Facial paralysis in dogs – symptoms and eye protection

Overview

A motor nerve problem affects the face

The facial nerve is cranial nerve number 7, carrying commands to the muscles of facial expression. It controls movements including those of the eyelids, lips, ears and nostrils. In complete paralysis, movement is absent; in partial paralysis, or paresis, the muscle moves more weakly than usual.

The problem is usually one-sided, but both sides of the face can be affected. The bilateral form is harder to notice because the expression may simply look subdued. Facial paralysis alone rarely severely compromises a dog's overall ability to function. A dry eye can nevertheless require long-term care.

The facial nerve leaves the brainstem near the hearing and balance nerve and passes through the temporal bone before branching. It also contains fibres regulating the tear glands, salivary glands and glands in the nasal mucosa. After leaving the skull, it branches towards the ear, eyelids and muzzle. Damage limited to the eyelid branch can paralyse the eyelid without paralysing the lip or nostril. Damage to a branch running over the cheek surface may instead affect only lip and nostril movements. Nerve damage therefore does not always leave the entire side of the face completely motionless.

Causes

The underlying cause may remain unknown

The most common form is idiopathic facial paralysis, in which no explanatory underlying disease is identified. It usually starts suddenly without other clinical signs. The exact mechanism of the idiopathic form is unknown. The term facial neuritis therefore does not describe every cause of facial paralysis.

Ear disease and other nervous system diseases

Middle or inner ear infection can damage the facial nerve because it passes close to the ear structures. Ear surgery or tumour removal along the nerve's course can also cause damage. An injury to the head is another possible cause.

An underactive thyroid can affect several cranial nerves, including the facial nerve. Other causes include generalised peripheral nerve disease and immune-mediated diseases. A tumour may be within or near the nerve, for example in the middle ear. Brainstem inflammation, a tumour or a disturbance of blood flow can also cause facial paralysis.

Risk factors

Idiopathic facial paralysis is most often diagnosed in dogs older than 5 years. Cocker Spaniels and Cavalier King Charles Spaniels appear more predisposed. No confirmed hereditary or genetic cause has been identified. Other breeds can also be affected.

Long-standing ear problems increase suspicion of middle ear infection in a dog with facial paralysis. Cocker Spaniels also develop middle ear infection and hypothyroidism, both possible underlying causes of paralysis. In an ophthalmic follow-up study published in 2026, short-nosed dogs had more frequent and severe corneal ulcers associated with facial nerve dysfunction. This describes the risk of an eye complication, rather than an overall ranking of disease risk across breeds.

Typical symptoms

Signs can start suddenly, and the visible change depends on which nerve branch is damaged. You may notice the following at home:

• Your dog does not blink normally or fully close the affected eye.
• The lip droops on one side and saliva drips from the corner of the mouth.
• An ear hangs lower than before or moves poorly.
• Food collects between the lip and teeth or falls from the mouth.
• Eating or drinking becomes difficult because of facial muscle weakness.
• Thick greyish discharge collects in the eye.
• The nose appears pulled towards the unaffected side.

With nerve-related dry eye, the area around the nostril on the same side may also become dry. An accompanying head tilt, balance difficulty or involuntary eye movements additionally suggest a balance system disorder.

Ear-related nerve damage can be accompanied by Horner's syndrome. This causes a small pupil, a drooping upper eyelid and an eye that appears more sunken than usual. Middle ear infection can also impair hearing.

Complications and consequences

The cornea needs protection

Poor blinking and reduced tear production predispose the eye surface to drying. Keratitis associated with facial paralysis can slow the healing of a corneal ulcer. Untreated dry eye can cause scarring, blood vessel growth and secondary infections. Vision can be permanently damaged.

In a Spanish ophthalmic follow-up study, 52 of 84 eyes, or 61.9%, had ulcerative keratitis. These were patients selected for specialist care, so the proportion is not the prognosis for every affected dog.

Nerve recovery may be incomplete

Dogs that recover fully from idiopathic paralysis usually do so within 8–12 weeks. In some, movement returns only partly or not at all. If there has been no improvement within 6 months, recovery is unlikely.

In the 2026 ophthalmic follow-up study, movement improved at least partly on the side of 30 of the 63 eyes assessed, or 47.6%. Full recovery occurred on the side of 15 eyes, or 23.8% of those assessed. Partial recovery in this study therefore did not mean normal blinking in every patient.

Diagnosis at the vet

Examination locates the damage

Your vet establishes when signs began and examines facial movements and the rest of the nervous system. With facial nerve damage, the blink reflex to eyelid touch and blinking in response to a threatening gesture may be absent. A missing blink alone does not mean the dog is blind: examination assesses both perception of the stimulus and eyelid movement.

Facial skin sensation is mainly carried by the trigeminal nerve, rather than the facial nerve. The mandibular branch of the trigeminal nerve also helps control the chewing muscles. This helps distinguish a drooping lip from other mouth and jaw dysfunction.

Impaired limb proprioception, weakness or altered consciousness increases suspicion of brainstem damage. Facial paralysis alone without other deficits is consistent with peripheral nerve damage.

