Lethargy in cats is something I have encountered frequently in my 14 years as a veterinary surgeon. It is a very common reason for owners to bring their cats into the clinic, often describing them as “not themselves,” “not quite right,” or just “more sleepy than usual.” Because cats naturally enjoy long naps, it can sometimes be tricky to tell if they’re just resting or if there’s an underlying problem.
In veterinary practice, I’ve seen cases where lethargy was caused by something minor, like a mild viral infection, and others where it was the first sign of a life-threatening condition. Cats are masters at hiding illness, so subtle changes in their behavior or activity levels can be important clues.
