I happened across this some time ago, at Terrierman’s Daily Dose. He has a large number of old photos of dogcarts all around the world; mostly they are carts for milk delivery or other kinds of small delivery, pulled by one or more dogs.
An example of a milk cart, full of canisters. The unhitched terrier is probably a guard dog.
Dog cart mobile tea delivery, Brussels, with three dog team.
Dog cart postcard, Quebec.
There are lots more pictures on his blog; check it out. He is a great believer in working dogs; in fact, the blog is connected with his website about working terriers: his hobby or possibly profession is hunting groundhogs, foxes, etc in their holes using terriers (often the prey are caught around farms and relocated to wilder areas).