The pet lamb died of shock after having someone try to remove him from a fenced paddock facing Sedgwick Road.

The incident happened about 5pm on Sunday. Property owner Matthew Glascott, 26, happened to be home at the time.

He said it was not unusual for people to pull over and pet the animals in the front paddock.

But those that stopped weren't usually adults.

"That's what caught my attention," Mr Glascott said.

He said he saw two men, who arrived in a white twin-cab Toyota Hilux, reaching for his lamb Puzzle's legs.

Mr Glascott's property is home to more than 100 animals, the result of about five years of adopting animals otherwise destined for slaughter. The front paddock is usually reserved for the youngest and frailest among them.

Babies like Puzzle were bottle fed, which also meant they were friendly towards humans.

In five years, Mr Glascott said he had never been given cause to question whether the front paddock was safe for use as an animal nursery.

"We're rethinking whether that's a good place for them," he said.

He said the attempted theft had been reported to police. It was believed there had been a number of other attempted livestock thefts in the area, of late.

Mr Glascott urged property owners to keep an eye out for suspicious activity.

"A lot of people have pet animals in the front paddock," he said.

He said he yelled out when he saw what was happening, which meant Puzzle never left the property. But the lamb, who was believed to be less than a year old, was shaken up and suffered a fatal seizure.

"All of the lambs seem a bit frazzled," Mr Glascott said.

He initially feared other animals had been taken.

Mr Glascott works as a chef in Bendigo. He rescues and cares for animals in his spare time - a cause to which he gladly devotes some of his sleeping time, living space and salary.

He said he considered the animals he rescued to be pets.

Mr Glascott had rescued a range of animals, from cows to camels, throughout the years. His mother helped feed the lambs and calves, but Mr Glascott largely managed by himself.

He said raising lambs could be a challenge at the best of times.

"We got [Puzzle] this far and lost him," Mr Glascott said.

Police received 17 reports of stolen livestock in the western region between November and February.

Most of the thefts were within a 200-kilometre radius of Horsham.

Farm crime coordinator Inspector Karl Curran said at the time it was important farmers reported all incidents to police for investigation, even if they didn't know when it occurred.

"Any information you can provide will make a difference," he said.

Police have been contacted for comment.

Anyone with information about a non-emergency crime is urged to call Victoria Police on 131 444.

In an emergency, phone 000.