Auerbach's myenteric plexus and Meissner's submucosal plexus of the gastrointestinal tract. One piglet had 2 types of skin lesions. One lesion appeared on the hip and ear and was characterized by ballooning degeneration, necrosis of epithelial cells, and intranuclear inclusion bodies. The other was found on the ear and hematoma-like lesion and was composed of fibrinoid exudation and degenerative connective tissue. PRV antigen was clearly demonstrated in both skin lesions. These results suggested that degeneration of myenteric plexuses might be another characteristic of lesions in PRV-infected pigs and that the virus spreads by interaction between the skin and myenteric plexuses to the central nervous system.
Evaluation of an Indirect ELISA for the Diagnosis of Bovine Brucellosis
Authors: Uzal Francisco A. , Carrasco Alejandra E. , Echaide Susana , Nielsen Klaus , Robles Carlos A.
Published: May 2011

Control and eradication of bovine brucellosis is usually based on the serological detection of antibodies. In Argentina, the rose bengal test (RB) and the buffered plate antigen test (BPA) are the 2 screening tests officially recognized, whereas the 2-mercaptoethanol test (2ME) and the tube agglutination test (SAT) are the confirmatory assays currently in use. In order to improve the serological diagnosis of bovine brucellosis in Patagonia, Argentina, an indirect enzyme-linked immunosorbent assay (I-ELISA) kit distributed by the International Atomic Energy Agency was evaluated. Sera from negative nonvaccinated, negative but vaccinated, and positive animals were tested by all the above techniques. The specificity of the I-ELISA (98.9% and 97.2%) was similar to that of the BPA, RB, 2ME and complement fixation (CF) tests when used to test sera from negative nonvaccinated and negative but vaccinated animals, respectively. The sensitivity of the I-ELISA (98.7%) was higher than the BPA test (96.1%) and the CF test (95.2%). The I-ELISA kit evaluated in this study was thought to be a valuable tool for the diagnosis of bovine brucellosis in the Patagonia region where little epidemiological information is available about this disease, and where large numbers of sera should be tested to obtain such information.
Experimental Reproduction of Haemophilus Parasuis Infection in Swine: Clinical, Bacteriologic, and Morphologic Findings
Authors: Vahle John L. , Haynes Joseph S. , Andrews John J.
Published: May 2011

Haemophilus parasuis is a common cause of polyserositis and polyarthritis in swine. Little is known about the mucosal and systemic sites of replication and lesions which follow an aerosol exposure to H. parasuis. In this experiment 5–week-old cesarean-derived, colostrum-deprived (CDCD) pigs were inoculated intranasally with an inoculum containing 2 × 109 colony-forming units of H. parasuis. Two principals and one control pig were necropsied at 12, 36, 84, and 108 hours postinoculation (PI) and samples obtained for bacteriologic culture and microscopic examination. Inoculated pigs developed clinical signs of inappetence, reluctance to move, lameness, and a serous nasal discharge. Macroscopic findings included a fibrinous polyserositis and polyarthritis 36 hours PI which became progressively more severe at 84 and 108 hours PI. No lung lesions were grossly visible. Microscopic lesions included a mild purulent rhinitis at each post inoculation interval and fibrinous to fibrinopurulent synovitis and serositis at 36, 84, and 108 hours PI. A focal suppurative bronchopneumonia was observed in one pig examined at 36 hours PI. The nasal cavity and trachea were the only mucosal sites from which H. parasuis was reisolated. Haemophilus parasuis was isolated from the blood and systemic sites at 36, 84, and 108 hours PI. Findings presented indicate that intranasal inoculation of 5-week-old CDCD pigs with H. parasuis results in clinical signs and lesions of polyserositis and polyarthritis typical of field cases and is a useful model for the study of H. parasuis pathogenesis. The results also suggest that H. parasuis initially colonizes the nasal mucosa.
Enzyme-Linked Immunosorbent Assay for Salmonella Serology using Lipopolysaccharide Antigen
Authors: Smith Bradford P. , Dilling George W. , House John K. , Konrad Hans , Moore Nadia
Published: May 2011

Enzyme-linked immunosorbent assay (ELISA) using Salmonella lipopolysaccharide (LPS) to measure specific IgG titers in cattle has proven useful. Serology can be used to assess vaccine responses and infection rates, to detect carriers, and to aid in epidemiologic studies. The objective of this study was to assess cross-reactions using sera from cattle vaccinated with different Salmonella serogroups. ELISA plates using lipopolysaccharide from serogroup B, C1, C3, D1 or E1 as the plate antigens were tested. LPS was extracted from Salmonella typhimurium (Serogroup B; somatic antigens 01, 4, 12), S. montevideo (C1; 06, 7), S. kentucky (C3; 08, 20), S. dublin (D1; 01, 9, 12) and S. anatum (E1; 03, 10) using the Westphal method.

