Werewolf lore claims that vampires are manifestations of an entity they call the Wyrm, which obviously contradicts the Vampires' legend of being created by Caine. So do vampires have their own 'myth' explaining how werewolves came into existence?
One of the most popular versions says that werewolves have been created by Ennoia, the Gangrel Antideluvian (Source, history section), which explains why Gangrels and Garou share few common traits (shape change into animal form, control over animals and even they have a degree of non-aggression pact). So in other words werewolves would be some sort of failed experiment of the ancients.
But let me first point something: Garou KNOW that Wyrm exists in a same way you know that Earth is round - you might not been in space to see it but there is enough evidence to prove it. And using simple "sense Wyrm" gift werewolf can find (most) vampires, so vampires are "of the Wyrm"
Kindred on the other hand don't even have a proof that Caine ever existed! They have some legends about Abrahamic God and the First Murderer... but who really believes in that? What if vampire is (was?) Buddhist, Pagan or an atheist? So following this thoughts, who really believes that Ennoia really existed? Definitely not every vampire.
So there might be more theories, i.e. suggesting that Garou have simply evolved in similar way like i.e. sabretooth tigers: this would explain why normal mortal cannot become werewolf, while they can be awaken, embraced and of course killed to create (respectively) Mage, Vampire or Wraith. Or that maybe they are vampires that lost humanity. Or they are aliens.
In any way vampires know that werewolves are dangerous and mostly want to kill them.