A subsidiary company of animal health and drug company Pfizer has been forced to undertake the staged withdrawal of a coccidiosis treatment after the Food and Drug Administration found it can cause the build-up of arsenic in chicken meat.


Trading under the name 3-Nitro in the USA the drug Roxarsone, used as a feed treatment to prevent gut diseases such as coccidiosis, contains less toxic organic arsenic, which has been shown can transform into inorganic arsenic.

Recently, scientists at the FDA perfected a new method of detecting low levels of inorganic arsenic in poultrymeat, specifically in chicken livers, and discovered elevated levels of inorganic arsenic compared to untreated control chickens.

Arsenic is a known cancer-causing agent in humans, but the FDA says the levels in chicken don’t pose any immediate threat.

Alpharma has said it will sell the drug for only 30 more days from 8 June to allow poultry and pig producers to convert to other treatments to stop gut diseases before withdrawing the drug completely from the US market.

3-Nitro is still available for use in pig and poultry in Canada, Mexico, Malaysia, Indonesia, the Philippines, Vietnam and for poultry only in Chile, Argentina, Peru, Venezuela, Brazil, Australia, Pakistan and Jordan.

All arsenic-based animal health treatments are banned in the EU.