Veterinary advice should be sought from your local veterinarian before applying any treatment or vaccine. Not sure who to use? Look up veterinarians who specialize in poultry using our directory listing. Find me a Vet

Lead Poisoning

Other Names: Lead Toxicity

Lead poisoning is an increasingly common problem in backyard chickens living in urban environments. It is not only detrimental to the bird's health, but also to the humans who consume the eggs laid by the hens. In one study conducted on backyard hens living in the Boston area, 98% of the eggs contained detectable concentrations of lead, due to exposure to contaminated soil.

Lead is a very dense metal and a strong neurotoxin. If ingested, since the metal is so dense and not easily oxidized, it will remain in the chicken's gastrointestinal tract. There it will slowly get absorbed and released into the bloodsteam, resulting in anemia and interference with the bird's ability to absorb calcium (leading to hypocalcemia, especially in hens).

Clinical Presentation

Lead poisoning can present in chickens in acute or chronic form, depending on the extent of exposure and the amount of lead ingested.
  • Acute form: Results in sudden onset of muscle weakness, loss of appetite, marked weight loss, ataxia, drop in egg production and severe anemia.
  • Chronic form: Causes demyelination of the vagus and other nerves, which results in decreased gastrointestinal motility secondary to blockage of nerve conduction. Chickens often present with delayed crop emptying, sour crop, or crop impactions. Greenish diarrhea may stain feathers around the vent (pasty butt).

How Lead Poisoning is Diagnosed

Lead poisoning can be confirmed through a simple blood test----by sending a small sample of the chicken's blood to a laboratory to confirm the presence of elevated concentrations of lead. Amounts of 11 u/dL and above are indicative of toxicity. In some cases, lead particles may be seen in radiographs, however not in all cases. Radiographic identification of a metallic foreign body with clinical signs of lead toxicosis is suggestive of lead poisoning. However, the absence of metallic density does not rule out lead toxicosis.

Treatment for Lead Poisoning

Treatment of chickens with lead poisoning consists of four different aspects: supportive care, chelation therapy, removal of the foreign bodies, and elimination of the source of lead from the bird's environment.
  • Supportive care: May include fluid therapy, parenteral multivitamins, and tube feeding.
  • Chelation therapy: Various agents include edetate calcium disodium (CaEDTA), D-penicillamine, and dimercaptosuccinic acid. CaEDTA is the agent of choice to initiate therapy, because birds often have decreased gastric motility or are regurgitating. Combination therapy can be used in severe cases. More than one course of treatment may be necessary, as lead concentrations equilibrate from the soft tissue into the bone and blood. CaEDTA chelates lead in the bone and the blood, but not in the soft tissue.
  • Removal of the foreign body: Can be achieved with administration of cathartics such as mineral oil, peanut butter, and magnesium sulfate (Epsom salt), which may facilitate the passage of small metallic particles through the digestive system. Endoscopy may also be used to retrieve metallic particles, but endoscopic removal of small particles may be difficult and sometimes impossible if ingesta are present in the proventriculus and ventriculus. Proventricular and ventricular flushing assisted with fluoroscopy is another means to remove foreign material.

Common Sources of Lead

Common sources of lead exposure include:
  • Lead-contaminated soil: There are many ways that soil can become contaminated with lead. Soil located on the side of the road of busy streets is frequently contaminated with lead, since lead was an ingredient in gasoline until the late 1970s. Soil that surrounds older painted structures, as lead-based paint may still be in the soil adjacent the building. Note that 74% of privately owned US homes built before 1980 still contain hazardous quantities of lead paint. The land could also contain lead contaminated waste (batteries, asphalt products, leaded gasoline, lead shot, putty, and spent oil) which may be above or buried within the soil. Any vegetation that grows on the soil will be contaminated with lead, making the vegetation hazardous to chickens who frequently seek out forage to eat when free ranging in grass.
  • Lead-contaminated water: Water can become contaminated with lead if it flows through old lead pipes or faucets--which was common during pre-1978 days.
  • Lead-contaminated food: Food that is stored or left for long periods of time in ceramic glazed bowls or glass (especially for red and yellow shades), or imported from countries that use lead to seal canned food.
  • Consumer products: Batteries, curtain weights, foil from champagne bottles, stained glass, chandeliers, electronic devices, ammunition, inks, small toys, lubricants, bearings, linoleum, jewelry, fishing gear, solder, ceramics, and plastics.
  • Building materials: Lead is used in roofing material, cladding, flashing, gutters and gutter joints, and on roof parapets.
  • Sound dampening materials: Sheet-lead is used as a sound deadening layer in the walls, floors, and ceilings of sound studios.
Potential Toxic Lead Sources for Chickens

