Staff from the RSPCA's Wales head office have lobbied the animal charity's AGM on Saturday in protest at up to 25 proposed job cuts.
Staff fear animal welfare will suffer in the cuts
Workers at the charity's centre in Brecon had been told that the posts were safe as the organisation sought to make £7.5m savings over five years.
But just a month after these assurances, they learnt around two dozen jobs are to go as the charity seeks to halve its UK regional management areas from 10 to five.
Nine staff from the office, including animal welfare inspectors, travelled to Birmingham to hand out leaflets and speak to RSPCA members heading in to the meeting.
Bryn Pass, of the union Amicus, said many rank-and-file RSPCA members were not aware of the plans to make 200 staff redundant around the UK.
Brecon workers deal with animal welfare calls 24 hours a day
"We wanted to highlight this problem to the ordinary members of the society.
"The decisions taken by management and council will have a direct effect on animal welfare."
He said the plan to replace regional centres with a national control centre run by a private operator would hit the society's ability to respond to calls about sick or injured animals.
"All that advice and experience is going to be lost when the closure happens.
"A call centre's main task will be to raise money. With 30 less staff taking 1.5m calls, the service is going to be reduced.
"If calls are put on waiting, animals are going to suffer."
Lyn Williams, the inspector for west Gwynedd and Snowdon and also staff representative for the union MSF, agreed.
He said: "Experience has taught us that it's retrograde step. We feel that there has been another agenda on the table for a long time."
The RSPCA hit financial problems following heavy losses on its stock market investments last year.
It has said RSPCA Cymru will continue and retain its identity.
Mr Williams said the office would lose its ability to deal with inquiries from Welsh speakers.