Why They Are So Rare
The truth is that the silver fox is just a variation of the red fox. However, the dark coloring makes them attractive to people in the fur industry. This is the reason a lot of them are bred in captivity. The black and silver fur is a recessive trait, so they are scarce. In the wild, they breed with other foxes too.
They Are Not Good Pets
There is a good reason we generally do not have pet foxes. For one thing, they are wild animals. While they can be trained to a certain extent, they were not domesticated in the same way that dogs and cats have been. Humans typically take care of foxes that are going through rehabilitation programs. Even though they can be loving, they are generally aloof creatures that do not show much affection.