A former dog breeder from Sydney's north-west has been found guilty of animal cruelty after officers found five dead dogs in freezers on his property and others living in "grotesque" conditions.

RSPCA NSW and police also found the partially burnt remains of a dog in a fire pit near live dog pens, and pools of blood and bodily fluids in a kennel where an animal is believed to have decomposed.

Eighteen dogs of varying breeds were seen to be suffering from potentially life-threatening conditions during the inspection last March of a property in Vineyard that had previously been used by Herizon Kennels to breed dogs, the RSPCA said in a statement on Wednesday.

Todd Baker, 41, was convicted of 15 counts of animal cruelty in Penrith Local Court last week and sentenced to a three-year good behaviour bond, prohibited from owning animals for 10 years and ordered to pay more than $80,000 in costs.

Inspector James Arentz said the state of the animals on Baker's property was hard to comprehend.