Facial Paralysis in Dogs: What You Need to Know

Have you heard of facial paralysis in dogs?

This is a surprisingly common condition in middle-aged or older dogs, and yet few people are aware of it.

The first thing many people realize is that their dog simply “doesn’t look right.”

The change often happens suddenly:

• The dog wakes in the morning, eats breakfast more messily than usual, dropping food from one side of the mouth.
• Then, when their human stares more closely, they realize the dog has a droopy face on one side.

So what exactly is facial paralysis in dogs? What causes it — and can we do about it? That's what we'll talk about in this article.

Facial Paralysis in Dogs

This is an issue with the nerve supply to the muscles and senses on that side of the head. Telltale signs of facial paralysis in a dog include: Usually only one side of the face is affected.

• One side of the lip hangs down lower than the other.
• One ear is more limp than the other.
• The nose is drawn to the opposite side.
• One eyelid is more droopy than other.
• The dog blinks less frequently on the affected side.
• The surface of the eye becomes dry and inflamed.
• Food gets stuck in one side of the mouth.

The most common reason people take their dog to the veterinarian with this condition is that their face is drooping.

The Facts of Facial Paralysis in Dogs

First of all, another term for facial paralysis in dogs is "facial palsy." You might hear your vet call it that.

To better understand the condition, think of the nerves as the electrical wiring supplying a light switch (the muscles). If there’s damage to the wiring, you can press the switch all you like, but the light still won’t come on.

With facial paralysis in dogs, inflammation -- from the nerves to the muscles of the face -- stops them from working.

The muscles themselves are fine but aren’t getting any messages telling them to work. The result is slack muscles, lacking in tone and that characteristic facial droop.

But those facial nerves don’t just supply muscle. They also service: The tongue’s taste glands Tear production Salivary glands

This is why the dog may develop a dry mouth on the affected side due to lack of saliva, or a dry eye due to lack of tear production.

Causes of Facial Paralysis in Dogs

At this point, you might be drawing a comparison with people and wondering if the dog has had a stroke.

But in that wonderful way that pets are different from people (and why human doctors aren’t allowed to treat animals), a stroke rarely causes a droopy-faced dog.

Around one-fourth of all cases of facial paralysis in dogs are caused by one of the following:

• Hypothyroidism: This refers to a lack of thyroid hormone, leading to a general slowing of the metabolism.
• Middle or inner ear infections: The facial nerves pass through the inner ear on their way to the face. Inflammation in the inner ear pinches the nerves and stops them from working.
• Inflammatory conditions: These include meningitis or sterile inflammation of the nervous system.
• Trauma: A knock or blow to the head can cause pressure and inflammation.
• Brain tumor: Happily, this is a rare cause.
• Poor blood supply: Poor circulation to the nerves means they don't function as well.

So if the above reasons account for only 25% of cases, what is the single biggest reason accounting for 75% of cases?

Well, 3 out of every 4 dogs with facial paralysis are diagnosed with idiopathic facial nerve paralysis

(IFNP). The long, intimidating word “idiopathic” means “no one knows the reason.” In other words, for the majority of facial palsy dogs, no reason has been found.

If it’s your dog who's affected, this all sounds rather unsatisfactory. How can it be that no one has the answer?

Well, it isn’t for lack of trying -- the full weight of modern technology, such as CT and MRI scans, has been thrown behind this, and still no one’s the wiser.

OK, so maybe I’m oversimplifying things slightly, because nerve inflammation does seem to be involved. But again, no one is certain why the nerve inflammation happens in the first place, so we end up back with that word "idiopathic" again.

Treating Facial Paralysis in Dogs

This is a good news/bad news scenario.

The bad news is that if your dog is in the 75% of cases where no other problem is found, then there is no specific treatment. For those idiopathic cases, nothing is proven to help:

• For a while, steroids were in fashion (to help reduce inflammation), but there’s no conclusive evidence they help, and so now they’re out of vogue.
• The only thing that may help is to put artificial tears into the affected eye to stop the cornea drying out from lack of tear production.

However, the good news is that the condition is unlikely to bother the dog greatly, and may -- just may -- slowly improve with time.

And as for the other 25% of case, if an underlying problem is found, then treating that is going to help. With that said, even then the paralysis may be permanent and only improve slightly over time.

The video below shows a facial paralysis exam in a normal dog:

Testing Your Dog

Your dog’s droopy face may be a cry for help and a warning they have underactive thyroid glands or a deep-seated ear infection.

Treating these conditions will greatly improve their quality of life and prevent deterioration in the facial paralysis.

But be prepared to spend a lot of money on tests only to have the vet give you the all clear. There again, this is actually a good thing.

So if one day your dog wakes up with a droopy face and you suspect facial paralysis, don’t panic — but do get the dog checked out by a vet.

This pet health content was written by a veterinarian, Dr. Pippa Elliott, BVMS, MRCVS. It was last reviewed May 11, 2018.

If you have questions or concerns, call your vet, who is best equipped to ensure the health and well-being of your pet. This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. See additional information.