So long as your dog is crated, many airlines, such as Alaskan or American Airlines, allow large dogs to be checked baggage. As the pet owner, you will bring your dog to check in as you would normally with your other bags, and then they will be weighed and moved like the rest of your bags.
How big can a dog carrier be for an airline?
There are no laws dictating the type of carrier to use, but remember that it must be small enough to fit under a standard airplane seat and should generally not exceed 45 linear inches (length + width + height), or roughly 21.5 by 15.5 by 9 inches. Depending on the airline, carrier size limits may be even smaller.