Common misconceptions about spay/neuter surgery include beliefs that the procedure causes weight gain, alters a pet's personality, or is unnecessary for indoor pets. Weight gain can occur, but it is typically due to overfeeding and lack of exercise, not the surgery itself. Spaying or neutering does not change a pet's core personality but may reduce undesirable behaviors like marking or aggression. Indoor pets can still experience accidental breeding or health issues related to reproductive organs. Addressing these myths helps encourage responsible pet ownership and reduces pet overpopulation.