Clinical Signs

Reduced appetite
Pale comb
Weight loss
Greenish diarrhea
Polyuria (watery droppings)
Head tilt
Wing droop
Leg paresis or paralysis
Head tremors
Delayed crop emptying


  • History of exposure
  • Clinical signs
  • CBC - mild to moderate anemia
  • Blood test - who blood lead levels above 0.2 ppm
  • Radiographs - presence of a metallic density

Reported Cases

  • Case 1: Lead poisoning in a Guinea fowl A male guinea fowl was presented to the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) for necropsy. History noted the bird was bright and alert, but moved very little, appeared cold and very thin – only weighing 514 grams. Upon evaluation, marked breast muscle atrophy was present. The bird appeared pale and the blood was thin and watery. The crop was severely dilated and impacted with seed. The gizzard contained dark brownish-black fluid and the koilin layer was necrotic with numerous erosions and was dark in color. Upon further examination, approximately 75 small lead pellets were discovered in the gizzard contents. Representative pellets. Additionally, intestinal scrapings demonstrated small numbers of roundworm larvae. Chronic lead poisoning was the presumptive diagnosis. Due to the presence of lead shot in the gizzard, confirmatory testing of the liver was declined. Ref

  • Case 2: Lead toxicosis in a Chicken Lead toxicosis was the cause of an inability to stand, a twisted neck and not eating and drinking in a one-year-old backyard chicken that died. Brain and gizzard koilin lesions were found on histopathology. Ref

  • Case 3: Ingestion of lead drapery weights in a Macaw A juvenile domestic green-winged macaw was admitted to the veterinary clinic within an hour of ingestion of lead drapery weights. Radiopaque objects were evident in the crop and ventriculus. The bird was anesthetized, and the crop was lavaged to remove lead fragments. Because lead fragments remained in the ventriculus after lavage, chelation treatment was instituted. Serial radiography was done on days 2, 5, 9, and 14 to determine passage of the lead. By day 14, lead fragments were not visible radiographically. The macaw did not have ill effects from the lead ingestion or from medical treatments. Because this bird had been observed ingesting the lead weights, treatment was for foreign body ingestion initially and for lead ingestion secondarily. Ref


Supportive careIsolate the bird from the flock and place in a safe, comfortable, warm location (your own chicken "intensive care unit") with easy access to water and food. Limit stress. Call your veterinarian.
Calcium disodium edetate30-35 mg/kg IM, IV q8-12h x 3-5 days, off 3-4 days, repeat prnB Speer
Penicillamine50-55 mg/kg PO q24 x 1-6 weeksB Speer
Dimercaptosuccinic acid25-35 mg/kg PO q12h x 5 days/week x 3-5 weeksB Speer
Removal of the foreign bodyAdministration of cathartics such as mineral oil, peanut butter, or magnesium sulfate (Epsom salt). Endoscopy or surgery may be required.
Control of seizuresDiazepam (0.5-1.0 mg/kg IM two or three times daily or as needed)



  • Provide chickens their feed in feeders, and avoid scattering on the ground.
  • Test soil and water for lead concentrations
  • If chickens are enclosed in an outdoor run, prevent them from access the ground soil by elevating the floor using wood pallets, covered with large rubber mats (like those used for horse stalls).
  • Check exterior paint on old buildings and nearby structures as it can peel or flake off and contaminate the soil.

Scientific References

Risk Factors

  • Allowing chickens to freely graze on land adjacent US homes that were built before 1980
  • Unsupervised house chickens
  • Soil surrounding old, painted structures such as houses, barns, tools sheds, etc.
  • Lead pipes or faucets used for water supply
  • Chickens on a low-protein and low calcium diet will be more adversely affected by lead toxicity.