Disorder - Horner syndromeOrgan Systems Involved
Alternative disorders described within LIDA
Hyperparathyroidism; Hyperthyroidism; Otitis externa, susceptibility to; Otitis media, susceptibility to; Orbital disease; Ipsilateral laryngeal hemiplegia
Bernard-Horner syndrome; Oculosympathetic palsy
Horner's syndrome results when some of the nerves that supply the eye are disrupted. These nerve fibres have quite a long path to travel between the brain and the eye. They leave the brain, pass down the spinal cord to the bottom of the neck and into the chest before returning back up towards the eye via the middle ear. Horner's syndrome may result following damage to this nerve supply at any point. Common causes include a traumatic event to the head, neck or shoulder region, ear infections, or tumours in the brain or chest cavity. The affected eye in cats with Horner’s syndrome will have a smaller pupil than the opposite eye, the third eyelid may be visible and the eye may appear sunken. Cats will often blink more than usual and may appear unsteady on their feet. Siamese cats with Horner's syndrome may also display a change in coat and iris colour.
Cats at Risk
Horner's syndrome can affect any age, sex and breed of cat.