Chronic lead exposure in flock of backyard chickens
By Martin Ficken, DVM, PhD
The Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) in Gonzales received a phone call concerning a decrease in production and poor performance of a backyard flock of chickens used as an egg source for the family. Further discussions with the caller revealed the chickens had access to an old building with peeling paint that the chickens readily consumed.
It was requested that the family send in any dead chickens and some eggs for lead testing. TVMDL also suggested the chickens be denied access to the paint in case it contained lead and the family refrain from eating any eggs until testing could be completed.
A white-feathered rooster in poor body condition weighing 2.08 pounds was received for necropsy evaluation. In addition, four eggs were submitted.
Upon necropsy examination, a marked decrease in the size of the breast muscles with the keel being prominent was noted, evidence of emaciation. No other abnormalities were noted in any other tissue or organ system.
The liver from the rooster and the four eggs were submitted for lead analysis at the College Station laboratory with the following levels:
Liver – 1.18 parts per million wet weight (ppm);
Egg Yolk 1 – 0.62 ppm;
Egg Yolk 2 – 0.65 ppm;
Egg Yolk 3 – 2.05 ppm;
Egg Yolk 4 – 1.40 ppm.
Based on reference values for lead in poultry, the lead liver values were within the normal range. Levels aren’t considered toxic until they are more than 18 ppm. There are currently no reference values for egg yolks, therefore no comparisons were made.
Although toxic levels of lead, toxic to the chicken, were not present in the liver sample or any egg, levels above what are considered normal, background levels for food, were present in the liver and each egg. The family was contacted and it was highly recommended the chickens no longer be used for egg production and consumption. If raising chickens for eggs was desired, it was recommended new chickens be procured and the lead paint exposure be eliminated.
For more information about this case, contact Gonzales Resident Director Dr. Martin Ficken. To learn more about TVMDL’s test offerings, visit tvmdl.tamu.edu or call 1.888.646.5623.
Reference:
Fulton, RM. Toxins and Poisons (Lead) in Diseases of Poultry 13thedition Wiley-Blackwell, ed. Swayne, DE et al. pp. 1295-1297, 2013.