Well, you see, there's nothing wrong on doing the predominantly animal cast. It will probably attract furry lovers but if you don't mind that then there's nothing wrong with it 
I mean, there's things like aggretsuko that are interesting to watch even if they are furries, so, in the end, what matters is what you want to draw!
Draw what you feel yourself is comfortable, since a comic is a project that will take you years to finish (or months depending how long it is), you need the motivation and dedication necessary to finish it, so what's important is what you want to draw, what makes sense and you find enjoyable to do!
The audience will always vary but the important thing is that you can convey a good story and people can notice the passion you have for it! There's audience for every kind of genre, you don't need to worry about putting people off, since there's always going to be a person put off with something! Don't try to pull in everyone, decide on what your audience is and cater to them, they will support your work no matter what you choose to do ^-^
And if you want to make another story with human characters later on, you can do that too
If you say your story has a mix of races and so on you could try having a mixed cast for variety ofc, but it'll be good as long and you feel compelled to draw the characters how you feel make more sense within your storyline and world 
