A crucial breakthrough against dog-fighting has been found, with more than 50 dogs rescued and evidence gathered after four Queensland properties were raided in the past week.

The search warrants executed by RSPCA inspectors and Queensland police, targeted two properties in Logan, one in Redland City and another in Richmond.

RSPCA spokesperson Michael Beatty, said that most of the animals rescued have been already used in fights due to them suffering injuries consistent with dog fighting, amongst the collection of evidence seized were treadmills, breaking sticks and phones.