Lethargy in cats

Lethargy means low energy and is a very common problem in cats. There are many different causes of lethargy in cats. Conditions that cause lethargy can range from something mild that passes quickly to more serious conditions. 


Lethargy can be a symptom of almost all conditions that affect cats, so a physical exam or diagnostic tests are often needed to determine the cause. We can also describe lethargy as listlessness, tiredness, or weakness. Lethargy is a symptom that can affect cats of any age.

What to do

What to do if your cat is lethargic


There are many different causes of lethargy, and some can be very serious. If your cat suddenly becomes lethargic, try to assess the following

  • Check your cat for any new lumps, swellings, wounds or changes in the way they are walking
  • If possible, check your cat’s gums; white or yellow gums can indicate extremely serious disease
  • Monitor your cat carefully to assess if they are drinking or peeing more than normal
  • Check your cat for any weight loss
  • Monitor carefully for any changes to your cat’s appetite, stool or vomiting
lethargy in cats
Cat with a facial lump

Speak to a vet as soon as possible if your cat is lethargic. Our Joii Vets are available 24 hours a day for advice.


Most common causes of lethargy in cats


There are a vast number of causes of lethargy in cats; the following list are some of the most common


When to worry

When you should be worried about lethargy in cats


Seek help from a vet if

  • Your cat is drinking excessively
  • You have any questions about prescription medications
  • Your cat is constantly vomiting
  • Your cat is losing weight


Call us and speak to one of our Joii Vets if

  • Your cat has been lethargic for less than 24 hours
  • You are unsure if your cat is in pain
  • Your cat has developed a new lump and you are unsure what to do
  • Your cat has mild vomiting or diarrhoea


Tips on how to prevent lethargy in cats


There are so many different causes of lethargy, and not all are preventable. Read the following tips to help protect your cat wherever possible.

  • Make sure your cat is up to date with their yearly vaccinations
  • Protect your cat against ticks, mites and other parasites using regular preventatives
  • Neuter your cat to reduce the risk of fighting and cat bite abscesses
  • Don’t feed fatty snacks and keep your cat on good quality, balanced cat food
  • Do not leave medications or human food in areas where your cat can reach them.
  • If you travel abroad with your cat, make sure to keep up with vaccines and parasite preventatives and avoid contact with stray or wild animals. Constant supervision is advised when abroad.
  • Avoid sudden changes in your cat’s routine and environment to reduce stress.
  • Keep your cat in a healthy body condition and use joint supplements to help balance arthritic changes


Body Condition Score (BCS) is a scale that gives a practical evaluation of the fat coverage of your cat’s body. By checking how easy or not it is to feel certain bony areas of the body, a score is then produced. There are several scales, from 1 to 5 or 1 to 9. The ideal body condition lies in the middle, so either 3/5 or 5/9.

The body areas normally checked for fat coverage are:

1. ribs and spine

2. hips and shoulders

3. waist

Body condition scoring (BCS) in cats

Here are a few tips on how to do it.

With your pet in a standing position:

  • Place your hands on the rib cage and gently feel for each rib, without pressing too hard
  • Feel the waist and look from the top and the side (if you have a very furry breed, it may be harder to assess)
  • Feel the spine, which runs down the middle of the back
  • Feel the top of the hips and shoulders


How to know if your cat is lethargic


Lethargy is a very vague symptom and may not be noticed right away. Cats normally sleep between 12-14 hours a day. You may notice your cat is not quite their normal selves. Other symptoms include

  • Reluctant to go outside
  • Slower than normal when walking
  • Hiding, not seeking attention
  • Not interested in normal activities
  • Sleeping more than normal
  • Not reacting when called or patted

show to know if cat is lethargic

Home treatment

How to treat a lethargic cat at home


It is important to speak to a vet if your cat is lethargic. A vet will be able to help you decide if they need a physical exam and diagnostic tests or if it is ok to monitor at home. Our Joii vets are available 24 hours a day for advice.

  • Encourage your cat to drink water to reduce the chance of dehydration developing
  • Allow them to rest in a quiet, shaded and comfortable area of the home
  • Encourage your cat to eat. Heating up their food slightly can help, or small meals of bland food may be advised.
  • Monitor carefully for any changes in their appetite, any vomiting, or any changes to their stools.
  • A physical exam will usually be advised if the lethargy is severe or not improved after 24 hours

Vet treatment

Vet treatment for lethargy in cats


A physical exam will help your vet narrow down some of the causes of lethargy. This includes

  • Taking their temperature
  • Feeling for any pain in their tummy
  • Checking their lymph nodes
  • Listening to their heart and lungs, and measuring their heart rate.

It’s important to let your vet know if your cat has ever been abroad, been in contact with anything abnormal (such as human medications), or had any other recent changes.


Further diagnostic tests may include

  • Blood and urine tests
  • Biopsy or surgical removal of any abnormal lumps
  • Imaging: x-rays, ultrasound, CT, or MRI.


Vet treatment for lethargy will depend on the cause and may include

  • Hospitalisation for monitoring, intravenous fluids and injectable medications
  • A course of antibiotics
  • Anti-inflammatory medication to help with pain and fever if present
  • Pain relief medications
  • Tummy protectants
  • Surgery or more specific medications may be required, depending on the cause of the lethargy.


Are some cats more at risk of lethargy than others?


Any age, breed, or sex of dog can develop lethargy.

  • Outdoor and unneutered male cats are more prone to cat bite abscesses
  • Cats that are not vaccinated have a much higher risk of illness from different infectious causes of lethargy, such as cat flu and leukaemia.
  • Cats that are not covered against parasites have a higher risk of Lyme disease, mange, and several others.
  • Arthritis, kidney disease, and neoplasia (cancer) are more common in older cats.
  • Heart disease is more common in the following breeds: Maine Coon, Ragdoll, British Shorthair, Persian, Siamese, Burmese, Sphinx, and Devon Rex. Different types of heart disease can affect these breeds and can occur at different ages.
  • Cats that have been abroad are more at risk of rabies, Babesia, Leishmania and several other diseases.


Other causes of lethargy in cats


  • Liver disease. There are many different types of liver disease in cats. It can affect cats of all ages. Along with lethargy, symptoms also include vomiting, jaundice, weight loss, and diarrhoea. Blood tests and imaging are needed for a diagnosis.
  • Dental disease
  • Anal gland disease
  • Dementia
  • Pancreatitis
  • Heat stroke
  • Certain medications, such as antihistamines, steroids, and anxiety treatments.
  • Recent vaccinations, especially primary course as kitten
  • Poisons, such as rat bait, xylitol (sweetener), chocolate, and grapes.
  • Obesity
  • Anaemia. This is a condition where there is a lack of red blood cells. There are many different types and causes of anaemia. Some are easy to treat, and others are much more serious. Other symptoms include weight loss, reduced appetite, and pale gums. Blood tests and imaging are usually required to diagnose the different causes.
  • Skin diseases: Mange, Food allergies, atopy (environmental allergies), Flea allergy.
  • Infections: Feline immunodeficiency virus, Feline leukaemia virus, Lyme disease, Leishmania.
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