The Canterbury SPCA has taken in more than 150 pets from people displaced by the earthquake and has promised to care for them until they can be taken back.
Manager Geoff Sutton said the SPCA had given a commitment to those owners that it would care for the pets until they were ready for them.
Some of the pets were likely to be sent to other SPCA branches - such as Timaru - because the Christchurch SPCA could not hold them all.
"We have no idea if it's going to be for days, weeks or longer."
He said it was possible some would simply abandon their pets with the SPCA, so all owners had been told to stay in touch weekly.
"This is a member of your family and we will take absolute care of it in the meantime.
"But the expectation is that as a member of your family it is going to be part of your resettlement and we'll help until you manage to do that."
Scott Craigen delivered five of his six cats to the SPCA yesterday while the Herald was there.
His family was moving in with parents because their own house in Linwood was "sinking".
The cats could not go with them.
He said one cat - Trouble - was still missing "but I'm going to try and find him".
Clearly emotional, he said he did not want the cats to be put down and he was struggling with all the changes the earthquake had wrought on his life.
However, others were also bringing in "found" pets.
Lovena Fraser found "Benji" running on nearby Springs Rd.
She was keeping him at her own home with her father's dog Thomas and her three cats until the owner came for him.
A microchip could not be found, so she left her details with the SPCA.
Mr Sutton said if there were cases where the owner lost contact for a month to six weeks and the SPCA could not contact them, pets could be adopted out. However, it was sometimes difficult for people to find new homes that allowed pets, especially with rental properties where many landlords would not accept pets.
"It would be fantastic if landlords could be just a little bit softer for people who genuinely need to find new homes under these circumstances."
Mr Sutton said the SPCA was inundated with runaway dogs in the two days after the earthquake but most had since found their owners.
After that, cats began to come in "and that is going to snowball".
He said cats tended to hide away when scared and owners should not panic immediately because they could be hiding nearby.
A specialist team from Massey University and Wellington SPCA rescue crews were in Christchurch and would help with checking homes where animals could have been abandoned, including in evacuated areas.By Claire Trevett @CTrevettNZH Email Claire