Well, you can, but it sets up the possibility of some unshowable colors down the line. Both seal and tort are self-based colors; all of the babies will be self-based colors too. Seal is two shaded genes at the C locus, so all of the babies will get a shaded gene from that parent. Chocolate tort is two chocolate genes and two non-extension genes, so all of the babies will get a copy of those two, as well.
The most likely color to see from this cross is black. If the seal is carrying chocolate, some of the babies might be chocolate-somethings. If the seal isn't carrying chocolate, you won't see any in this generation, but since all of the kits will inherit it, they will be able to throw chocolate when bred to a chocolate/chocolate carrier. Most of the possible colors are not a problem, but getting chocolate and the shaded gene together brings up the possibility of things like chocolate sables and chocolate creams (or chocolate pearls), which while pretty, aren't showable (except maybe in the Angoras).
We had to put down our oldest rabbit yesterday. Very sad. She was an older Holland lop, a pet, and she had been limping for months. Then last week she lost the use of one of her front legs entirely all of the sudden and was falling over with every step, just pulling it behind her. I think her only option would have been amputation and I think she would not have lived a good life after that if we could have even found a vet to do it.
