Selenium poisoning in dairy cattle

An outbreak of chronic selenium poisoning occurred in a mob of 30 Friesian dairy cows. These cows were all autumn calvers on a well-managed dairy farm.     

奶牛铅中毒

1　发病情况及流行病学调查1 999年 3月下旬 ,我市某区专业户郑某共养 4头黑白花奶牛 ,其中犊牛 1头 ,泌乳牛 3头。 3月 1 9日开始饲喂玉米秸杆 ,2 2日开始 1头奶牛产奶量下降 1 0 kg,2 3日 1头犊牛不采食 ,2 4日死亡 ;2 5日死亡 2头 ,2 6日死亡 1头。死前体温 3 8.2℃ ,脉搏 5     

Diquat poisoning of dairy cattle by topical application

This case report describes poisoning of dairy cattle from a dermal challenge of 50 to 100 mg/kg body weight diquat. Five of 36 cattle exposed, demonstrated clinical signs of intoxication, dehydration, and death over 5 days. Diquat poisoning of cattle by the dermal route has not previously been reported.     

Case of suspected theobromine poisoning in dairy cattle

High-yielding dairy cows collapsed and died displaying signs of a disturbed central nervous system (muscle tremor, convulsion) and a considerably reduced body condition score. An intense diagnostic screening did not allow to confirm a definite diagnosis. Therefore, further analyses including an evaluation of feeds and feeding were initiated. The herd was fed a total mixed ration (TMR) based on corn and grass silage of moderate nutritive value supplemented with various amounts of chocolate chips. In retrospect, the amount of chocolate chips added to the respective TMR batches could not be quantified. These chips were purchased from a company producing bakery and chocolate products for human consumption and added to the silage and therefore to the TMR in order to increase the energy intake of the animals. Because the TMR, which was fed during the time of the incidence, was no longer available, a sample of a later batch of silage was examined. The amount of chocolate chips was quantified (0.44% per fresh matter), and a theobromine analysis was performed in the chocolate chips of the available batch (69.7 mg/100 g fresh matter). Because of the possible link between chocolate intake and observed signs, an immediate cessation of using the chocolate chips was recommended in addition to an optimisation of the TMR, that is an increase of the energy density. Even though the theobromine intake during the time of the incidence is unknown and information about toxicity of theobromine in ruminants is limited, we suspect that the feeding of chocolate in this case caused all signs including the sudden death of the cows. Further reasons are that no differential diagnoses were established and the problems at the farm stopped after removing the chocolate from the TMR.     

黑白花奶牛误食鼠药中毒的治疗

2004年11月18日，六十二团东风街维吾尔族养殖户阿不都黑力赶来兽医站求诊。     

An outbreak of poisoning by Kalanchoe blossfeldiana in cattle in northeastern Brazil

Tropical Animal Health and Production - In the world, Kalanchoe species are primarily ornamentals and houseplants, but some have escaped cultivation and can be found in the field. In Latin America,...     

Seroprevalence of Neospora caninum in dairy cattle in Bahia, Brazil.

Sera collected from 447 dairy cattle on 14 dairy farms were tested for Neospora caninum antibodies by use of an immunofluorescent antibody technique. Positive reactions with titres > or =1:200 were found in 63 (14.09%) of animals. Neospora positive sera were also tested for Toxoplasma gondii antibodies by using a commercial latex agglutination test. Antibodies to T. gondii were detected in 3 (4.76%) of 63 N. caninum positive sera. These results indicate that N. caninum infection is widespread among dairy cattle in Bahia state.     

