The grim discovery was made by a walker near Inch Church at Castle Kennedy who notified the police.
The Scottish SPCA is also helping in the investigation to try and find the people who dumped the dogs in a wooded area near the church, just off the A75 Stranraer – Gretna Euro-route.
They are believed to be working on the theory that the dogs may have come to the end of their working days and have been dumped from a passing vehicle.
A number of incidents of dogs being found in lay-bys have been recorded in recent years across the country.
Police Scotland said they received the first report of the bodies of the three dogs on Thursday. The dogs had apparently been dumped at the side of the road near to Inch Church, Castle Kennedy.
They were located and enquiries are currently underway to establish the full circumstances of how they came to be there and how they died.
Arrangements have been made to have the dogs, which are in an advanced state of decomposition further examined.
Constable Clark Logie at Stranraer said: “We would like to hear from anyone who has any information as to how these dogs, which appear to be greyhound types, came to be dumped at the side of the road near to Inch Church.
“It does appear that they have been there for some considerable time and so we would be keen to hear from anyone who may have seen any suspicious activity around this area over the past weeks.”
He added: “We are at this time following a number of lines of enquiry however any help from the public would be appreciated.”
Over the past few years greyhounds and lurcher type dogs have been found dumped in lay-bys across the country with a number on the A75.
