Glenties District Court heard that Hugh Mooney had been moving 42 sheep on September 21st last year at Doohill, Ardara when Seán Whyte approached in his car in which his four-year-old son was a passenger.
38-year-old Sean Whyte of Kinnaughty, Ardara, pulled out of a line of cars on to the other side of the road and overtook two cars before driving into the flock.
Mr Mooney, who works as a fisheries officer, told the court Whyte had driven with excessive acceleration.
All the sheep had to be vet- checked that evening while the deceased animal was sent to an incinerator in Cavan, all at a cost of €630 to Mr Mooney, which was paid into court.
Mr Mooney told the court that Whyte left the scene immediately after the incident but returned a short time later and “casually asked if he had injured any sheep”.
Judge Paul Kelly heard Whyte had one previous conviction for a fishing offence from last year.
Defence solicitor Cormac Hartnett said his client, a father of three, was pleading guilty to dangerous driving and animal cruelty.
He was fined €500 and disqualified from driving for two years on the dangerous driving charge.
Judge Kelly adjourned the case until October for a probation and community service report in relation to the animal cruelty charge, adding that he did not rule out dealing with the matter by way of a custodial sentence but would consider alternatives.