We have a 1.5 year old puggle named Maia and a 4 month old doberman-retriever mix named Thor. Everything seemed fine between the two of them when we adopted Thor but now Maia won't share any toys with him. She will drop any toys that she's playing with to take away whatever toy Thor gets a hold of and will go out of her way to steal the spotlight at all costs.
We have always been very careful to give both of them equal attention and affection.
Any ideas on how to approach this problem are greatly appreciated.