Fifteen cows were found to be seronegative for all 5 of these serogroup antigens. Each cow was then vaccinated 3 times at 2-week intervals with a killed Salmonella bacterin. The 15 different serotypes used for vaccination were chosen to represent a wide array of Salmonella serogroups with a wide array of somatic “O” antigens expressed, including somatic antigens 1, 2, 3, 4, 6, 7, 8, 9, 10, 11, 12, 13, 14, 18, 19, 20, 22, 23, 25, and 27. With each antigen tested, the highest ELISA titers were seen with sera from cattle vaccinated with homologous O antigens, indicating that reactions were highly O antigen-specific. Some cross reactions between serogroups sharing one O factor antigen were found; these titers were lower than those found with homologous serogroups sharing 2 or more antigens. Only serum from the cow vaccinated with S. anatum (group E; antigens 03, 10) cross-reacted at a low titer with group C1 (O somatic antigens 6, 7) and D1 (O somatic antigens 1, 9, 12) plate antigens, with which no somatic antigens were shared. We conclude from these results that Salmonella serology using LPS antigens is highly O antigen-specific and predictable.
Examination of Gills from Salmonids with Bacterial Gill Disease using Monoclonal Antibody Probes for Flavobacterium Branchiophilum and Cytophaga Columnaris
Authors: Speare D. J. , Markham R. J. F. , Despres B. , Whitman K. , MacNair N.
Published: May 2011

Bacterial diseases of the gills of commercially reared salmonids in freshwater are common problems. They accounted for 18% of all diagnostic submissions to the Atlantic Veterinary College from commercial fish hatcheries. Definitive diagnosis is difficult because of the growth characteristics of the putative bacteria in culture. Research into the pathogenesis of these diseases has also been similarly limited. Monoclonal antibodies (MAbs) were developed to 2 globally significant gill bacterial pathogens, Flavobacterium branchiophilum, the causative agent of bacterial gill disease, and Cytophaga columnaris, the causative agent of columnar-is disease of salmonids. These MAbs were then used as the basis for an indirect fluorescent antibody test to assess archived cases of gill disease in our region. Flavobacterium branchiophilum was the dominant bacterium detected in the biofilm of diseased gills in our study region. Of the cases tentatively diagnosed based on histopathology as bacterial gill disease, 76.2% tested positively with the MAbs to F. branchiophilum. Also present within 18.7% of these cases were bacteria which reacted positively to the MAbs for C. columnaris. We conclude that the MAbs produced are valuable diagnostic and research probes for common bacterial diseases of the gills of salmon and trout in Atlantic Canada. This study also adds further proof that F. branchiophilum acting alone can be sufficient cause for bacterial gill disease.
Comparison of Two Commercially Available Single Radial Immunodiffusion Kits for Quantitation of Llama Immunoglobulin G
Authors: Hutchison Jennifer M. , Salman Mowafak D. , Garry Franklyn B. , Johnson LaRue W. , Collins James K. , Keefe Thomas J.
Published: May 2011

Immunoglobin G (IgG) quantitation was performed by a commercially available single radial immunodiffusion kit on 528 plasma samples obtained from llamas. Fifty samples encompassing the range of values obtained were selected for further evaluation. The IgG concentration of these samples was measured by a second commercially available single radial immunodiffusion kit and a sodium sulfite precipitation kit. γ-Globulins also were measured. IgG values predicted by the single radial immunodiffusion kits were not in agreement. Failure to appreciate this lack of agreement could result in misinterpretation of a llama's IgG level derived from one kit when clinical guidelines established using the other kit are followed.
Serohematologic Alterations in Broiler Chicks on Feed Amended with Fusarium Proliferatum Culture Material or Fumonisin B1 and Moniliformin
Authors: Javed Tariq , Dombrink-Kurtzman Mary A. , Richard John L. , Bennett Glenn A. , Côté L. Marie , Buck William B.
Published: May 2011

