Showing papers in "Journal of Veterinary Diagnostic Investigation in 1990"
TL;DR: Pulmonary edema and hydrothorax were observed in mature swine that died approximately 5 days after consuming corn screenings, and a fungus was isolated from the corn screenings that is identical to Fusarium moniliforme MRC-826 in colony morphology and under microscopic examination.
Abstract: Pulmonary edema and hydrothorax were observed in mature swine that died approximately 5 days after consuming corn screenings. These postmortem observations were reproduced in younger swine (16-24 kg) that died within 1 week when fed the corn screenings under experimental conditions. Additionally, pulmonary edema and hydrothorax occurred in a pig (7.1 kg) that died after receiving 4 daily intravenous injections of fumonisin B1. A fungus was isolated from the corn screenings that is identical to Fusarium moniliforme MRC-826 in colony morphology and under microscopic examination.
848 citations
TL;DR: During the fall of 1989, an episode of equine leukoencephalomalacia involved 18 of 66 purebred Arabian horses at a breeding/training stable in Arizona and was fatal in 14.
Abstract: During the fall of 1989, an episode of equine leukoencephalomalacia involved 18 of 66 purebred Arabian horses at a breeding/training stable in Arizona. Of the 18 horses affected, the condition was fatal in 14. These horses, as well as 48 unaffected horses, had been fed a diet containing a substantial amount of white corn screenings. Gross pathologic findings included liquefactive necrosis in parts of the cerebral white matter and hemorrhagic foci of various sizes in the brain stem. Histopathologic findings included rarefied white matter with pyknotic nuclei and eosinophilic cytoplasm. Thin-layer chromatography, high-performance liquid chro- matography, and gas chromatography/mass spectroscopy were utilized to identify and quantitate fumonisin B1 in 3 samples of corn from the farm. Concentrations of fumonisin B1 range from 37 to 122 ppm. Fumonisin B1 was also detected. Using information on diet, animal weights, and feeding practices, estimates of total fumonisin B1 dosage were determined. This is the first definitive report on equine leukoencephalomalacia and associated fumonisin B1 concentrations. Equine leukoencephalomalacia (ELEM) is distrib- uted worldwide 3,5-7 and is caused by the mycotoxin fumonisin B1 (FB1), a metabolite of Fusarium monili- forme. 6 The disease often results from feeding F. mo- niliforme-infected corn and has been associated with the consumption of commercially prepared diets. 12 Studies also indicate that metabolites from various strains of F. moniliforme may be hepatocarcinogenic to rats. 4,10 A recent review of the history, seasonality, clinical syndromes, epidemiology, and differential di- agnosis of ELEM has been published. 8 Analytical methods for FB1 in feeds are now evolving 9 since the isolation and chemical identification of FB1. 1,4 Previ- ously, only fungal isolation and pathologic findings were used to diagnose ELEM. During the fall of 1989, an epizootic of ELEM oc- curred at a breeding/training stable of 66 purebred Arabian horses in Arizona. We report here the results of the clinical, pathologic, and analytical investigation of this episode. It also represents the first report of the feeding duration and ELEM-associated FB1 levels.
196 citations
TL;DR: The knowledge of biochemical confirms that types other than capsular type 2 could characterization and serotyping of S. suis may be pathogenic for more than 1 animal species and there is an urgent need for a standardization of the techniques for capsular typing.
Abstract: Streptococcus suis is a worldwide cause of a variety sular type 2 isolate was recovered in pure culture from of porcine infections. It has been isolated from cases lungs and kidneys of a 41⁄2-month-old aborted bovine of meningitis, bronchopneumonia, arthritis, pericarfetus and its placenta. This suggests that S. suis may ditis, endocarditis, polyserositis, septicemia, rhinitis, be pathogenic for more than 1 animal species. and abortion.20,22,24 Different alpha-hemolytic strepIn Canada, it was reported that 94% of 4-8-weektococci were ascribed to Lancefield groups R, S, RS, old clinically healthy piglets harbored S. suis in their and T in 1963.5 Other investigators working with capnasal cavities, and 79% of these isolates did not belong sulated streptococci similar to de Moor’s groups S and to the 9 capsular types.3 Recently, we demonstrated R realized that the polysaccharides involved in serothat almost 90% of these untypeable isolates belong to typing originated from the capsular material rather than only 4 of the new capsular types (types 17, 18, 19, and from the cell wall. They considered these isolates as a 21, unpublished data). Other investigators have atnew species (Streptococcus suis) within the Lancefield tributed the development of rhinitis4,7,22 to untypeable group D, with 2 capsular types: 1 and 2, respectively. S. suis isolates. At this time, it is not possible to know The de Moor’s group RS was also added as S. suis type whether any of the capsular types of S. suis belong to 1⁄2.26 In 1983, 6 new capsular types of S. suis origithe normal flora of the nasal cavity or whether they nating from diseased pigs were described. 20 In 1987 represent real pathogens. Of the new capsular types, the species was officially recognized, l4 but the authors types 9 and 22 are more frequently found in diseased demonstrated by DNA hybridization that S. suis was pigs than in healthy ones. An outbreak of S. suis type not closely related to group D streptococci. 