SPCA centres across the country have been inundated with animals since November, as the cost of living crisis has created barriers for adoptive pet-owners.
There are 3900 animals in SPCA shelters nationwide awaiting homes.
Dogs in particular are struggling to find owners, as adoptions have slowed down, meaning canines are spending 20 more days than usual in SPCA care.
"The reality is that there's a lot of pressure on us at the moment. We are at capacity, specifically for dogs, across most of our centres," said general manager Dr Corey Regnerus-Kell.
The busy period for the animal shelter had hit earlier than expected, and hundreds of cats and kittens were coming through centre doors each week, Dr Regnerus-Kell said.
"Holiday season is always a challenging time for us, particularly because it runs over the summer, which happens to overlap with kitten season."
The SPCA had nearly 3000 cats and kittens in its care nationwide, Dr Regnerus-Kell said.
"We were already getting March numbers of kittens and pregnant cats as early as early November."
While there has been an influx of kittens, it is dogs that are waiting for adoption the longest.
Dr Regnerus-Kell said the cost of living meant people were hesitant to commit to the cost of owning a dog or puppy.
"The feedback that we've been getting is that cost of living is definitely contributing to this.
"Keeping an animal does require a financial accountability from the new pet owner, and some people are concerned they might not be able to provide that, so they aren't as willing to pick up and care for a new dog."
Another pressure on the inundated shelters is a lack of foster families.
"We definitely do not have enough. We're always in need for more foster families."
The SPCA has more than 600 foster families who often take on more than one animal at a time.
But at this time of year, there is an extra need for fosters for recovering animals.
"We do find with a lot of our foster families, they want to go away on holiday too, so that increases the numbers back to the centres again."
The SPCA are launching an adoption push at the end of January, offering half-price adoption fees.
They hope this will help remove cost barriers for people who could provide homes for waiting pets.
RNZ