Final answer:
Most pets would struggle and possibly perish without humans due to a lack of food, shelter, and medical attention, with feral animals and wildlife outcompeting them for resources.
Step-by-step explanation:
If humans were to disappear, most of our pets would be doomed primarily due to lack of food. Domesticated pets, especially those that are used to being fed by humans, might not have the necessary skills or instinct to find food in the wild. Moreover, the abrupt disappearance of humans would lead to pets facing immediate competition for food resources from wildlife and surviving feral animals.
Pets would also struggle with lack of shelter, as houses and other structures gradually deteriorate without maintenance. The absence of medical attention would leave pets vulnerable to diseases and injuries that could easily be fatal without human intervention. Lastly, although less critical for immediate survival, the lack of care and companionship that humans provide can lead to psychological stress and anxiety for social animals like dogs and cats.