I take out the "travel" toothbrush, aka the cheap ones. Then, when they're better, i give them their regular toothbrush with a brand new head. I also change the heads every 3 months.
I heard you’re supposed to change your toothbrush every few months, other than that… I’d swap it out after he’s done being sick or give a cheap one while sick and new one after
Our doctor has only told us to change their toothbrush three days after they start antibiotics for strep throat.. never advised otherwise due to sickness
I change it the second the illness starts. Use it til I feel better and get a new one again