The Suffolk County SPCA said the pit bull was found tied to a shopping cart behind the Wal-Mart in Commack Monday.
Veterinarians said she was about 1 to 2 years old and has a skin disease, likely due to malnutrition. The animal was lactating, and SPCA investigators say they're concerned about where her puppies are.
The organization said the dog appears friendly and sweet.
Surveillance cameras captured an image (above left) of a man authorities want to question in connection with the abandonment.
Anyone with information about him or the dog is asked to call the Suffolk County SPCA at (631) 382-7722.