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881.
882.
Host range of avian influenza virus in free-living birds   总被引:17,自引:0,他引:17  
Isolation of avian influenza virus (AIV) has been reported from 12 orders and 88 species of free-living birds. Most isolations are reported from species in the orders Anseriformes and Charadriiformes and it is recognized that species in Anseriformes represent important reservoirs of AIV. Morbidity and mortality among free-living birds attributable to AIV infection are rare, but differences in prevalence of AIV occur within and between avian species. Seasonal variation has been reported from free-living and sentinel ducks with peak AIV infection occurring in late summer and early fall. Prevalence of AIV is age-related, with highest isolation rates reported from juvenile birds. Differences in susceptibility to AIV infection among species have been demonstrated under experimental conditions. The dynamics and epidemiology of species-related variation in populations of free-living birds require further study.  相似文献   
883.
An enzyme immunoassay (complex-trapping-blocking ELISA, CTB ELISA) for the detection of antibodies against classical swine fever virus (SFV) has been developed. The CTB ELISA employs two monoclonal antibodies directed against different antigenic sites of SFV. A set of 2545 pig sera was tested in the CTB ELISA and in the neutralizing peroxidase-linked assay (NPLA) for neutralizing antibody to SFV. The CTB ELISA and the NPLA confirmed each other in 97% of the sera. The CTB ELISA detects low-level antibodies that can be found early after infection with low-virulent SFV strains or in postvaccination sera or sera with maternal antibodies. The CTB ELISA scored no false-positive results, whereas the NPLA scored 9 sera positive for SFV on a set of 81 pig sera that had antibodies against bovine viral diarrhoea virus.  相似文献   
884.
885.
The aim was to investigate if intraoperative registrations of blood pressure and heart rate could be used to estimate surgical trauma. In a prospective clinical trial, registrations in eight dogs neutered by laparoscopic ovariectomy (LOE) were compared with eight dogs subjected to open ovariohysterectomy (OHE). For comparisons phases were used: phase zero = steady state after induction of anaesthesia; phase one = opening of abdomen; phase two = severing of ovarian pedicles; and, phase three = abdominal closure. During LOE, mean systolic blood pressure increased by 7 mm Hg (= 0.05) and 15 mm Hg (= 0.01) from phase zero to phase one and two, respectively, and during OHE by 3 mm Hg (ns) and 29 mm Hg (< 0.0001), respectively. The increase from phase one to phase two differed between groups (= 0.03). Heart rate did not change. Frequent intraoperative measurements of blood pressure appear a promising method for evaluating surgical trauma.  相似文献   
886.
A herpesvirus and cytopathogenic bovine viral diarrhea virus were isolated from a bovine fetus aborted in the 6th month of gestation. The herpesvirus was serologically indistinguishable from bovine herpesviruses DN-599 and Movar 33/63.  相似文献   
887.
A 3-month-old English Bulldog was found to have a discontinuity between the ascending and descending aorta. There were no signs of illness associated with the interruption. The descending aorta was supplied with blood by collateral circulation. An aortic graft of woven synthetic material was surgically implanted to connect the ascending and descending aorta. Without any restrictions on the dog's activity, the dog has lived for over 1 year and continues to do well.  相似文献   
888.
Quantitative fat and trypsin analysis was done on the feces of dogs with chronic diarrhea. The results of clinical examination, quantitative fecal analysis, and other laboratory tests permitted assignment of the dogs into one of 4 groups: (1)pancreatic exocrine insufficiency,(2)small intestinal malabsorption,(3)colitis, and(4)other nonspecific or incompletely diagnosed diarrhea. The mean 24-hour fat output was significantly higher (p less than 0.01) in dogs with malabsorption or pancreatic insufficiency than in clinically normal dogs, dogs with colitis, or dogs with nonsteatorrheic diarrheas. The mean 24-hour trypsin output with pancreatic insufficiency was significantly (P less than 0.01) lower, and in dogs with malabsorption, significantly (P less than 0.05) higher than in clinically normal dogs. Normalization of the output data for body weight enhanced the value of fat and trypsin analyses in the differentiation of pancreatic insufficiency and intestinal malabsorption from other causes of chronic canine diarrhea.  相似文献   
889.
Sentinel calves were placed in pastures for 1 month in two environmentally dissimilar areas of the Texas Gulf Coast to determine the seasonal transmission of various gastrointestinal nematodes. Transmission was determined for Cooperia spp, Haemonchus placei, Ostertagia ostertagi, and Trichostrongylus axei. Large numbers of Cooperia spp were acquired from May through November, with the peak of transmission occurring in July and August. Haemonchus placei was encountered on both field sites but was transmitted in large numbers only at one site, during August. Ostertagia ostertagi was acquired primarily from November through May, with the peak of transmission occurring in January and February. January through March was the period when the greatest numbers of Ostertagia larvae undergoing arrested development were acquired. Trichostrongylus axei was abundance in December and January at one field site. In general, trends of transmission were the same in both areas, indicating that weather conditions were most important than vegetation type in larval transmission.  相似文献   
890.
Trombiculosis (dermatitis caused by trombiculid mites) in a Domestic Shorthair cat was characterized by diffuse thickening and crusting of the skin of the abdomen and limbs and by multiple papules on the face, ears, and sides of the trunk. Skin biopsy revealed acanthosis and hyperkeratosis involving the epidermis and hair follicles, mites in epidermal tunnels, and edema of the dermis, with infiltration of eosinophils and mast cells. Mites from skin scrapings were identified as Walchia americana. The cat was treated systemically with a broad-spectrum antibiotic and topically with a carbaryl and pyrethrin powder preparation. The lesions were resolved within 2 months.  相似文献   
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