To the city dweller, farms conjure up fluffy chicks, appealing lambs and rural purity. But the reality can be very different, according to the Health and Safety Executive, which is advising teachers to make their pupils aware of the potential dangers before a farm visit.

“Farm visits are a wonderful experience which children relish. We want pupils to have fun and learn from their day out, but we don’t want them to come away with zoonoses, diseases that can be transmitted by animals,” says Liz Justice, spokesperson for the HSE, which has just launched a campaign to improve children’s safety on farms.

Two research reports commissioned by the HSE reveal that farm visitors rarely understand the risks of catching a serious illness from a farm animal. In 1994, 288 people became ill after pupils visited a farm in Humberside where the animals had cryptosporidium, a parasite that causes diarrhoea in humans. Visitors are more at risk than those living on the farm, who are likely to have developed immunity.

The HSE advises that teachers should include possible hazards such as contracting the potentially fatal E. coli 0157 in the risk assessment they make before a trip.

The main message is that children must always wash their hands after touching or feeding animals; bacteria such as salmonella are easily spread if pupils eat or drink without washing their hands, or by younger children putting their fingers in their mouths. If the farm has no warning signs or proper facilities, teachers need to be extra careful, as this shows the farmer is not safety-conscious as far as young visitors are concerned.

Children view animals as friendly and approachable, but even small animals can give a nasty nip if they feel nervous or threatened, so don’t let pupils into a pen without a grown-up. Animals with young are the most likely to act aggressively.

Trailer rides are also risky, as children can fall off and be crushed by the wheels. Make sure there are enough adults for the pupils to work in small groups; this makes supervision easier and guards against the adventurous wandering off and falling into slurry pits or being suffocated by hay bales.

But the best way to avoid catastrophe, according to the HSE, is to discuss the risks with pupils before you go. It has produced a video aimed at older pupils and a workbook with stickers, puzzles and word searches for younger children, outlining the dangers.

The HSE is also keen to put the hazards in perspective; a pupil is still far more likely to be injured in a road accident or in the playground than on a farm.

The free booklet, Stay Safe - Farm Safety, and video, Safe! Helping Children to Stay Safe on the Farm (pound;29.38 inc VAT), are available from HSE Books, P O Box 1999, Sudbury, Suffolk CO10 2WA. Tel: 01787 881165