Lead poisoning in cattle

Lead poisoning is a frequent cause of poisoning in domestic animals. Signs of encephalopathy and gastroenteritis are commonly observed in cattle following lead poisoning. This article discusses the etiology, epidemiology, pathogenesis, clinical signs, diagnosis, postmortem findings, and treatment of lead poisoning in cattle.     

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     

Suspected botulism in dairy cows and its implications for the safety of human food

A large outbreak of suspected botulism occurred on a dairy farm. The affected animals were listless and showed signs ranging from hindlimb unsteadiness to lateral recumbency, although the most common presentation was sternal recumbency with an apparent hindlimb weakness when stimulated to rise. Postmortem examinations revealed no conclusive gross pathology or histopathology. The affected cattle were found to have neutrophilia and hyperglycaemia with no other consistent haematological or biochemical abnormalities. The combination of clinical signs, disease epidemiology and the ruling out of other differential diagnoses strongly supported a diagnosis of unconfirmed botulism; however, the source of toxin was not demonstrated. Botulism is a severe disease in human beings and there are uncertainties about the pharmacokinetics and pharmacodynamics of Clostridium botulinum toxins. In such circumstances, a precautionary approach to food safety is essential. Restrictions were placed on the movement of livestock and sale of milk from the farm premises until 14 days after the onset of the last clinical case.     

牛饲料中毒的几种预防、救治方法

在牛养殖过程中,饲养户多以当地各种草、菜、农副产品、工副产品作为饲料,有时因饲料处理不当而导致牛生病,降低牛乳和牛肉产量及质量,甚至导致牛死亡,影响养牛业的发展.现将由饲料引起牛患病的防制方法介绍如下.     

Lead poisoning in dogs

Extract

Lead poisoning in dogs is insidious in onset, difficult to diagnose, and frequently overlooked. It is more prevalent in the older and more run-down areas in cities, where deteriorating paint, old lead plumbing, and untidy yards present many opportunities for dogs to acquire toxic amounts. My own practice is situated in one of the older areas of Christchurch and, over the 11 years covered by this paper, I have confirmed 107 cases of lead poisoning.     

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.     

Cocklebur poisoning in cattle

Cocklebur poisoning occurred in a herd of cattle in Oklahoma during the month of July. The poisonous dicotyledonary stage of cocklebur plant growth usually occurs during the early spring in Oklahoma. In this instance, dicotyledonary sprouts were in a lowland pasture adjacent to a river. Sprouting and growth occurred after receding water and hot dry weather had created favorable conditions for germination. The diagnosis was made on the basis of the finding of the dicotyledonary stage of plant growth and evidence of the plants having been grazed, as well as the clinical signs, gross necropsy findings, and histopathologic findings in the affected cattle.