Fainting in Dogs or Syncope: What to Do?

Has your dog ever lost consciousness for no apparent reason? Syncope is the medical term for fainting, caused by a lack of oxygen or nutrients reaching the brain. These episodes tend to be brief, with a sudden recovery.

However, they can point to an underlying illness that's chronic, progressive, or even life-threatening. If you want to learn more about its causes, symptoms, and possible treatments, you're in the right place.

Symptoms of Syncope in Dogs

You should know that fainting isn't a disease in itself. It's more of a situational, reversible condition or syndrome, which can hint at an underlying condition that requires treatment.

It's generally linked to cardiomyopathy, hypoglycemia, or a nervous system disorder; adverse drug effects or interactions can also cause it, which is why early diagnosis is the best way to protect our dog's health.

It tends to happen during exercise or physical stress. In small breeds with a history of heart disease, episodes have been described lasting anywhere from a few seconds to 1 minute.

In larger breeds, also with a history of cardiovascular conditions, syncope can last between 5 and 15 minutes. Syncope linked to adverse drug reactions can take anywhere from minutes to hours, until the body on its own, or with treatment, is able to reverse the drug's effect.

As a general rule, it tends to occur with the following symptoms:

• Sudden, momentary loss of consciousness.
• Lack of awareness or response to us calling the dog.
• Stiff limbs and head tilted back (opisthotonus).
• Vacant stare.
• Urination (the dog wets itself).
• Muscle spasms that can be mistaken for an episode of epilepsy.
• Pale mucous membranes, whitish gums.

It tends to be more common in older dogs, and particularly in Cocker Spaniels, Miniature Schnauzers, Boxers, German Shepherds, Pugs, and Dachshunds.

Why Does This Fainting Happen?

There are many factors that can lead our dog to faint, lose consciousness, or even appear to be having a seizure.

What's basically happening is a lack of oxygen reaching the brain, which can be caused by a drop in blood pressure or reduced blood flow to the brain.

The main triggers, broadly speaking, are:

• Slow (bradycardia) or fast (tachycardia) heart rate.
• A heart tumor (not necessarily malignant).
• Hypoventilation.
• Stress (one of the leading causes).
• Exposure to certain medications that lead to clots or thickened blood.
• Hypoglycemia.
• Low calcium or sodium levels in the blood.

What's known as situational syncope deserves special attention. This refers to loss of consciousness triggered by coughing, difficulty swallowing, urinating, or defecating, as well as by overstimulation of the carotid sinus — for example, from a sharp pull on the leash. In all of these cases, the prognosis tends to be positive and recovery is immediate.

What Should I Do If My Dog Has Fainting Episodes?

During the episode, avoid leaving the dog alone, and if you step away to get the vet or help, try to move any objects it could bump into. Dogs often hit nearby objects while trying to get back on their feet.

In a situation like this, you should get to your vet as soon as possible. Since this is a symptom pointing to something else, the specialist needs to determine the exact cause to stop it from progressing and set up the right treatment.

Remember to tell them about any past illnesses or any medication the dog is taking, if applicable. It's a good idea to check the areas your pet has been in for toxic plants, seeds, and to report this to the vet.

A detailed medical exam will likely be needed, including bloodwork, a urinalysis, and a biochemical profile. Sometimes the results come back normal. However, if the cause is hypoglycemia, it will be easily detected, as will low calcium or sodium levels.

If cardiomyopathy is suspected as the real cause of the fainting, additional tests such as an ECG or echocardiogram will be performed. The same applies to a CT scan or cerebrospinal fluid analysis, if a brain disorder is thought to be behind it.

What Are the Right Treatments?

It's worth repeating that the cause will determine the best treatment to reverse the situation and prevent it from worsening in a way that could threaten our pet's survival.

In cardiomyopathy-related cases, there are medications available to regulate heart rate. You'll also need to monitor the dog's vitals for at least 24 hours. In the most extreme cases, a pacemaker may need to be fitted.

If, instead, the cause lies in low glucose, sodium, or calcium levels, certain changes to the diet will be needed — it's a good idea to ask your vet about the BARF natural diet, given its many health benefits.

For stress or extreme emotional responses, medication can also be effective, without forgetting to provide a calmer environment and go for regular check-ups, at least until things stabilize.

In short, syncope in dogs isn't usually a cause for great concern for owners, as long as the cause is identified early and treated accordingly.

To prevent it, keep the dog's veterinary check-ups up to date, provide a balanced diet, and regular exercise. We're confident that with your love and these tips, you'll be able to enjoy countless adventures together.