Two hundred twenty-eight male broiler chicks (Columbia x New Hampshire) were given feed amended with autoclaved culture material of Fusarium proliferatum containing fumonisin B1 (FB1) at 61, 193, and 546 ppm, fumonisin B2 (FB2) at 14, 38, and 98 ppm, and moniliformin at 66, 193, and 367 ppm in 3 separate feeding trials (amounts of toxin in each trial, respectively). Birds were started on amended rations at days 1, 7, and 21 and continued on their respective ration until they were 28 days old. Purified FB1 (125, 274 ppm) and moniliformin (27, 154 ppm) were given separately and in combination (137 and 77 ppm, respectively), starting on day 1 and continuing for 14 days. Of serum chemistry parameters, only glucose was significantly decreased. Significant increases were noted in serum cholesterol, sodium, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and γ-glutamyl transferase. Of the hematologic parameters, significant decreases were noted in red blood cell counts, hemoglobin, packed cell volume, and white blood cell counts. Immunologic changes included impaired anti-Newcastle disease antibody hemagglutination inhibition titers associated with relative decreases in total serum globulins and increases in albumin/globulin ratios. The changes were noted in all treatment groups when compared to controls.
Lead Poisoning and Toxicokinetics in a Heifer and Fetus Treated with CaNa2 EDTA and Thiamine
Authors: O'hara Todd M. , Bennett Lloyd , McCoy Pat C. , Jack S. W. , Fleming Sherrill
Published: May 2011

Lead (Pb) poisoning of a pregnant heifer was diagnosed based upon clinical signs (head pressing, blindness, muscle twitching) and a blood lead concentration of 1.73 ppm. Blood and urinary Pb half-lives with CaNa2 EDTA/thiamine therapy were determined to be 2.08 and 1.38 days, respectively. Many cations (Ca, Fe, Zn, Na, Cu), including Pb, were excreted at higher concentrations in urine during therapy. Blood (0.425 ppm) and liver (4.85 ppm) Pb concentrations in the fetus were 71.7% and 84.3% of the same tissue Pb concentrations of the dam, indicating a significant transfer of Pb in utero. Severe polioencephalomalacia was described in the adult, and hepatic lysosomes with metallic electron densities were present in the fetus.
Feline Leukemia Virus Detection by ELISA and PCR in Peripheral Blood from 68 Cats with High, Moderate, or Low Suspicion of having FeLV-Related Disease
Authors: Jackson Marion L. , Haines Deborah M. , Taylor Susan M. , Misra Vikram
Published: May 2011

Clinicopathologic criteria were used to group 68 cats according to high, moderate, or low suspicion of having feline leukemia virus (FeL V)-related disease. Peripheral blood samples were tested for FeL V antigen by enzyme-linked immunosorbent assay (ELISA) and for FeL V DNA by polymerase chain reaction (PCR). There was no significant difference between ELISA and PCR results in the 68 cats. In the high-suspicion group, 46% (11/24) of cytopenic cats were test positive (ELISA and PCR) and 87% (13/15) with hemopoietic neoplasms were test-positive. Also within the high suspicion group, test-positive cats were 2.5 times more likely to die within the 1 year follow-up period than were test-negative (ELISA and PCR) cats. Among cats in the moderate-suspicion group, 15% (2/13) were test-positive, and none (0/16) of the cats in the low suspicion group was test positive. The relative risk of a positive test (ELISA and PCR) in the high suspicion group was 3.7 times that for the moderate-suspicion group and 22.8 times that for the low suspicion group. There was no significant difference in the relative risk of a positive test result between the moderate and low suspicion groups. The results indicate that FeL V detection by PCR can be adapted for diagnostic purposes using peripheral blood samples, however, results do not differ significantly from FeL V ELISA results. Also, a proportion of cats with a high suspicion of having FeL V-related cytopenia and hemopoietic tumors are negative for both circulating FeL V antigen and DNA. These cats may not have FeL V-related disease, or FeL V may exist in a disease-producing but nonreplicating form ultimately detectable by PCR in tissues other than peripheral blood.
Evaluation of Antibiotics for the Elimination of the Tonsillar Carrier State of Streptococcus Suis in Pigs
Authors: Amass Sandra F. , Wu Ching Ching , Clark L. Kirk
Published: May 2011

