When we do see lead poisoning, the prognosis for the affected animal is usually quite poor.
Causes Of Lead Poisoning
The cause of lead poisoning is ingestion of high levels of lead by animals, and a common source of this can be damaged car batteries in fields (either intentionally in the field to power an electric fence, or dumped in the field by fly-tippers). Ensuring that any batteries being used to power electric fences are covered and that animals cannot access them is a good way of preventing such incidents.
Signs Of Lead Poisoning
The clinical signs of lead poisoning begin with sudden-onset blindness with no obvious damage to the eye, hypersensitivity to touch and to noise and often the animals will be hanging away from the rest of the group. This can progress to staggering and seizure like activity (similar to what you may see in an animal with grass staggers, which would be among the differential diagnoses in an animal presenting like this).
Treating Lead Poisoning
Treatment is usually un-rewarding in all but recently unwell animals, as the damage to the brain is often severe in more chronic cases. In acute cases we can try to treat via administering specific drugs IV and orally, but again the prognosis would always be guarded. Preventing access to potential lead sources (batteries, old woodwork/gates painted with lead paint etc.) is the best option in terms of minimising the risk of disease. This would include regularly checking fields and ditches for fly-tipped material, which may be a source of contamination.