Why is my cat not eating, listless, and always lying down?
The following are the reasons why your cat is not eating, is lethargic, and keeps lying down:
First, there are normal physiological reasons. For example, a cat may not be in good spirits in winter and may sleep more. However, its appetite and interaction with its owner are normal. It eats when it's time to eat and plays with its owner as usual. It's just that it's sleepier, which is a normal physiological phenomenon.
Secondly, the cat might have some problems or illnesses. For example, common issues include gastrointestinal inflammation, discomfort, or a cold. One common condition, especially prevalent in winter, is feline urinary tract infection (UTI). If a cat with UTI cannot urinate and its urethra is blocked, it may become lethargic and lie down constantly. It might also stay in the litter box indefinitely, indicating a blocked urethra. 
How to deal with a cat's loss of appetite
1. Supplement with probiotics. If your cat suddenly stops eating, it may be due to a gastrointestinal problem, such as indigestion. In this case, you can adjust your cat's diet and supplement with vitamins or probiotics to help stimulate their appetite.
2. Increase your cat's exercise. Cats don't eat indefinitely; once they're full, they won't touch other food. Many domestic cats often refuse to eat and spend two-thirds of their day sleeping. If a cat doesn't exercise much throughout the day and just sleeps after eating, it's normal for them to have little appetite. To address this, cat owners can appropriately increase their cat's exercise to expend energy, promote digestion, and help improve their cat's poor appetite.
