The dog was found lying motionless on a bed in its cage with red eyes and was not breathing properly.
Mr Chin told witnesses he had given the dog a pill, but the following morning the animal was dead.
At about 2pm the same day, a witness received a mobile phone message from Mr Chin stating that he had killed the dog.
An RSPCA inspector spoke to Mr Chin on March 5 and he told him the dog had a needle stuck in its throat. He admitted he would smack the puppy and knew it was wrong.
He also claimed he took the dog to a vet, but further enquiries revealed there were no records of the dog attending a veterinary clinic.