Why don't you take inspiration from one of the many PETA (People for the Ethical Treatment of Animals) slogans:
- If you wouldn't wear your dog, please don't wear fur
- Feeding your children meat is child abuse.
- I'd rather go naked than wear fur.
try to use visuals as well, PETA do that very well.
'Animals don't deserved be abused.'
Animals are our best friends