A Dictionary of Dream Symbols
by Eric Ackroyd(2) It may be a symbol of animal impulses, not in any aggressive or savage sense, but in the sense of what is pre-rational, non-intellectual - in other words, unconscious, intuitive.
In folklore, animals may have visions and speak with great wisdom. In dreams the humble ass or donkey may be telling you that you need to return to nature and observe the natural law of your being.
(3) Tony Crisp (Dream Dictionary) mentions the ass as a symbol of‘the plodding, long-suffering body5. Yes, but also remember that the body may eventually kick out at you if you go on neglecting or maltreating it.
Ten Thousand Dream Interpretation
by Gustavus Hindman MillerTo see donkeys carrying burdens, denotes that, after patience and toil, you will succeed in your undertakings, whether of travel or love.
If an ass pursues you, and you are afraid of it, you will be the victim of scandal or other displeasing reports.
If you unwillingly ride on one, or, as jockey, unnecessary quarrels may follow.
See Donkey.
Dream Symbols and Analysis
by DreamForthTo see an ass carrying a burden in your dream indicates that you will finally succeed in work as well as in relationships; but only after much time and effort.