The DSPCA have released CCTV footage of a man squeezing an injured dog under the shelter's gates.
The dog is said to have multiple fractures to its pelvis, nerve damage and bruising. With these injuries the manner in which the animal was pushed under the gates would have caused immense pain.
The shelter claimed the person who dumped "Peach" made no effort to contact the DSCPA, and described the act as "Upsetting and not acceptable".
The dog, a 1-2 year old terrier cross, is being looked after by the vets.