The racing pigeons had their necks broken after the lofts at an allotment at Malleny Croft, near Currie Rugby Club, Edinburgh, were forced open overnight on Thursday.
Owner James Dickson said he was devastated to find the birds dead when he went to the lofts yesterday morning. He said he did not believe it was the act of rival enthusiasts.
He said: "I just went up to feed them and I could see the door swinging open. They were all dead. They were throttled. Every single one. They weren't champions, but they were good doos.
"I don't know how I'm going to explain it to my granddaughters. They're just four and five and come up here with me."
The estimated cost of the dead pigeons is approximately £5000.
A Lothian and Borders Police spokesman said: "We are appealing to anyone who was in the area yesterday evening or overnight, who saw or heard any suspicious activity, to contact police immediately."