Is this mold?

This stuff keeps appearing on the bottom of my snake plant. It’s yellowish/brown and when I scrub it off it’s kind of crystal-y. I re-potted and changed the soil and it keeps coming back. Any recommendations to get rid of it? The plant itself is doing great, making new shoots etc.

FWIW I also have a dog… could it be dog pee? And on that note- is it safe for dogs and cats to be around whatever this is?