Fleas/ticks HELP.

Pet owners !

I have a question.

So we have a 5 month old husky, and a 13 week old Pitbull. They stayed in our room/only upstairs since we got them. I did my next potty training them, taking them outside, etc. well. I can still take out the Pitbull as she’s not heavy (I’m pregnant) but the husky is... heavy and big and he’s terrified of the stairs. So my husband and I said let’s just keep them both outside for a while and he’ll teach him how to go up and down stairs in the meantime. And once he’s ready, we’ll put in back upstairs with us. Well. Koda (husky) and nala (Pitbull) now have fleas and some ticks. Which I’m not sure how because he’s treated, we’ve sprayed the yard with insect killer because we’ve been planting new grass. Anyways.

Are there any recommendations on flea/tick killer/preventions?

I got all the fleas and ticks off from nala because.. you know, short hair. And she’s a light brown so it was easy.

But, Koda, I can’t get them off him.

Please help 😭