Hi, Well let's start with your current lawn. First, you don't say why it's thin. Is it because of poor soil, too much shade, or heavy traffic from the dogs. If I had some insight into why it's thin, I could be more help. However, if your yard gets plenty of sunlight, it could be that your soil is compacted and needs to be improved first. I don't think you should spend money on weed/feed products or even grass seed until you figure out why you don't have a lawn now. if it's a soil problem, you'll need to consider improving your soil by bringing in fresh soil, compost or other product to incorporate into your existing soil. If, however, your thin turf is caused by the dogs, then nothing you are wanting to do will probably work. If you have large dogs that have free reign in the backyard all day long, you won't have a good lawn. It's that simple. Unless you cordon off an area just for the dogs or only leave the dogs loose in the yard while you can supervise. This is especially true if you don't walk your dogs and they are forced to use the backyard as a bathroom. If they relieve themselves there all day long, your dreams of a lawn will be dim. If this is the case, I highly recommend walking your dogs regularly for their exercise and to allow them to relieve themselves elsewhere (be sure to pick up after them) and then, creating a space for them in the backyard with a gravel or concrete base where they can spend time. Now, assuming the dogs aren't the problem and you've fixed your soil, you should seed first. After the turf germinates you can begin a weed and feed program. But, again, don't spend the money unless you figure out why you have bad turf to begin with. And, if it turns out you have overhanging trees that are actually shading out your lawn, you may need to go with a mulch instead of grass. If it's too shady to keep your current lawn going, re-seeding won't help.