Seventy clinically normal 13-day-old crossbred pigs from 10 litters from a Streptococcus suis-infected herd were randomly assigned by litter and weight to 7 groups of 10 pigs each to determine whether different antibiotic regimens would eliminate the tonsillar carrier state of S. suis. Six antimicrobial regimens were tested: penicillin intramuscularly (IM) once daily (s.i.d.) for 3 consecutive days; penicillin IM s.i.d. for 5 consecutive days; ampicillin IM s.i.d. for 5 consecutive days; ampicillin per os s.i.d. for 5 consecutive days; ampicillin intranasally s.i.d. for 5 consecutive days; and ceftiofur sodium IM s.i.d. for 5 consecutive days. The seventh group consisted of untreated control pigs. Tonsillar swab samples were collected before treatment, and tonsillar tissue samples were collected after treatment for cultural examination for S. suis. Streptococcus suis was identified in pigs from all groups prior to treatment and after treatment. Pigs did not have clinical signs of disease during the study. All antimicrobial treatments tested in this study failed to eliminate the tonsillar carrier state of S. suis. Early weaning and medication used in this study were not effective for the elimination of the tonsillar carrier state of S. suis in pigs. Optimization of management and environment of pigs coupled with strategic medication of clinically ill animals should be used for control and prevention of mortality caused by streptococcosis.
Pyrrole Detection and the Pathologic Progression of Cynoglossum Officinale (Houndstongue) Poisoning in Horses
Authors: Stegelmeier Bryan L. , Gardner Dale R. , James Lynn F. , Molyneux Russell J.
Published: May 2011

Houndstongue ( Cynoglossum officinale), a noxious weed that contains pyrrolizidine alkaloids (PAs), infests pastures and fields in the western United States and Europe. The purpose of this study was to develop techniques to better diagnose PA poisoning and describe the progression of gross and microscopic lesions caused by houndstongue intoxication. Six horses were gavaged daily with a suspension of houndstongue containing 5 or 15 mg/kg total PA for 14 days. Two horses were treated similarly with ground alfalfa as controls. Liver biopsy samples and serum biochemical and hematologic values were evaluated biweekly. Within 7 days after dosing, horses treated with 15 mg/kg PA developed severe liver disease characterized by altered bile acid metabolism, elevated serum enzymes, and extensive hepatocellular necrosis with minimal periportal fibrosis and biliary hyperplasia. The condition of these animals continued to deteriorate, and they were euthanized. For several weeks after dosing, horses treated with 5 mg/kg PA were depressed, had transient elevations of serum enzymes and bile acids, and developed minimal periportal hepatocellular necrosis with fibrosis. The biochemical changes resolved by 6–8 weeks; however, the histologic disease persisted with extensive megalocytosis by week 14. Throughout the study, the rate of hepatocellular proliferation remained constant. Biliary cells had an increase in mitotic rate that correlated with the histologic changes. Hepatic tissue-bound pyrroles (PA metabolites) were identified in necropsy samples of treated animals using gas chromatography/mass spectrometry and photometrically with Ehrlich's reagent. These findings suggest that pyrrole extraction and identification are useful in documenting PA exposure and that houndstongue is extremely toxic to horses.
Detection of Eastern Equine Encephalomyelitis Virus RNA in Formalin-Fixed, Paraffin-Embedded Tissues using DNA in Situ Hybridization
Authors: Gregory Christopher R. , Latimer Kenneth S. , Niagro Frank D. , Campagnoli Raymond P. , Steffens W. L. , Ritchie Branson W.
Published: May 2011

Eastern equine encephalomyelitis (EEE) virus was detected in infected formalin-fixed horse and emu tissues and in infected chicken embryo fibroblasts. Results of in situ hybridization using a digoxigenin-labeled 40-base DNA probe complementary to a conserved region of the EEE virus RNA compared favorably with results of both virus isolation and serum neutralization tests. This technique may be useful for diagnosis of EEE virus infection in various animal species, especially when fresh tissues are not available for analysis, and also will provide a means for studying the involvement of alphaviruses in pathogenesis studies.
Immunohistochemical Diagnosis of Eastern Equine Encephalomyelitis
Authors: Patterson Jon S. , Maes Roger K. , Mullaney Thomas P. , Benson Cherie L.
Published: May 2011

