NEW YORK (AP) — Drugmaker Pfizer Inc., which is spinning off its animal health business through an initial public offering, intends to sell 86.1 million shares of common stock.

New York-based Pfizer estimates the price for shares of the unit, called Zoetis (zoh-EHT'-ihs) Inc., at $22 to $25. At those prices, the IPO would raise $1.89 billion to $2.15 billion.

The business, which sells vaccines and medicines for pets and farm animals, had 2011 revenue of $4.2 billion.

That makes it the world’s largest animal health business, according to a prospectus Pfizer filed with the Securities and Exchange Commission. It notes Zoetis products are sold in more than 120 countries, in five major product categories.