I have been told that when using he/she/it, it's usually simple to use der/die/das to work out how to refer to the thing.
- "The pen is big" becomes "Der Stift ist groß" leading to "Er ist groß"
- "The sun is hot" becomes "Die Sonne ist heiß" leading to "Sie ist heiß"
- "The ice is cold" becomes "Das Eis ist kalt" leading to "Es ist kalt"
So doing this with animals would be ...
- "The dog is black" becomes "Der Hund ist schwarz" leading to "Er ist schwarz"
- "The cat is white" becomes "Die Katze ist weiß" leading to "Sie ist weiß"
- "The horse is brown" becomes "Das Pferd ist braun" leading to "Es ist braun"
Without getting into too much biology, what would happen with a female dog, male cat or a horse of defined gender?
If the dog were known to be female and if that were important in the sentence, would I say "Sie is schwarz", or would I have to say "die Hündin ist schwarz"? Or have I got something else wrong?