The short-tailed opossum is a small marsupial that is indigenous to South America. They were first brought to the US in the late 1970s, although the raising of STOs as pets did not begin until almost twenty years later. These nocturnal creatures are highly inquisitive, extremely cleanly, low odor, and invitingly soft to touch. They don't require a huge amount of space and they are extremely entertaining during evening and night hours. The downfalls of keeping STOs as pets is they absolutely must be kept solitary, their diet can get rather expensive, dehydration is always a concern, and their life span in captivity is limited. As with any exotic pet, if you ask breeders, veterinarians, and owners their opinions, you will almost always receive just as many different answers. It is up to you as the owner to do your own research and make decisions based on what you believe is in the best interest of you and your pet.
STOs are know to be escape artists. There are a variety of enclosures that breeders recommend. For our STOs, we use vivariums and custom screen topped tanks. Whatever enclosure you select, it should never be smaller than a 20 gallon tank at a minimum. STOs are climbers. While the foot print of the enclosure does not have to be huge, the more space you can give the better and they enjoy height when ample branches and furnishings are offered for them to climb. They are nomadic in the wild, making an 8" or larger exercise wheel highly necessary as they can run numerous miles a night. The enclosure should maintain a temperature between 70-85 degrees, but they are susceptible to skin cancer, so UV light and direct sunlight are not recommended. They are not chewers, so the STOs can enjoy a large variety of furnishings, hides, pouches, hammocks, tunnels, etc. without concern of them eating the material. Bedding can be pine or aspen shavings, care fresh, or fleece liners. They designate one area to eliminate in, so litter pans can be used to easily maintain their potty area. Tissue paper, shredded fleece, etc. can be offered as nesting material. Their tails are semi-prehensile. They will not hang from them as other species of opossums, but will use their tails for guidance and toting nesting materials. Water bottles are recommended. Make sure the water bottle never runs dry, as they are quick to dehydrate. A dish for kibble can be kept in the enclosure at all time. Dishes for live, raw, or perishable foods should only be left in the enclosure for a few hours. Diet wise, STOs should be offered a kibble of 30% or greater protein, 9-13% fat with up to 5% fiber at all times. They should also be fed insects, rodents, some fruits and cooked vegetables. Baby foods are often used. Boiled eggs may be offered. They can have treat like yogurt or yogurt drops as well. They will hid and bury some foods in the bedding.
Handling should be introduced at an early age. They will instinctively open their mouths when startled or woken. Biting is possible, but generally the showing of teeth is their first line of defense. Like many nocturnal animals, they have poor eyesight. They rely highly on their sense of smell. Washing hands before handling is recommended to keep them from mistakenly nipping you. This is especially important if you have recently handled something that would smell tasty to them, like food or even some other pets. Their fur is extremely soft to the touch. They are climbers and will often climb up you to the highest point. Some are satisfied to snuggle into the hood of your jacket or even the crease of your arm. Always keep an eye on them. They are inquisative, quiet, and will wonder off quickly. They enjoy bonding scarfs and bonding bags.
Short-tailed opossums are not easy to breed. They are well known for harming each other during the mating process. Sever injuries, such as torn ears and eyes, are common. They must be separated immediately after to avoid serious injuries and, in some cases, death. Additionally, males will kill any babies they encounter. Although they are marsupials, they do not have a true pouch. The gestation period is extremely short. Babies are born undeveloped. Once born the babies attach to the mother's nipple and will continue their development over the next 3-4 weeks. If the baby becomes unattached from the nipple during the time, it will likely die. Babies are fully weaned at approximately 8 weeks of age. During this time, the STOs must be monitored closely as siblings are known to cause harm to smaller siblings. STOs reach maturity around 6 months of age. One should keep in mind when selecting an STO as a pet, their life span in captivity is generally short. While most sources say up to 4 years of age, a large majority of experienced owners suggest that this estimate is high and the span can be much shorter.
So are they worth it? There's pros and cons to every species. Ultimately only you can decide if a STO is the right pet for you. They are hard not to love, but like any pet they come with their own challenges. We hope that by passing along information and experience, that it will help transition prospective buyers into informed owners.