Not interchanged. Cat Milk and Dwarf Milk are FOR cats/dwarves, while Cow Milk and Sheep Milk are FROM cows/sheep.
A somewhat similar case is that a metal door is made FROM metal, while a basement door leads TO a basement, but there you'd at least have the indication that one is a material and one is a location (although what would a cheese door be? Made from cheese or leading to the cheese storage...). In Planescape Torment they had Baby Soap, if I remember correctly...
Interesting. I didn't realise our beloved game distinguished between milk intended for animals to drink and milk intended for sapients to drink, I thought it just registered it as milk. So only one definition would be relevant.
The cheese door is a more likely example here (strange moods are... well... strange sometimes) but can be solved with the word
room. "cheese room door" vs "cheese door", "cavern tree room door" vs "cavern tree door", or "camel hair room door" (sodding reanimating biomes and their reanimation of unkillable body parts
mutter mutter keep that door locked!) vs "camel hair door" (the result of a strange mood in a tannery). As native speakers we leave out the "room" part.
But I think we're getting off topic! Cannons!
Made me think of my wagon being scuttled, then used for parts. If you can butcher a wagon and get wagon wood, why not butcher the cannon and get cannon meat? I recommend young cannons, the older ones would be tough as an old lump of iron...