"Whereas, we used to see six months of kittens and six months without. It is becoming an all-year game now."
Flis said the recent lockdowns had definitely contributed to the influx of kittens, as well as a few other factors.
"It's getting warmer. Cats breed when the weather is warm so we are getting milder winters and longer summers, so the breeding season increases. There are lots of factors.
"The main point we want to push out is de-sexing will see a reduction, it will take a few years, but just keep de-sexing."
Flis said in whatever capacity a family could help, SPCA would work alongside them to make it happen.
"We've got a family that home school their kids so they are home all day. We have some places that allow staff to bring in bottle fed kittens. We've got some that can only do in the school holidays. We will work around you. Short-term, long-term, weekends only, we will work with you."
Tracey Davis and her family became fosters at the start of level 4 lockdown in 2020, when they found a puppy that was lost and roaming the streets.
"We took it to SPCA and I found out you can foster puppies so we gave that a go."
They had two dogs before becoming a foster family and have since adopted one of the dogs that was in their care.
"It has been quite nice. There is always a little settling in period where you are getting used to having them. Once you get through that, it is a lot of fun."
Davis said they've had around 15 fosters come through over the last 18 months.
"I found that if I have two at a time, then I get to keep one for longer because some of them get re-homed really quickly. The SPCA has been really good to work with."
She loved the SPCA's new system that allowed people to 'trial' puppies in their homes to make sure they are a good fit for both the family and the dog.
Emma-Lise Simlick has fostered pets for the last two and a half years, with around 60 animals being in her care over that time.
"I will take anything that needs help. It is pretty challenging at times, but also pretty rewarding."
Cats, dogs and ducks are all among those who have been in Simlicks care.
She said SPCA was very supportive and provided all the food, medication and whatever else the animals needed.
"You are basically just donating your time and effort. If you need anything, they are just a call away."
Simlick said it is extremely rewarding helping animals in need and giving them the best chance at a long and healthy life.
"There was a group of puppies found in a box down at the North Mole last year. There were nine of them and I took in two of them. They were only a couple of days old so I had to bottle feed them.
"I had them for three months and they became super confident and healthy dogs and they both got adopted out. Recently, the owners have sent photos of what they look like now and it is just so rewarding seeing that."
To find out more about becoming a foster family, call SPCA Whanganui at 06 345 3369.