Overview:

Lethargy isn't a disease in itself but it is a sign that there may be something wrong with your cat. This could be something relatively minor or a sign of something more serious.

What are the causes of lethargy in cats?

There are many possible reasons why your cat is behaving lethargically. Some of which include

• Anemia (reduced number of red blood cells)
• Acute or chronic kidney failure
  
• Addison's Disease
  
• Cancer
• Certain medications
• Constipation
  
• Depression
• Feline herpesvirus
  
• Feline infectious anemia
  
• Dietary (inadequate amount of food, poor quality food)
• Feline Infectious Peritonitis (FIP)
• Feline Immunodeficiency Virus
  
• Feline Leukemia Virus
  
• Glomerulonephritis
  
• Heartworm
  
• Heat stroke
  
• Hepatic lipidosis
  
• High blood pressure
  
• Hypercalcemia
  
• Hypertrophic cardiomyopathy
  
• Hypocalcemia
  
• Inflammatory bowel disease
  
• Jaundice
• Liver disease
  
• Nutritional disorders & or deficiency
• Pancreatitis
  
• Poisoning
• Pregnancy
  
• Pyometra
  
• Recent viral infection
• Yellow fat disease
  

This list is by no means conclusive, there are also many other possible causes of lethargy.

What are the signs of lethargy?

Lethargy describes inactivity, drowsiness, loss of interest in surroundings. It may or may not accompany other symptoms, depending on the cause. Some may include;

• Anorexia (loss of appetite)
• Behavioural changes
• Diarrhea
  
• Fever
  
• Increased thirst & urination (polyuria/polydipsia)
  
• Vomiting
  
• Weight loss or weight gain
  

How is it diagnosed?

Your veterinarian will perform a complete physical examination of your cat & obtain a medical history from you, including other symptoms you may have noticed. Some routine tests your veterinarian may wish to perform include;

• Biochemical profile
• Complete blood count
• Ultrasound
• Urinalysis
• X-Rays

These tests may or may not show results which warrant your veterinarian to investigate further with more specific tests such as;

• ACTH stimulation test
• Fecal examination
• FIV & FeLV tests
• Specific tests for pancreatitis
• Heartworm tests
• How is it treated?

Treatment depends on the underlying cause of the lethargy.