It is most imperative that you protect the eye from sun, wind, dust, debris and insects. The Guardian Mask is designed for this and while more expensive than a fly mask it is infinitely more effective in preventing additional flare ups when used religiously and protects the eye well during an acute stage. They are about $90 but they last a long time even if they don’t remain cosmetically pretty (eye cups will get dented on the sides, etc.) They are handmade by seamstresses in the U.S. and sturdy. I’ve got Guardian Masks that are about 4 years old and still in use. I’ve never had a Cashel Crusader or other mask last that long.
It is also absolutely necessary to use the Guardian Mask when you have used atropine. Because atropine relaxes the pupil the horse cannot constrict the pupil when light is introduced and therefore cannot self regulate how much light/sun is entering the eye. This is painful and is damaging to the retina. I prefer not to turn out a horse that has had atropine in the last 3-5 days and I will leave the Guardian Mask on his/her face during the day if stalled and we have an active flare up. My horses appreciate it because they can move around freely in the stall instead of confining themselves to the darkest corner of the stall.
The worst part of ERU is that it can be active without obvious outward appearances so even if the eye seems better quite quickly that does not mean it is not still in an active phase of ERU. I think this is particularly true of Appaloosas. It can be brewing under the surface at any time without signs. This is why it is important to protect the eye at all times and watch closely for even the slightest indication of a problem. This might include squinting even a bit, a bit of eye goop, swelling, slight cloudiness in the pupil, and inability of the pupil to constrict when exposed to light when atropine has not been administered for some time. The way you test for this is take the horse in a dark stall. The pupil should open wide to allow more light in so the horse can see. Shine a flashlight to the eye and see if the pupil constricts as it should and at the same speed as the normal eye. If both eyes are effected I would compare with a horse that has healthy eyes so you can see how long it takes.
I have three horses with ERU, two of which already had it when they came to me. The other was predisposed as he is a homozygous appaloosa with little pigment around the eye. Using the Guardian Mask I have been able to reduce the number of flare ups. One mare went 4 years before having a flare up. Her flare ups have always been with obvious symptoms. We caught it fast it was quickly taken care of.
If your horse is stalled you need to protect his eyes from dust, etc. indoors. Be cautious of dusty shavings and put his hay at floor level so dust from his hay is less likely to fall into his eyes. If we are cleaning stalls or dust is stirred up in the barn while any of the ERU horses are in there I put the Guardian Mask on them until the dust settles.
Some horses have flare ups when dewormed or vaccinated and there is a recommendation to administer banamine beforehand to help prevent flare ups. I’ve not had this problem so I cannot tell you the specifics of how much or when. Again, I think the ERU effecting many appaloosas tends to be different.
Other things off the top of my head are MSM given orally helps with inflammation. I keep mine on MSM daily but have only been doing that for about 3 months. Also be careful not to give too many Omega 6’s which can promote inflammation. In moderation Omega 6’s are good and Omega 3’s are very important. Some foodstuffs are imbalanced in Omega 6’s such a rice bran.
While I like the Cashel Crusader and have a few horses wearing them I wouldn’t rely on that mask or any “fly mask” to protect a horse with ERU…or to prevent ERU for that matter. Remember the 3rd horse with ERU that didn’t have it when I got him? Well, I used the Cashel on him religiously from the time I got him as a yearling and he still did develop ERU. I used that one on him because it stayed on his stallion face better at the time. For whatever reason he keeps the Guardian Mask on fine now.
The Guardian Mask relieves discomfort. My ERU horses lower their heads and wait for the mask to be put on, often sighing. I rarely have them lose one in the pasture but when it happens they usually stand there like “Crap, now what do I do?!” They wait for me to put their mask back on, give a big sigh of relief and then go about their business.
As I said, the mask is very sturdy. A drawback for some horses is that it can irritate their skin if they have a very fine summer haircoat. Two of mine can wear it with no problems, winter and summer. The other horse has a summer coat so thin that you can see her skin and she does get rubs on one part of her face (a dime-sized spot on either side of her nose). You can use mole skin to cushion the mask in any area that might get irritated.
I don’t believe that all ERU is alike in all horses, in both cause and symptoms. Appaloosas with any pink or unpigmented skin around the eyes are definitely more sensitive to the sun. It is thought that the constant onslaught of irritants (sun, dust, wind, insects, etc) on pink eyes could trigger the immune system in such a way as to initiate ERU. They recently have concluded that there is not a positive correlation between leptospirosis and ERU. Perhaps it does cause some cases of ERU but not all or most cases. Some would be caused by injury, some due to immune system triggers and who knows what else. What one person experiences with their ERU horses is not the same for all.
I now have 3.
