<===> input.scss
%dog {
    @media (min-width: 10px) {
        &:hover {
            display: none;
        }
    }
}

.puppy {
    @extend %dog;
    background-color: red;
}
<===> output.css
@media (min-width: 10px) {
  .puppy:hover {
    display: none;
  }
}

.puppy {
  background-color: red;
}