Manhattan Surrogate Judge Renee Roth has reduced the trust fund for the little dog, named "Trouble," from $12 million to $2 million.
The remaining $10 million now goes to Helmsley's charitable foundation.
The 9-year-old Maltese lives in Florida with Carl Lekic, the general manager of the Helmsley Sandcastle Hotel. Helmsley died last August.
The New York Post, which first reported the story, said Lekic put Trouble's annual cost at $190,000. That figure includes Lekic's $60,000 guardian fee, $100,000 for security, $8,000 for grooming, $3,000 for miscellaneous expenses, $1,200 for food and 2,500 to $18,000 for medical care.
The Post also that Judge Roth also gave $6 million to Helmsely's two disinherited grandchildren.
Roth's decision was made April 30, but only became public on Monday.