Home › Animalia › Animal health › Animal diseases › Lead poisoning

environmental disease Sheep, Goat

Lead poisoning

Lead is a nervous system poison. In sheep, it causes behavioral and vision disorders that suggest a brain disease, although the cause lies in a corner of the farm. The sources are almost always ordinary objects: old paint peeling off doors...

Find a veterinarian All sheep diseases

Definition Signs Causes Diagnosis Treatment Prevention Complications When to see a vet Prognosis FAQ Sources Affected species

What is it?

Lead is a nervous system poison. In sheep, it causes behavioral and vision disorders that suggest a brain disease, although the cause lies in a corner of the farm.

The sources are almost always ordinary objects: old paint peeling off doors or beams, tractor or car batteries abandoned behind a building, used oil, fishing or hunting sinkers, pieces of gutter or pipe, illegal dumps and sites of former activities.

The animals, curious, lick and chew whatever is lying around. Young people are the most explorative, and therefore the most affected.

Key point

Lead poisoning extends beyond the herd: lead is deposited in bones, offal and milk, and is particularly dangerous for children. An exposed animal should neither be slaughtered nor milked for consumption without veterinary advice, even if it appears cured.

Commonly observed signs

These signs are neither exhaustive nor specific. Only a veterinarian can establish a diagnosis.

Related signs — each one links to its page:

Seizures Bumping into objects Circling Loss of sight Staggering gait Excessive salivation Grinding of teeth Diarrhea Reduction Unusual aggression

Behavioral disorders dominate the picture: animal which isolates itself, seems lost, no longer responds when called, pushes its head against a wall.

Sudden blindness: the animal bumps into obstacles, falls into ditches, no longer follows the herd. The pupils often remain wide open and no longer react to light.

Walks in a circle, always on the same side, staggering and uncoordinated gait.

Tremors of the muscles of the face and eyelids, chewing in space, grinding of teeth.

Profuse salivation.

Unusual aggression or, conversely, deep apathy in other animals.

Convulsions, falling, pedaling legs, death within a few hours to a few days in acute forms.

In slower forms: blackish diarrhea, colic, cessation of rumination, weight loss, general weakness, with more discreet nervous signs.

Several animals from the same batch can be affected at the same time, which points towards a common source.

When to consult without delay

This list does not replace veterinary advice. It gathers situations that justify a prompt consultation.

Causes and risk factors

Ingestion of lead, most of the time out of curiosity or boredom.

Old lead paint peeling from doors, gates, beams and walls of old buildings: animals lick the scales and surfaces.

Abandoned used batteries, whose plates are particularly dangerous. It is one of the most classic sources on farms.

Used oils, used greases, filters, workshop waste left accessible.

Wild dumps, rubble, contaminated landfill, former industrial sites or shooting ranges.

Hunting and fishing pellets, pieces of guttering, pipes or roofing.

Water circulating in old lead pipes.

An animal deficient, particularly in phosphorus, chews more on everything it finds: deficiencies therefore increase the risk of poisoning.

Old buildings with peeling paint, especially doors, gates and ledges that animals can lick.

Storage of equipment, batteries and workshop waste in areas accessible to the herd.

Grazing near landfills, illegal dumps, roadsides or backfilled land.

Young, curious and exploratory animals.

Animals with mineral deficiency, which chew everything they find.

Periods of lack of grass, when animals forage more.

Newly opened or recently cleaned plots where material may have been left.

Diagnosis and care

Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.

A blind sheep that runs in circles must be seen by a veterinarian quickly: several diseases give this picture and some, including this one, can be treated.

The veterinarian carries out a complete nervous examination and rules out other common causes in sheep: coenurosis, enterotoxemia, deficiencies, infectious brain diseases, other poisonings. This distinction is essential because the behaviors differ completely.

The history of the farm is decisive: the veterinarian will ask if work has been done, if batteries or waste are lying around, if the animals have had access to a new building or a new plot. Answer precisely, this guides the diagnosis better than an examination.

Blood tests are used to measure lead; the analysis can also be carried out on the liver and kidney of a dead animal, which is very useful for protecting the rest of the herd.

