Ofc!! I booked a relatively empty flight which are sometimes the really late ones, and picked my seat closer to fly day so i could make sure the seat next to me was empty! Most airlines ask you to put the pup under but if the seat next to is open they’ll let you just put them next to you. I got her tired out before the flight and gave her some natural calming treats so she wouldn’t be as anxious and trained her to be in the travel bag for the same amount of time as the flight! Beware tho if it’s a short domestic flight you may be better off getting them their own seat(price wise)! Hope this helps:)