9 infection recently occurred in swine in Canada? Despite the presence of 9 capsular types of S. suis, Although 22 of 23 capsular types of S. suis are present untypeable isolates were still frequently reported. These in North America, our studies revealed that almost isolates were recovered from diseased4,10,12,13,22,24,25 and 30% of isolates recovered from diseased pigs are still clinically healthy pigs.2,3,21 More recently, 14 new capuntypeable (unpublished data). sular types have been described.9 Some of the reference As the number of capsular types increases, serotypstrains originated from diseased pigs, whereas others ing becomes more complicated, and it could soon bewere from the nasal cavities of clinically healthy pigs. come limited to reference laboratories. Even biochemOne strain was isolated from a diseased calf (capsular ical identification, when used alone, can be misleading. type 20) and another from a human case of meningitis Thus, veterinary diagnostic laboratories face a difficult (capsular type 14). Isolates belonging to capsular type situation. There is an urgent need for a standardization 14 have recently been recovered from diseased pigs in of both the biochemical identification of S. suis and our laboratory as well as in Denmark and Belgium (Dr. the techniques for capsular typing. The purpose of this J. Henrichsen, personal communication, 1989). This paper is to summarize the knowledge of biochemical confirms that types other than capsular type 2 could characterization and serotyping of S. suis and to suggest be involved in a zoonosis.9 In addition to the bovine means to facilitate the proper identification of this incapsular type 20, several other S. suis isolates have fectious agent of growing importance. been recovered from ruminants.9,12 Capsular type 16 Streptococcus suis is a gram-positive coccus that ocwas recently isolated in our laboratory from lungs of curs singly, frequently in pairs, or occasionally in short a calf suffering from bronchopneumonia, and a capchains. The organism grows well in aerobiosis, but growth is often enhanced by microaerophilic condiFrom the Research Group in Swine Infectious Diseases, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, tions. The majority of strains are alpha-hemolytic on
169 citations
TL;DR: The respiratory infection in these bulls may have predisposed them to the iron intoxication and should increase the susceptibility to parenterally administered iron intoxication.
Abstract: Bull 1 Bull 2 The respiratory infection in these bulls may have predisposed them to the iron intoxication. It has been previously Blood ammonia nitrogen 2.8 mg% NT* stated that inflammatory processes in the body result in a Creatine phosphokinase 8,740 IU/liter 4,720 IU/liter decrease in the total iron-binding capacity of the serum, which Aspartate aminotransferase 1,390 IU/liter 2,450 IU/liter should increase the susceptibility to parenterally adminis-
117 citations
TL;DR: LSD virus was isolated for the first time from cattle in Egypt in 2 disease outbreaks by neutralization with specific antiserum and by their ability to produce generalized LSD in experimentally inoculated cattle.
Abstract: Lumpy skin disease (LSD) virus (LSDV) was isolated for the first time from cattle in Egypt in 2 disease outbreaks. Bovine herpesvirus-4 (BHV-4) and LSDV were detected in a pooled sample from the first outbreak (Suez). Only LSDV was isolated from the second outbreak (Ismalia). The capripoxviruses were identified as LSDV by neutralization with specific antiserum and by their ability to produce generalized LSD in experimentally inoculated cattle.
95 citations
TL;DR: Radioimmunoassays with a panel of monoclonal antibodies indicated that the Indiana respiratory variant and the European PRCV are antigenically similar.
Abstract: A respiratory variant of transmissible gastroenteritis virus (TGEV), designated PRCV-Ind/89, was isolated from a swine breeding stock herd in Indiana The virus was readily isolated from nasal swabs of pigs of different ages and induced cytopathology on primary porcine kidney cells and and on a swine testicular (ST) cell line An 8-week-old pig infected oral/nasally with the respiratory variant and a contact pig showed no signs of respiratory or enteric disease These pigs did not shed virus in feces but did shed the agent from the upper respiratory tract for approximately 2 weeks Baby pigs from 2 separate litters (2 and 3 days old) also showed no clinical signs following oral/nasal inoculation with PRCV-Ind/89 In a third litter, 5 of 7 piglets (5 days old) infected either oral/nasally or by stomach tube developed a transient mild diarrhea with villous atrophy However, virus was not isolated from rectal swabs or ileal homogenates of these piglets, and viral antigen was not detected in the ileum by fluorescent antibody staining even though the virus was easily recovered from nasal swabs and lung tissue homogenates Swine antisera produced against PRCV-Ind/89 or enteric TGEV cross-neutralized either virus In addition, an anti-peplomer monoclonal antibody, 4F6, that neutralizes TGEV also neutralized the PRCV-Ind/89 isolate Radioimmunoassays with a panel of monoclonal antibodies indicated that the Indiana respiratory variant and the European PRCV are antigenically similar
75 citations
TL;DR: Estrogen-responsive proliferation in the MCF-7 cell line was used as a bioassay for detection of dietary estrogens and was confirmed by competitive inhibition with the antiestrogens tamoxifen or LY156758 to show that stimulation of growth by feed extracts was through an estrogenic mechanism.
Abstract: Estrogen-responsive proliferation in the MCF-7 cell line was used as a bioassay for detection of dietary estrogens. The bioassay procedure was adapted to screen for estrogenic activity in feedstuffs that have been associated with hyperestrogenism in livestock. Methanolic feed extracts were added to the cell culture medium at μ1/ml concentrations for 4 days, after which the cell proliferation response was measured as DNA content. The half-maximal response for estradiol occurred at 2 pM, or 0.54 pg/ml. For zearalenone, a weaker estrogen, the half-maximal response occurred at approximately 200 pM, or 64 pg/ml. The bioassay was calibrated against a number of known estrogens (estradiol, diethylstilbestrol, zearalenone, zearalanol [cattle implant], β-zearalenol, zearalane), including the naturally occurring phytoestrogens (formononetin, genistein, daidzein, biochanin A, and coumestrol). The estrogenic activity of feed samples was expressed as equivalents of zearalenone (ppm zearalenone) that would have to be pr...
