When I only had 1-23lb dachshund, a pannier basket with a solid, modified bottom and a counter-weight worked very well. Gained a second dachshund, (22-pounder) and it was a perfectly balanced load. Off to the dogpark we went. Then (3 years later) came the 3rd dachshund, a 12-pounder. All three fit well into a modified kid-trailer. 3 years after that, came dachshund #4, a 27-pounder. Now we walk.