can prestidigitation change the scent of a character to mask an invisible/stealthy mage to allow the mage get past guard dogs?
thanks in advance
The general rule of thumb tends to be that a lower level spell cannot replicate an effect associated with a higher-level spell. The level 1 spell Negate Aroma exists for this specific purpose, so I'd say no, you couldn't use Prestidigitation to achieve the same effect.
I say that you couldn't necessarily do that, but you could project your scent into another area to throw off guard dogs. The spell is meant to be used for RP purposes, and that would be a clever form of RP.
THIS I might allow, from a table perspective. Essentially I would allow you to use Prestidigitation to force a penalty on the creatures trying to track you by scent; it might not be much, but it would be enough.