Fainting in Cats

PetMD Editorial
By PetMD Editorial
Published: October 4, 2010
Fainting in Cats

Syncope in Cats

Syncope is a medical condition that is basically characterized as a temporary loss of consciousness and spontaneous recovery. This is the clinical term for what is otherwise often described as fainting.

The most common cause of syncope is a temporary interruption in the brain blood supply, which causes impairment in oxygen and nutrient delivery to brain. Another important cause of syncope in cats is heart disease leading to interruption in the blood supply to the brain. Syncope is more likely to be seen in older cats.


  • Heart diseases
  • Heart tumor
  • Emotional stress
  • Excitement
  • Low concentration of glucose, calcium, sodium in blood
  • Diseases leading to thickening of blood
  • Use of certain drugs

Situational syncope may be associated with:

  • Cough
  • Defecation
  • Urination
  • Swallowing
  • After pulling the cat’s collar, even lightly


Although syncope often only causes temporary loss of consciousness, diagnosing the underlying cause is important for the affected patient, since the underlying condition may be of a chronic and progressive nature, or may even be life-threatening.

Your veterinarian will take your cat's health history and will carry out a detailed physical examination. Routine laboratory tests include complete blood count, biochemistry profile, and urinalysis.

The results of these tests are often within normal ranges, but if hypoglycemia is the cause of syncope, the biochemistry profile will indicate lower than normal levels of glucose in the blood. In these patients, insulin concentration is also measured. Further testing may be required in patients with low sodium or potassium levels in blood. As heart disease remains one of the important causes of syncope, an electrocardiogram (ECG) and echocardiography will be conducted to determine whether there is an underlying heart disease.

Your veterinarian will also ask you to calculate the heart rate during syncopic episodes at home. Your veterinarian may recommend 24-hour ECG monitoring if your cat has been determined to have an underlying heart problems. A computed tomography (CT) scan of the head, and an analysis of cerebrospinal fluid (the fluid that bathes the brain and spinal cord) will be conducted if brain disease is suspected.


Syncope is a temporary and reversible condition, with the patient regaining consciousness soon after an episode of unconsciousness. However, if the underlying cause is not treated in time, it can lead to recurrent episodes of syncope and aggravation of other symptoms related to the underlying disease.

If side effects due to medication are responsible for the syncopal episodes, your veterinarian will halt the use of the medication. If the medications are necessary for your cat's long term health, your doctor will look into other medications that can be used without the harmful side effects.

Living and Management

Protect your cat from being exposed to the types of stimulus that can provoke an episode of syncope. If cardiac insufficiency is the cause, physical activity should be minimized to prevent further stress on the heart. Moreover, stress and excitement can also contribute to an episode of syncope and should be prevented as much as possible. You will need to take your cat for regular checkups until it has fully recovered.

Watch your cat closely at home for another episode of fainting and call your veterinarian immediately if cat begins to show symptoms of losing consciousness again. The usual prognosis for patients with heart disease related to syncope is not good. However, for patients that do not have a non-cardiac related condition underlying the syncope, the overall prognosis is good, especially if the primary disease is treated.

Help us make PetMD better

Was this article helpful?

Get Instant Vet Help Via Chat or Video. Connect with a Vet. Chewy Health

Subscribe to PetMD's Newsletter

Get practical pet health tips, articles, and insights from our veterinary community delivered weekly to your inbox.