Neospora-like protozoan infection as a major cause of abortion in California dairy cattle   总被引：17，自引：0，他引：17  

M L Anderson  P C Blanchard  B C Barr  J P Dubey  R L Hoffman  P A Conrad 《Journal of the American Veterinary Medical Association》1991,198(2):241-244

Ninety-five aborted bovine fetuses received from California dairies over a 4.5-year period had histologic lesions of focal encephalitis. Protozoa that reacted with Neospora caninum antiserum were detected in the brain of 88 of these fetuses and in the heart of 1 fetus. Sarcocystis spp schizonts were seen in the vascular endothelium of 1 fetus. It was concluded that a Neospora-like cyst-forming coccidian may be a major cause of abortion in California dairy cattle.  相似文献   

Lesions in fetal pigs with transplacentally-induced toxoplasmosis   总被引：1，自引：0，他引：1  

J P Dubey  D H Schlafer  J F Urban  D S Lindsay 《Veterinary pathology》1990,27(6):411-418

Two sows (Nos. 1, 2) were each fed 1,000 Toxoplasma gondii oocysts. Sow No. 1 was fed oocysts at 60 day of gestation and was euthanatized 49 days later. Sow No. 2 was fed oocysts at day 45 of gestation and euthanatized 62 days later. Sow No. 1 had eight dead fetuses of which one was mummified and unsuitable for histologic study. Sow No. 2 had 11 fetuses, of which four fetuses were mummified and unsuitable for histologic examination, two fetuses were dead and five were live. Lesions and Toxoplasma parasites were identified in seven fetuses from sow No. 1 and three fetuses from sow No. 2. No lesions were found in four fetuses from sow No. 2. Toxoplasma gondii was present in trophoblasts and produced areas of necrosis of the chorioallantois with focal placental separation. The predominant lesions were necrotizing placentitis, non-suppurative encephalomyelitis, and myocardial degeneration, necrosis and mineralization. Numerous tachyzoites were seen in trophoblast cells lining areolae in placenta.  相似文献   

Acute hepatic necrosis associated with a Sarcocystis-like protozoa in a sea lion (Zalophus californianus).     

M G Mense  J P Dubey  B L Homer 《Journal of veterinary diagnostic investigation》1992,4(4):486-490

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Sarcocystis infections in mule deer (Odocoileus hemionus) in Montana and the descriptions of three new species     

J P Dubey  C A Speer 《American journal of veterinary research》1986,47(5):1052-1055

Four structural types of sarcocysts of Sarcocystis were found in skeletal muscles of mule deer in Montana. Type I sarcocysts were thin walled (1 to 3 micron) and belonged to S hemionilatrantis. Types II to IV sarcocysts were thick walled (2 to 10 microns) and new names were proposed for them. Type II sarcocysts with long villar projections were named S hemioni. Type III sarcocysts with club-shaped villi of uneven thickness were named S youngi. Type IV sarcocysts with walls of uneven thickness and containing hair-like protrusions were named S americana.  相似文献   

Sarcocystosis in goats: clinical signs and pathologic and hematologic findings   总被引：1，自引：0，他引：1  

J P Dubey  S E Weisbrode  C A Speer  S P Sharma 《Journal of the American Veterinary Medical Association》1981,178(7):683-699

Clinical sarcocystosis was studied in 37 goats after inoculation with graded doses of sporocysts of Sarcocystis capracanis. Eight uninoculated goats served as controls. Clinical response varied with the dose. Goats inoculated with 10-40 million sporocysts died between 11 and 13 days after inoculation (DAI), from interstitial pneumonia, vasculitis, and necrosis of mesenteric lymph nodes. All goats inoculated with 100,000 or 1 million sporocysts died between 19 and 23 DAI; clinical signs were anorexia, fever (40-41 C), anemia, and weight loss. Four of 4 goats inoculated with 50,000 sporocysts and 1 of 4 inoculated with 10,000 sporocysts died 24, 28, 39, 68, and 61 DAI, respectively. Goats inoculated with 1,000 sporocysts and uninoculated goats remained clinically normal. After day 18 and before day 68, packed cell volume and hemoglobin content decreased to as low as 11% and 3.6 g/dl, respectively. Alanine aminotransferase and lactic dehydrogenase activities were inconsistently increased. Blood urea nitrogen and bilirubin values were increased, reaching as high as 63 mg/dl and 10 mg/dl, respectively. Histologically, thymic atrophy, vasculitis, hepatitis, cholangitis, myocarditis, generalized myositis, and encephalomyelitis were the main microscopic findings. The cause of the anemia in goats that died after day 19 was not determined.  相似文献   

