Dear Larissa,
Is this your first cat? You’re already doing an amazing job looking out for kitty’s best interests. Cats have a different social structure from dogs, and many of them are happy to remain the only pet in the household. Some, however, benefit from the companionship of having another cat in the house.
Signs your cat might be missing the connection of a fellow feline include changes in behavior, like eating more or less than usual, neglecting grooming habits, or being excessively clingy (like you mentioned). While adopting two littermates provides the best chance for two cats to bond, your cat is still young enough to connect with another cat. If you opt to bring another cat home, the introduction process should be gradual. Some hissing and territorial behavior is normal at first, but that should fade in time.
Most of the time, cats adjust to having a new cat in the house, although how close they become is hit or miss. Older cats tend to be more set in their “only cat” ways, so adopting sooner than later is your best bet for a successful introduction.
Both kitties should be spayed or neutered, and there should be a minimum of one litter box per cat in the house, plus an extra. If you work with a reputable pet adoption agency, they should allow for a test period to make sure the pairing works out before making a lifetime commitment.
If you do choose to bring home another cat, send us photos. I promise I won’t chase them, no matter how fun it looks.
— Doctor Dog
