Nevill E M
Onderstepoort J Vet Res. 1985 Dec;52(4):221-5.
The possible adverse effect of arsenical tick control dips on Parafilaria bovicola infections was investigated in 48 artificially infected cattle. A treatment group of 24 cattle was dipped in a plunge dip containing 1600 ppm arsenic trioxide. A control group of the same size was dipped in an organophosphate dip containing a mixture of chlorfenvinphos and dioxathion. Regular weekly to 3-weekly dipping had no effect initially on the prevalence of ovipositional blood spots of P. bovicola in either group. However, from 4 months after bleeding commenced there was a significant reduction in blood spots in the arsenic-dipped cattle and, on slaughter at 12-14 months after infection, the arsenic group had significantly fewer live worms and fewer carcass lesions. Arsenic residues in muscle samples of treated cattle were 11.6 times higher than in the controls. It is proposed that arsenic residues in the sub-cutaneous muscle layers increase with repeated dipping until a level toxic to P. bovicola is finally reached. Older cattle would therefore be refractory to infection and their carcasses at slaughter would not be affected.
在48头人工感染的牛身上研究了含砷杀蜱浸液对牛副丝虫感染可能产生的不良影响。将24头牛的治疗组浸入含有1600 ppm三氧化二砷的浸液池中。将相同数量的对照组浸入含有毒虫畏和二恶硫磷混合物的有机磷浸液中。最初，每周至每三周定期浸液对两组中牛副丝虫产卵血斑的发生率均无影响。然而，自开始放血4个月后，浸砷处理的牛的血斑显著减少，并且在感染后12 - 14个月屠宰时，砷处理组的活虫数量显著减少，胴体损伤也较少。处理过的牛的肌肉样本中的砷残留量比对照组高11.6倍。有人提出，皮下肌肉层中的砷残留量会随着反复浸液而增加，直至最终达到对牛副丝虫有毒的水平。因此，年龄较大的牛对感染具有抵抗力，屠宰时其胴体不会受到影响。
