Donations are pouring in for the owner of a cat which was deliberately mauled by a dog in Porirua.

More than $21,000 has been raised in a Givealittle campaign for Jan Walton to cover the vet bills for her cat Tom.

READ MORE: Dog encouraged to savagely attack cat in Porirua

SPCA Wellington says two people told their muscular dog to "sic" Tom on New Year's Day at Camp Elsdon - and when the attack stopped, they left the scene laughing.

Tom is unable to walk after his pelvis was broken in the attack.

READ MORE: Injured cat's owner pushed to homelessness to cover vet bills

The SPCA says any extra funding raised through the Givealittle campaign will be put towards the cost of their investigation.

You can donate to Jan and Tom's Givealittle page here