Animal manager Julie Richardson said while the society did not encourage giving animals as gifts, those kittens picked up on Christmas Eve had been planned adoptions.
The parents had come in earlier to discuss adoption and choose a kitten, and had planned to be at home during the Christmas holiday period while the kitten settled into its new home.
"Generally, people adopting from us know we are against pets being given as gifts."
This time of year was always busy for the society as its catteries and kennels filled up with unwanted kittens and puppies, and there were still "heaps [of kittens] in the wings" needing new homes.
The period between Christmas and New Year was often quiet for adoptions, with many families away on holiday, but Ms Richardson was hopeful it would pick up again after New Year.
A plea last week for donations of kitten and puppy food had some impact, which was fantastic, she said.
As the society's Opoho haven was full, she asked people to consider bringing unwanted kittens and puppies to them only as a last resort if they had been unable to find new homes themselves.
The society also has about 34 adult cats and about 15 dogs and puppies waiting for adoption.