Battersea Dogs & Cats Home said Scotland’s maximum 12-month prison sentence for the worse cases of animal cruelty is one of the lowest in Europe.
Only a few countries have lowest sentences, including England and Wales where the maximum sentence is six months.
The animal home wants the law to be changed to bring it in line with current legislation in Ireland and Northern Ireland, where the maximum sentence is five years.
SNP MSP Rona Mackay, Holyrood Justice Committee deputy convener, is supporting the call for tougher animal cruelty sentences.
She said: “I am very much in favour of exploring opportunities to increase the sentencing for those charged with crimes of cruelty to animals.
“We need to send out a strong message that these vile crimes against defenceless animals are unacceptable, and we need to put it into perspective of all types of violent crime.”
Battersea director Dee McIntosh is urging Scots to contact their MSPs to call for a five-year maximum prison term for the most serious animal cruelty offences.
She said: “Scots like to see justice be done and play a part in righting some of society’s wrongs. And Battersea believes this can only help to build the momentum to get the law changed in Scotland to five years for animal cruelty.
“We now need all of Scotland’s politicians to make this change.
“Scots may remember the horrific photographs of a Staffordshire Bull Terrier tied to a piece of concrete and left to drown in a Lanarkshire pond in 2015.
“Nobody was convicted of that dreadful offence and even if they had been, is it right that they would have received less time in prison for drowning that poor dog than for dumping commercial litter? It would be laughable if it wasn’t so shocking.”
She also highlighted the case of a man who admitted torturing his pet cat to death in Fife last year and was jailed for eight months as the sheriff was unable to impose the maximum year-long sentence due to the required reduction for a guilty plea.
Ms McIntosh added: “Terrible cases like these show that the Scottish courts are doing their best to hand down the toughest sentences they can but the powers currently available to them make it impossible for the punishment to fit the crime.
“Battersea believes it’s time for a change north and south of the border. We’ve been campaigning for a five-year sentence in England and Wales, where courts can only give an offender six months in prison.
“Scotland has an impressive track record of changing its laws on key issues ahead of some other nations, so let’s ask all MSPs to do that for animal cruelty as well.”
A Scottish Government spokeswoman said: “Scotland is a nation of animal lovers and we take this issue very seriously.
“We have recently announced a range of measures to protect animal welfare, including reviewing the penalties available for animal welfare offences.”