Why Is My Dog's Mouth Drooping on One Side?

When people invite a pet into their home, it typically becomes another member of the family; as such, finding a pet in distress, such as a dog with a drooping mouth, can be upsetting. A dog's mouth may droop for several possible reasons, which will require varying solutions, depending on the cause of the dog's facial nerve paresis, as this condition is called. With the help of a veterinarian, identifying the cause will help determine the next steps on the dog's road to recovery.

  1. About Facial Nerve Paresis

    • Facial nerve paresis is an ailment more commonly experienced by dogs than cats. While the condition can affect any dog, dogs more than five years old are more susceptible than younger dogs. Moreover, certain breeds are more commonly affected than others. These breeds include cocker spaniels, Pembroke Welsh corgis, boxers and English setters. Facial nerve paresis typically only affects one side of the face, although cases of bilateral paralysis have occurred.

    Ear Infection

    • A middle or inner ear infectionalso known as an otitis media-interna, is the most common known cause of a dog's facial nerve paresis. After a veterinarian examines your dog and the ear infection is confirmed, you will likely be sent home with antibiotics to treat it, which should also resolve the paralysis. After the ear infection has healed, you must keep your dog's ears clean with frequent grooming. Return to the vet at the first sign of future ear infections.

    Thyroid or Nervous System Disorders

    • A thyroid issue such as hypothyroidism includes symptoms such as facial paralysis, but if this condition is the cause of your dog's facial nerve paresis, your dog will likely be experiencing other symptoms such as lethargy, decreased appetite, increased weight gain and a significant change in your dog's coat such as dulling or even balding. A variety of nervous system disorders can cause partial or whole facial paralysis. If your dog has been showing signs of lethargy and sleeping more often, the vet may also test for a brain stem disorder.

    Idiopathic

    • Sadly, the cause of many cases of canine facial nerve paresis is unknown. Sometimes it clears up on its own, though it may return, and in other cases, the facial paralysis will be a lifelong ailment for your dog. If so, the vet will likely prescribe eye lubricant to ensure the stressed eye muscles do not damage the eye. Also, your vet must monitor your dog's condition closely in the event that ulcers occur.