Almost 3,000 dogs are currently in rescue centres or dog pounds across Ireland, according to the latest national census on homeless dogs.
The survey, the second of its kind, was compiled by MADRA Dog Rescue using information from more than 120 rescue organisations and local authority pounds.
The Galway-based charity said rescue centres and pounds remain at capacity, with 2,924 dogs currently without a home.
Director of Operations Dawn Divilly said it was the "norm" now for every rescue and shelter to be at capacity.
Speaking on RTÉ's News at One, she said the bigger challenge was the number of dogs they do not know about that are waiting to come in and that is where the "pressure is coming from".
"Everyone is working at capacity trying to rehome these 3,000 dogs they have so they can make space for the next dog that's waiting to come in," she said.
She said it is "really hard work" trying to rehome dogs, as it has become harder since the Covid-19 pandemic when owners' circumstances changed, swelling the numbers of unwanted dogs.
While the pandemic was one of the "major contributing factors" to the number of dog abandonments, others are human homelessness, and the cost-of-living crisis.
Ms Divilly said the new restrictions on XL bully dogs "will definitely put added pressure on rescues without a doubt".
"We've already seen since the ban was announced, lots more abandonment of dogs that may or may not fit the criteria to be an XL bully. So lots of bull breeds dogs that might look like an XL bully have been abandoned and surrendered in the last few months."
She said that as a result of the extension to the deadline ban, rescues and shelters which have XL bullys have until February 2025 to find homes for them.
But she said that because of the ban and "demonisation" of the breed, it is "not going to be easy" to find them homes and "there are some tough times ahead for those of us in rescue".
