I'm a single pet owner who works all day as well. I adopted Chloe (it'll be two years ago in July) from a local rescue. She was two years old at the time. I took some vacation time when I got her so that I could be there as she adjusted to her new surroundings. She gets walked three times a day (5:30 am weekdays, a little later on weekends, again when I get home from work and a final walk at 9 pm.) She's pretty much a slumbering slug the rest of the time. Sometimes after dinner she'll want me to play with some of her toys with her or she and the cat will chase each other through the apartment.

I deliberately did not get a puppy (athough the thought of having one was tempting) because I knew I would not have the time to spend with it during the day.