COMPLAINTS of animal cruelty have rocketed, said the RSPCA.

The animal charity investigated more than 153,000 complaints last year - 3,000 more than in 2012 - with dogs still the most likely to be abused.

Cases include 32-year-old Martyn Dashwood from Poole who admitted a string of cock-fighting offences and was jailed for 18 weeks.

His crimes included causing unnecessary suffering, causing animal fights to take place and arranging and attending animal fights.

Figures released today also reveal convictions for cruelty to horses, donkeys and ponies have more than doubled in three years.

Almost 600 people were found guilty in 2013, up from 500 the year before.

Cases included Bluey, a young mare who was found in an emaciated condition with her dead foal lying nearby.

In total, the RSPCA recorded 3,961 convictions in 2013, down from 4,168 in 2012. The number of individuals convicted also fell last year, from 1,552 in 2012 to 1,371.

There were 2,505 convictions related to dogs including cases such as Rocky, a cross breed who was shot in the head five times, hit with a shovel and left to die in a ditch.

Other cases investigated by the RSPCA included dogs being set on wild animals and a shar pei dog called Ruby who was kicked, punched and dragged along a pavement before she died.

David Bowles, head of external affairs at the RSPCA, said: ''Whilst we are heartened that the numbers of people convicted of cruelty have decreased, the fact that we are investigating more and more complaints shows that there is still a culture of cruelty out there.

''Nothing illustrates this like the massive increase in equine-related convictions.

''This is due mainly to irresponsible owners who have let their animals breed indiscriminately, together with an economic downturn which has seen feed prices go up and horses going for just a few pounds at market.

''As a result, horses have been left to suffer without food and vet treatment.''

The RSPCA rescued an increased number of horses in 2013, up from 1,275 in 2012 to 1,797 last year. The charity also rescued 17,665 dogs.

The RSPCA rehomed 55,323 animals last year, it said.