An immunohistochemical (IHC) assay was developed for the detection of eastern equine encephalomyelitis (EEE) virus antigen in formalin-fixed, paraffin-embedded tissues. All cases of EEE diagnosed at the Michigan State University Animal Health Diagnostic Laboratory from 1991 through 1994 were evaluated. The diagnosis was based on histopathologic examination of the brain and confirmatory virus isolation. Sections of cerebrum from 26 equids and 5 birds were assessed by IHC. Histologically normal brain tissues from 2 horses and 1 pheasant and brain tissues from 2 cases of equine neurologic disease with diagnoses other than EEE served as negative controls. The IHC assay was based on standard streptavidin-biotin technology, using a commercially available kit and a monospecific polyclonal primary antibody preparation derived from murine ascitic fluid. Nineteen of 20 equids and all 5 birds positive by histopathology and virus isolation were positive for EEE virus antigen by IHC. Three equids with histologic lesions compatible with a diagnosis of EEE but negative by virus isolation also were negative for virus antigen by IHC. In 3 other equids, histopathology and IHC were positive for EEE, but virus isolation was not attempted because of contamination of the brain specimen. The IHC assay of formalin-fixed, paraffin-embedded brain tissues for EEE virus antigen is a rapid, effective test for confirming a histopathologic diagnosis of EEE, and assay results correlate well with virus isolation results.
Immunohistochemistry of Transmissible Gastroenteritis Virus Antigens in Fixed Paraffin-Embedded Tissues
Authors: Shoup David I. , Swayne David E. , Jackwood Daral J. , Saif Linda J.
Published: May 2011

An immunohistochemistry technique was developed using fixed tissues to study the presence and location of transmissible gastroenteritis virus (TGEV) antigens in situ. Experimentally infected gnotobiotic and conventional pigs as well as pigs with natural TGEV infection were examined. The staining technique was based on detection of the major structural protein of TGEV, the nucleocapsid, by using a pool of 3 monoclonal antibodies. Formalin and periodate-lysine-paraformaldehyde (PLP)-fixed intestinal tissues from a gnotobiotic pig inoculated with virulent TGEV were used to determine optimal antibody concentrations and incubation times. The intestinal tissues remained in their respective fixatives for 6 months, and serial sections were removed at sequential times and embedded in paraffin blocks. PLP and 10% neutral buffered formalin were acceptable fixatives and preserved TGEV nucleocapsid antigenicity for up to 6 months. Formalin, in comparison with PLP as a fixative, was better for preserving original tissue morphology and provided better antigen detection. Conventional crossbred pigs were inoculated with virulent TGEV, and animals were euthanized on various postexposure days. Intestinal tissues were positive for TGEV nucleocapsid antigens on postexposure days 2, 4, and 8. The immunohistochemistry technique detected TGEV antigen in stored paraffin-embedded tissues from 14 naturally infected pigs previously confirmed as positive for TGEV using a direct immunofluorescence assay on intestinal mucosal smears, whereas 9 naturally infected pigs confirmed negative for TGEV antigen by the same immunofluorescence assay showed no staining consistent with the presence of TGEV antigen. Immunohistochemistry provides a method to detect TGEV and possibly other closely related coronaviruses such as porcine respiratory coronavirus in situ. A diagnostic test using the same fixed tissues processed for histopathology provides veterinary practitioners an alternative to delivering live pigs or refrigerated fresh intestinal samples containing infectious virus to a diagnostic laboratory. Investigators can utilize this technique to retrospectively screen fixed tissues for TGEV antigen.
Evaluation of a Semiautomated Latex Agglutination Test for the Detection of Pseudorabies Antibody in Swine Sera
Authors: Rodgers Sandra J. , Karges Shelia L. , Saliki Jeremiah T.
Published: May 2011

Rapid screening of large numbers of swine sera for antibody is an essential element in the current eradication program for pseudorabies in the United States. We evaluated a recently introduced commercial semiautomated latex agglutination test (LAT) kit for pseudorabies antibody. A total of 1,191 swine sera were tested using the new procedure and 3 established tests: the manual LAT, the serum neutralization test (SNT), and an enzyme-linked immunosorbent assay (ELISA). There was close agreement among results of semiautomated LAT, the manual LAT, and ELISA but less agreement between semiautomated LAT and SNT. Overall, the sensitivities of the 4 tests were as follows: semiautomated LAT = manual LAT > ELISA > SNT. For 74 samples of known pseudorabies antibody status, the overall specificities were as follows: semi-automated LAT = manual LAT = SNT > ELISA. Because of its relative insensitivity, the SNT should no longer be considered the official “gold” standard for pseudorabies testing in the on-going eradication program. However, because no single test was perfect for all samples, a scheme including 3 tests in the following sequence is recommended: 1) screening using semiautomated LAT or ELISA and 2) confirmation testing of positives by manual LAT and SNT, with any sample that tests positive by any 2 tests being regarded as true positive.
Streptobacillus Moniliformis Infection in Swiss White Mice
Authors: Glastonbury John Reginald Wilson , Morton Jennifer Gilmour , Matthews Lyn Margaret
Published: May 2011

