How would you attempting to convince an audience that animal testing is morally wrong using ethos

absolutely it most certainly can.

i would just say something like,

i need to go outside owner to pee, hold on owner let me mark this tree. i'm thirsty now "starts drinking water" now i am tired. what are you eating owner can i have some, you can't refuse my cute puppy eyes.

just make sure you write that in your own words that way you don't get in trouble.