The phrase "average shedder" refers to a person or animal that loses or sheds a normal amount of hair or fur. It means they don't shed too much or too little, but instead shed an average amount. Full definition
The dogs are considered average shedders. (hillspet.hk)
Great Danes are short haired and average shedders so their coats don't require constant brushing and matty fur or knots is not an issue. (about-great-danes.com)
These dogs are considered average shedders. (hillspet.hk)