69 citations
TL;DR: The causes of abortion in cattle in the San Joaquin Valley of California were surveyed from submissions to the California Veterinary Diagnostic Laboratory at Tulare andfetuses with protozoal infection had histologic lesions of focal nonsuppurative necrotizing encephalitis, and protozoa were detected.
Abstract: The causes of abortion in cattle in the San Joaquin Valley of California were surveyed from submissions to the California Veterinary Diagnostic Laboratory at Tulare. Four hundred sixty-eight abortion cases were examined. Most submissions (89%) were from large drylot dairies, milking an average of 814 cows. Abortion evaluations included necropsy, histopathology, bacteriology, virology, and other immunologic and serologic tests. A specific cause was identified in 29.5% of the abortions. Bacterial infections, most of which were sporadic, accounted for 16% of all abortions. Viral causes and protozoal infections were diagnosed in 5.6% and 3.2% of the abortions, respectively. Fetuses with protozoal infection had histologic lesions of focal nonsuppurative necrotizing encephalitis, and protozoa were detected. Similar histologic lesions were seen in 80 additional fetuses (17.1%), and although an etiologic agent was not identified for these cases, a protozoal infection was suspected.
65 citations
TL;DR: Thirty-five birds that died with naturally acquired psittacine beak and feather disease were necropsied to identify extracutaneous viral inclusions, and inclusion-bearing lesions were widely disseminated but often closely associated with the alimentary tract.
Abstract: Thirty-five birds that died with naturally acquired psittacine beak and feather disease (PBFD) were necropsied to identify extracutaneous viral inclusions. Inclusions were found in various tissue sections from 34 of 35 birds. By immunoperoxidase staining, intranuclear and intracytoplasmic inclusion bodies were shown to contain PBFD viral antigen. Inclusion-bearing lesions were widely disseminated but often closely associated with the alimentary tract. Lesions within the palate, esophagus, crop, intestine, bursa of Fabricius, and liver probably serve as sources for viral shedding into the feces.
64 citations
TL;DR: The ease of use, specificity, and the sensitivity comparable to that of the immunoblot assay make the RIPA a useful confirmatory assay for sera that yield conflicting results in other ASFV antibody assays.
Abstract: A radioimmunoprecipitation assay (RIPA) has been developed for detection of antibody to African swine fever virus (ASFV) and compared with the immunoblot assay with regard to sensitivity and specificity. Two hundred seven field sera, obtained from pigs in Spain from different geographic areas between 1975 and 1986, that were positive by ASFV enzyme-linked immunosorbent assay (ELISA) were also analysed by immunoblot assay and RIPA. By serum dilution experiments, the RIPA appeared at least as sensitive as the ELISA and immunoblotting tests, although ELISA and RIPA detected antibodies to ASFV earlier in natural infection than did the immunoblot assay, as disclosed by animal inoculation studies. The most antigenic ASFV-induced proteins in natural infection detected by RIPA were the viral proteins p243, p172, p73, p25.5, p15, and p12 and the infection proteins p30 and p23.5. In the immunoblot assay, the proteins that were most reactive with the same sera were the viral protein p25.5 and the infection proteins p30, p25, and p21.5. Only 1 serum, from an animal infected with ASFV, was negative by immunoblot assay but showed a positive result by RIPA. A modification of conventional RIPA was performed using a dot transference of immunoprecipitated proteins to a nitrocellulose filter. This modification simplified the conventional RIPA procedures by eliminating the electrophoresis of immunoprecipitated proteins without affecting sensitivity and specificity. The ease of use, specificity, and the sensitivity comparable to that of the immunoblot assay make the RIPA a useful confirmatory assay for sera that yield conflicting results in other ASFV antibody assays.
59 citations
TL;DR: A 2-year-old Shorthorn heifer aborted an &month-old fetus was necropsied shortly after being aborted, and N. caninumassociated myocarditis and encephalitis in an aborted calf was reported.
Abstract: Neospora caninum is a recently recognized protozoan parasite, previously misdiagnosed as Toxoplasma gondii. 1,3,5-8 It can cause fatal myositis, encephalitis, and polyradiculoneuritis in transplacentally infected neonatal and adult dogs. Neospora caninum parasites have also been associated with abortion and neonatal disease in cattle? 6,11 The life cycle and source of infection are unknown. We report N. caninumassociated myocarditis and encephalitis in an aborted calf. A 2-year-old Shorthorn heifer aborted an &month-old fetus. The fetus was necropsied shortly after being aborted. The carcass was edematous with several liters of fluid present in pleural and peritoneal cavities. The liver was friable. Because of suspected heart disease, heart and liver, as well as portions of kidney, spleen, cerebrum, cerebellum, pons, and medula were fixed in 10% buffered neutral formalin. Paraffinembedded tissues were cut at 5 μm, stained with hematoxylin and eosin (HE), and examined. Portions of heart were embedded in methyl glycolate, and 2-3-μm sections were cut and stained with HE or periodic acid-Schiff (PAS) reaction. Portions of formalin-fixed heart were also processed for transmission electron microscopy. 10 Paraffin-embedded sections of heart and other organs were stained with T. gondii and N. caninum antisera. Blood was collected from the heifer, and the serum was examined for antibodies to Toxoplasma gondii using a direct agglutination test. The levels of selenium, copper, and nitrate were determined in liver homogenate (selenium, copper) and in aqueous humor (nitrate).” a 2 Routine bacteriological cultures of liver and heart were performed. Virus isolations were attempted” on liver homogenate in fetal bovine turbinate cell cultures. Microscopic lesions were seen in the heart, liver, and brain. The myocardial lesions consisted of multifocal areas of edema, hemorrhage, necrosis of myocytes, and infiltrations of neutrophils and mononuclear cells in and around myocytes and Purkinje fibers (Fig. l A-lD). There was also diffuse nonsuppurative pericarditis. Numerous intracellular tachyzoites were found in myocytes and were occasionally seen in Purkinje fibers. Tachyzoites in the heart were found indi-
TL;DR: The length of time that virus could be recovered from a viremic blood sample was compared in an evaluation of storage methods for virus isolation samples and the ELISA described in this paper was group specific.
Abstract: Five serological methods of diagnosing African horse sickness were evaluated, using a battery of serum samples from experimental horses vaccinated and challenged with each serotype of African horse sickness virus (AHSV1 through AHSV9): agar gel immunodiffusion (AGID), indirect fluorescent antibody (IFA), complement fixation (CF), virus neutralization (VN), and enzyme-linked immunosorbent assay (ELISA). The 5 tests were also compared using a panel of field samples, convalescent equine sera with antibodies to domestic equine viral diseases, and sera from horses awaiting export. The ELISA described in this paper was group specific. It did not require calibration with a standard positive serum but did yield elevated values with negative sera that were repeatedly frozen and thawed or heat inactivated. The IFA test was sensitive but could not be used on some field sera as the control cells exhibited fluorescence, possibly due to the animal being recently vaccinated with cell culture material. Sixty-two experimental sera were compared by VN, CF, AGID, and ELISA. Forty sera, 10 positive and 30 negative, were correctly classified by the 5 serologic assays. The 22 remaining sera gave mixed reactions. The AGID had no false positive results but had false negative results for up to 20% of the samples, depending upon the comparison. The VN, CF, and ELISA were similar in their variability. The length of time that virus could be recovered from a viremic blood sample was compared in an evaluation of storage methods for virus isolation samples. Washed erythrocytes were held at 4 C, washed erythrocytes plus stabilizer were held at -70 C, and blood that was drawn into a preservative (oxalate/phenol/glycerol) was held at 4 C.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: It is suggested that at parturition lead is mobilized into the blood of cattle previously exposed to excessive lead.
Abstract: In September 1988, 100 of 300 yearling dairy heifers developed blindness, tachypnea, foaming at the mouth, chewing, and facial fasciculations. Twenty-five animals died. Lead toxicosis was diagnosed based on the clinical signs and the presence of excessive concentrations of lead in whole blood, liver, kidney, and rumen contents of affected animals. The source of the lead was sudan grass silage that had been contaminated by soil that contained up to 77,000 mg/kg of lead. Lead concentrations were determined approximately 7 months after the acute episode of lead toxicosis. Whole blood and milk samples were obtained from heifers and a group of control cows 2 weeks prior to (blood only), at the time of, and 2 and 4 weeks after freshening. No lead was found in any of the milk samples (detection limit = 0.055 mg/liter). Animals that had been severely affected by lead toxicosis experienced a transient increase in whole blood lead concentrations at freshening that was not high enough to be considered toxic. No similar increases in blood lead were observed for control cows or heifers that had experienced milder toxicosis. These findings suggest that at parturition lead is mobilized into the blood of cattle previously exposed to excessive lead.
TL;DR: Based on the history, clinical signs, pathological lesions, and chemical analyses, cocklebur toxicosis associated with consumption of mature Xanthium strumarium in hay was confirmed.
Abstract: Cockleburs (Xanthium spp.) are herbaceous annuals with worldwide distribution. Toxicoses are usually associated with the consumption of the seedlings in the cotyledon stage, which contain a high concentration of the toxic principle, carboxyatractyloside. The seeds are also known to contain the toxin, but it has long been assumed that the spiny capsule would deter their consumption. Six of 70 yearling calves died while being fed round bale hay composed predominantly of foxtail and mature cocklebur plants with burs. Clinical signs ranged from acute death to hyperexcitability, blindness, tense musculature, and spastic gaits with heads held high and ears erect. Some symptomatic calves would stumble, fall to lateral recumbency, convulse, and later recover. Overall, the herd was very uneasy. Prominent gross lesions were ascites and a firm, pale liver with a mottled hemorrhagic pattern on cut surface. The rumen contained numerous intact burs and well-ruminated grass. Histological examination of the liver revealed marked centrolobular degeneration and necrosis with associated hemorrhage and congestion. Brain lesions were present. Plant and tissue samples were analyzed for carboxyatractyloside with various results. Samples of rumen contents, urine, and burs contained 100-200 ppm, 0.1-0.05 ppm, and 0.1 ppm, respectively. Based on the history, clinical signs, pathological lesions, and chemical analyses, cocklebur toxicosis associated with consumption of mature Xanthium strumarium in hay was confirmed.
TL;DR: Infectious pancreatic necrosis virus serotype Sp was identified by immunohistochemistry in formaldehyde-fixed and paraffin-embedded tissue of Atlantic salmon and the immunoreaction was present in degenerating and necrotic cells in exocrine pancreatic cells.
Abstract: Infectious pancreatic necrosis virus serotype Sp was identified by immunohistochemistry in formaldehyde-fixed and paraffin-embedded tissue of Atlantic salmon (Salmo salar) The immunoreaction was present in degenerating and necrotic cells in exocrine pancreatic cells Cross reactions were observed with rabbit antisera against serotypes Sp, Ab, and VR-299 in neutralization tests and western blotting Immunohistochemically, only Sp antiserum produced positive immunostaining to Sp antigens, whereas antisera to serotypes Ab and VR-299 were negative
TL;DR: A comparison of two detection methods for the prevalence of equine Sarcocystis in British titres in horses with experimental sarcosporidial infections and a comparison of one of the methods found success.
Abstract: 2. Cunningham CC: 1973, Sarcocysts in the heart muscle of a foal. 6. Fayer R, Hounsel C, Giles RC: 1983, Chronic illness in a SarVet Rec 92:684. cocystis -infected pony. Vet Rec 113:216-217. 3. Dubey JP, Speer CA, Fayer R: 1989, Sarcocystosis of animals 7. Schneider T, Zimmermann U, Matuschka FR, et al.: 1985, Clinand man, p. 215. CRC Press, Boca Raton, FL. ical signs, serum-enzyme activity and the dynamics of antibody 4. Edwards GT: 1984, Prevalence of equine Sarcocystis in British titres in horses with experimental sarcosporidial infections. Zenhorses and a comparison of two detection methods. Vet Rec 115: tralbl Veterinaermed Reihe B 32:29-39. 265-267. 8. Tinling SP, Cardinet GH III, Blythe LL, et al.: 1980. A light and 5. Fayer R, Dubey JP: 1982, Development of Sarcocystis fayeri in electron microscopic study of sarcocysts in a horse. J Parasitol the horse. J Parasitol 68:856-860. 66:458-465.
TL;DR: Information indicates that the feline cutaneous papillomavirus is a unique virus type and thus expands the list of hosts known to be infected by papillombavirus and limited restriction endonuclease restriction mapping.
Abstract: Papillomavirus infection was confirmed in 2 Persian cats with sessile hyperkeratotic skin lesions. Skin lesions were not typical papillomas as found in other species. Papillomavirus virions were demonstrated in negative stain preparations of homogenized tissue and within nuclei of cells in the stratum granulosum. Papillomavirus group-specific antigens were detected within nuclei corresponding to those containing virions. Attempts to transmit this disease to other cats or propagate the virus in tissue cultures were unsuccessful. A 7.8-kilobase DNA molecule was present in low-stringency Southern blots using a bovine papillomavirus type 1 cloned DNA probe. In reverse Southern blots, the cat papillomavirus hybridized under conditions of low stringency with all papillomavirus genomes tested. Combined with limited restriction endonuclease restriction mapping, the above information indicates that the feline cutaneous papillomavirus is a unique virus type and thus expands the list of hosts known to be infected by...
TL;DR: Bromethalin was detected in kidney, liver, fat, and brain tissues, using gas chromatography with electron capture detection andUltramicroscopic examination of midbrain stem revealed occasional swollen axons, intramyelinic vacuolization, and myelin splitting at the intraperiod line.
Abstract: Dogs given a single oral dose of bromethalin at 6.25 mg/kg developed a toxic syndrome charac- terized by hyperexcitability, tremors, seizures, depression, and death within 15-63 hours after bromethalin administration. Gross lesions included mild cerebral edema (2/5) and mild pulmonary congestion (2/5). His- tologic lesions included diffuse white matter spongiosis (5/5), mild microgliosis (3/5), optic nerve vacuolization (3/5), mild thickening of Bowman's capsule (2/5), and occasional splenic megakaryocytes (2/5). Ultramicroscopic examination of midbrain stem revealed occasional swollen axons, intramyelinic vacuolization, and myelin splitting at the intraperiod line. Bromethalin was detected in kidney, liver, fat, and brain tissues, using gas chromatography with electron capture detection. Photodegradation of extracted bromethalin may limit accurate quantification of tissue residues. Acute, single-feeding rodenticides containing 0.01% bromethalin were introduced in 1985. a,b,c Bromethalin- based rodenticides are pelleted (tan or green color) grain- based products that contain 0.75-1.5 ounces (21-42 g) of bait in paper "place pack" enve1opes. l In the ex- posed animal, bromethalin is N-demethylated by he- patic microsomal enzymes (cytochrome P450) to form the desmethylbromethalin metabolite (Fig. 1). 2,11 The biochemical mechanism of action for bromethalin- based rodenticides differs from anticoagulant and cho- lecalciferol-based rodenticides and involves the un- coupling of oxidative phosphorylation. 2,11,12 Oxidative phosphorylation is dependent upon the normal func- tion of mitochondria1 cytochromes and is the primary means of ATP production in nervous tissues. Uncou- pling of oxidative phosphorylation by bromethalin and desmethylbromethalin, therefore, results in a lack of adequate ATP production and disruption of ATP de- pendent Na+-K+ ion channel pumps. 11 Disruption of normal ion pump activity in the central nervous system results in the development of cerebral edema and el- evated cerebrospinal fluid pressure (CSFP). Addition- ally, brain and spinal cord moisture and cation con- centrations are elevated in rats given a lethal oral dose of bromethalin. 11
TL;DR: Coelectrophoresis with prototype OSU and Gottfried strains revealed a great diversity in electropherotype among field strains of rotavirus.
Abstract: Polyacrylamide gel electrophoresis was conducted on genomic RNA extracted from rotaviruses detected in diarrheic pigs from conventional swine herds. Ninety samples contained sufficient virus for RNA band visualization and genome classification. Genome profiles were characteristic of typical group A rotaviruses in 67.8% of the 90 samples, of group B rotaviruses in 10.0%, and of group C rotaviruses in 11.1%. In 11.1% of the samples, the presence of more than 11 bands suggested concurrent infection with more than 1 strain of rotavirus. In infections among nursing pigs, 76.4% were group A rotaviruses, 7.4% were group B, 7.4% were group C, and 8.8% were coinfections. In infections among weaned pigs, 40.9% were group A, 18.2% were group B, 22.7% were group C, and 18.2% were coinfections. Coelectrophoresis with prototype OSU and Gottfried strains revealed a great diversity in electropherotype among field strains of rotavirus.
TL;DR: The grading scheme described provides the pathologist with an objective criterion for the microscopic evaluation of colonic mucosal samples obtained by endoscopic techniques and offers clinicians a method of assessing the dog's progress and response to therapy.
Abstract: Colonic mucosal samples were obtained every 4 weeks for 13 months from 6 clinically normal dogs and from 47 dogs with a clinical diagnosis of chronic inflammatory bowel disease. All samples were graded on a scale of 0–5, based upon the quantity of lymphocytes and plasma cells in the lamina propria, epithelial changes, and the presence of ulcers and erosions. A grade of ≤2.0 was considered normal and was assigned to 77 of 78 samples from clinically normal dogs and 28 of 48 samples from dogs with diarrhea. A transient increase in cellulaiity was noted in 1 sample from 1 control dog. Nineteen dogs with clinical disease had obvious histologic abnormalities. The grading scheme described provides the pathologist with an objective criterion for the microscopic evaluation of colonic mucosal samples obtained by endoscopic techniques and offers clinicians a method of assessing the dog's progress and response to therapy.
TL;DR: Results indicate that subclinical trace mineral deficiencies of copper and/or selenium exist in the range cattle in west central Nebraska and Wyoming.
Abstract: The etiology of abomasal ulcers/tympany was investigated in 48 animals from 36 ranches in Wyoming and Nebraska. Results indicate that subclinical trace mineral deficiencies of copper and/or selenium exist in the range cattle in west central Nebraska and Wyoming. Etiological agents most frequently incriminated by bacteriologic cultures and/or histopathic examination were Clostridium perfringens and Campylobacter species. Histopathologic evaluation of abomasums revealed 31 of 38 cases contained abundant gram-positive bacteria associated with the damaged abomasal mucosa. Campylobacter-like organisms were demonstrated in 9 of 38 cases using the modified Dieterle stain. Clostridium perfringens was isolated in 14 of 38 cases, and Campylobacter jejuni was recovered from 5 of 38 cases.
TL;DR: Vascular hamartoma has been described in 2 cross-bred Frieproximately 3 weeks later, the owner noted regrowth of the sian calves, and a second veterinarian was consulted, and in each case, the mass arose in the mandibular mass, and
Abstract: 7proximately 6 cm in diameter. The mass was located in the This report describes gingival vascular hamartomas in 3 rostra1 mandibular gingiva just lateral to the left central incalves. Tissue was surgically removed from each of the 3 cisor tooth. The owner had discovered the lesion 1 week cases, placed in 10% buffered neutral formalin, and submitted prior to presentation, and the mass had enlarged rapidly to C. E. Kord Animal Disease Laboratory for histologic eval- during the previous week. Surgical excision was attempted. uation. Margins of the lesion were indistinct and extended deep into A 5-day-old female Chianina calf was presented to the the submucosa. Microscopically, the lesion was virtually veterinarian for an oral mass that was noted at birth. The identical to the previously described cases. mass was located in labial gingiva at the level of the right Congenital lesions of vascular tissue are rare in animals. lower first incisor tooth and was surgically removed. Ap- Vascular hamartoma has been described in 2 cross-bred Frieproximately 3 weeks later, the owner noted regrowth of the sian calves. 8 In each case, the mass arose in the mandibular mass, and a second veterinarian was consulted. The tissue gingiva near the central incisor. Regrowth of the tissue ocwas again surgically resected and submitted for histopath- curred following incomplete excision. Thermocautery was ologic evaluation. The clinician’s impression at the time of effective in preventing recurrence. surgery was that of an “infective or invasive organism, or Gingival vascular hamartoma was also reported in a 5-week tissue.” Fresh tissue was submitted for bacterial culture. The old male Simmental-cross calf and a 2-month-old female initial tissue submitted for examination measured 3.0 × 2.3 Holstein Friesian calf. 9
TL;DR: No significant differences in farrowing averages and reproductive problems were observed between vaccinated and nonvaccinated NAHMS herds or between herds with higher or lower percentages of animals that were serologically positive against serovar bratislava.
Abstract: The epidemiology of leptospirosis in Iowa swine was examined on the basis of serologic results and herd data from 55 herds in the National Animal Health Monitoring System (NAHMS) program and culture results and histories from 578 cases of reproductive failure submitted to the Iowa Veterinary Diagnostic Lab- oratory during a 3-year period. Thirty-eight percent of sera from NAHMS herds contained antibodies against 1 or more of 12 leptospira antigens. Leptospires were isolated from 9 (1.6%) of 578 cases of reproductive failure. Seven (78%) of the isolates were identified as Leptospira interrogans serovar kennewicki and 2 (22%) as serovar grippotyphosa. In 7 herds from which leptospires were isolated, attack rates ranged from 1% to 84%. Clinical leptospirosis, characterized by reproductive failure and confirmed by isolation of leptospires, was sporadic. No significant differences in farrowing averages and reproductive problems were observed between vaccinated and nonvaccinated NAHMS herds or between herds with higher (43-63%) or lower (14-40%) percentages of animals that were serologically positive against serovar bratislava.
