Final answer:
A horse with a swollen eye needs immediate veterinary care due to potential underlying causes like infections or trauma, which may lead to serious complications. Prompt diagnosis and treatment are crucial to relieve pain, reduce swelling, and prevent vision loss.
Step-by-step explanation:
A horse with a swollen eye is considered an emergency because it can be indicative of serious underlying conditions, such as infections, trauma, or other systemic diseases that may threaten the horse's vision or overall health. Swelling around the eye can impair vision, cause significant discomfort, and, if left untreated, may lead to complications such as the development of eye infections, uveitis, or glaucoma, which are painful and potentially sight-threatening conditions.
Such symptoms require prompt veterinary attention to diagnose the exact cause and begin appropriate treatment to relieve pain, reduce swelling, and prevent any serious complications that could compromise the horse's vision or even its life. Diagnosing the cause may involve a thorough eye examination, tests like ultrasound or culture of discharge, and an evaluation of the horse's overall health to rule out systemic diseases. Treatment could range from anti-inflammatory drugs and antibiotics to more invasive treatments like surgery, depending on the cause.