Carriers: strollers, push carts

There are a variety of options available.

Pet Gear sells some sturdy, well thought out designs.

Croozer Mini Dog Bike Trailer attaches to a bike.

The Stroller Chassis's are nice for short walks. Some look sturdy enough for some hikes.

Check on Walmart, select pets (from the drop down menu) in 'Search' box and then type, stroller.

Or shop Pet Street Mall too.

Do your research before you buy. Some product photos may not accurately show how a carrier functions. And make sure to measure and weigh your dog, then select the best fitting product.