The buttons are completed but I'm wondering if they need to be sealed in some way? Spray acrylic perhaps?

TIA Kimmers

Are the buttons visible? If so I would spray them with lacquer. Just because buttons are still antlers and will whitten over time. Better safe then sorry, just as long as you don't get any on the fur or anything else.

they really need to be sealed with something like lacquer.

Laquer is best