It was not new to me that the same spotted patterns we see in domestic cattle sometimes also occur in cervids. But until I did a quick google seach I didn't know how widespread it actually is. Spotted patterns can be found in red deer, roe deer, white-tailed deer and elk. At first I thought that these colour variants are the result of incipient domestication. There are deer populations that have been kept in game parks for many generations and it is likely that they have also been selected for tameness to a certain degree, simply for practical reasons. I think it is unlikely that these populations have been totally reproductively isolated, but they were probably isolated enough to develop the typical "novel traits" of domestication: new colour variants (f.e. totally white red deer, or fallow deer with very dark shades), piebald patterns, or shortened skulls (fallow deer). However, the presence of these piebald patterns in elk and white-tailed deer, which have certainly not been kept under the same conditions as those semi-domestic deer populations (at least elk), suggests to me that these traits are not necessarily connected to incipient domestications. Rather it seems that the same mutations that cause piebald patterns in domestic animals also occur "naturally" in wild animals, and sometimes not even rare. For example, there are skandinavian elk populations in which such deviant colour variants are particularly common. Although it has been suggested by scientists involved in the farm fox experiment that such colour mutations are pleiotropically coupled with mutations in the nervous system responsible for tame behaviour, we maybe should not connect such patterns too much with domestication. For example, the African wild dog is piebald in a certain way as well, certain bovids have white "socks" too, and the leopard-like patterns we see in some seals resemble those of some spotted horses as well.
So perhaps a number of those spotted patterns of domestic animals is not as tightly related to behavioural modifications during domestication as I previously suggested on this blog. I don't know why deer show them particularly often compared to other wild animals.
Now here are some links of piebald deer.
There is even a stuffed hare with a streak along its face and sockings, photographed by Markus Bühler: