The Scottish SPCA says 2009 was the worst year in recent memory for animal cruelty.
"One of the most mindless attacks happened in Fife when a newborn foal was slashed across the neck, receiving a deep eight inch wound," said Scottish SPCA chief superintendent Mike Flynn.
"Remarkably, she survived her ordeal but many other animals didn't," he said.
"It's not just outright cruelty. We are also tackling a constant stream of neglect, where owners, for whatever reason, don't feed their animals or take them to a vet when they are sick."
During 2009, animals had been burned, stabbed, shot and left to starve to death.
Flynn revealed that the charity had noted significant increases in rescues and calls to its Animal Helpline.
"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. What is shocking though, even to us, is the nature of recent attacks against animals," Flynn said.
"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.
"One case which stands out from last year was a wee staffie dog we rescued that was so gentle and loving despite having survived being shot in the head 13 times with an airgun by her drunken owner in Glasgow.
"Her owner was prosecuted and banned from keeping animals and she was successfully rehomed. However, there are times when we don't get the information we need to bring the perpetrators to justice.
"We appealed for information after a dog was cruelly tied up and left to starve to death in woods in Brechin. Despite receiving several calls from the public, we have never been able to trace the owner and bring them before a court.
"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.
"Taking all of this into account it is fair to say that 2009 was the worst year in recent memory for animal cruelty."
The Scottish SPCA's animal rescue and rehoming centres cared for 14,019 unwanted, abandoned and neglected animals in 2009, compared with 12,545 in 2008.
Its 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 to 114 during the previous year.
Calls from members of the public to its Animal Helpline leapt by 16 per cent in 2009, with 146,000 calls received. This follows a year-on-year increase in calls for the past six years.
Flynn said the SPCA would encourage anyone who knows of an animal in distress to call its Animal Helpline on 03000 999 999.
"That call could save an animal's life or change it for the better."