This was asked elsewhere but the querent has never been back. It has, however, got me very curious as to the answer. Please note: I can't answer anything on the content as I'm not the OP
looking for this book had humans genetically engineered with different animals genes to withstand harsh planets after leaving earth one race was mixed with black bears and were called bors. there were races mixed with otter a race called tarbek which had poisonus breath. races mixed with polar bears for harsher colder planets