While the Government plans to introduce open access to the countryside, Plaid Cymru has issued a warning following the publication of HSE figures.
Recent HSE figures show 74 deaths involving cattle in the last 15 years and a series of high-profile animal welfare incidents linked to public access to farmland.
The prospect of introducing a right of access to all land in Wales was outlined in a Government consultation on improving opportunities to access outdoors for recreation.
Plaid Cymru shadow minister for rural affairs, Llyr Gruffydd, said: "A quarter of Wales is already designated as open land and we have over 20,000 miles of public rights of way. There has been a threefold increase in land accessible by right by the public since 2005 meaning that over a million acres of Welsh countryside is already accessible to the public.
"If the Government genuinely wants to encourage more access then it should start by promoting the better use of what we already have. Flinging the farm gates wide open by introducing open access to all land in Wales is the wrong approach."
Earlier this year, a dog walker in her 50s was trampled by cows in a field in North Wales and there have been other incidents, including one fatality throughout the UK in the last 12 months.
Mr Gruffydd continued: "Recent incidents involving dog attacks on livestock have reminded us that allowing public access onto farmland brings with it risks to land owners and for animal welfare.
"Health and Safety Executive statistics also highlight the dangers to the public in terms of injury and deaths. Among the 74 fatalities involving cattle were 18 members of the public who were either rambling or walking their dogs."
Farmers Guardian has been running its Take The Lead campaign to encourage dog walkers to take more responsibility of their animals when walking in the countryside.
Mr Gruffydd explained how almost all of the incidents stated in the HSE report involve dogs.
He said: "If a dog comes between a cow and its calf then that can trigger an attack, which makes it all the more important that people do not wander at random and put themselves in danger."
"Wales has a countryside of which we can all be proud. Allowing responsible use of it by the public has clear benefits for health and our economy. As well as the national coastal path, our citizens already have access to hundreds of thousands of hectares of land and I don’t believe we’re making the best of this existing potential.
"The Government would do well to deliver more effectively on what we already have before seeking to introduce open access to all land in Wales."
FG launched its Take the Lead campaign last Easter in response to the growing problem and has been working hard to educate pet owners about the devastating impact loose dogs can have on livestock.
If you would like some of our Take the Lead signs which warn dog owners to keep their pets on a lead around livestock, send a stamped, self-addressed A4 envelope to:
FG Take the Lead, Farmers Guardian,
Unit 4, Fulwood Business Park,
Preston, Lancashire, PR2 9NZ