Word for the animal providing motive power for a vehicle?

Is there a general word or phrase that denotes an animal providing the motive power for a vehicle?

Something that might conceptually complete the phrase: "cars have engines; chariots have _______."

(I don't mind if the word semantically refers to horses, but ideally I would rather one that doesn't contain the string "horse".)

Some words or phrases that are similar to what I'm looking for, but don't quite fit:

• "Steed" or "Mount" - except that such an animal is being ridden, not moving a vehicle.
• "Beast of burden" - except that the emphasis is placed upon carrying a load, not moving a vehicle.
• "Workhorse" - except that the meaning is much, much broader than moving a vehicle; and it also contains the string "horse", which I would ideally avoid.

Such a beast (usually for hauling a freight vehicle) is called a draught animal:

A strong working animal used to draw a load like a cart, a plow etc, as opposed to a mount.

[Wiktionary]

Passenger carriages are rarely hauled by animals other than horses, and specially bred horses for performing this service are unsurprisingly known as carriage horses (see, for instance, Cona.org).

I think the term is:

Draft animal

any domesticated animal used in drawing heavy loads. Draft animals were in common use in Mesopotamia before 3000 BC for farm work and for pulling wheeled vehicles. Their use spread to the rest of the world over the following 2,500 years. While cattle, usually in teams, have been used most often as draft animals, horses and donkeys have supplanted them in many areas.

(britannica.com)