NFU Mutual said a significant proportion of attacks were caused by owners who let their dogs roam from homes adjoining countryside.
The number of sheep farmers in Wales losing stock to dog attacks has risen 113 per cent.
The figures were outed by NFU Mutual today (February 25) which revealed the cost of claims in the rest of the UK were however down 17 per cent, to £1.21 million.
It said the figures were suggestive of the number of dog owners leaving their pets unaccompanied in gardens, with a nine per cent rise to 52 per cent since last year.
Sixty per cent of respondents also admitted to allowing their dogs to roam off the lead when walking in the countryside.
North Wales Police Rural Crime Team manager Rob Taylor said livestock attacks were ‘all too regular’ in the country, with officers attending incidents on a weekly - and often daily - basis.
He said: “The law simply isn’t fit for 2019 and we are working hard to get that amended and also to educate irresponsible dog owners.”
NFU Mutual rural affairs specialist Tim Price said it was likely the national fall in claims was due to higher public awareness of the damage livestock worrying could cause.
Mr Price said: “While we have seen a very welcome fall in the costs of dog attacks on farm animals, the level of attacks is still very high – and we are very concerned by the huge surge in claims we have seen in Wales.
“The vast majority of dog owners act responsibly when exercising their pets in the countryside, and while more people may be putting their dog on the lead when farm animals are nearby, we think a significant proportion of attacks are caused by owners who let them roam from homes adjoining countryside and do not know – or do not care – that they are attacking farm animals.”
The research did however find most dog owners would support measures to crack down on livestock worrying, with 75 per cent supporting heavy fines, 66 per cent supporting a ban on dogs in livestock fields during lambing season and 57 per cent supporting laws enabling DNA testing of dogs suspected of attacking livestock.
A further 42 per cent said they would support a move to ban owners whose pets have worried livestock from keeping dogs.
It comes as the insurer ramps up awareness in the run up to Easter holidays with a new campaign urging dog owners to keep their pets under control in the countryside.