奶牛铅中毒的诊断与防治

2002年7月中旬，河北省某个体奶牛饲养场的奶牛发生疾病，此次发病不仅急，死亡快且死亡数量亦大，在短短1周内，牛只死亡几乎过半，造成较为严重的经济损失。后经实验室诊断确诊为铅中毒，现将有关情况报道如下。     

Nitrogen dioxide (silo gas) poisoning in dairy cattle

Toxic silo gases are a potential danger to livestock housed in close proximity to roughage silos. These gases, such as nitrogen dioxide (NO2), may be produced during the early stages of (maize and grass) silage making. In humans, inhalation of these gases causes a condition known as 'Silo Filler's Disease' (SFD), which is a recognized occupational hazard for workers in upright forage silos in many countries. NO2 accumulates on top of silage, is inhaled by workers, and reacts with water on the airway surfaces to form nitrous acid, which damages the lung and causes pulmonary oedema, bronchiolitis, and death in severe cases. On a dairy farm, a cloud of reddish-brown NO2 gas (which is heavier than air) was noticed to escape from underneath the plastic sheet of a horizontal maize bunker and to enter a cubicle house for dairy cows 1 day after ensiling. Eleven cows became dyspnoeic, 3 of which subsequently died. A combination of weather conditions, an insufficient sand load on the maize bunker, the utilization of a lactobacillus starter culture, and the close proximity of the silo to the cubicle house may have caused the incident.     

Arsenic poisoning in dairy cattle from naturally occurring arsenic pyrites

An outbreak of arsenic poisoning occurred in which most of a 200 cow dairy herd were affected and six died. The source of the arsenic was naturally occurring arsenic pyrites from the Waiotapu Stream, near Rotorua. Arsenic levels in the nearby soil were as high as 6618 ppm. There was little evidence to suggest that treatment affected the course of the disease. Haematology was of little use in diagnosis, post-mortem signs were not always consistent and persistence of the element in the liver appeared short. Control of further outbreaks have been based on practical measures to minimise the intake of contaminated soil and free laying water by the stock.     

Infection by spotted fever rickettsiae in people, dogs, horses and ticks in Londrina, Parana State, Brazil

Spotted fever is a disease caused by bacteria from the genus Rickettsia of the spotted fever group (SFG). Rickettsia rickettsii is likely the main agent of Brazilian spotted fever (BSF). With the objective of gathering information on the circulation of SFG rickettsiae in Londrina, Parana state, ticks from dogs and horses and also blood from dogs, horses and humans were collected in a neighbourhood of the city which presented potential for circulation of rickettsiae between hosts and vectors. Amblyomma cajennense, Dermacentor nitens, and Rhipicephalus sanguineus ticks were subjected to Polymerase Chain Reaction targeting a fragment of the Rickettsia gltA gene. This specific gene encodes the enzyme citrate synthase of Rickettsia spp., and results on all ticks were negative. Human and animal sera were tested by Indirect Immunofluorescence Assay in which R. rickettsii and R. parkeri were used as antigens. Sera from 4.7% human, 2.7% canine and 38.5% equine were positive for R. rickettsii. For R. parkeri, 0.9% human, 2.7% canine and 11.5% equine samples were positive. All samples reactive to R. parkeri also reacted to R. rickettsii. An epidemiological questionnaire was applied, but there were no statistically significant results. Comparison of our serological results with previous studies in Brazil, among BSF endemic and non-endemic areas, indicates that there is no established rickettsial infection in the study area, a statement corroborated with our molecular analysis. Nonetheless, as humans of the present study are highly exposed to tick infestations, health education within the population is needed to obtain efficient tick control.     

Factors associated with seroprevalence of Neospora caninum in dairy cattle in southeastern Brazil