An epizootic of disease attributed to infection with Streptobacillus moniliformis occurred in a colony of Swiss white mice. The mortality rate among the 180 breeding females in the 6 affected pens was 100%, and most of the sucking young died from starvation. Acute septicemia, subacute septicemia, and polyarthritis were the 3 forms of disease observed. Clinically, septicemic mice either were found dead or were depressed and hunched for 1-2 days prior to death. About a half of these mice had brown skin crusts overlying the mammae. Pathologic findings in cases of acute septicemia were few; in mice with subacute septicemia, there was acute, multifocal, suppurative, embolic interstitial nephritis, and the arthritic form was characterized by many subcutaneous and periarticular abscesses. Severe, acute, diffuse neutrophilic dermatitis was responsible for the brown skin crusts. The S. moniliformis isolate conformed morphologically and physiologically to classical descriptions of the organism. The infection may have gained entry to the colony via wild rats.
Dairy Cattle Abortion in California: Evaluation of Diagnostic Laboratory Data
Authors: Jamaluddin Aziz A. , Case James T. , Hird David W. , Blanchard Patricia C. , Peauroi John R. , Anderson Mark L.
Published: May 2011

A descriptive study was undertaken on 595 dairy cattle abortion submissions to the California Veterinary Diagnostic Laboratory System from July 1, 1987, to December 31, 1989, to determine the etiologic nature and distribution (seasonal and geographical) of dairy cattle abortion in California as reflected by laboratory submissions. Univariate analysis was performed to characterize abortion-related submissions by farm and laboratory variables, and logistic regression analysis was performed to determine factors that may influence success of abortion diagnosis in the laboratory. The proportions of dairies that submitted abortion-related specimens from northern, central, and southern milksheds during the 2.5-year period were 20.3%, 15.7%, and 13.1%, respectively, and 60% of submissions were from medium-sized (200–999 cows) dairies. Submissions consisted of fetus (58%), placenta (2%), fetus and placenta (12%), and fetus, placenta, and maternal blood (0.84%); fetal tissues and uterine fluid constituted the rest. An apparent pattern in abortion submissions was indicated by a peak in submissions during the winter and summer of 1988 and 1989. Infectious agents were associated with 37.1% of submissions; noninfectious causes, 5.5%, and undetermined etiology, 57.3%. Bacterial abortion accounted for 18% of etiologic diagnoses; protozoal, 14.6%; viral, 3.2%; and fungal, 1.3%. Submissions comprising fetus, placenta, maternal blood, or their combinations were associated with a higher likelihood of definitive diagnosis for abortion than tissues, as were fresher specimens and submissions associated with the second trimester of fetal gestation.
Bovine Hereditary Zinc Deficiency: Lethal Trait a 46
Authors: Machen Margo , Montgomery Tim , Holland Robert , Braselton Emmett , Dunstan Robert , Brewer George , Yuzbasiyan-Gurkan Vilma
Published: May 2011

Bovine hereditary zinc deficiency, also referred to as Adema disease, is an autosomal recessive disorder which results in inadequate amounts of zinc being absorbed from the gastrointestinal tract and leads to a number of clinical abnormalities. Using semen from a homozygous affected bull and obligate heterozygote cows in embryo transfer studies, 7 offspring were obtained. These included 5 affected calves and 1 heterozygous carrier; the seventh calf died within 48 hours of birth undiagnosed. One unaffected, unrelated bull calf was raised as a control. All the calves were raised and maintained under similar management conditions designed to minimize secondary complications that would obscure the clinical and biochemical observations of a zinc deficient state. The first clinical manifestation of zinc deficiency was diarrhea, followed by skin lesions, poliosis, and a decreased ability to sustain a suckle reflex. Trace mineral analysis of plasma blood samples revealed that plasma zinc concentrations of all the calves were normal at birth; however, they gradually declined in affected calves over the course of 3–8 weeks postpartum to below 0.5 ppm. Biochemical analysis of serum samples showed alkaline phosphatase activity consistently paralleled changes in the plasma zinc concentrations. The oral administration of zinc acetate caused a reversal of all clinical, biochemical, and histologic abnormalities in affected calves. The study of these affected calves allows further insight into the biological role of zinc as well as provides an animal model for the continued investigation of the human homologue acrodermatitis enteropathica.