Corpora Nigra cyst - experience? opinion? (pics)

[Old_Mac_Donald]

I have attached a couple of pictures of my 11yo OTTB’s eyes, and am looking for opinions about his corpora nigras. If you have had experience with corpora nigra cysts, did you find your horse’s eyes looked like this / worse / better, and how your horse went with treatment.

I haven’t asked my vet yet - not even sure if treatment is even an option here, if he does have an issue.

He is spooky, and what made me take a look this morning was that he spooked at my cat sitting in the garage. And fell on his face. Then was like, oh it’s the cat. meh.

Left eye (“non spooky”) - no there is no weird growth on his sclera, that is just some weird reflection.

Right eye (the “spooky eye”)

[Nevada10]

I can’t diagnose it, but I had a horse with one. She was a little spooky but also had uveitis in the other eye, so hard to say if the cyst was an issue or not. An ophthalmologist lasered it and greatly reduced its size.

[Old_Mac_Donald]

His eyes are otherwise very normal - no tears, no ‘spots’. But super spooky / “looky” at times and chill at others. He looks like he has tiny pupils which makes the CNs look bigger. My other horses all have wider ‘oval bean’ pupils rather than ‘thin slit’ pupils like this dude.

[vxf111]

I’ve treated multiple eyes on multiple horses with laser ablation. It’s an easy process and aside from one horse who needed two treatments, no issues or complications. In the grand scheme of things, if a horse has to have something— I’ll take CN cysts because they’re so easily and effectively treated.

[Minxitbabe]

I have one that has a little something extra in their lower right eye about the size of a bb as well as overly generous sized corpora nigra in both eyes. Horse is a bit on the spooky side but after years together I am finding spooky behavior escalates in the fall. Which I attribute to the weird shadow behavior as the sun changes position in times that the horses are actively being moved around and worked. I was quoted about $1000 per eye to laser to try and get rid of the excess.

[Minxitbabe]

What was the cost on the laser treatment and did it actually help with the spooky behavior?

[OTTB-Hunter]

My mare had the laser treatment in both eyes. Hers were worse than yours from the pictures. She would spin to look at something that she had already cantered by multiple times and I would have to be careful with light changes because that would freak her out a bit. After the treatment that all stopped. Very simple procedure done right in the trailer then eye meds and fly mask for a bit. The only complication she had was it took almost 2 weeks for her eyes to stop being dilated. My vet said its a weird side effect of the meds they use during the procedure. Cost was about $400 total a few years ago.

[lorilu]

WHen I PPE’d my guy one was noted but vet said its a “nothing” to worry about and easily treated. Much smaller than the OP pictures, and no spooking behavior (knocking hard on wood)

[Old_Mac_Donald]

I’m not even certain if any vet around here has the equipment to do it (if they can be reduced) - I’ve never heard to anyone locally having it done. Even nationally here, searching some of the larger Aussie FB groups comes up with very few mentions of CN cysts. He’s definitely getting spookier as he ages - he was a pretty quiet 6yo by all accounts - on when on the right rein.

Last time I took him for a trail ride he jumped over his own poo in fright.

[vxf111]

Laser ablation completely removed the cysts (one horse required 2 treatments) and once the cysts were gone the horses were not spooky at all anymore. I did it several times on different horses over a decade so the costs have fluctuated but the most recent time was in 2019 at New Bolton for a single eye. It was $1700ish all in. That includes the exam, meds, the ablation, etc. Just the ablation part of the bill was about $750ish.

[Old_Mac_Donald]

So, an update: the reason I started looking into CN cysts was because my other OTTB (who is not usually spooky) has been demonstrating poor behaviour in the form of maybe mild headshaking and a single, massive spook that gave me a mild black eye. CN cysts were mentioned so I thought I’d have a deepdive.

Well. I finally got a good look in her eyes today and she appears to have huge ones! Couldn’t take a decent photo as she found being eye-stared very unsettling.

I rode Mr Spooky at dawn. Perfect. Not a spook. Maybe he needs UV goggles and she needs the surgery

Time to talk to my vet.

The second photo is hard to see, but you can tell that the outline of pupil is disrupted.

[BlueDrifter]

This might not be helpful, but on PPE, my vet noticed the large CN. I bought him anyway. Then I started to have a lot of problems with him: rearing, spooking, head-shaking, refusing to go forward, backing up really fast. (Admittedly, he was a ranch horse now confined to a SoCal stall and me, an older rider who wasn’t taking chances, so not handling him assertively enough.)