Neosporosis is an infectious disease caused by Neospora caninum, an obligate intracellular cyst-forming protozoan considered a major cause of miscarriage in dairy cattle in many parts of the world. This cross-sectional study evaluated the relationship between reproductive abnormalities and seropositivity to N. caninum in 1,204 dairy cows from 40 farms located in the state of Minas Gerais, southeastern Brazil. Producers were interviewed, and blood samples were collected to perform indirect immunofluorescence tests (IFAT 1:200). Association between reproductive abnormalities and seropositivity in cattle was evaluated with generalized estimating equations. The true herd-level seroprevalence of N. caninum was 95 % (83.3–99.1), while the individual-level true seroprevalence was 21.6 % (19.2–24.2). Several reproductive abnormalities were significantly associated with seropositivity to N. caninum: occurrence of repeated estrus (p?=?0.02; OR?=?3.84; 95 % CI?=?1.239–11.893), repeated miscarriages (p?=?0.001; OR?=?2.54; 95 % CI?=?1.423–5.402), and temporary anestrus (p?=?0.001; OR?=?3.44; 95 % CI?=?1.976–5.994). Furthermore, loose dogs (p?=?0.041; OR?=?2.20; 95 % CI?=?1.033–4.672) when fed raw meat (p?=?0.001; OR?=?1.91; 95 % CI?=?1.443–2.519) are risk factors for N. caninum infection. We observed that seropositivity to N. caninum in cattle increases risk of miscarriage by almost twice throughout the reproductive life of cows (p?=?0.004; OR?=?1.978; 95 % CI?=?1.249–3.131). Serologic evidence in this study indicates that N. caninum infection is widely distributed among dairy herds and significantly associated with reproductive disorders, especially miscarriage, repeated estrus, and temporary anestrus.     

葛根、枳椇子解酒组合物体外抗氧化活性的研究

为研究葛根、枳椇子解酒组合物抗氧化活性,以葛根素及总黄酮含量计,设定葛根、枳椇子11组不同配比组合物,以乙醇脱氢酶(ADH)和超氧化物歧化酶(SOD)活性为指标确定葛根、枳椇子最优配比解酒组合物,以维生素C为对照,研究最优配比组合物对DPPH自由基清除能力、羟基自由基清除能力和总还原力的影响。结果表明,葛根提取物中葛根素含量为72.24mg/g;枳椇子提取物中总黄酮含量为101.15mg/g;11组不同配比组合物对ADH和SOD活性均具有促进作用,当葛根和枳椇子配比为8∶2时,ADH和SOD活性最高;葛根、枳椇子组合物能增强DPPH自由基清除能力、羟基自由基清除能力及总还原力,前两者IC50分别为0.038mg/mL、0.697mg/mL,总还原力最高为1.171。说明以葛根素及总黄酮含量计,葛根、枳椇子解酒组合物最佳配比为8∶2,最优配比组合物具有明确的体外抗氧化活性,研究结果为葛根、枳椇子组合用于解酒及抗氧化提供科学依据。     

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.     

Nitrate poisoning in cattle

Summary

In a series of experiments the effect of administering KNO₂ was studied, during parturition, on the capability of oxygen transport of maternal blood and on oxygen transfer to foetal blood. The following blood parameters were analysed, MHb percentage, pO₂, O₂‐saturation, pH, pCO₂, and (NO₂) in maternal arterial blood (carotid art.) and venous blood (jugular vein) and in foetal arterial blood (umbilical art.) and venous blood (umbilical vein). The relative O₂‐saturation was calculated from the estimated O₂‐saturation by multiplying with the factor Hb (mmol/1) minus MHb (mmol/1), divided by Hb (mmol/1). In addition, blood pressure in the carotid artery, heart rate, and respiration rate in the dam were continuously recorded for some hours.

A dosage of 9 to 12 mg of NO₂/kg body weight intravenously or of 30 mg of NO₂/kg body weight orally to the dam caused much higher MHb percentages and NO₂ contents in the maternal blood than in the foetal blood. In maternal blood the ratio of NO₂ content td MHb percentage was proportional to that in foetal blood. In the arterial blood, MHb percentages were almost as high as in the venous blood. After administering of nitrite, relative O₂‐saturation dropped simultaneously with the increase in methaemoglobin.

Nitrite treatment caused a drop in the maternal blood pressure; heart rate and respiration rate increased. O₂‐saturation in the blood in the umbilical vein was much lower in the animals with nitrite treatment than in those without. These experimental results show clearly that the oxygen capacity of the blood decreases after nitrite treatment. In pregnant cows the oxygen supply to the foetus will be adversely affected after nitrate intake, especially by the lower oxygen transfer via the placenta, though hardly at all by methaemoglobin formation in the foetal blood.

When the oxygen transfer to the foetal blood decreases too sharply, intra‐uterine death and ultimately abortion may result.