A planning study will again assess whether the RSPCA could be co-located with Domestic Animal Services or whether its current Weston site should be upgraded, as part of additional funding announced by the ACT government.
The extra $300,000 announced on Tuesday would also fund new kennel facilities and a dental X-ray machine.
City Services Minister Chris Steel said he looked forward to continued collaboration between the RSPCA and Domestic Animal Services.
"The RSPCA works collaboratively with Domestic Animal Services and we will explore whether co-location of both facilities will improve animal welfare and provide benefits for both animal welfare organisations.
Mr Steel said the RSPCA and Domestic Animal Services both had ageing facilities and the study would look at all options, including two separate facilities or a joint facility.
"This is an opportunity to both ensure animal welfare outcomes but also deliver more effective and efficient services," he said.
Chief Minister Andrew Barr said government funding helped the RSPCA provide animal management and welfare services.
"I am pleased that this year we are able to provide additional funding for the RSPCA to continue to meet its demanding workload and further enhance its level of service," he said.
In 2013, the ACT government announced the RSPCA would be forced to move to Symonston with Domestic Animal Services to free the Weston site up for development but backed away from the plan in 2016.
RSPCA chief executive Michelle Robertson said the 2013 plans for the organisation to move to Symonston did not materialise for a number of reasons.
"Although there has been a lot that has changed since then, any historic relevant contributing factors and considerations will be taken into account as the future plans are finalised," she said.
An ACT government spokeswoman said the RSPCA did not consider Symonston to be a suitable location and had indicated a preference to stay in the Weston Creek and Molonglo region.
"The Project Home planning study will take this into account, along with opportunities to better align RSPCA and ACT government services in relation to animal welfare," she said.
Ms Robertson said the outcomes achieved by the RSPCA were in spite of the facilities it had.
"If we have the facilities that we need, we can achieve even greater outcomes. Every week we've got animals on the surrender list, every week we get phone calls for emergency boarding.
"We wish could help every single animal and every single person that requires our help, but we're simply not able to at this stage," she said.
Ms Robertson said the RSPCA needed to work through the planning process to make sure the organisation had the right equipment and facilities, whether shared or not.
The business case would help the organisation move forward with plans for its site, to make upgraded facilities a reality within five years, she said.
"In our last financial year, we had 3300 animals coming through the RSPCA. At this present moment, we've gout 208 animals in our care," Ms Robertson said.
"I can very proudly say that we've got one of the best live outcomes in the whole of Australia. We never, ever euthanise for space.
"We only euthanise on medical welfare reasons or for behaviour reasons. So we had close to 93 per cent live outcome rates in our last financial year," she said.