Author TB Thompson DVM has been a licensed, practicing veterinarian since 2000.
I recently spoke to the owner of a young adult Lab mix dog. She had experienced something alarming with her pup and wanted answers! The conversation went like this:
“Dr. T., last night when we were getting ready for bed, my dog’s eyes rolled back into her head and she went stiff and fell over. She laid on the floor like that for what seemed like an hour but was probably only a couple of minutes. Then she slowly went back to normal and now she seems fine. What the heck happened and what should I do next?”
An abnormal eye position in dogs should be considered an emergency especially if they have other symptoms. Seizures or loss of consciousness are the main causes for a dog’s eyes to “roll back in their head.” Abnormal eye positions can also be caused by tumors near the eye, facial nerve disease and congenital eye muscle problems.
Surprisingly, many times when dog owners tell me their dog has rolled eyes, I find that the eye position is actually normal. Dogs have a “third eyelid” that can rise up from the inside eye corner. It typically has a pink appearance and partially hides the eye. It may appear to some people that the dog’s eye is rolled back when the third eyelid is elevated.
Dog Eye Anatomy and Positions
A dog’s eye does not float loosely in the eye socket! It is attached to the surrounding area by muscles and connective tissue. The muscles move the eye so the dog can see his surroundings. When a dog is conscious, the muscles of the eye are under his voluntary control.
During anesthesia, seizures or fainting, a dog’s eyes may roll out of their normal position. Eye position is one way to judge how deeply a dog is anesthetized. When they are anesthetized deeply enough for surgery, their eyes will appear to be rolled inward and downward, kind of like they’re looking at a bug on their nose.
Is the Eye Rolling Back or Is the Third Eyelid Raised?
Take a deeper look before assuming that your dog’s eyes are rolling back in their head. A raised third eyelid (nictitating membrane) can sometimes make it look like the eye is rolled upward. But it’s easy to check this…
Use your thumb and first finger to gently part the dog’s eyelids. Now identify the iris, or colored part of the eye. You’ll see the black pupil in the center of the iris. If you see this part looking at you and there is a triangle of pinkish tissue covering the inside corner of the eye, it’s most likely a raised third eyelid. Sometimes the third eyelid will go back down while you’re examining the eye.
If the colored iris and pupil are barely visible and you mostly see the “white” of the eye, it’s possible the eye is truly rolling to an abnormal position.
Causes of Third Eyelid Elevation in Dogs
Dogs have a useful physical feature that humans lack: the third eyelid. When a dog is awake, this nictitating membrane—which is hairless, smooth, and pink—remains hidden beneath the inner corner of the eye.
Most dogs don’t show the third eyelid when they’re awake. It rises up during sleep, anesthesia, eye inflammation, or when something is irritating the eye.
This tissue aids in eye protection. It’s normal for it to partly cover the eye in response to anything that causes pain. Sedatives and neurological diseases can also cause elevation of the third eyelid.
Some of the causes for third eyelid elevation in dogs include:
- Pain originating from the inside of the eye-uveitis from infection or trauma
- Scratch on the front of the eye
- Inflammation of the cornea (keratitis)
- Conjunctivitis-a.k.a. “Pink eye,” but more often caused by allergy than infection
- Neurological disease-Horner’s syndrome
- Diseases of the third eyelid-prolapsed gland of the third eyelid (a.k.a. cherry eye), tumor, infection
- Sedatives-especially acepromazine
- Advanced illness-kidney disease, sepsis, internal bleeding, etc.
Causes of Dog’s Eyes Rolling Back
Once you’ve verified that your dog’s eyes are indeed rolling back in their head, you need to find the source of the issue quickly. The best course of action is to take your dog to the vet right away. It’s not typical for dogs to roll their eyes back in their heads unless they’re napping.
Alteration in a dog’s level of mental consciousness is a serious emergency. Even if the cause of abnormal eye position is pain, it’s important to get help from a vet right away.
Consciousness-Altering Drugs and Toxins
When a dog is put under anesthesia, it’s normal for their eyes to roll since they are unconscious. When the dog is about to awaken from anesthesia, veterinarians note the patient’s eyes begin to move back to their normal position.
Dogs who take sedatives may experience eye-rolling. But their eyes usually return to a more normal position when you rouse them. Acepromazine, alprazolam/diazepam, high doses of phenobarbital, and dexmedetomidine are common sedatives that may cause a dog’s eyes to roll back.
Dogs can become unconscious as a result of ingesting human medications and some poisons. If your dog’s eyes start to roll back unexpectedly, check your home and yard for evidence of toxic substances your dog might have swallowed. Dogs can occasionally experience seizures and loss of consciousness due to toxic mushrooms, alcohol, prescription and over-the-counter medications, and even moldy garbage.
