Tigris and Onyx are standard long-haired dachshunds, each weighing about 16 lbs.   Tigris (red-blond) is 6 years old, while Onyx (black) is 8 years old.  They have been together from birth.  Both are spayed and microchipped, housebroken and well-behaved. Tigris and Onyx are being fostered in Albuquerque and their adoption fee is $350.