TL;DR: The monoclonal antibody D89 against bovine viral diarrhea virus (BVDV) was used in conjunction with fluorescein-conjugated anti-mouse immunoglobulin in an indirect fluorescent antibody (IFA) procedure on frozen tissue sections and cell culture to permit faster confirmation of BVDV diagnosis.
Abstract: The monoclonal antibody (MAb) D89 against bovine viral diarrhea virus (BVDV) was used in conjunction with fluorescein-conjugated anti-mouse immunoglobulin in an indirect fluorescent antibody (IFA) procedure on frozen tissue sections and cell culture. During the 2-year study, BVDV was isolated from specimens submitted in 460 cases. The D89 Mab detected all but 2 BVDV isolates, both cytopathic. In 316 of the cases in which BVD virus was detected by IFA, specimens were inoculated on bovine turbinate cells and examined for BVDV antigens at 3–5, 10, and 20 days postinoculation. The BVDV was detected in 238/316 cases (75%) after 3–5 days incubation. The remainder were not detected until 10 or 20 days postinoculation. Virus isolation was enhanced in the early test if plates were centrifuged at the time of inoculation. Results suggest that D89 monoclonal antibody is a suitable diagnostic reagent for the detection of BVDV isolated from diagnostic specimens. The D89 MAb can be used for the detection of BVDV in both cell culture and tissues. Combination of D89 with another BVDV MAb (C 17) did not improve the ability to detect BVDV in tissues compared to using D89 only, and the combined Mab's resulted in an increase in nonspecific fluorescence when used on tissues. Although pooling of different BVDV monoclonal antibodies may be necessary to detect all strains of BVDV in cell culture, pooling should be used with caution on tissues. Early detection of BVDV in cell culture by this IFA procedure permits faster confirmation of BVDV diagnosis when compared to the usual routine testing for noncytopathic BVDV at termination of first passage in cell culture.
TL;DR: It is hoped that the widespread use of the cELISA test for the detection of antibody to a critical group antigen of BTV will be furthered by the availability of new Mab’s.
Abstract: hope that the widespread use of the cELISA test for the detection of antibody to a critical group antigen of BTV will be furthered by the availability of new Mab’s. Acknowledgements. We express our gratitude to the ARS scientists working at Plum Island Animal Disease Center (Drs. Appleton, Letchworth, Grubman, and Mr. Whyard) who produced, characterized, and kindly supplied the hybridomas for this study. We also thank Dr. Dulac, Agriculture Canada, for his helpful discussions, and Mr. Richard F. Meyer and Mr. Christopher D. DeMaula for their assistance.
TL;DR: The parasite in the present case resembles a Sarcocystis parasite inflammation that causes fatal encephalomyelitis in horses, cattle, and man.
Abstract: onts were seen in the brain and were not associated with parasite in the present case resembles a Sarcocystis parasite inflammation. that causes fatal encephalomyelitis in horses, cattle, and Although the diagnosis was initially mistaken as toxosheep. plasmosis, the parasite in the present study is definitely not either T. gondii or N. caninum because T. gondii and N. References caninum divide by endodyogeny, whereas in the present 1. case, the parasite divided by schizogony. In endodyogeny, Dubey JP, Beattie CP: 1988, Toxoplasmosis of animals and man. CRC Press, Boca Raton, Florida. 220 pp. the parasite divides into 2, and there is no multinucleated 2. Dubey JP, Carpenter JL, Speer CA, et al.: 1988, Newly recogstage. Examination for bacteria, and rabies and distemper nized fatal protozoan disease of dogs. J Am Vet Med Assoc 192: viruses were negative. 1269-1285. Both tachyzoites and tissue cysts of T. gondii and N. ca3. Dubey JP, Speer CA, Fayer R: 1989, Sarcocystosis of animals ninum are distinct from the parasite found in the present and man. CRC Press, Boca Raton, Florida. 215 pp. case. Tissue cysts of T. gondii and N. caninum contain PAS4. Lindsay DS, Dubey JP: 1989, Immunohistochemical diagnosis positive bradyzoites enclosed in a well-defined cyst wall. No of Neospora caninum in tissue sections. Am J Vet Res 50:198lsuch stage was found in the present case. In structure, the 1983.
TL;DR: Foot-and-mouth disease virus A24 was not detected from esophageal-pharyngeal fluid specimens beyond 8 days postexposure using in vitro techniques, and virus-neutralizing antibody titers remained elevated for over 200 days postinoculation or exposure.
