Bluetongue virus as a cause of hydranencephaly in cattle.

Hydranencephaly was produced in a foetus and a calf by intra-uterine infection with an attenuated Type 10 bluetongue virus. Laparotomy was performed on the respective dams and the foetuses, respectively 126 days and 138 days old, were inoculated intramuscularly through the uterine wall with 1 ml of a virus suspension containing 5 x 103 tissue culture infective doese. The younger feotus was aborted on Day 262, while the other one was born alive on Day 273. Both foetuses showed marked hydranencephaly.     

Bartonella spp infection as a possible cause of uveitis in a cat

A 6-year-old castrated mixed-breed cat was evaluated because of unilateral anterior uveitis. The cat was seronegative for antibodies to Toxoplasma gondii, coronaviruses, and feline immunodeficiency virus, and antigens for FeLV p27 and Cryptococcus neoformans. Antibodies to Bartonella spp were detected in serum and aqueous humor. The antibody coefficient (C value) for IgG antibodies to Bartonella spp in the aqueous humor was 4.42; values > 1 suggest ocular production of antibodies and supports a diagnosis of ocular infection. Topical administration of prednisolone and oral administration of prednisone failed to induce a response; however, the uveitis resolved rapidly after the cat was given doxycycline orally. Clinical or laboratory evidence of immunodeficiency in this cat was not detected. Detection of a serum IgG antibody titer to Bartonella spp and ocular production of IgG antibodies to Bartonella spp, exclusion of other causes of uveitis, and response to doxycycline suggests that the cat may have had bartonellosis resulting in uveal tract inflammation.     

Tick-borne encephalitis virus as a possible cause of optic neuritis in a dog

A 3-year-old spayed female Siberian Husky was presented due to acute vision loss. Examination revealed bilateral optic neuritis and lymphocytic meningoencephalitis. The serum (1:800) and cerebrospinal fluid (CSF; 1:200) immunoglobulin (Ig)G titers for tick-borne encephalitis virus (TBEV) were elevated as were the serum IgG titer for Anaplasma phagocytophilum (1:640) and serum IgM titer for Toxoplasma gondii (1:20). Intracytoplasmic inclusion bodies such as ehrlichial or anaplasmal morulae were not observed in the CSF or blood smear. The dog was treated with methylprednisone and doxycycline. The left eye regained vision; the right eye remained blind. Anti-inflammatory therapy was stopped on day 18 after diagnosis. Four days later the dog showed evidence of hyperesthesia in the cervical region. Analysis of CSF showed no abnormalities and CSF IgG titers for TBEV and A. phagocytophilum were negative. Funduscopic evidence of active papillitis was absent on day 22 in the left eye and on day 86 in the right eye. On day 243, the dog was presented again with lethargy, ataxia, disorientation and temporary head tilt. The IgG titer for TBEV was again elevated in the CSF (1:800) and in serum (1:400). After interpretation of all findings, we assume that meningoencephalitis and optic neuritis in this patient was caused by TBEV and associated immune-mediated inflammation. In endemic areas, TBEV should be considered as cause of optic neuritis in dogs.     

Copper toxicity in ruminants: air pollution as a possible cause

Pathological findings and liver and kidney analyses confirmed that cattle had died of chronic copper poisoning on a farm in the north-eastern Transvaal. This is the first known published record of chronic copper intoxication of cattle in southern Africa. An epidemiological study revealed that a source of copper was air pollution which could have arisen from a nearby copper smelting unit. Buffalo and impala in an adjacent area of the Kruger National Park were found to have significantly higher liver copper levels than animals elsewhere in the Park. Prophylactic licks, containing zinc sulphate and sulphur, seemed to be successful in protecting cattle against the effects of the copper in the contaminated grazing.     

Dissecting aneurysm of the carotid artery as a cause of respiratory distress in adult cattle

A two-and-a-half-year-old Friesian cow and a five-year-old Charolais cow developed severe respiratory distress and palpable swellings to the left of the larynx as a result of a dissecting aneurysm of the common carotid artery. Neither cow responded to medical treatment. The underlying pathogenesis of the condition was uncertain, but direct trauma to the carotid artery was a possible contributory factor. Aneurysms of the common carotid artery should be considered when swelling occurs in the region of the larynx or when respiratory distress is due to laryngeal compression.     

Neospora-like protozoan infection as a major cause of abortion in California dairy cattle

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.     

