Cats can grieve the loss of another pet, an owner, or even a favorite toy.
Cats can be sensitive to changes in their environment, such as a new home, a new pet, or a new family member.
Cats may become depressed if they are sick or injured.
Cats need mental and physical stimulation to stay happy. If a cat is bored, it may become depressed.
As a result of eating less, a depressed cat may lose weight.
A depressed cat may sleep more than usual during the day and/or at night.
A depressed cat may meow less than usual or may meow more than usual.