Which of the following is a source of arsenic exposure in animals?

• A. Old pesticides
• B. Vitamin supplements
• C. New bedding materials
• D. Seawater

Answer: (A)

Arsenic exposure in animals is most often linked to persistent residues from historical arsenic-containing pesticides. These compounds were widely used on crops and in wood treatments, and they can remain in soil, dust, feed, and water for years. Animals grazing or housed in environments with these residues can ingest arsenic and gradually accumulate it, leading to toxicosis.

Vitamin supplements are not a typical source of arsenic in practice, and new bedding materials aren’t commonly treated with arsenic in a way that would cause significant exposure. Seawater does contain arsenic, but the forms and concentrations usually present are not a reliable or major source of toxic exposure for animals in everyday settings.