A member of the general public discovered the female cat inside a provider at the south entryway of Old Military Road on August 15.
The animal was handed in to the Scottish SPCA’s Dunbartonshire Animal Rescue and Rehoming Centre.
The charity is now appealing for details.
Centre assistant supervisor Ally Bibby said: “The cat is a female, black and white cat.
“She was discovered in a blue and white provider, which had a little label connected by string with ‘Snowball’ composed on it.
“Unfortunately she is not microchipped.
“We value that whoever left the cat might have planned for her to be discovered however this is not the appropriate method to quit an animal if you can no longer take care of them.
“If anyone has any information about this incident, or recognises the cat, we would encourage them to call our confidential animal helpline on 03000 999 999.”