Dog's Face Drooping on One Side: What It Can Mean

A new one-sided facial droop in a dog usually means the muscles of facial expression are not moving normally. Facial-nerve dysfunction is a leading explanation, but ear disease, trauma, a mass, hypothyroidism, or a brainstem disorder can look similar. Arrange prompt veterinary assessment, especially because an eye that cannot blink can be injured.

When to call your vet right away

Go to an emergency clinic now if the facial change occurs with:

• Collapse, seizures, marked sleepiness, confusion, circling, or weakness in a limb.
• A severe head tilt, repeated falling, rapid eye movements, or inability to stand.
• Trouble breathing or swallowing, repeated choking, or blue, gray, or very pale gums.
• Major head trauma, possible toxin exposure, or a painful, cloudy, or injured eye.

If the dog is otherwise stable, contact your veterinarian the same day. Loss of blinking is important even when the dog seems comfortable.

Signs that fit facial-nerve dysfunction

The facial nerve moves the eyelids, ears, lips, nostrils, and other muscles of expression. Merck identifies inability to blink as the most consistent sign of facial paralysis.[2] On the affected side, the ear may hang lower, the upper lip may sag, saliva may escape, and food or water may fall from the mouth. The nose can appear pulled toward the normal side.

Facial sensation is supplied mainly by a different nerve. A dog may still feel a touch near the face even though the eyelid or lip does not move normally. Do not test the eye by touching it.

Why the eye matters

An eyelid that does not close spreads tears poorly and leaves the cornea exposed. Tear production may also decrease when the lesion affects nerve fibers traveling toward the tear gland.[2] Watch for redness, cloudiness, discharge, squinting, or rubbing. Those signs need urgent assessment.

Do not use redness-relief drops, leftover antibiotic or steroid drops, or human ointments. Some products are unsafe for a damaged cornea. The dog eye-problem guide explains why different eye conditions require different treatment.

Ear disease, peripheral nerve disease, and brain disease can overlap

The facial nerve passes close to the middle and inner ear. Deep ear inflammation can therefore cause a facial droop, sometimes with head tilt, nausea, abnormal eye movements, or poor balance.[2] Surface redness alone does not show whether the middle ear is involved. See the dog vestibular-disease guide for related balance signs to record.

Some dogs develop isolated facial paralysis with no cause found after appropriate testing. That diagnosis is made after other explanations are considered; it cannot be confirmed from appearance alone. Brainstem disease is more concerning when the facial droop occurs with altered awareness, limb weakness, abnormal paw placement, or other cranial-nerve deficits.[2]

What to observe before the visit

Record when the change began and whether it was abrupt or progressive. Note whether the dog can blink fully on both sides, whether the ear or lip droops, and whether eating or drinking is messy. Also record head tilt, stumbling, vomiting, voice change, trouble swallowing, eye redness, ear odor or discharge, recent ear cleaning, trauma, and all medicines or supplements.

A short video of the face at rest, blinking, walking, and eating can help if it is obtained without delaying care. Do not repeatedly startle the dog to trigger a blink, probe the ear, or force the mouth open.

What the veterinarian may check

The examination may include the eyes, tear production, corneal staining, ears, facial movement, facial sensation, balance, limb strength, and other cranial nerves. The pattern helps distinguish an isolated peripheral facial-nerve problem from disease near the middle ear or brainstem.[2][3]

Depending on localization and history, testing may include ear cytology, blood work and thyroid testing, imaging of the middle ear or brain, or other neurologic tests. Treatment and prognosis depend on the cause; protecting the cornea may be necessary while function is reduced.[1][2]

The clinician-facing canine facial-paralysis workup outlines the localization sequence.

Frequently Asked Questions

Why is one side of my dog's face drooping?

Facial-nerve dysfunction is one possibility, but middle-ear disease, trauma, hypothyroidism, a mass, or a brainstem problem can produce similar changes. An examination is needed to localize the problem.

Is a drooping face in a dog an emergency?

Seek emergency care if the droop appears with collapse, seizures, confusion, weakness, circling, severe imbalance, trouble breathing or swallowing, or recent trauma. Otherwise, arrange prompt veterinary assessment.

Can facial paralysis stop a dog from blinking?

Yes. The facial nerve controls eyelid closure. Poor blinking can allow the cornea to dry or ulcerate, so the eye should be checked promptly.

Does a facial droop mean my dog had a stroke?

Not necessarily. A stroke is only one of several possible central causes, and isolated facial-nerve disease or middle-ear disease may look similar at home.

Can an ear infection cause a dog's face to droop?

Yes. The facial nerve travels near the middle and inner ear, so deeper ear disease can affect facial movement and may also cause head tilt or balance problems.

What should I do before the appointment?

Prevent rubbing, offer food and water in an easy-to-reach container, record a short video, and note whether the dog can blink. Do not put leftover drops or medication in the eye or ear.

References

1. Merck Veterinary Manual — Facial Paralysis in Dogs. https://www.merckvetmanual.com/dog-owners/brain-spinal-cord-and-nerve-disorders-of-dogs/facial-paralysis-in-dogs
2. Merck Veterinary Manual — Facial Paralysis in Animals. https://www.merckvetmanual.com/nervous-system/facial-paralysis/facial-paralysis-in-animals
3. Merck Veterinary Manual — Neurologic Examination of Animals. https://www.merckvetmanual.com/nervous-system/the-neurologic-examination/the-neurologic-examination-of-animals