Abstract: Foot-and-mouth disease virus (FMDV) was shown to be transmitted from either cattle to llamas, llamas to swine (interspecies), or llamas to llamas (intraspecies). Response to FMDV varied greatly in the 6 llamas studied; 3 llamas developed generalized clinical disease with mild pyrexia, 2 after intradermolingual inoculation, and 1 after exposure to a calf infected with FMDV serotype A24. Another contact llama developed vesicular lesions on all 4 extremities but no oral lesions. Two contact llamas, in separate study groups, did not seroconvert or develop clinical signs of FMDV infection. All 4 llamas showing clinical disease developed virus- neutralizing antibodies against FMDV A24 and antibodies against the virus-infection-associated antigen. Virus- neutralizing antibody titers remained elevated for over 200 days postinoculation or exposure. Antibodies to virus-infection-associated antigen were detected several days after virus-neutralizing antibody appeared and became weaker 100-125 days post-FMDV exposure in 3 of the 4 clinically affected llamas. One inoculated llama was still positive for virus-infection-associated antigen at 360 days after inoculation. Foot-and-mouth disease virus A24 was not detected from esophageal-pharyngeal fluid specimens beyond 8 days postexposure using in vitro techniques. Four native species of camelids are found in the Americas: the llama (Lama gama), the alpaca (L. pa- cos), the guanaco (L. guanacoe), and the vicuna (L. vicugna). The South American camelids are indigenous to the Andean mountain peaks and high plains and prairies of Peru, Bolivia, Ecuador, Argentina, and Chile 26 Since 1978 Chile has kept foot-and-mouth disease (FMD) from becoming reestablished as an en- zootic disease by extensive border surveillance and vigorous control measures. 3,6,7 However, efforts by Chile to be recognized as free of FMD by national and in- ternational governing bodies have been twice thwarted by outbreaks of the disease in 1984 and in 1987. 1,3,7,20- 25 On both occasions, alleged contraband movement of infected cattle into Chile was responsible for the outbreaks. 3,7 In neither of these FMD outbreaks were camelids known to be clinically affected. Epidemiological studies of FMD in Old World camelids, Camelus dromedarius and C. bactrianus, members of the same family as the llama, have been conducted in the Middle East. In one of these studies, foot-and-mouth disease virus (FMDV) was isolated from esophageal-pharyngeal (OP) samples through 5 weeks postinoculation, and seroconversion was doc-
TL;DR: Enzyme immunoassay was more sensitive than the microscopic agglutination test for detecting antibodies in serum from experimentally and naturally infected cattle, but it was not possible to differentiate vaccinated from infected animals or to detect a secondary immune response in vaccinated animals that were subsequently infected.
Abstract: Sensitivity and specificity of 4 different antigen preparations from Leptospira interrogans serovar hardjo were compared in an enzyme immunoassay for detection of antibodies against serovar hardjo type hardjo-bovis in serum. Two antigens prepared using detergents showed serogroup cross-reactivity. A mechanically extracted membrane and a lipopolysaccharide antigen showed a high degree of leptospiral serogroup specificity. The lipopolysaccharide antigen was the most suitable antigen for detection of anti-hardjo antibodies. Enzyme immunoassay was more sensitive than the microscopic agglutination test for detecting antibodies in serum from experimentally and naturally infected cattle. It was not possible to differentiate vaccinated from infected animals or to detect a secondary immune response in vaccinated animals that were subsequently infected.
TL;DR: There was a poor correlation between ocular fluid and serum values for all electrolytes; a significant correlation was found only for urea concentrations in both humors.
Abstract: This study was undertaken to evaluate the diagnostic usefulness of postmortem ocular fluid analysis in estimating the antemortem status of various serochemical constituents. Chemical values of serum and aqueous and vitreous humors were compared following different procedures. A blood sample and the 2 eyes were collected from each of 100 sows at a nearby abattoir. The results obtained from immediate centrifugation of ocular fluids after sampling were compared with those samples in which centrifugation was delayed by 2 hours. Two different postmortem intervals were used for sampling ocular fluids, 2 and 24 hours. Concentrations of urea, calcium, phosphorus, potassium, sodium, and chloride were determined from serum and humors. Delayed centrifugation did not affect chemical values of ocular fluids nor the relationships between serum and humors. Phosphorus and potassium values increased significantly with the postmortem interval in both aqueous and vitreous humors. The relationships between chemical values of ocular fluids and serum were determined using simple linear regression. There was a poor correlation between ocular fluid and serum values for all electrolytes; a significant correlation was found only for urea concentrations in both humors.
TL;DR: Comparisons of latex agglutination and serum neutralization tests for the detection of pseudorabies antibodies in swine sera and recommended minimum standards for an enzyme-linked immunosorbent assay (ELISA) in Pseudorabies serodiagnosis.
Abstract: nosis of pseudorabies (Aujeszky’s disease). Proc Annu Meet Am Assoc Vet Lab Diagn 20:375-390. 5. Hill HT, Seymore CL, Egan IT, Harris DL: 1983, Evaluation of the enzyme-linked immunosorbent assay and the microtitration serum-virus-neutralization tests as used in an epidemiological survey of Iowa, Illinois, and Missouri swine. Proc 3rd Int Symp World Assn Vet Lab Diagn 1:235-240. 6. Joo HS, Molitor TW, Leman AD: 1984, Radial immunodiffusion enzyme assay for detection of antibodies to pseudorabies virus in swine serum. Am J Vet Res 45:2096-2098. 7. Kelling CL, Standinger WL, Rhodes MB: 1978, Indirect solidphase microradioimmunoassay for detection of pseudorabies virus antibody in swine sera. Am J Vet Res 39: 1955-1957. 8. Scherba G, Gustafson DP, Kanitz CL, et al.: 1980, Delayed hypersensitivity reaction to pseudorabies virus as a field diagnostic test in swine. J Am Vet Med Assoc 173: 1490-1493. 9. Synder ML, Erickson GA: 1981, Recommended minimum standards for an enzyme-linked immunosorbent assay (ELISA) in pseudorabies serodiagnosis. National Veterinary Services Lab, US Department of Agriculture, Ames, IA. 32 pp. 10. Wade TW, Brees J, Goyal SM: 1986, Comparison of latex agglutination and serum neutralization tests for the detection of pseudorabies antibodies in swine sera. Proc Annu Meet Am Assoc Vet Lab Diagn 29:401-408.