Authors: Sheila Archer, Rebecca Bellone PhD, and Lynne Sandmeyer, DVM
This article is provided by members of the Appaloosa Project research team for the education of website visitors. It is protected by international copyright. No portion may be reproduced without the express written consent of the authors.
General Notes
- Night vision is completely absent in affected horses – only the brightest of lights are visible.
- Light levels from dusk to dawn are too low for horses to see – must have at least enough light that you could read a book by.
- Affected horses are already adapted to the condition, because it is present at birth, and does not change over time.
- Although all CSNB affected horses have the same condition, not all are equally at ease in the dark. Keep in mind that some will show higher levels of anxiety than others in dark circumstances.
Signs Suggestive of Night Blindness
- Horse has a homozygous coat pattern, either fewspot, snowcap or “white” roan with few or no dark spots (see diagram on main page).
- In the dark, horse tends to move very slowly with head down, may bump into obstacles, and/or is reluctant to move forward without assistance.
- If paddock has a light source, horse prefers to stay in most brightly lit area of paddock at night.
- Injuries occurring at night in dark paddocks or stalls
- Shies when ridden into or near shadow or large dark areas during the daytime or inside an arena.
- Horse shows unusual resistance to entering dark trailers, buildings, etc.
Management Guidelines
1. Protect Your Horse - Provide a Safe Environment
- Appaloosas with CSNB can easily injure themselves at night or in a dark building, so make all places the horse will be as safe as possible by performing the following management steps:
· Use SAFE fencing that is either solid or of a breakaway material that is designed to minimize injuries. Electric fence is ideal, as it can be heard at night by horses, especially those made of rope or tape. These usually tick, allowing the horse to know where it is after dark. AVOID barbed or smooth wire.
· Install yard lights where horses are kept outdoors to ensure feed, water and shelter areas are well-lit
· Remove hazards on the ground
· Don’t put a night-blind horse in a new area without giving it time to adjust and learn the layout before dark
· Pasture only with non-aggressive companion horses that have normal night vision
· Do not leave night-blind mares to foal outside in a dark area
· Walk-in shelters and stalls should have smooth, solid walls and nightlights
· Use trailers with bright and/or lit interiors
2. Protect Yourself
- Always remember that how you see the world is not how your horse with CSNB sees it.
- Low-light areas are black holes with no details at all.
- In dark conditions, use voice cues before making physical contact, and:
o Approach the shoulder
o Keep physical contact as you move around the horse
o Follow predictable procedures
- Keep in mind that the horse’s keen sense of hearing will not detect you approaching on a windy night, or with loud background noise occurring.
- When moving the horse from one area to another, enter and exit dark areas slowly
- Practice loading on and off trailer, anything you either may have to do in the dark at some point, or that involves darkness normally, so that the horse has adequate time to learn and become well trained to the procedure.
- Do not clip whiskers on muzzle OR above and below the eyes, as these "feelers" keep the horse from injuring itself when it cannot see.
3. Educate Others
- Owners, breeders and registries have a legal responsibility to provide complete information about CSNB in the Appaloosa to anyone who is in contact with affected horses. Individuals and groups to notify include the following:
– Veterinarians
– Trainers
– Farriers
– Buyers
– Visitors
4. And Hey, Remember This: CSNB Doesn’t Mean “Can’t Perform”!
- The only time that riding may be unsafe is at night, or in a dark area
- Some horses with CSNB can be ridden in these conditions. However, they must have a strong trust in their rider, and communication between horse and rider should be excellent.