The RSPCA has slammed the person or people who broke into its animal rescue centre in Townsville, north-east Queensland, and set 31 dogs free.

About 30 volunteers and employees have been searching the suburbs of Shaw and Bohle for the dogs since 6:30am.

So far they have found 21 dogs and are continuing to search for the remaining 10.

Staff arrived at Townsville Animal Care Centre this morning to find all the doors open and the dogs gone, spokesman Michael Beatty said.

"Unfortunately some idiot has decided it would be a good idea to break into the shelter ... and let out all the adoption dogs," he said.

"Thirty-one dogs were on the loose this morning.

"It's just a totally irresponsible thing to do."

Mr Beatty said the RSPCA had called in every available volunteer to help find the dogs.

He asked members of the public to keep an eye out for any loose dogs in the suburb of Shaw and the surrounding area.

"If they do find a dog running loose, they're all micro-chipped, if they could either bring them into the shelter or give us a call," Mr Beatty said.

Staff and volunteers at the animal centre are searching Shaw and Bohle for the dogs. ( Supplied: Jacinta Wight )

"We just need to recover the dogs.

"They were all dogs that were looking for homes."

Mr Beatty said the person or people who broke into the shelter had no regard for the dogs or the employees and volunteers who work at the shelter.

"You've effectively ruined any form of Easter for staff and volunteers," he said.

"You've also put the lives of those dogs at risk, if they wander out toward the highway."

The centre's assistant manager, Jacinta Wight, said staff were angry and disappointed when they arrived at work this morning.

"It's just shocking, no-one can understand why anyone would do this," she said.

"We were hoping to get all the dogs new homes today, being a long weekend.

"We had an immediate response from our volunteers and foster carers."

A Queensland police spokesman said the incident was being investigated.