Horse owners often have to deal with the fact that these animals develop eye diseases. In order to restore health and not cause harm by inept actions, it is necessary to understand how horse vision works. The eye is a complex organ that is a multilevel system. We will tell you how it works, what are the features of horses’ vision, what ophthalmological diseases one has to deal with, how to prevent the occurrence of health problems in the future.
Horse Eye Anatomy
The horse’s visual system has the following structure:
- the muscles that are located around the apple and set it in motion;
- organs that are adjacent to the eyeball – lacrimation system, eyelids.
The structure of the eyeball contains the following structural elements:
- fibrous membrane – protects the eye and provides it with moisture;
- shells consisting of vessels – they regulate the amount of light entering the eye, the iris determines the color of the eyes;
- lens – thanks to the presence of this organ, the animal can focus its gaze;
- retina – it determines how clear the vision will be, whether the horse will be able to distinguish colors, shadow, and light, and see at night. There is also a blind spot here.
The choroid contains the iris, on which the color of the horse’s eyes depends. Most often they are brown, but there are also blue, mainly in piebald horses, and also green. The color of the iris is determined by the color and the presence of a special gene in the animal:
- green-eyed horses have a champagne gene;
- magpies (with a spot of white) and blue eyes have horses of isabella color;
- light brown irises are possessed by animal suits of palomino and bulan.
Animals do not have purple and red eyes, since due to genetic characteristics, there are practically no albinos among them. Sometimes they are stillborn, but with blue eyes. In this regard, it is important to keep in mind that when a horse’s eye is stained red, emergency veterinary assistance is required.
Understanding How Horses See the World
Due to the fact that the eyes of this animal have a special structure and are located on the sides of the head, the horse sees differently from the person. The main feature of her vision is the ability to look back without having to turn her head. In addition, the animal can see at night and distinguish colors.
Line Of Sight
The total viewing angle is approximately 360 degrees. However, the horse sees objects in different areas of his field of vision differently. Even with one eye, she can see more than a person with two. The vision is corrected by changing the position of the head. That is why, in order to successfully overcome an obstacle, riders raise their horse’s head so that they can assess where the object is located.
It is extremely difficult to determine in what color scale horses see the world, and today scientists have yet to figure out this issue. It is generally accepted that animals distinguish yellow best, then green, blue, and red.
At a distance of 500 meters, the horse sees well. You can assess how sharp an animal’s vision is by conducting a test using letters. For a human, vision is considered good, showing a result of 20/20, and for a horse, the average is 20/30. In other words, a horse can clearly see an object from a distance of 20 feet, and a person can see it from 30. But a rat has a visual acuity of 20/300.
The horse’s eye has a special membrane called the tapetum, which reflects light, and the animal has the ability to see at night. For the same reason, the eyes glow if you put light on them in the dark. Equine night vision is not as developed as a feline, but it is better than humans.
This disease is caused by a virus. Treatment is carried out through external treatments and medication. In a horse with uveitis, the pupil is narrowed, spots appear, and the cornea becomes cloudy.
Bacteria and injury can cause this serious illness. It is treated with immunostimulating and antibacterial drugs as prescribed by a veterinarian. With an ulcer, a spot appears, discharge from the eye, and the horse tries to keep it closed.
Injuries, bacteria, and fungi often cause the development of conjunctivitis. Treatment may vary depending on the type of disease and the degree of infection. A yellow liquid is released from the eye of a sick horse, the muscles surrounding the eye become swollen, and redness is observed.
Blocked Tear Ducts
This problem is often exacerbated in warm weather. Typically, the drainage of tears is conducted into the nasal cavity through the lacrimal or nasolacrimal duct. But these pipes are very thin. Damage to these can prevent tears from draining, so they overwhelm the eye area and wet the coat, causing it to fall or discolor. Watery eyes can attract flies that carry bacteria and cause eye infections.
Cataracts are the opacity of the lens of the eye, which is responsible for focusing light on the retina. It occurs due to an illness and can progress over time, often resulting in loss of vision. Poor vision and white spots are signs of cataracts.
Tumors. Squamous Cell Carcinoma
Tumors are warts or growths and are often found in the area of the eyelid, in the third eyelid, or on the surface of the eye. Treatment is carried out by a specialist using radiation therapy or cryotherapy (freezing). For tumors in the third eyelid, the entire third eyelid is usually removed. Tumors within the eyelid are the most difficult, and treatment consists of surgery followed by chemotherapy.
Diseases can occur due to contact with sick animals, as well as harnesses, structures of buildings, equipment from farms that are unfavorable for eye diseases. Infectious eye diseases can occur after injuries, eye contamination caused by improper keeping of animals, non-observance of the light regime.
- Regular inspection. Only a veterinarian should treat eye diseases. However, the horse owner must pay special attention to prevention in order to prevent serious consequences for the animal, and pay attention to the first signs: redness and increased lacrimation, conjunctival edema, which may be followed by eyelid edema. To do this, it is necessary to inspect the animal’s eyes and adjacent areas of the fur daily. On examination, the owner should pay attention to the symmetry and shape of the eyes, whether the eyelids open at the same time or not.
- Proper care. It is important to keep the room in which the animals are kept clean, the horse must eat rationally and variedly. Immediate isolation and separate keeping of sick animals is necessary. The stall or stall should be free from sharp protrusions, protruding nails. The manger should be set up so that bright daylight does not blind the horse, as the animal can injure the eyes with the ends of straw or hay stalks. The horse needs to be cleaned every day, there should be no straw or hay in its bangs.
If you notice any abnormality in the horse’s health, you should immediately consult a veterinarian.