STOCKMEN who accidentally inject oil-based vaccines into a thumb or finger could lose the digit without prompt and expert medical treatment, warns Fort Dodge Animal Health, the UK's largest supplier of pig vaccines.

Mr Ian Carroll, pig account manager, said vaccination by injection was now common practice to control a variety of diseases and 40-45pc of all UK pig herds were vaccinated against pneumonia.

"Unlike many continental countries where this task is performed only by a veterinary surgeon, in Britain it is invariably carried out by stockpeople with little or no supervision," he said.

Piglets were a particular problem. "When handling small, wriggling piglets it can be easy to inject into your own hand," said Mr Carroll. With oil-based vaccines this could be serious, and might need surgery to avoid long-term problems."

Fort Dodge has decided to use only oil-free vaccines - unless oil adjuvants offer major advantages - and has urged all farmers to ensure their staff are properly trained in correct injection techniques.