The Scottish Society for the Prevention of Cruelty to Animals says the discovery was made near Langbank, just outside Glasgow.

I have never encountered anything like it and never believed I would

Wendy Robertson, SSPCA

The dogs were found heavily bloodstained and huddled in a heap near to a transmitter mast.

A lurcher, possibly four years old, was found barely alive, but had to be humanely destroyed at the scene.

SSPCA investigators believe the animals had been tethered to a gate post where they were clubbed and then dragged and dumped in nettles at the base of the transmitter.

The area around the gate was bloodstained and a trail of blood ran across the grass to the spot where their bodies lay half-hidden.

One of the dead dogs - a large wolfhound - was so brutally beaten a post mortem was needed to identify the breed.

Jaw broken

The others were a six-month-old tan-coloured lurcher/greyhound cross mongrel pup with a wound to its shoulder and a black and white Jack Russell bitch which had suffered such a severe blow to the side of its head that its jaw was broken.

SSPCA inspector Wendy Robertson said officers had been sickened by what they had seen.

She added: "I have never encountered anything like it and never believed I would.

"I was thoroughly disgusted. Who could do a thing like that?

"The lurcher was in a dreadful state, shaking violently, but unable to move.

"It had a red plastic flea collar as well - providing a possible link."

The society hopes that someone will be able to recall seeing the dogs in question and lead them to those responsible.