The eye, ear and additional tests

The Schirmer tear test measures tear production over 1 minute. Fluorescein staining reveals damage to the corneal surface. The ears are examined carefully, which may require sedation or anaesthesia. With middle or inner ear disease, the ear canal may look unaffected from the outside.

A urine sample may complement investigations for other diseases. Blood tests investigate other diseases and thyroid function where needed. MRI shows the facial nerve and brainstem structures. CT or MRI helps assess middle ear changes. Even in idiopathic paralysis, the nerve may show abnormal contrast enhancement on MRI. Cerebrospinal fluid sampling and infectious disease testing may be needed to investigate central nervous system disease. A tumour is confirmed by a tissue sample where necessary.

A test stimulus may make the eyeball retract and the third eyelid rise even though the eyelids cannot close properly. A normal-looking, intact eardrum does not rule out middle ear infection. A sample is taken from the middle ear for bacterial culture and cytology where needed. An outer ear sample may be more contaminated and less reliably represent the middle ear. CT and MRI detect middle ear infection more sensitively than ordinary X-rays. Electromyography and electrical stimulation of the facial nerve can also assess the severity of nerve damage.

Treatment

Protecting the eye and treating the cause

Your vet prescribes treatment according to the identified cause and the eye's condition. Lubricating eye products protect the cornea when the eyelid cannot spread tears normally. Lubrication may be needed even when tear production is normal but blinking is absent. A corneal ulcer is treated promptly as a separate complication.

Medication stimulating tear production may be used for nerve-related dry eye. A secondary bacterial infection may require a topical antibiotic. Severe eye problems responding poorly to treatment may require eye surgery.

Bacterial middle ear infection is treated with antimicrobial medication selected according to the findings and sometimes ear flushing or surgery. Early infection treatment improves the chance of neurological recovery, but nerve damage may still be permanent. Paralysis associated with hypothyroidism typically improves within 6–8 weeks after hormone replacement starts. In some dogs, paralysis persists even after thyroid values normalise.

Supportive care for the idiopathic form

No treatment for idiopathic facial paralysis has been shown to alter the outcome. Corticosteroids have not clearly been shown to speed up or improve recovery in dogs. Results of treatment for Bell's palsy in humans cannot be applied directly to dogs.

Soft food or a more suitable water bowl may help with eating and drinking. Keeping the area around the mouth clean helps prevent skin sores caused by saliva and food debris. Recovery is monitored through repeat examinations because the facial nerve regenerates slowly.

Surgery for severe eye problems

One surgical option for severe dry eye is moving a salivary gland duct to the eye. The duct is redirected into the conjunctival sac so that saliva moistens the eye surface. Some dogs still need medication after surgery. The aim is to maintain eye moisture, rather than restore facial nerve movement.

Prevention

The cause of idiopathic facial paralysis is unknown, so there is no established specific prevention. Early recognition and treatment of ear infection improve the chance of avoiding permanent facial muscle weakness. Vigorous ear cleaning is avoided because handling can damage the eardrum. Protecting your dog from head injuries prevents one possible cause of nerve damage. In an already affected dog, corneal lubrication helps prevent eye complications even if facial movement does not return.

If the cornea is damaged, an appropriate protective collar or eye shield selected by your vet prevents rubbing.

Important for dog owners

Monitor whether the eye truly closes and whether redness, watering or discharge increases. Record eating difficulties and any new balance or limb signs for the treating vet. New signs or deterioration are reasons for reassessment.

With long-standing paralysis, facial muscles can scar and tighten. The drooping lip may then rise and the face look more symmetrical without nerve function returning. At this stage, the nose may be pulled towards the affected side. The opposite side of the face can also become affected later. Quality of life can nevertheless be good when dry eye in particular and other consequences are controlled.

Frequently asked questions

Is facial paralysis in a dog a stroke?

A drooping face does not automatically mean a stroke: the most common form of facial paralysis is idiopathic. A disturbance of brainstem blood flow is nevertheless one possible cause. Your vet also assesses limb proprioception, other cranial nerves and your dog's level of consciousness, among other findings, to locate the damage.

Can a dog recover completely?

Full recovery is possible, but some dogs recover only partly or remain permanently paralysed. Dogs that recover completely from the idiopathic form usually do so within 8–12 weeks. If there is no improvement within 6 months, the outlook for recovery is poor.

Why treat the eye if my dog can see?

The facial nerve helps close the eyelid, and paralysis can also reduce tear production. Even an eye with normal vision can therefore dry out and develop a painful corneal ulcer. Lubrication may be needed despite a normal tear test result if blinking does not work.

Do corticosteroids help facial paralysis?

In idiopathic facial paralysis in dogs, corticosteroids have not clearly been shown to improve or speed up recovery. Treatment is selected according to whether the cause is an ear infection, hormonal disease or another nervous system lesion, for example. Eye lubrication forms part of supportive care regardless of whether an underlying cause is found.

Can a straighter face mean something other than recovery?

Yes. Facial muscles paralysed for a long time may tighten because of scarring. Drooping then decreases without nerve function necessarily improving. Recovery is therefore monitored through facial movements and repeat examinations; a photograph of the face at rest alone does not show the whole situation.