Gardaí found them close to Rathcline cemetery in Lanesborough on Tuesday.
The ISPCA says it is hard to know how long they were in the bag, but they are concerned the animals are suffering from exposure.
Three tiny little #kittens were discovered dumped in a plastic bag yesterday by An Garda Síochána, are now safe in #ISPCA care at the National Animal Centre #Longford.
Read more about this grim discovery here and how you can support the ISPCA if you can:https://t.co/RZ0PhLRkXP pic.twitter.com/mAGwva5Ges— ISPCA (@ISPCA1) August 26, 2020
Animal welfare officers believe the next few days will be critical, but they are hopeful the kittens will make full recoveries.
The kittens are now being cared for by animal welfare officers at the ISPCA's National Animal Centre.
ISPCA Centre Manager Hugh O'Toole says the kittens are lucky to be alive.
"The bag was soaked through so they were definitely out there a while, I presume overnight or at least 24 hours for the bag to get that wet.
"Luckily, with three of them, they were able to huddle in together to generate a bit of heat."
