In Cavel International, Inc., v. Madigan, 500 F.3d 551 (7th Cir. 2007), the Seventh Circuit found that the ban was not discriminatory against interstate commerce,
Notably, the opinion was written by Judge Posner, an outspoken – and even published – critic on the subject of animal rights. See e.g., http://www.slate.com/id/110101 (debate with Peter Singer) and "Animal Rights: Legal, Philosophical, and Pragmatic Perspectives," in Animal Rights: Current Debates and New Directions 51, Martha C. Nussbaum and Cass R. Sunstein, eds. (2004). Nonetheless, beyond finding that “[s]tates have a legitimate interest in prolonging the lives of animals that their population happens to like” he mused in dicta that a state “is also permitted to take one step at a time on a road toward the humane treatment of our fellow animals.”