A member of the public called the Scottish SPCA after spotting the pet while throwing out rubbish at Dundonald Street, Dundee, on Friday.
The male pointer crossbreed was severely malnourished, dehydrated and was unable to stand. He was taken to a vet and had to be put to sleep.
Chief inspector John Carle said: “The dog was found at the bottom of a large metal bin, which our local inspector had to climb into in order to rescue him.
“We think it’s possible he was put into the bin late on Thursday night or in the early hours of Friday morning when it was dark.
“He was wearing a black nylon collar and had a black bag wrapped around his body from his waist down, but we don’t know if he was fully inside the bag when he was dumped.
“The dog was estimated to be between 10 and 12 years old, so we have to consider that he may have been abandoned due to his age, which is unthinkably cruel.
“This poor dog would have been absolutely terrified and was suffering a great deal when he was found.
“We are currently checking whether there is any CCTV nearby and we are appealing to anyone with information about this despicable act to help us with our investigation.
“If anyone knows of a person in the local area who recently owned a dog matching this description, we would urge them to contact us.”
The charity can be contacted on 03000 999 999.