I guess we are both wrong, this quote is directly from the voice actor of Goofy
“He is not a dog. Pluto is a dog, but Goofy seems to be in the canine family in the same way that a wolf is not a dog, but they also are in the canine family.”
"Who said Goofy is a cow?
Bill Farmer
Many hold firm that he too is a dog, however, there's also been rumors circulating for years that he's a cow!? To solve this mystery Yahoo Entertainment went straight to the source this week and asked Bill Farmer who has been voicing the role of Goofy since the 80s. And what he has to say might surprise you."
