Three US animal welfare groups filed court papers in New York accusing Leona Helmsley's trustees of a "scheme to deprive dog welfare charities" of their share of her fortune.
The groups said Helmsley, who died in 2007, primarily intended to give her fortune to dog causes.
They said a judge's February decision giving the trustees sole authority to decide what to do with her fortune should be thrown out.
The trustees said Ms Helmsley did not intend for the charitable trust to focus on dogs.
Ms Helmsley's will named her dog as a beneficiary. The Maltese named Trouble is living in Florida on a two million US dollar trust fund.