Their mange was so bad they are covered in bald patches and were even more vulnerable in the cold weather.
The kitten was found lying in the middle of a Nottingham street by a member of the public on Sunday.
Dibbley the Staffordshire bull terrier was found in a property in Chesterfield.
Bichon Frise Oscar was in such a bad state that his entire body was covered in clumped fur.
Boris was brought into RSPCA's Little Valley Animal Centre in Exeter.
The animals were found sealed in a box with no food or water.
It is suspected that the animals were deliberately killed by anglers.