I'm very happy with my Burley. I know several people who've tried to save money and ended up having to buy a new trailer. So, don't skimp, get a good one.
I've pulled 2 dogs at a time in my Burley most of the time (my 3 dogs are 20, 22, and 11 lbs, respectively, so combos of that). It has a divider, so I can keep them apart or put a dog in there and groceries without the latter getting eaten. It's stable, tracks well and the dogs really like it. In the photos below is just Murphy with about 30 lbs of camera gear as well.
There are other trailers out there that are good for dogs. Another option is a good platform trailer to which you can attach a crate. The disadvantage is your pooch's view. The advantage is they are more secure. As you can see from the photo below, only if your dog is 100% comfortable can you trust him/her. My other dogs get leashed in and the doors are closed, but they can still see through the mesh.

Try feeding your dog in it first. Lock whichever trailer you get so it will not roll, put it in your house and use it as a crate for feeding, or to toss toys into... whatever to get your dog to go in it on their own. Do this for a week or so. Then add a gentle rocking to the trailer while they are chewing on a juicy bone. Then and only then, walk them around your house pushing the trailer by hand.