The trainer on the set reportedly provided a slow loris, a baby kangaroo and an exotic goat, but none of the creatures were used in the shoot after Gaga was bitten.
Not here for the biased OP leaving the part in the Article indicating that Gaga just laughed off the incident in good sports trying to make her look evil and hating on innocent animals.
However, the star wasn’t badly hurt and was able to laugh off the incident. The source adds, “She just laughed about it. She was a good sport.”
It's an animal, they bite. 
then
