Earlier this week, a farmer in Cork lost seven animals after his herd came in contact with old batteries in a disused quarry. This week, specialist veterinary officers from the Department of Agriculture respond to queries and the risks involved.

Lead poisoning is the most commonly diagnosed cause of fatal poisoning in cattle presented for post-mortem examination to the Department’s veterinary laboratories. The 2014 All-island Animal Disease Surveillance Report shows that lead poisoning accounted for over 40% (28 cases) of all fatal poisonings in cattle on the island of Ireland.

It is likely that the true prevalence is higher than suggested in the surveillance report. Many cases can go undiagnosed; a sudden death that is not investigated may be attributed to another condition such as blackleg.

Key risks

  • Discarded lead batteries, lead-based paint, vehicle sump oil, lead shot, lead weights (fishing tackle), old vinyl from floor coverings and car seat covers, bonfire ash.
  • All age groups can be affected, and while most commonly seen in calves as they are more curious feeders, it is also found in beef animals and milking cow herds often causing more significant and far reaching losses for the farmer.
  • Cases tend to peak in early summer after animals are turned out to grass.
  • Catastrophic losses have occurred on occasion, where discarded batteries have been ensiled and this silage then fed to cattle.

    • Clinical signs and diagnosis

    Lead poisoning tends to cause sudden death in calves while clinical signs may last for longer in older cattle.

    There is usually a sudden onset of nervous signs including depression, blindness, frothing at the mouth, champing of the jaw, muscle tremors, staggering and convulsions, head pressing or a dummy like syndrome. In many cases, animals are found dead.

    Lead poisoning can often be diagnosed on clinical signs and finding a source of lead to which the animals had access. Measurement of lead levels by your local DAFM veterinary laboratory will confirm the diagnosis.

    Fresh samples of kidney from dead animals or whole blood from live animals (using EDTA / purple top bottle) are the samples of choice for submission to the laboratory.

    Treatment is rarely successful. In addition, from a public health perspective lead exposure in milking cattle or beef cattle being readied for slaughter has potential risks for the food chain, as well as having a severe financial impact on the farmer. Therefore prevention of lead poisoning is the best policy.

    Key prevention steps

    Prevention is a matter of not allowing cattle access to sources of lead:

  • Dispose of all lead batteries carefully according to local authority guidelines. Prior to disposal, ensure that batteries are kept where cattle can’t access them or where they or their leaked contents can’t end up in silage or in a diet feeder.
  • Ensure cattle do not have access to old cars or tractors or leakage from their batteries or sump oil.
  • Before cattle are turned out to grass in the spring and at regular intervals during the grazing season, search the fields for discarded batteries, lead shot or other possible sources of lead. This is especially important in fields bounded by a public road where illegal fly-tipped material may be a potential risk to grazing animals.
  • 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.

    • If you suspect lead poisoning in an animal, contact your vet. They will be able to advise you regarding the diagnosis and can arrange to have clinical samples tested or a post mortem conducted on your animal at a DAFM veterinary laboratory to confirm the diagnosis.