What typically causes blepharospasm in dogs?

Blepharospasm in dogs is primarily a reflexive response that occurs due to stimulation of the eyelids or conjunctiva. This involuntary blinking is often a protective mechanism, triggered by irritation or discomfort in the ocular region. When the eyelids or the conjunctiva are stimulated, whether from environmental irritants, allergies, or even physical touch, the dog's natural response is to squint or close the eyes tightly to shield them from further irritation or potential harm.

While other factors such as exposure to sunlight, the presence of a foreign body, or head injuries can certainly lead to eye discomfort or irritation, they are not the direct cause of blepharospasm. Instead, they may contribute to the overall sensitivity of the eyes, which can result in the stimulation of the eyelids or conjunctive tissues. Understanding the primary mechanism—stimulation of the eyelids or conjunctiva—helps to clarify the nature of blepharospasm as a symptom rather than a standalone condition and indicates that treating the underlying irritant is crucial for alleviating the spasms.