VCA Animal Hospitals

Horner’s Syndrome in Cats

What is Horner's Syndrome?

horners_syndrome_in_cats1Horner's Syndrome is a common neurological disorder of the eye and facial muscles, caused by dysfunction of the sympathetic nervous system. The condition usually occurs suddenly and without warning. The most common clinical signs of Horner's Syndrome are:

  • Drooping of the eyelid on the affected side (ptosis)
  • The pupil of the affected eye will be constricted (miosis), or smaller than usual
  • The affected eye often appears sunken (enophthalmos)
  • The third eyelid of the affected eye may appear red and raised or protruded (conjunctival hyperemia)

What is the sympathetic nervous system?

The sympathetic nervous system is one part of the autonomic nervous system. The autonomic nervous system controls automatic or involuntary functions in the body. The two separate and complementary parts of the autonomic nervous system are the sympathetic nervous system, which controls 'fight or flight' functions of the body and the parasympathetic nervous system, which regulates routine functions during a relaxed state such as digestion. The autonomic nervous system helps control normal functions of the eyes and facial muscles, including blinking, muscle tone, the amount of dilation or constriction of the pupils, and so on. When the sympathetic nervous system is activated or stimulated, the pupils dilate, the muscles tense, the heart rate increases, and the body gets prepared for 'action'. The sympathetic nerves that control the eye follow a long path and they can become damaged anywhere along the route. They leave the spinal cord just inside the chest and travel up the neck to the head, where they connect to nerves just below the ear. From there, they continue their journey to the eye.

We’ve Got Positive Cattitude! We help to make cat care easier for you – Get a Free Feline First Exam* (for new clients).

What causes Horner's Syndrome?

If the sympathetic nervous system that supplies the eyes is damaged or is malfunctioning, the parasympathetic system 'takes over', and the symptoms of Horner's Syndrome appear. The damage or malfunction can occur in the neck area, the ear area or the eye area. Damage may occur because of blunt force trauma such as that caused by an automobile accident or because of a bite wound from another animal. Other problems that can cause damage or inflammation of the nerves in this area include diseases within the eye or in the retrobulbar (behind the eye) area, problems in the middle ear (otitis media), or tumors in the chest, neck or brain.

"With many cats that develop Horner's Syndrome there is a recent history of trauma..."

In dogs, Horner's Syndrome is 'idiopathic', which means it has an unknown cause, in about half the cases. In cats, however, a cause is virtually always found, and idiopathic Horner's Syndrome is very rare. With many cats that develop Horner's Syndrome there is a recent history of trauma, particularly being hit by a car.

Depending on your cat's recent history and other physical findings on examination, your veterinarian may recommend a series of diagnostic tests to determine if there is an underlying cause. Initial tests will usually include a neurologic evaluation, an otoscopic examination (examination of the ears) and x-rays of the chest and neck area.

Are there any other problems that could look like Horner's Syndrome?

In some cases, the only obvious symptom is elevation of the third eyelid. If this is the case with your cat, your veterinarian will rule out the possibility of problems such as facial paralysis (common with severe ear infections), facial muscle paralysis, severe dehydration, or Haw's paralysis. With Haw's paralysis, animals, particularly cats, will elevate their third eyelids in response to illness, particularly intestinal irritation; the third eyelids may remain elevated for up to 4-6 weeks, but will eventually go back to normal. There is a rare disorder in cats called Feline Dysautonomia (Key-Gaskell Syndrome) that has symptoms of constricted pupils, elevated third eyelids, urinary retention, constipation, and other problems related to severe disruption of the sympathetic nervous system.

What is the treatment?

horners_syndrome_in_cats_2Most cases of Horner's Syndrome will resolve spontaneously or on their own over time. Since the cat may have an inability to blink normally, your veterinarian may recommend symptomatic treatment in the form of eye medication to minimize the development of corneal ulcers from what is called 'exposure keratitis'. Other symptomatic treatment that might be recommended is the use of phenylephrine drops in the affected eye to dilate the pupil. If an underlying disease is identified, it is important to treat that disease.

