Haw's syndrome is a common eye disease of cats, characterised by bilateral elevation of the third eyelids. Bilateral elevation of third eyelids is seen when a cat wakes from sleep, but if prolonged, may reflect a disease state. All other aspects of the ophthalmic examination are usually normal.
Haw's syndrome normally resolves once the underlying disease is corrected. In cats, disease states which can cause Haw's syndrome include:
- cat flu or other viral infections (e.g. FeLV, FIV)
- tranquilization - many pre-anaesthetic drugs such as acepromazine cause relaxation of third eyelid muscles resulting in bilateral elevation.
- fatigue - can cause transient third eyelid elevation, especially in cats prone to ectropion.
- Horner's syndrome
- Dysautonomia (Key-Gaskell syndrome)