The veterinarian will, if necessary, inspect the buildings and plots to find the source. Without this, new cases will arise.

It will necessarily address the issue of residues in the meat and milk of exposed animals, and the steps to follow.

Treatment

It's an emergency: the sooner the treatment starts, the more likely it is to work.

Treatments to capture and eliminate lead exist and are administered by the veterinarian, on prescription and under supervision. They cannot be improvised and are themselves dangerous when misused.

Supportive treatment accompanies: control of convulsions, infusions, protection of the animal against injuries.

The first step, even before treatment, is to remove the entire lot from the affected area and find the source. As long as it is accessible, animals will continue to poison themselves.

No product should be administered by the breeder on his own initiative: farm remedies have no effectiveness here and delay the only useful treatment.

Animals having received lead cannot be slaughtered or milked without notice: the veterinarian will indicate the action to be taken and the applicable deadlines, because the residues persist for a long time in the body.

In very advanced forms, with established convulsions, euthanasia may be the most reasonable decision; it belongs to the veterinarian.

Treatment depends on the cause and the animal's condition: it must be determined by a veterinarian. No self-medication.

Prevention

Walk around the farm with fresh eyes, looking for anything a curious sheep might lick or chew. This is the most effective measure and costs nothing.

Remove and properly dispose of all used batteries, including those left behind a building for years.

Dispose of used oils, greases, filters and workshop waste in the designated channels, never in a corner of the plot.

Treat or replace old peeling paint in livestock buildings, and prevent access to affected surfaces during work.

Fence dumping areas, illegal dumps and suspect land, and do not graze animals there.

Particularly monitor young and batches placed in a newly opened building or plot.

Correct mineral deficiencies, which cause animals to chew on anything.

If in doubt about soil or water contamination, seek advice from the veterinarian before placing animals there.

Possible complications

Death from convulsions in acute forms, often in less than two days.

Permanent blindness and nervous after-effects in animals treated too late.

Injuries and fractures during seizures and falls.

Kidney and liver damage.

Abortions and lamb weakness in exposed pregnant females.

Persistent lead residues in the meat, offal and milk of exposed animals, even apparently cured: this is a public health issue, particularly serious for children, and this requires following the veterinarian's instructions before any slaughter or consumption.

New cases in the herd as long as the source remains accessible.

When to see a veterinarian

A sheep suddenly becomes blind, bumps into obstacles or can no longer find the flock.

An animal runs in circles, pushes its head against a wall or seems lost.

An animal presents facial tremors, chewing in space or convulsions: emergency, call immediately.

Several animals from the same batch present nervous disorders at the same time.

You discover a battery, waste or flaking paint in an area accessible to animals: call even if no one appears sick.

An animal died suddenly after gaining access to a new building or storage area.

Prognosis

Taken very early, before the convulsions set in, the animal can recover, sometimes completely.

Blindness and behavioral disorders that have existed for several days often leave permanent after-effects.

Acute forms with convulsions have a poor prognosis despite treatment.

At the herd level, the prognosis depends entirely on the discovery of the source: this alone puts an end to the series of cases.

The question of residues in meat and milk arises over the long term, even in animals which recover well.

Frequently asked questions

My sheep went blind overnight, is it the lead?

This is one of the possible causes, and it is one of those that can be treated, hence the urgency of consulting. Other sheep diseases give the same picture, notably whirling or enterotoxemia. Only the veterinarian can decide, with a lot of help from what you tell him about the farm and recent work.

Where could lead be found in my home?

Almost always in ordinary objects: an old battery behind a building, flakes of old paint on a door or a barrier, used oil, rubble, a dump at the edge of a plot. A careful tour of the farm is often enough to find the source.

Can I eat a sheep that has been poisoned and then treated?

Not without the advice of the veterinarian. Lead is deposited permanently in the bones, liver, kidneys and passes into milk. An animal can appear perfectly recovered while still retaining some residue. This is a serious public health issue, especially for children.

Only one animal is affected, should I take care of the others?

Yes. If one animal found lead, the others had access to it too. You need to remove the lot from the area, look for the source and talk to the veterinarian about screening exposed animals, even those that appear normal.