Seizure
Dog seizures are caused by abnormal electrical activity in a dog’s brain. A typical grand mal seizure causes unconsciousness, falling, eye-rolling, and leg paddling. Partial (petit mal) seizures are less common in dogs and do not cause loss of consciousness.
Primary epilepsy is a disease caused by seizures of no apparent cause. Most epileptic dogs start to have seizures around 2-3 years of age. Primary epilepsy is more prevalent in some dog breeds including the American Cocker Spaniel, German Shepherd and Shih Tzu.
It can be difficult to identify the underlying cause of a dog’s seizures. Brain infection, inflammation, tumors, poisons, and trauma are all potential causes.
If you believe your dog has just had a seizure, contact your veterinarian immediately. The majority of dog seizures last only 1 to 3 minutes but they can go on indefinitely in some cases. It’s critical to get your friend to the vet as soon as possible because long-lasting seizures might result in permanent brain damage.
Low Blood Sugar
A normal blood sugar level in dogs is about 74-145 mg/dL. Healthy dogs rarely have numbers that fall outside of this range.
A rapid drop in blood sugar or even prolonged low blood sugar (hypoglycemia) can result in seizure activity. Other symptoms of hypoglycemia include drooling, wobbly walking, a glazed look on the face and lethargy.
Low blood sugar seizures are most commonly seen in dogs with diabetes mellitus who receive insulin injections. There are a few other diseases that can cause hypoglycemia including severe infection, liver disease and a type of cancer called insulinoma.
Hypoglycemic seizures in dogs are an emergency situation. If your dog is getting insulin injections and you suspect low blood sugar, you can apply maple or corn syrup to his gums but do it quickly then get to the vet clinic. Don’t try to wait until the dog is back to normal before you take action!
Cardiovascular Disease
Dogs with serious heart and circulatory diseases may lose consciousness, similar to fainting. The medical term for this sort of fainting is a syncopal episode. They are not caused by uncontrolled brain electrical activity like seizures but instead a lack of proper blood circulation.
Seizures and syncopal episodes can look very similar. In both cases, dog owners see their dog suddenly fall down and lose consciousness.
Syncopal episodes are seen in some dogs with cardiovascular disease including congestive heart failure and pulmonary hypertension.
Coughing, weight loss and exercise intolerance are other common symptoms of these diseases. But sometimes, the first symptom of heart or lung disease is fainting or syncope.
Low Blood Pressure
Low blood pressure, or hypotension, is uncommon in dogs and could result in loss of consciousness with eyes rolled out of their normal position.
Some causes of hypotension in dogs include blood loss from trauma or immune-mediated disease, heart disease, toxin/drug ingestion, severe infection, severe dehydration and chest or head trauma.
Strabismus
The term “strabismus” is used to describe an eye condition in which one or both of a dog’s eyes deviate from their usual position. The eye may be directed upward, downward, inward, or outward. The disorder may be intermittent or permanent.
Strabismus may be caused by
- Eye injury
- Disease involving cranial nerves
- Congenital abnormalities
- Old dog vestibular disease
- Vestibular disease from an inner ear infection
- Tumors
- Abscess behind the eye
Tumor Near the Eye
Tumors and abscesses on or next to the eyeball can cause one of a dog’s eyes to roll up, down or sideways. You may not be able to see the mass if it is deep in the eye socket (retrobulbar mass).
Your vet can use ultrasound or computed tomography imaging to see where the mass is. Surgical biopsy, culture and removal are usual treatments for retrobulbar masses.
Eye Muscle Abnormality
Puppies are occasionally born with abnormal eye muscles that cause one or both eyes to deviate from the normal position. Birth defects of this kind can make a dog look like their eye(s_ are rolling back, down or to one side.
Is It Normal For A Dog’s Eyes To Roll Back When Sleeping?
Dogs are unconscious when they sleep. So, YES, it is normal for a sleeping dog’s eyes to be rolled back. You might notice it more if your dog doesn’t close his eyelids completely while sleeping.
In that situation, the pink or white tissue of the eyeball will be visible rather than the iris and pupil. When they awaken, the eyes immediately return to their usual position with the iris and pupil visible.
Summary
In the decades I’ve been practicing as a veterinarian, I’ve seen many dogs who were described as having their eyes rolling back when they really had third eyelid elevation. A quick examination of your pup’s eye will help you know which one is happening. Third eyelid elevation is a problem but not always an extreme emergency.
On the other hand, if your dog is unresponsive and you can’t see the pupil of the eyes, this is an extreme emergency. Transport him to the nearest emergency veterinary clinic immediately for help.