Distribution of cysts and tachyczoites in calves and pregnant cows inoculated with toxoplasma gondii oocysts     

J.P. Dubey 《Veterinary parasitology》1983,13(3):199-211

Sixteen calves and 6 cows were each inoculated with 100 000 infective oocytes of the GT-1 strain of Toxoplasma gondii. Cattle were necropsied between 3 and 287 days post-inoculation (DPI) and their tissues were inoculated into mice or fed to Toxoplasma-free cats for the detection of Toxoplasma in bovine tissues. Ten to 10 000-fold more T. gondii were recovered from small intestine and mesenteric lymph nodes of calves at 3 and 6 DPI than from lungs and liver, and the number of T. gondii in bovine tissues was reduced 1000-fold between 6 and 8 DPI. By using the pepsin digestion technique, or feeding tissues to Toxoplasma-free cats, it was demonstrated that T. gondii encysted in bovine tissues as early as 11 DPI and persisted as late as 287 DPI. More Toxoplasma gondii cysts occurred in livers than in any other bovine tissue. Of the 6 cows inoculated at 95–155 days after breeding, 5 delivered normal calves and T. gondii was isolated from only one of these calves. One cow was barren. Toxoplasma gondii was not isolated either by mouse inoculation or by feeding cats tissues from 2 cows killed 132 and 190 DPI. Toxoplasma gondii was not isolated in mice inoculated with tissues of cows killed 98 and 109 DPI, but cats fed on bovine tissues shed T. gondii oocysts. The organism, however, was isolated in mice inoculated with the mesenteric lymph nodes of 1 of the 2 cows killed 162 and 168 DPI, and from the small intestine of the other. Cats fed tissues of these cows later shed T. gondii oocysts.  相似文献   

Sarcocystosis, toxoplasmosis, and cryptosporidiosis in cattle     

J P Dubey  R Fayer 《Veterinary Clinics of North America: Food Animal Practice》1986,2(2):293-298

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Steatitis in a red kangaroo (Macropus rufus) associated with a coccidia-like protozoon.     

J P Dubey  W J Hartley 《Journal of veterinary diagnostic investigation》1992,4(1):93-96

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Induced transplacental transmission of Neospora caninum in cattle.     

J P Dubey  D S Lindsay  M L Anderson  S W Davis  S K Shen 《Journal of the American Veterinary Medical Association》1992,201(5):709-713

Three Jersey cows were inoculated SC and IM with 26 million Neospora caninum tachyzoites at 129 (cow 1), 126 (cow 2), and 81 (cow 3) days after mating. Cows remained clinically normal for at least 1 month after inoculation of N caninum. Cow 1 was euthanatized 32 days after inoculation because of gangrenous mastitis. Cow 1 had a live fetus with no gross lesions; however, microscopic lesions were seen in the fetus and consisted of severe nonsuppurative necrotizing encephalitis of the cerebral white matter. Neospora caninum was identified in lesions by staining with anti-N caninum serum in an immunohistochemical test, by bioassays in mice, and by inoculation of bovine monocyte cultures with fetal tissue homogenate. Neither N caninum nor lesions were associated with infection with the protozoon identified in tissues of cow 1. Cows 2 and 3 aborted small autolysed fetuses 101 and 74 days, respectively, after inoculation with N caninum; the fetuses and attached placenta were unsuitable for laboratory investigations. Cows 2 and 3 remained clinically normal 4 months after abortion. Results of this study indicated that N caninum can be transmitted transplacentally in cattle.  相似文献   

Clinical neosporosis in a 4-week-old Hereford calf.     

J P Dubey  E B Janovitz  A J Skowronek 《Veterinary parasitology》1992,43(1-2):137-141

Most reports of neosporosis associated with abortion in cattle are in dairy cattle and infected calves do not survive beyond 7 days of age. This paper reports neosporosis in a 4-week-old Hereford calf. The calf was full term and appeared clinically normal at birth. At 2 weeks of age, the calf had weakened and was unable to nurse unassisted. The calf was killed at 4 weeks because of paralysis. The primary lesions were in the brain and were associated with Neospora caninum tachyzoites. The diagnosis was confirmed by immunohistochemical staining with anti-Neospora rabbit serum.  相似文献