You used a possessive there?

Is Schwab what Klaus calls his small dachshund next to the tiny shrivelled tennis balls?

Downvoted, huh? When something ends on an S, you (usually) do not end it like this: "Klaus's". You would (usually) end it with just the apostrophe, thus " Klaus' ". So when you say "Klaus' Schwab", you are saying Klaus's Schwab. A possessive.

You used a possessive there?

Is Schwab what Klaus calls his small dachshund next to the tiny shrivelled tennis balls?