Lead poisoning

Dairy cow with lead poisoning

What to look for

Ranges from sudden death to nervous signs, weight loss and weakness. Signs depend on the amount and form of lead eaten by the animal

In the more acute form:

  • Staggering, depression, blindness
  • Failure to eat, changed behaviour and convulsions

In the more chronic form:

  • Weight loss, poor appetite
  • Depression and a range of nervous signs


Ingestion of toxic amounts of lead

Animals likely to be affected

Most often seen in younger animals. Calves tend to be more curious and are more susceptible to poisoning, especially when on milk based diets.

Other diseases with similar signs

Can be confused with other causes of sudden death and also diseases that cause nervous signs such as grass tetany, listeriosispolioencephalomalacia or ketosis.

Confirming the diagnosis

Lead poisoning may be confirmed by blood tests but these are not very reliable. In dead animals the lead levels in tissues can be determined and, in some cases, it may be possible to find lead particles in the rumen or reticulum.

Risks to people

People are also vulnerable to lead poisoning and care always needs to taken in handling lead sources especially in old buildings where lead-based paints may have been used.


Animals may recover from lead poisoning if they receive veterinary treatment at an early stage. Young animals are less likely to respond to treatment.

Risk factors

• Animals have access to sources of lead e.g. discarded car batteries, lead flashing or pipes
• Housing calves in buildings with walls or woodwork painted with old lead-based paints

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