Three trolleys containing close to 20 cats and kittens have been abandoned outside the Rotorua SPCA.
Workers arrived at the shelter this morning to find the trolleys and a single cat-cage covered over containing 10 adult cats and eight kittens, Rotorua SPCA area manager Sue Kinsella said.
The felines were found about 7.45am today, with workers unsure of how long they had been there.
Kinsella said they expected that the abandonment happened early this morning or late last night.
All of the cats were showing signs of cat flu and distress and were being checked over by a vet, she said.
The cats would be quarantined until it was determined how sick they were to ensure the rest of the animals at the shelter were not at risk.
The sudden influx was putting "stress on our limited resources", Kinsella said.
As the weather warmed up, there was often a spike in abandonments for a number of different reasons. These included unplanned litters, unwanted pets or for social reasons like moving away, she said.
Kinsella was pleading for anyone who may have seen the people with the trolleys or had any information regarding the abandonment to get in contact.
The team had contacted the council and local businesses to view available CCTV images in the area.
The cats would be advertised individually on the SPCA Rotorua website and Facebook soon.