One of the worst cases investigated by SSPCA chiefs was the dog left to starve to death in rural Angus.

The body of the female Rhodesian Ridgeback-Rottweiler cross, similar in type to a mastiff, was discovered in March at Kinnaird Park estate near Brechin.

It had been tethered to a barbed wire fence and left to die in appalling circumstances.

Following the horrific discovery, SSPCA senior inspector Mark Lumgair described the incident as one of the worst cases of cruelty he had encountered.

He said the animal would have endured “unimaginable cruelty over a prolonged period of time” as it suffered an agonising, lingering death.

“The last days of her life must have been filled with extreme fear and pain,” said the inspector.

A post mortem confirmed the dog had died from starvation and dehydration and an examination of her stomach contents revealed only grains of soil and fragments of wood, evidence of her growing desperation.

The animal’s plight sparked outrage and resulted in thousands of pounds of reward money being put up.

The SSPCA appealed for information and despite receiving several calls from the public the owner of the dog was never traced. The case remains open.

“While our workload has increased, we believe that this is due in part to people being more aware of who we are and how we can help,” said Chief Superintendent Flynn.

“What is shocking though, even to us, is the nature of recent attacks against animals.

“Our inspectors and ambulance drivers have had to deal with some of the most sickening and harrowing scenes you can imagine.

“Thankfully, the vast majority of pet owners in Scotland take great care of their animals, but the animal cruelty we are dealing with is horrific.”

Other cases handled by the SSPCA in the past year include a dog that survived being shot in the head 13 times with an airgun by her drunken owner in Glasgow. The owner was prosecuted and banned from keeping animals and the dog was successfully rehomed.

In Peebles, a dog was found by a member of the public burned to a crisp. Again, the SSPCA turned to the public for information but the case remains unresolved.

In Fife, when a newborn foal was slashed across the neck, receiving a deep eight-inch wound. Remarkably she survived her ordeal but many other animals didn’t.

The SSPCA also has to tackle a constant stream of neglect, when owners, for whatever reason, don’t feed their animals or take them to a vet when they are sick.

“We had several successful prosecutions last year against people who simply turned a blind eye to the animals living in their homes suffering in silence from painful skin diseases, riddled with cancerous tumours or emaciated because they’ve not been fed for a prolonged period of time,” said Chief Superintendent Flynn.

The Scottish SPCA’s latest figures make harrowing reading.

The charity’s animal rescue and rehoming centres cared for 14,019 unwanted, abandoned and neglected animals last year, compared with 12,545 in 2008.

Scottish SPCA inspectors and ambulance drivers attended more than 42,500 incidents and rescues, a rise of more than 4000 since 2008.

An increase in investigations led to 129 cases of cruelty to animals being dealt with by the courts, compared with 114 during the previous year.

Calls from members of the public to the Scottish SPCA Animal Helpline leapt by 16% in 2009, with 146,000 calls received. This follows a year on year increase in calls for the past six years.

“Taking all of this into account it is fair to say that 2009 was the worst year in recent memory for animal cruelty,” Chief Superintendent Flynn said.

“Sadly, cruelty to animals continues to be a major problem in Scotland.”

Anyone who knows of an animal in distress should call the SSPCA’s Animal Helpline on 03000 999 999.