A couple suffered serious injuries when they were attacked by a Rottweiler on Sunday.Erika and Peter Petzner went for a walk in St. Stefan ob Leoben, Styria, when the three-year-old dog jumped over a fence and turned on the 48-year-old woman. She had to undergo surgery on both her arms at Leobens LKH clinic, while her husband, 52, also needed treatment of his injured lower arms.Dog owner Alois Rauter, 53, said today (Tues): “I dont know what was wrong with Arco. Im shocked by the incident.”The dog training school boss refused to reveal whether he had already made a decision over whether to put the 70-kilo animal down as a consequence.Rauter faces negligent bodily harm charges, while police are investigating whether the 120-centimetre fence was too low.The incident is only the latest in a series of canine attacks against humans.A 36-year-old from Bad Ischl, Upper Austria, had a chunk of her upper lip bitten off by her own Bernese Mountain Dog earlier this month. The woman had opened the boot of her car to let the animal out her when it suddenly attacked her.Last month, a two-year-old boy was seriously injured by a Rottweiler on a playground in the Lower Austrian town of Ternitz.NGOs have criticised that all nine provinces of Austria have different dog-keeping bylaws. While some provinces ban certain breeds, others have comparably relaxed regulations.Pollsters Oekonsult found that 83 per cent of Austrians want tougher rules for the ownership of dogs which are considered dangerous.