No, Au Pairs cannot have pet care responsibilities. Au Pairs can only provide child care related services and cannot be required to care for a pet.
Au Pairs can however, assist with pet care when it pertains to child care. For example, your Au Pair can assist your children who have pet care responsibilities. Some Au Pairs become so embedded into your family’s life that they voluntarily care for your pet(s) in addition to your children. Au Pairs can willingly assist with pet care, but it cannot be a formal responsibility or duty.
Au Pair applications contain information about pet restrictions the candidate may (or may not) have.
"I decided to become an Au Pair after I realized my true passion. I'd like to be an Au Pair because I enjoy taking care of children, their little minds work in the most interesting way, and this intrigues me. I'm also excited to travel, to learn about new cultures and experience life with children from different socio-economic backgrounds."