Zoetis, a New Jersey-based producer of medication for pets and livestock, has retained lawyer Philip L. Hirschhorn of Panitch Schwarze Belisario & Nadel as defense counsel in a pending patent infringement lawsuit. The case was filed May 4 in New Jersey District Court by FisherBroyles LLP on behalf of Epitopix LLC, doing business as Vaxxinova US. The court action asserts a patent for a siderophore receptor protein compound. The case, assigned to U.S. District Judge John Michael Vazquez, is 2:23-cv-02467, Epitopix, LLC v. Zoetis Inc.