People convicted of cruelty against animals should face much harsher prison sentences, charities claim.
The current maximum custodial sentence for the worst cases of animal cruelty in England and Wales is six months, but campaigners want this increased tenfold to five years.
Right groups have branded the six-month limit as "shocking" and "laughable" and urged greater punishments.
On Monday, Battersea Dogs & Cats Home (BDCH) will launch a campaign saying England and Wales lag behind other western nations in penalising abusers.
Under current legislation, the largest sentence in Northern Ireland and Ireland is five years, while in Scotland a conviction can lead to one year of imprisonment.
According to figures, the average prison term for someone convicted of animal cruelty in England and Wales is 3.3 months.
BDCH chief executive Claire Horton said: "It isn't acceptable that our courts are unable to hand out tougher sentences in such extreme animal cruelty cases, yet the likes of fly-tipping can result in prison sentences of up to five years.
"So let's get this into proportion and let the punishment for abusing animals truly fit the crime."
In a BDCH report, the charity said England and Wales' six-month maximum sentence puts them on a par with Belgium, Macedonia and the US states Idaho and Mississippi.
But BDCH says it lags behind countries like Latvia (five years) and Finland (four years), Connecticut and Louisiana (both 10 years) and Queensland (seven years). In Germany and France the maximum sentence is two and three years respectively.
The report concludes that while the Animal Welfare Act was "a landmark piece of legislation" when introduced in 2006, "its provisions for dealing with animal cruelty have been overtaken by progressive legislation in Europe and the USA".
Department for Environment, Food & Rural Affairs figures show that 936 people were sentenced for animal cruelty offences in 2015.
Of those, 91 received an immediate custodial sentence, with the average length 3.3 months.
A further 202 offenders got a suspended sentence and 341 received a community sentence. Some 177 offenders were punished with a fine, with the average being £244.
The RSPCA said its own polling showed that there was public support for stronger sentences.
Chief executive Jeremy Cooper said: "The strength of feeling behind a move to toughen up these sentences is huge - but at the moment the courts are limited by the law.
"The new sentencing guidelines are a step in the right direction but are confined by the sentencing ceiling in the Act.
"We would like to see a further review of sentencing under the AWA to allow magistrates to give stronger sentences to those guilty of the worst animal offences."
The campaign launch comes ahead of a debate in Parliament on the subject, with a Private Member's Bill set to be discussed on February 24.