The RSPCA has passed wide-ranging reforms to its governance, including more than halving the size of the board and introducing term limits.
At the charity’s annual general meeting on Saturday, it was agreed to reduce the size of the board from 28 to 12 trustees, including nine national charity members and three co-opted members.
The three co-opted members are already serving on the board and the RSPCA will now hold an election for the other nine positions.
Trustees will serve a maximum of nine years on the board at one go, with a three-year "clean break" required before they can stand again for a board position.
The term limits will apply retrospectively to anyone who has already served nine years or more on the current board.
Branch representatives will no longer sit on the board automatically and will instead sit on a new Branch Affairs Committee, which will report to the board, the RSPCA said.
The RSPCA has also modernised the language used to describe its governance arrangements, such as replacing the word "council" with "board of trustees".
The changes come after an independent review of the charity’s governance was published in 2017 and completed by Pesh Framjee, global lead on non-profits for the accountancy firm Crowe.
That review made a number of recommendations, including introducing three co-opted members of the board and enforcing the charity’s code of conduct more rigorously in board meetings.
The reforms come after a difficult few years for the charity. It operated for two years, between 2014 and 2016, without a chief executive, then Jeremy Cooper served only a year in the role before standing down in July 2017.
Chris Sherwood was appointed chief executive last year.
Sherwood said the membership’s decision on Saturday to vote more than 90 per cent in favour of the governance changes "represents the final step in a bold set of reforms".
He said: "These changes will result in a smaller, more nimble national board, in line with other major charities.
"It will ensure membership is refreshed regularly, bringing in different ideas and skills, and make being a trustee of the RSPCA more accessible and attractive to a wider range of people."
A spokeswoman for the Charity Commission said: "Good governance is fundamental to a charity’s success. We therefore welcome the RSPCA’s commitment to good governance after our regulatory engagement with the society over a number of years.
"It is for the charity to make decisions about its strategic direction. We note the changes that have been voted on and hope that they help the RSPCA move forward with high standards of governance."
The regulator will continue to engage with the charity until it is confident the reforms have been a success, the spokeswoman said.
The reforms were also welcomed by the trade union Unite, which said that they were a "big step forward" for the charity and the union had repeatedly pushed for an overhaul of the charity’s governance structures.