The Department of Agriculture, Food and the Marine has reiterated a warning for livestock farmers on lead poisoning as stock are being turned out to pasture.

The department's Animal Health Surveillance service has said that lead poisonings diagnosed by the Veterinary Laboratory Service commonly peak in late spring and early summer.

To reduce risk of lead poisoning, farmers are urged to carefully check their fields and hedgerows for sources of lead, such as old car batteries, before turning cattle out to pasture and before silage making.

Hedgerows bounding public roads should be checked carefully for fly-tipping of risk materials. Where identified, sources of lead should be removed and disposed of safely.

Lead is highly toxic to animals, mainly affecting cattle and sheep, with calves being particularly at risk due to their increased susceptibility and curious nature.

The department said that catastrophic losses have occurred on occasion, where discarded batteries have been accidentally incorporated into silage and this silage then fed to cattle.

From a public health perspective, lead exposure in milking cattle, or beef cattle being readied for slaughter, also has potential risks for the food chain.

To protect the human food chain, cases of lead poisoning are investigated thoroughly, and certain restrictions may be applied, the department said.

Losses due to lead poisoning, not only of animals but also financially, can be substantial for the farmer.

Common sources of lead on farms are:

Lead batteries, including electric fencing batteries;
Discarded lead flashing and lead piping;
Bonfire ash;
Old lead paint tins and flaking lead paint.

Toxicity in animals can occur within 24 hours of exposure and signs range from sudden death to blindness, ataxia (poor muscle control), head pressing and convulsions.

Lead poisoning can often be diagnosed on clinical signs and finding a source of lead to which the animals had access. Measurement of lead concentrations in tissue or blood by a local department regional veterinary laboratory, on referral by a vet, will confirm the diagnosis.

Prevention of lead poisoning revolves around not allowing animals access to sources of lead.

Before cattle are turned out to grass in the spring and at regular intervals during the grazing season, farmers should search fields for discarded batteries, lead shot, old painted items or other possible sources of lead.

This is especially important in fields bounded by a public road where fly-tipped material may be a potential risk to grazing animals.

Farmers should also dispose of all lead batteries carefully, according to local authority guidelines. Prior to disposal, it should be ensured that batteries are kept where cattle cannot access them or where they, or their leaked contents, cannot end up in silage or in a diet feeder.

Other prevention tips include:

Ensure cattle do not have access to old cars or tractors or leakage from their batteries or sump oil;
Do not use timber painted with old toxic lead paints, like an old painted door, to block a gap or doorway, or leave them in areas that are accessible to cattle, especially calves, which have a tendency to lick such items;
Do not use lead pipes for plumbing, or red lead paint for preserving metalwork.

Farmers should contact their vet if they suspect lead poisoning in an animal.

Vets can advise the farmer regarding the diagnosis and can arrange to have clinical samples tested or a postmortem conducted on the animal at a department veterinary laboratory to confirm a diagnosis.