Animal welfare workers are to be balloted on whether to take strike action over a major restructuring which will cut 230 jobs across Britain.
Workers fear changes will hit the service provided
The RSPCA announced earlier this year that more than 20 of the jobs would be axed at its headquarters in Brecon in September.
The centre itself - the charity's main base in Wales which houses the control room taking calls from the public - will close in February.
Union leaders are also angry because they say the manager's job in Wales is being downgraded, and the post of press officer made part-time.
Both positions, along with that of the assembly officer, will relocate to Cardiff.
The number of inspectors who respond to calls will stay the same, but the number of market inspectors covering livestock sales in Wales has been reduced from nine to two, leaving smaller markets uncovered.
From Thursday, staff across Britain - including about 90 in Wales - will be balloted on whether to take strike action over the cut-backs.
The RSPCA is saving more than £7m by halving the number of management areas from 10 to five.
The charity has, however, promised that the it will retain its identity in Wales.
Emergency calls will be taken at a centralised control room
In June, staff from Brecon lobbied the animal charity's AGM in protest.
Workers are worried that 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.
The RSPCA hit financial problems following heavy losses on its stock market investments last year.