Dr Svetlana Formenova. DVM. Veterinary ophthalmologist on Instagram: "Chemosis is a conjunctival edema due to acute inflammation of conjunctiva. This is a non-specific symptom and can occur due to various causes such as an acute allergic reaction, infectious causes, trauma, toxic injuries. In cats, chemosis occurs most often due to infectious diseases (especially Chlamydia felis, FHV-1). In dogs, the most common cause of chemosis is acute allergic conjunctivitis. It always looks spectacular but