Last Updated Jul 16, 2015 11:05 AM EDT
In a letter to the chief executive of the warehouse retailer Thursday, Pitt told Craig Jelinek that caged birds suffer atrophy of their muscles and bones from years of immobility, and "cramming hens into cages for their entire lives constitutes cruelty to animals."
"As you know, these birds producing eggs for your shelves are crammed five or more into cages that are not large enough for even one hen to spread her wings," Pitt writes. "In these cruel cages, the animals' muscles and bones atrophy from years of immobilization. That's why the cages are illegal in most of Europe, and why California banned the cages by an overwhelming vote years ago."
Maher took aim at the company in an editorial published last week by The New York Times, and Gosling last month made the same appeal, with all three commending Costco for its other animal-welfare efforts and calling on the company to make good on its 2007 promise to move toward uncaging its egg-laying hens.
"Multiple investigations into battery cages document animals with deteriorated spinal cords, some who have become paralyzed and then mummified in their cages," Maher wrote. "Imagine cramming five cats or dogs into tiny cages, hundreds of thousands in each shed, for their entire lives. That would warrant cruelty charges, of course. But when the egg industry does it to hens, it's considered business as usual."
Pitt and Maher each spoke out on behalf of Farm Sanctuary, an organization that advocates against the mistreatment of animals and factory farming.
Gosling referred to a video recently released by the Humane Society of the United States, saying it showed "abhorrent cruelty including rows upon rows of birds confined in filth-laden cages with the mummified corpses of their cage-mates."
Beyond concerns for the well-being of animals, critics of caging hens have cited multiple studies that found housing hens in battery cages heightens the odds of salmonella poisoning.
Sen. Richard Blumenthal, a ranking member of the Senate Commerce Subcommittee on Consumer Protection, in June called on Costco to halt sales of eggs from caged hens, with the Connecticut Democrat citing the increased risk of salmonella outbreaks posed to Costco customers.
Costco declined comment when contacted about Gosling and Maher's appeals, and did not immediately respond to a request for comment to Pitt's letter.