A convicted cocaine smuggler has been arrested for running what US authorities say appears to be a bestiality farm in Washington State in which visitors could engage in all sorts of twisted sex acts with animals.

Douglas Spink was arrested at his ramshackle, heavily wooded compound near the Canadian border along with a 51-year-old tourist from Great Britain who is accused of having sex with three dogs.

Dozens of dogs, horses and pet mice were seized, along with what investigators described as thousands of images of bestiality and apparent child pornography. The mice were euthanised, said Whatcom County Sheriff Bill Elfo, whose office assisted federal agents in the case.

"This stuff is just truly bizarre," he said. "These were mice that had their tails cut off, they were smothered in Vaseline and they had string tied around them."

It wasn't immediately clear whether other zoophilic tourists had been to Spink's farm, but Assistant US Attorney Susan Roe said on Friday, "I expect there may have been other people visiting the property".