Dogs may suffer from facial paralysis due to several reasons such as injuries to the facial nerve resulting from accidents and abuse, metabolic disorders, and infections. In some cases, it is not possible to determine the cause. Paralysis may affect only one side of the face if the facial nerve to that side is damaged in any way, but it can occur on both sides too, in which case it is not as easy to spot it compared to one-sided paralysis. Drooling from the mouth and a listless expression on the face are the usual indications. Total facial paralysis can also occur in dogs. It is characterized by the inability to move lips, ears, nose and eyelids. Reduced range of motion of these facial features is the symptom of partial facial paralysis.
The symptoms of facial paralysis may differ depending on the location of the trauma as well as its extent and severity. The dog may display some or all of the following symptoms such as drooping of the ear, constant drooling, hanging upper lip, inability to blink the eyes and making other facial expressions etc. It may drop food and water while eating due to lack of motor control. The nose may look as if it’s pulled away from the paralyzed side because the muscles are lax on that side.
Inner ear infections often result in facial paralysis. Dogs having certain chronic skin disorders are more prone to this. A CT scan or MRI scan may be able to identify infections in the inner ear. If bacterial infections are the cause, prompt treatment with suitable antibiotics may help resolve the condition. But in some cases, where the facial nerve damage is severe and permanent, the paralysis may also be permanent. In such cases, eye drops may have to be administered frequently to prevent the dog’s eyes from drying out.
Thyroid gland dysfunctions such as hypothyroidism may result in the paralysis of facial nerve. Such cases may be completely resolved by thyroid hormone supplementation throughout the life of the dog.
Idiopathic facial paralysis
This kind of facial paralysis in dogs is similar to the Bell’s palsy affecting people. The diagnosis of this condition is arrived at by the elimination of other possible causes of facial paralysis such as traumatic injuries, thyroid dysfunction or infections. It can affect either a single side of the face or both sides. Though it can be a temporary condition in some cases, it can often recur, appearing in the same side or the other side. If the paralysis is permanent, it may not affect the normalcy of the dog’s life even though the appearance of its face may be a little peculiar. In the absence of any treatment, management of the disorder with measures such as the use eye drops to lubricate the eye is the only option.
The severity of the damage may be assessed by electromyography along with stimulation of the facial nerve by delivering an electric charge. The treatment of facial paralysis is limited to certain procedures such as massage, application of heat, and administration of electroacupuncture, aimed at relieving symptoms. The dog may require a diet of soft food and a specially designed container for drinking water. Regeneration of the facial nerve is possible, although it is a very slow process. Periodic testing is done in the initial 6 months to check for signs of recovery, but chances are slim beyond that period.