TL;DR: If your cat cannot blink, it typically indicates facial nerve paralysis and requires a veterinary examination within 24–48 hours to prevent corneal ulcers and permanent eye damage.
What causes my cat to be unable to blink?
When a cat is unable to blink one eye, it is often a sign of facial nerve paralysis or an issue with the palpebral reflex. The facial nerve controls the muscles used for blinking and facial expressions. If this nerve is damaged due to inflammation, ear infections, trauma, or idiopathic reasons, the eyelid may remain open, leaving the eye vulnerable to drying out.
Is it a veterinary emergency if my cat cannot blink?
- Urgency level: Low. It is generally not a life-threatening emergency if the cat is otherwise acting normally.
- Risks: Because the eye cannot properly lubricate itself without blinking, there is a high risk of developing corneal ulcers or secondary infections.
- Next steps: Schedule a veterinary appointment within 24 to 48 hours to prevent long-term damage to the eye surface.
How can taking a photo help my veterinarian triage this condition?
- Allows the vet to assess facial symmetry and look for drooping of the lip or ear on the affected side.
- Helps the team check for signs of ocular discharge, redness, or inflammation.
- Provides visual information to determine if the issue is localized to the eye or part of a larger neurological concern.
Clinical Context (Merck Veterinary Manual)
In cats, the acute onset of unilateral inability to blink may be caused by idiopathic facial paralysis, a common disorder characterized by paresis or paralysis of facial muscles. Other potential causes include trauma and ear disease, necessitating the exclusion of these factors via clinical features. Diagnosis is based on clinical signs and exclusion of other causes of facial paralysis. Electromyography and electrical stimulation of the facial nerve can help determine the location and severity of injury, although changes may not be evident for 5-7 days. Treatment for idiopathic facial paralysis is supportive, focusing on preventing corneal damage with artificial tears, as there is no specific cure. While partial improvement may occur, persistent dysfunction is common.
Chapter: Neurology
Source: The Merck Veterinary Manual, 11th Edition (Page 1239)