The FDA authorized Zoetis’s Simparica TRIO—already sold since 2020 for heartworm, fleas and ticks—for treating New World screwworm in dogs and puppies.

  • Acting FDA Commissioner Kyle Diamantas said the agency is giving vets and pet owners more options “in the unlikely event animals under their care become infested.”
  • The FDA’s move builds on Zoetis’ earlier steps to expand emergency access for its livestock products against the same parasite.
  • Michael Burry recently increased his Zoetis stake and has publicly backed the stock, viewing it as undervalued after its decline. 

Shares of Zoetis (ZTS) rose 3% on Thursday after the U.S. Food and Drug Administration (FDA) cleared emergency use of the company’s popular dog pill for treating a rare parasitic infestation.

The FDA authorized Simparica TRIO—already sold since 2020 for heartworm, fleas and ticks—for treating New World screwworm in dogs and puppies. The authorization covers treatment only, not prevention, and lasts until the emergency ends or is canceled.

Acting FDA Commissioner Kyle Diamantas said the agency is giving vets and pet owners more options “in the unlikely event animals under their care become infested.” Timothy Schell of the FDA’s Center for Veterinary Medicine added that owners should stay informed, not alarmed, and watch for signs such as visible maggots or bad odors in wounds. Cases so far are limited to parts of Texas and New Mexico, and risk remains low for most dogs.

The FDA’s move builds on Zoetis’ earlier steps to expand emergency access for its livestock products against the same parasite. Just a week ago, the company reported second-quarter results showing flat revenue of about $2.5 billion and cut its full-year 2026 outlook amid softer U.S. pet-product demand.

Burry’s Bull Thesis On Zoetis

Michael Burry, the Scion Asset Management founder and investor best known for predicting the 2008 housing-market collapse, recently increased his Zoetis stake and has publicly backed the stock, viewing it as undervalued after its decline and highlighting its strong finances and research strength compared with peers.

Burry argues the company now trades at a meaningful discount to rival Elanco even though it boasts stronger free-cash-flow conversion, a far cleaner balance sheet, higher historical returns on investment, superior pipeline productivity and roughly a two-to-one research-spending advantage. He has described recent U.S. market-share losses in dermatology as temporary rather than a terminal-decline story, noting that Zoetis would be better positioned in any price war, and continues to see the current valuation as offering attractive long-term upside.

How Did ZTS Retail Traders React?

On Stocktwits, retail sentiment around ZTS stock remained in the ‘bullish’ range over the past 24 hours, while message volume was at ‘high’ levels.

A Stocktwits user opined that the stock is now due for a bounce after the FDA approval.

ZTS stock has fallen 40% year-to-date. 

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