My vet came on several occasions to observe. She didn’t think it was head-shaking, but I really did, and I thought the CN might be the culprit. She thought it was possible. We talked to local vets to find out about the surgery and it could not be done locally, just at Davis and then it required a lot of planning, so it went on the back burner while I tried to just do day-to-day management.

Handling got worse, so I moved to a barn with a trainer. He was a handful for trainer #1. Trainer #2 got him 4 months later. Trainer #2 was a Pony Club leader. Lo and behold… several months of training and all the headshaking, spooking, rearing, refusal to move – disappeared!

Five years later and he still needs regular workouts, but is absolutely the safest horse, and… the CN never was a problem. His is big. It looks like a bunch of grapes hanging over his iris. Fairly eerie looking actually. But it is not a bother.

You know your guy better, but for me, it was really a training issue. I am glad I didn’t put him through that.

[CHT]

I had a client do that surgery on her horse. The surgery went well, but his spook didn’t resolve after the surgery, and a later check showed that it partially grew back.

[Old_Mac_Donald]

Yes, Horse #2 definitely has training issues… But what concerned me was a display of the “evasive behaviour” (that we get under saddle) in the paddock! No saddle, bridle, or human pressure to trigger it. (It’s a head/neck behaviour - flicks her nose up like star gazing almost and runs forwards) She also has a history of running into things in response to other horses entering her space, including near-disembowelment on a post.

She was raced in blinkers and developed a habit of randomly running across the track (inside to outside), losing at least one race this way. Her early races show her racing straight and true. The last trainer called her stubborn. She is quite aggressive at dinner time if you approach her left side… but not her right. She settles if you pat her.

The other thing she does is when she gets on a float, she rubs her head violently. She’s great to load, travel, and unload. But if the float is stationary, she’s rubbing herself and near on rocks the float over. She is not an itchy horse. Never seen her itch on anything in the paddock or on the tie-up.

She is coming back into work after the near-guts-out, and is definitely displaying more interesting and fluctuating behaviours.

[Exracehorserider]

My horse was diagnosed with CN maybe six years ago. At the time I was told it should not be a big deal. Yet my horse was always spooky in odd ways. While I did a lot of de-spooking, natural horsemanship, trust etc, all of that just taught him to spook in a less dangerous way. Intstead of spinning, bolting, bucking across the entire arena, it might be a 4 step spook. I gave up on showing as new venues sent him into a white foam frenzy. Well, now in a new area, met with a Specialist regarding some hard to clear up ulcers. She was shocked at the size of his CN. As in do you really ride this horse??? Yes, I do. But I let him stop and look at things if needed. I figured out years ago that he tries to memorize where everything is, so for trail riding I have to hand walk him on a trail multiple times, give him time to see everything then ride. I also on my own figured out he was spookier in sunlight. So I used to try to ride in arenas , trails in low light. Previous trainers, and even some farm Vets, ignored me, said never heard of that etc. The one Vet that understood the condition moved. It was frustrating as traditional training does not work well on a horse that is truely scared and has part of their vision blocked. I recommmend if your horse has this speaking to an eye specialist. We are looking at surgury. I feel I owe him that. Considering how little of his eyes actually see, the fear and anxiety my horse had to suffer through, the over corrections and punishment he was handed during some of his professional trainging- my horse did the best he could based on what he could see. From what I have read, the surgury usually works well. Even if it restored 50 percent more to his eyes, I think he would be a lot more relaxed and happy. The specialist I worked with showed me pictures of horses with much smaller CN who had incredible improvment after surgury.

[Old_Mac_Donald]

There is no option for surgery here, unfortunately. Not at this stage. Horse #1 is still very spooky, horse #2 has been “retired” at this stage - until I grow some balls. Having said that she has calmed her farm a bit, just one of those OTTBs that need a very long spell from racing. She’s currently being a grumpy nana to her paddock mate’s weanling.

[Exracehorserider]

I had the surgery done this weekend. I remain surprised at how few general vets and trainers in my very horsey area are aware of this condition. I won’t know how much of a difference it has made for another week when his eye is not dilated. That said, my horse has also presented with near sighted behavior, so even if the surgery helps general vision he will still only see dark shadows in the far distance and think I am asking him to walk into Jurassic Park lol. . But even if it’s only 50 percent better, it’s got to feel more comforting to the horse to see better. I didn’t do it because he is a valuable show horse, he is more of a broken ex racer, but he is family and with me for the rest of his life. Just grateful I could do this for him.