Night Blindness in Appaloosas: How To Adapt To Your Horse's Condition.
Appaloosas tend to be stunning horses. The striking pattern is eye-catching, whether taking the blue ribbon at a show or with a foal at foot. Popular throughout the USA, the Appaloosa is much loved for its versatility, athletic performance and trainability. Renowned for its speed and fast pace, it not only excels at reining and roping, but is often a contender in the jumping ring . Although a generally easy-to-keep horse, the Appaloosa is prone to a unique condition rarely seen in any other breed. Many suffer from Congenital Stationary Night Blindness (CSNB), a condition that prevents them from seeing in the dark.
What is Night Blindness?
CSNB appears to effect approximately 25% of Appaloosas. It is a non-progressive, hereditary condition, first noticed in the 1970's. Sadly, there is no cure. In some cases, the horse's night vision is completely impaired whereas in others it may be only mildly affected. Current studies suggest that Congenital Stationary Night Blindness could be caused by a miscommunication in signaling in the neural pathways of the retina. In a normal eye, the retina has two types of photoreceptors that respond to light: Rods work in low, night time light whereas cones are responsible for daylight and color vision. In horses afflicted with CSNB, it appears there is a problem with the messaging between the rods and the retinal cells, leaving the horse virtually blind in dark settings.
Is there a specific coat pattern which is associated with CSNB?
A study carried out in 2006, (Sandmeyer) identified Appaloosas with coat patterns which are homozygous for LP (the gene responsible for the spotting of the coat) are exclusively affected, these are typically horses with few or no spots in white areas, and include snowcaps and fewspots. Those that are heterozygous for LP do not suffer with the condition, these include horses with numerous spots scattered over white areas, and include spotted blankets and leopards. (Homozygous for LP implies the horse inherited the same LP gene from both dam and sire. Heterozygous for LP means the horse inherited different LP genes from its parents.)
Signs your horse may have night blindness
If you have an Appaloosa with few or no spots on the white parts of its coat, there is a risk your horse will suffer from night blindness. It is present from birth and therefore monitoring a foal early on, in both low light and darkness is critical to determining whether the condition is present.
Here are some of the signs you should look for: - At night, the horse tends to move very slowly, keeping its head down.
- The horse bumps into obstacles in the dark.
- The horse favors brightly lit areas at night.
- The horse tends to sustain injuries at night.
- Spooks or shies away near dark areas.
- The horse suddenly becomes uncooperative when entering dark trailers, buildings or other dark areas.
Dealing with horses with CSNB
An Appaloosa with CSNB is not unwell. In most cases, it is a perfectly healthy horse with a manageable disability. Here are some tips for handling a horse with Night Blindness:
- Inform absolutely everyone who handles your horse about its condition. Make sure they understand what to expect and to take extra caution when approaching the horse in dimly lit settings.
- Keep your horse stalled at night with lights in the stall
- If you need to keep your horse outside, install safe fencing and ensure there are no tripping hazards such as: bramble, holes in the ground, or sharp edges in the pasture.
- An electric fence is ideal for field-kept Appaloosas. These fences make a "ticking," sound, making them easy for the horse to locate, sight unseen.
- Whenever possible, install outdoor lights in feed, water and sheltered areas to assist your horse.
- Don’t put a night-blind horse in a new area without giving it time to adjust to the new layout before sunset.
- In low light, always be careful and calm when handling a night blind horse. Continually, talking to him will help him gauge your location so he does not become startled.
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*Image courtesy of Dollar Photo Club
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