Your horse’s eyes allow perception of colors, forms, and depth. What you see from the outside represents a fraction of what the eye beholds. A horse’s eye is a complex organ that offers a window into the rest of the body. When looking inside the eye with specialized equipment, your veterinarian sees blood vessels, nerves, and lymphoid tissue that cannot be seen in other areas of the body from the outside.
The structures within the eye comprise 3 basic layers: 1) the protective, enveloping layer that you see from the outside-the white sclera and clear cornea; 2) the blood vessel layer, known as the uvea (includes the iris), and 3) the neurologic layer or retina. Inflammation in any of these layers of the eye results in a red eye. Careful examination of these three layers by your veterinarian determines if the cause of the red eye indicates a local problem, such as lid lacerations, conjunctivitis or ulcerative keratitis; or a systemic problem, such as anterior uveitis.
The skin is one of the largest organs in the body; it acts like a glove over your horse’s body providing warmth and protection. Secretions from the skin keep germs and water outside the body and bodily fluids inside the body. Breakdowns in this protective barrier lead to many conditions, such as, hair loss, infections, and fluid losses.
The appearance of your horse’s skin provides insight to the overall health of your horse. Common conditions affecting your horse’s skin include: allergies, bacterial infections, ringworm, internal and external parasitic infections, lacerations, sarcoids, and melanoma. Systemic conditions, such as autoimmune disorders, hormonal imbalances, or nutritional deficiencies, may manifest as characteristic patterns in the skin.
Your horse’s ears are an extension of their skin. Many of the conditions that affect the skin also affect the ears. The ears are divided into 3 sections: 1) the external ear canal extends from the outside to the ear drum, 2) behind the ear drum lays the middle ear (tympanic cavity), and lastly, 3) the inner ear. Abnormalities can occur in any of these sections, however, the majority of problems present on the outer portion of the ear.
The eyes, ears, and skin can be a gateway to the inside of your horse’s body. While the eyes, ears, and skin display their own pathologies separately, they can also be indicators of a more systemic process.