Porcine circovirus as a possible cause of postweaning wasting in pigs in Switzerland

Postweaning wasting is a major worldwide problem in pig production, particularly with respect to the disease termed postweaning multisystemic wasting syndrome (PMWS). In addition to wasting, PMWS symptoms include respiratory distress, diarrhoea, pallor and occasional cases of jaundice. The causative agent is porcine circovirus type 2 (PCV-2). The objective of the present study was to determine the significance of PMWS and similar conditions in Switzerland. A total of 72 weaned piglets from 26 farms showing wasting were examined for the presence of PCV-2 by immunohistochemical and histological analysis and 57 piglets from 21 farms were examined serologically. Possible causes for wasting other than PCV-2 were investigated by macroscopic, histological and bacteriological methods. PCV-2 antigen was identified immunohistochemically in the lymphatic organs in 11 of these 72 piglets. However, only 4 animals showed histological changes typical of PMWS. PCV-2 antibodies were found in 70% of the piglets. Piglets with wasting syndrome not associated with PCV-2 infection suffered from conditions including porcine proliferative enteropathy, gastric ulcers, polyserositis and polyarthritis. The most frequent condition was chronic enteritis not associated to circovirus infection. The results from the serological analyses indicate a wide distribution of PCV-2 in the Swiss pig population. However, confirmed cases of PMWS were rare in the investigated piglets.     

Investigation of repeated vaccination as a possible cause of glomerular disease in mink

The search for antigens capable of causing immune-complex-mediated glomerulonephritis continues. Modified live-virus vaccines commercially available for veterinary use are a possible source. In this study, repeated vaccination of mink with live-virus vaccines was investigated as a model for vaccine-induced glomerular injury. Three groups of 10-wk-old mink, 15 per group, were vaccinated once with 4-way vaccine against distemper, Pseudomonas aeruginosa infection, botulism and mink viral enteritis. Subsequently, all mink in each group each were vaccinated either with the 4-way vaccine, a monovalent canine distemper vaccine, or saline. Glomerular function was assessed at 2-wk intervals by determining the urinary protein:creatinine (P:C) ratio. Kidney sections taken at necropsy, 20 wk after the 1st vaccination, were examined by light and immunofluorescent microscopy for deposition of immunoglobulin and complement. There was no statistically significant difference between the treated and control groups based on average urinary P:C ratio medians. Light microscopic changes were detected in glomeruli, but Fisher's exact test showed no significant differences between any of the treatment groups. Deposition of immunoglobulin but not complement was significantly more frequent (P < 0.05) in the glomeruli of animals that received multiple injections of the 4-way vaccine than in the glomeruli of those given only the monovalent canine distemper vaccine or saline. These findings suggest that repeated vaccination may increase the glomerular deposition of immunoglobulin. Further studies are required to determine if the increased deposition of immunoglobulin contributes to the development of glomerular damage and to identify the antigens driving production of the deposited immunoglobulin.     

调查显示饲料是导致PED病毒传播的潜在源头

根据美国农业部流行病学和动物健康中心（Center for Epidemiology and Animal Health,CEAH）公布的初步研究结果和美国猪兽医协会（the American Association of Swine Veterinarians,AASV）的报告,对猪流行性腹泻（porcine epidemic diarrhea,PED）病毒传染源的流行病学跟踪研究已经暗示,饲料有可能是该病毒传播的来源。     

Neosporosis as a cause of abortion in dairy cattle in Rio Grande do Sul, southern Brazil.

Forty-six aborted bovine fetuses submitted to the Faculty of Veterinary, Department of Clinical Pathology, Universidade Federal do Rio Grande do Sul, were examined histopathologically. Non-suppurative inflammation was observed mainly in the brain and heart of 22 fetuses. Brain lesions consisted primarily of mononuclear inflammatory cell infiltrates with occasional foci of necrosis. Protozoa that reacted with Neospora caninum antisera were seen in 18 of the 22 (81.8%) brain specimens from fetuses with encephalitis. Blood samples collected from 223 Holstein cows on five dairy herds were tested for N. caninum antibodies by an immunofluorescent antibody technique. These samples were obtained from aborting cattle and normally calving cattle (control group). Overall, 11.2% of cows sampled had N. caninum antibodies at a dilution of 1:200. Seroprevalence was higher (P = 0.0053) in aborting (23.3%) than in non-aborting cows (8.3%). Association between seropositivity to N. caninum and abortion was found, with seropositive cows being 3.3 times more likely to abort than seronegative cows (OR = 3.33; 95% CI: 1.38, 8.062). Additionally, N. caninum antibodies were detected in sera from seven cows that had aborted fetuses with lesions suggestive of protozoal infection. These results suggest that N. caninum is an important cause of abortion in dairy cattle in Rio Grande do Sul State, Brazil.