Instructions
Monitor your cat's behavior. Determine whether the lethargy is accompanied by any other symptoms, such as a change in eating or drinking habits, vomiting, diarrhea or weight loss. Determine if your cat is reluctant to play or if it avoids contact with people or other pets.
Record your observations of your cat's lethargy, along with any other symptoms. Identify if the lethargy is constant or periodic. If periodic, note the times of day when your cat appears lethargic.
Take your cat to the veterinarian. Lethargy itself is not life threatening but it may be a symptom of a disease that is potentially life threatening, such as cancer. Bring your notes of your observations.
Undergo the veterinarian-recommended tests, which may include blood, urine and fecal analysis and possibly chest and abdominal x-rays.
How to Help a Lethargic Cat
Lethargy may be a symptom of a serious underlying systemic disorder. Cat owners shouldn't ignore lethargy that lasts more than a day. A lethargic cat appears drowsy, inactive or indifferent and typically has a delayed response to external stimuli. In older cats, lethargy may be a symptom of feline cognitive dysfunction, or FCD, resulting from aging. According to the ASPCA, 55 percent of cats aged 11 to 15 years and more than 80 percent of cats aged 16 to 20 years, are affected by FCD. Helping a lethargic cat involves isolating the cause.