Convictions for animal neglect and cruelty have risen by a third in England and Wales, according to an RSPCA report.
There was a 33.8 per cent increase up from 3,114 in 2011 to 4,168 last year, the RSPCA's annual prosecutions report stated.
Noting that it is possible for an individual to get more than one conviction, the RSPCA points out there was also a 15.7 per cent increase in the number of defendants convicted.
The number of those found guilty of offences rose to 1,552 in 2012 from 1,341 a year earlier, the report - which was released to mark RSPCA Week - said.
RSPCA chief executive Gavin Grant called on judges to take these offences "far more seriously".
He said his staff, volunteers and branches are "struggling to keep up" in their fight against "a growing animal cruelty crisis".
"For us, prosecution is always the last resort," he said.
"Our inspectors investigated 150,833 suspected cruelty cases and issued 78,090 advice notices last year - these are extremely effective in improving the care of animals.
"However if there is evidence of a crime and serious animal abuse then we will take legal action to protect the animals and prevent further abuse.
"We also want to see judges taking these offences far more seriously."
Successful prosecutions relating to cruelty to small mammals such as rabbits and hamsters rose from 97 in 2011 to 354 in 2012, while convictions linked to the treatment of farm animals rose from 22 to 49 in the same period.
The number of convictions relating to the treatment of equine animals, such as horses, ponies and donkeys, rose from 230 in 2011 to 500 last year.
Animals rescued or collected by the RSPCA increased by 9.7 per cent from 119,126 to 130,695.
The animal welfare group also helped rescue 64,000 farmed chickens from a flooded barn.
A dog being slashed with a knife by his owner and two tiny puppies who had been buried alive are among the "shocking catalogue of deliberate cruelty and neglect" which have been dealt with by the RSPCA, a spokesman said.
They also found more than 30 rabbits and guinea pigs living amongst dead animals in slurry-filled hutches and an emaciated pony pinned to the ground by his tether.
RSPCA Week 2013, which raised more than £395,000 last year, runs from April 29 to May 5.