加拿大奶牛肉牛鉛中毒

1、鉛中毒Lead PoisoningPrepared by: Dr. Terry Hunt Translated by Dr. Ren Xiaoling 病因/發(fā)病機(jī)理 Cause & Pathogenesis牛最常見(jiàn)的無(wú)機(jī)物中毒Most common inorganic poisoning in cattle牛采食不加選擇吸收是重要來(lái)源Cattle are indiscriminant eaters ingestion is the major source主要來(lái)源是舊電池，機(jī)油，從礦區(qū)來(lái)的植物和水，含鉛的燃料和油漆Major sources are old batteries, contam

2、inated soil, water and vegetation from mines & smelters, crankcase oil from lead base gas engines & lead based paints危險(xiǎn)因素Risk Factors在牧場(chǎng)丟棄含鉛的垃圾Discarded lead containing garbage in pasture areas臨床癥狀Clinical Findings急性Acute常見(jiàn)于犢牛，成年牛罕見(jiàn)Common in calves but rare in adults突然發(fā)作，可發(fā)現(xiàn)死亡Sudden onset and may be

3、 found dead顫抖（頭，頸，耳），步履蹣跚，牙關(guān)緊閉，口吐白沫，流涎Tremors (head, neck & ears), staggering gait, jaw champing & frothy saliva吼叫，轉(zhuǎn)圈，前沖和狂躁興奮Bellowing, circling, head pressing & maniacal excitement眼瞼 ，眼球轉(zhuǎn)動(dòng)，瞎，光膿腫和眼瞼反射Eyelid snapping, rolled eyes, dilated pupils, blind and abscess of light & palpebral reflex發(fā)展為臥地不起，間

4、歇性抽搐，12-24小時(shí)死亡Progresses to recumbency, intermittent convulsions and death in 12-24 hours亞急性Sub-acute成年牛常見(jiàn)More common in adults嚴(yán)重精神沉郁Severe depression厭食，瘤胃蠕動(dòng)完全停止Anorexia & complete absence of rumen motility變瞎，缺乏光和眼瞼反射Blind, absence of light & palpebral reflex步履蹣跚，轉(zhuǎn)圈，前沖，牙關(guān)緊閉Staggering gait, circling,

5、 head pressing & teeth grinding初期便秘，但可能繼而為黑色腹瀉Initial constipation but may continue on to black diarrhea發(fā)展為臥地不起，常間歇性抽搐，3-4天內(nèi)死亡Progresses to recumbency usually without convulsions and death in 3-4 days亞臨床Sub-clinical牛慢性消化不良Cattle subject to chronic ingestion of lead生長(zhǎng)緩慢Decreased rate of growth貧血Anemi

6、a診斷Diagnosis病史，臨床癥狀，尸體剖檢和全血鉛水平History, clinical signs, post mortem results & whole blood levels of lead鑒別診斷Differential Diagnosis腦灰質(zhì)軟化病Polioencephalomalacia維生素A缺乏癥Vitamin A deficiency低鎂抽搐癥Hypomagnesaemia Tetany神經(jīng)性酮病Nervous ketosis無(wú)機(jī)物砷中毒Inorganic arsenic poisoning偽狂犬Rabies腦膜腦炎Meningoencephalitis食鹽中毒S

7、alt poisoning 實(shí)驗(yàn)室和病理學(xué)診斷Laboratory and Pathology全血中有鉛沉積(0.3 ppm)Lead concentration in whole blood (0.3 ppm)肝、腎(25 mg/kg 濕重)、網(wǎng)胃中鉛水平Lead levels in liver, kidney (25 mg/kg wet weight) or reticulum尸體剖檢-網(wǎng)胃中有鉛碎片 Post-mortem lead fragments in reticulum組織學(xué)-水腫和腦皮質(zhì)充血Histology - edema & congestion of cerebral c

8、ortex治療Treatment治療效果通常不好Response to treatment is often poor用安替比林和戊巴比妥以減輕急性神經(jīng)癥狀Sedation with pentobarbital to relieve acute nervous signs從網(wǎng)胃和瘤胃中取出鉛Rumenotomy to remove lead from reticulum and rumen靜脈注射6.6%的乙二胺四乙酸鈣， 0.5 ml/kg每天二次，連續(xù)用3-5天Ca EDTA (Calcium versenate) - 6.6% soln. administered IV 0.5 ml/kg twice daily for 3-5 days鹽酸維生素B1每天2 mg/kgThiamine HCl 2 mg/kg daily仔細(xì)護(hù)理Good nursing care瘤胃內(nèi)容物移植Rumen transplants預(yù)后情況Prognosis治療效果不好的謹(jǐn)慎Guarded to poor后遺癥Sequelae慢性生產(chǎn)性能低下Chronic poor doer乳、肉中鉛蓄積Accumulation of lead in the milk & meat預(yù)防Prevention & Control適當(dāng)?shù)臓I(yíng)養(yǎng)以防異食癖Adequate nutrition to help