HBO "Real Time" host blasted factory farming as "just as despicable" as China's wet markets.
Maher said one reason he wasn't watching the "Tiger King" show was "because torturing animals is what got us into this mess."
"That's the lesson we keep refusing to learn, that you can't trash the environment -- including animals -- without it coming back and killing you," he warned.
Large meatpacking factories have been some of the biggest COVID-19 super-spreader hot spots in rural America.
"I've seen airports treat luggage better than we treat animals," Maher said.
The host broadcast his show from his back yard, where he had earlier been joined by Jay Leno.