Great question! I would love to know the precise answer.
You will find, I believe, that this is a tax agent question as it relates to assessible income and not something that we can answer without that asisstance. My suggestion would be to separate it from other revenue/drawings - so it is visible - and see if you can get tax agent advice specific to the client. The company structure will impact what they say, as well as the nature, size and reason for the donations.
Have a great week!