sledge vs dog sled

sledge and dog sled both are nouns.

Word	Noun	Adjective	Verb	Adverb
sledge	Yes	No	Yes	No
dog sled	Yes	No	No	No

As nouns, dog sled is a hyponym of sledge; that is, dog sled is a word with a more specific, narrower meaning than sledge:

sledge: a vehicle mounted on runners and pulled by horses or dogs; for transportation over snow
dog sled: a sled pulled by dogs

Other hyponyms of sledge include bob, bobsled, bobsleigh, bobsled, bobsleigh, dog sleigh, dogsled, luge, pung, toboggan.

sledge (noun)	dog sled (noun)
a heavy long-handled hammer used to drive stakes or wedges	a sled pulled by dogs
a vehicle mounted on runners and pulled by horses or dogs; for transportation over snow

sledge (verb)	dog sled (verb)
beat with a sledgehammer
transport in a sleigh
ride in or travel with a sledge