Guernsey farmer Marcel Worley is urging members of the public to keep their dogs on leads when walking near fields with livestock.
Mr Worley's flock of pregnant ewes were chased by a loose dog on 7 February. He says his "sheep were terrified" as they broke through electric fences and bolted across three fields and a road.
The video posted on social media by Mr Worley has been viewed more than 7,000 times.
On 10 February, Guernsey's Chief Minister said members of the public "should make sure their dogs are under control" in relation to the incident.
Mr Worley says the level of stress this causes to ewes can "make them abort their own pregnancies".
Lambing season begins in March and Mr Worley hopes members of the public "listen to the advice".