Symptoms and Causes of Blepharospasm in Cats and Dogs

Eye Spasms

Chihuahua with eyes closed inf ield of flowers

Danita Delimont / Getty Images

If your dog or cat is having repeated eye spasms, it is called blepharospasm, which can also occur in humans. Blepharospasm is a condition that causes a rapid blinking of the eye due to involuntary contractions of the orbicularis oculi muscle of the eyelid. This is a quick type of spasm that sometimes appears as if the eyelid is closed. The pet's eye may tear and the pet may be reluctant to look at bright lights in addition to the swift blinking. If you notice blepharospasm in your dog or cat, it should be checked by your veterinarian as soon as possible to determine the cause and treatment.

Is Blepharospasm a Disease?

Blepharospasm is not a disease in and of itself; in most cases, it is a clinical sign that something is wrong with the eye or eyelid. In most cases of blepharospasm seen in dogs and cats, the eye has been injured or infected and most often it is painful. Some cases may involve only the fifth cranial nerve (trigeminal nerve) or neither the eye nor the trigeminal nerve (essential blepharospasm).

Symptoms of Blepharospasm

The affected eyelid will usually look red and swollen, and the dog or cat will squint or blink spasmodically. The eye will often be itchy and the pet will scratch or rub at its face or eyelids, which can also damage the surrounding tissues. You may also notice a discharge from the eye that can be clear or contain pus. The skin over the eyelids may be crusty or flaky with small pustules, like pimples on the surface. Blepharitis can affect one or both eyes.

Causes of Blepharospasm

Any condition that irritates the eyelids can result in blepharitis, including:

  • Congenital abnormalities: Congenital abnormalities can also make a dog or cat prone to blepharitis include entropion, a condition in which the eyelid edges turn inwards, along with abnormalities of the eyelash in which they grow towards the eye instead of out.
  • Allergies: Allergies to insect bites and allergens that are inhaled can also cause blepharitis.
  • Shape of face and muzzle: Facial folds, long and narrow muzzles, and short flat faces predispose dogs and cats to develop blepharospasm. This means that some breeds are more prone to it than others. For example, Persian cats and Pekingese dogs.
  • Infections: Bacterial infections such as staph, abscesses of glands in the eyelids, and occasionally, a fungal infection can lead to blepharospasm.
  • Tumors: Tumors that are located in the meibomian glands (the oil glands along the edge of the eyelids) can be benign adenomas or malignant adenocarcinomas. A mast cell tumor can also cause blepharitis.
  • Inflammatory disorders
  • External trauma to the eyelids
  • Localized mange (caused by mites)
  • Nutritional disorders
  • Endocrine problems including hypothyroidism, Cushing's disease, or diabetes
  • Environmental irritants such as tobacco smoke
  • In some cases, no underlying cause can be found and the blepharospasm is deemed idiopathic.

Treatment of Blepharospasm

Treatment to reduce the inflammation involves applying warm compresses several times per day and removing discharges with saline eye drops. Additional specific treatment will depend on the diagnosis of the underlying cause.

Diseases of the eye can worsen quickly; it is important to see your veterinarian as soon as possible if you notice your pet squinting, showing tearing or other discharge, or experiencing blepharospasm of the eye(s).

If you suspect your pet is sick, call your vet immediately. For health-related questions, always consult your veterinarian, as they have examined your pet, know the pet's health history, and can make the best recommendations for your pet.