Droopy Eye in Cats

Horner’s Syndrome in Cats

Conditions of the body that affect the nerves supplying the face muscles and eyes can lead to a group of symptoms known as Horner’s syndrome. This condition is characterized by a drooping eye, an eyelid that is protruding from the eye, or a severely constricted eye pupil. Any brain or spinal injury may cause this syndrome, and it has also been linked to conditions affecting the middle ear, but in many cases the origin remains unknown. In almost 45 percent of diagnosed cats, the exact cause remains elusive.

Symptoms and Types

  • Smaller size eye pupil (miosis)
  • Abnormal elevation of the inner eyelid - located between the cornea and inner corner of the eyelids (third eyelid)
  • Drooping of the upper eyelid
  • Eyes appear to be sunken into eye socket
  • Inflammation of the ear


  • Unknown (idiopathic) in most cases
  • Brain injury, brain stem lesions
  • Brain tumor
  • Spinal cord lesions
  • Infections


You will need to give a detailed history of your cat’s health, onset and nature of symptoms, and possible incidents that might have brought this condition on, such as brain trauma, injury to the head or back, ear infections, and any other previous health problems. The veterinarian will perform a thorough physical exam on your cat, with a standard blood blood count, blood profile, and urinalysis. The routine laboratory tests are not required for diagnosis of this syndrome, but may be useful for determining other diseases or infections that may be present.

Radiography remains the important technique for evaluating brain and spinal cord lesions, and skull X-rays are helpful for evaluation of ear problems. More advanced techniques like computed tomography (CT-scan), magnetic resonance imaging (MRI), and ultrasonography are also frequently used to diagnose this syndrome. In some cases, a cerebrospinal fluid (CSF) sample is taken to analyze for brain and spinal cord disease.

  Next >