What is the prognosis and recovery rate?

"The prognosis depends on the underlying cause..."

The prognosis depends on the underlying cause. Patients with chest trauma tend to have a quicker recovery rate (days to weeks) than patients with other lesions. If the underlying problem is Feline Dysautonomia, the prognosis is poor.

Learn More about Horner's Syndrome in Cats

To learn more about Horner's syndrome from one of our knowledgeable veterinarians, please feel free to make an appointment at a VCA Animal Hospital near you. If you are not yet a VCA client, please feel free to download our Free Initial Pet Health Exam coupon to visit with a VCA veterinarian free of charge.

Related Tags

autonomic, dysautonomia, eyelids, horner, idiopathic, nervous, neurologic, neurological, paralysis, parasympathetic, sympathetic

Looking to learn more?

We also offer free, instant access to over 1,500 related articles on your pet's health including preventive medicine, common and not so common diseases, and even informative case studies. We encourage you to read any of these popular articles below or search our extensive pet health library.

Most Popular Articles

About our approach to exceptional pet health care

At VCA Animal Hospitals, our veterinarians take you and your pet's health seriously. With over 600 hospitals and 1,800 fully qualified, dedicated and compassionate veterinarians, we strive to give your pet the very best in medical care. We understand your pet is an extension of you, and appreciate the opportunity to share in providing exceptional pet care and quality of life.

* Free initial health exam for new clients only. Not to be combined with any other offer. Not good toward boarding, grooming, prescription and non-prescription medication, and retail items. Not good toward emergency and/or specialty veterinary services. Coupon good for up to two pets (dogs or cats only) per household. Redeemable only at a general practice VCA Animal Hospital. For pet owners who are aged 18 and older.

If you are a new client, you can get a free first exam* on your first visit.

Free First Exam

Get to know us by visiting one of our neighborhood hospitals.

Locate a Hospital
CLOSE CLOSE

General Practice

We have over 540 animal hospitals in 41 states that are staffed by more than 2,000 fully qualified, dedicated and compassionate veterinarians, with more than 200 being board-certified specialists. The nationwide VCA family of general practice hospitals give your pet the very best in medical care, providing a full range of general medical and surgical services as well as specialized treatments*: Wellness, Spay/neuter, Advanced diagnostic services (MRI/CT Scan), Internal medicine, Oncology, Ophthalmology, Dermatology, Cardiology, Neurology, Boarding, Grooming

*services may vary by location.

Our family of pet hospitals stands out by delivering the greatest resources in order provide the highest quality care available for your pets. By maintaining the highest standards of pet health care available anywhere, we emphasize prevention as well as healing. We provide continuing education programs to our doctors and staff and promote the open exchange of professional knowledge and expertise. And finally, we have established a consistent program of procedures and techniques, proven to be the most effective in keeping pets healthy.

Find a VCA General Care Animal Hospital near you:

 

See all VCA Animal Hospitals >

CLOSE CLOSE

Specialty Care

Sometimes sick or injured pets need the care of a veterinary medical specialist. When that happens, VCA specialty hospitals work closely with the general practitioner veterinarians who refer cases to us in order to provide seamless veterinary care to your pet. When your pet is facing any kind of serious illness or injury, our specialty referral hospitals will provide the compassionate and expert care your beloved pet needs.

Our goal is to make sure that when you and your pet are in need that you have access to board certified specialists who are up to date on the very latest developments in their field. In our state of the art hospitals, our specialists also have access to the most sophisticated diagnostic and treatment tools and techniques from ultrasonography and endoscopy to CAT scans and even MRI.

We have twenty-eight specialty hospitals across the US so there may be one near you. Our specialized services include: cardiology, critical care, dentistry, dermatology, internal medicine, neurology, oncology, ophthalmology, radiology and surgery.

Find a VCA Specialty Care Animal Hospital near you:

 

See all VCA Animal Hospitals >

CLOSE CLOSE

Emergency Care

In case of emergency, please call us immediately. If it is after hours, check with a local animal hospital emergency clinic.

CLOSE CLOSE