Are you ready for Eyes Part 2? Really, eyes could be a 5 or 6-part blog, but for now we’ll keep it to two. These will keep the most common eye problems horses have in the spotlight, so you know what to look out for. Conjunctivitis, abscesses, and lacerations happen often, and almost always on the weekend. If it hasn’t already been ingrained in your head, I’ll say it again: Eye problems are ALWAYS an emergency!

Conjunctivitis

The conjunctiva is the mucous membrane that covers the inside of the eyelids and lies over the white part, or sclera, of the eye. When this tissue becomes inflamed, the result is conjunctivitis. Conjunctivitis can have similar clinical signs to other common eye problems, including corneal ulcers, uveitis, and abscesses.

Horses with conjunctivitis often will have tearing from the eye, generalized redness, and swelling. It’s not uncommon for horses with conjunctivitis to be seen rubbing their eyes, making them more prone to developing corneal ulcers. As usual with horses, conjunctivitis can be caused by a number of different reasons, like allergies, insect hypersensitivity, and other environmental irritants. Conjunctivitis can also lead to secondary ocular problems such as obstructed tear ducts, which can require veterinary attention to resolve. 

Treatment of conjunctivitis includes anti-inflammatories, antihistamines, and occasionally, anti-biotics. Topical anti-inflammatories can be dangerous if there is any kind of insult to the cornea and can result in a small scratch becoming a large, melting, sight-threatening ulcer. Therefore, it is never a good idea to treat an eye before your veterinarian assesses the eye and prescribes the appropriate treatment. Similarly, treatment of an obstructed tear duct requires veterinary involvement. If performed incorrectly, there is risk for rupture of the tear duct. 

If your veterinarian suspects that your horses tear duct is obstructed, they will sedate your horse, as most horses HATE this process. They will then insert a small tube into a tiny hole in your horse’s nostril and flush a solution of saline and usually steroid up the tear duct to dislodge any mucous that has accumulated. I find it to be utterly disgusting, but for some reason the docs and techs love to do this. They say it’s rewarding. Humans.

Antihistamines are often prescribed if your horse has an overall allergic appearance. You know what I’m talking about, the itchy mane with hair missing and the crusty tail, those guys really need antihistamines. As a cat with allergies, I can tell you how important it is to control the itchiness before it results in a skin or eye infection. An easy way to help protect your horse’s eyes from external environmental factors is placement of fly mask. Some horses really just don’t know what’s good for them and often like to remove their fly masks. Don’t be afraid to ask my docs about the fly masks out there that are significantly more difficult for horses to remove.

Stromal Abscesses

Probably one of the most frustrating eye problems a horse can get is a stromal abscess. This is when bacteria or fungus gets trapped within the layers of the cornea and the top layer of the cornea heals, allowing the organism to reproduce and grown within the deeper layers of the cornea with no way out. Abscesses are extremely painful for your horse and result in extreme squinting and copious tearing, often with mucoid discharge present as well. These horses tend to be head shy and do not want anything or anyone near their eyes.

An abscess within the cornea is usually easily diagnosed by a yellow-white circular infiltrate surrounded by edema, and occasionally blood vessels. Recognizing an abscess early is extremely important when it comes to successful treatment. Also, recognizing that treatment will be long, intense, and likely expensive is very important. You as an owner must be upfront and open with your veterinarian about your willingness to be involved in treatment and your budget.

Treatment almost always includes placement of a subpalpebral lavage, along with every 2-hour administration of 4-6 eye medications around the clock for several weeks. These things are exhausting, let me tell you. When we have one here at the clinic, I literally get no sleep, which is saying something for a cat. Neither does the horse or my minions. This is a lot to take on at home, so think hard about your willingness to get up at midnight, and 2 am, and 4 am, etc. to go give your horse more eye meds. It will take over your life, so that’s why we encourage you to let us handle it for you. We have more people to share the load. 

One of the most important goals of treating an abscess is to control the inflammation. Once the inflammation is under control, the abscess has a chance to heal. Sometimes, medications will be injected directly into the conjunctiva or abscess itself to facilitate die-off of the organism and allow for healing to occur. These things can take 6 weeks or longer to heal. It’s a long hard road but, if it caught early and treated aggressively, they can heal, and sight can be normal.

If an abscess does not heal despite intense treatment, or if it’s been left too long without treatment, enucleation may be recommended. This is when the entire globe of the eye is removed. Sometimes enucleations are the best option for the horse and the owner, and sometimes it’s the only option.  

Lacerations

If you have ever owned a horse, then you’ve probably had a horse who has sliced his eye lid almost clean off. They find the most random places to do this too: screw eyes, bucket handles and hooks, double ended snaps, tree branches, horse trailers, fences, literally just about anywhere you can think of, a horse has lacerated his eye lid on it. You can be the most cautious owner in the world and your horse will still find a way to lacerate his eye lid. 

Looking at the lacerated eyelid, it might seem like a simple fix to just finish off the job and trim the flap off. Please, for the love of cats, do not do this! Your horse needs his eyelids! Their eyelids protect them from when they stick their heads in places they shouldn’t, they act as a lubricating system to the eye, and protect them from UV rays from the sun. Horses need their eyelids. Do not, I repeat, do not cut off their eyelids.

Always call your veterinarian if you notice a lacerated eyelid. The sooner they come out to fix it, the better. After a while, the flap will start to lose blood supply, and once that happens, fixing it may not be an option. When your veterinarian comes out, they will assess the damage, which 9 times out of 10 looks significantly worse than it is. They will sedate your horse, clean up the eyelid, and put it back together with sutures. They will also examine the eye itself to make sure there was no damage done to the eye. You will likely have instructions to apply topical antibiotic and administer anti-inflammatories daily. Sutures have to be removed after several days, as they can cause trauma to the eye if left in longer than directed. The best part about eye lid lacerations is, after your horse looks like he has been in a bar fight for a couple of days, you’ll barely notice anything ever happened and they heal up fantastically.

Eyes are the window to the world and your horse needs them just as much as you do. So, who are you going to call when your horse has an eye problem? YOUR VETERINARIAN! This cat could go on and on about eyes, so if you have any questions, please do not hesitate to call the clinic.

Until next week,

~Tony

P.S. If you want to really get deep into horse eyes, you should listen to the podcast the humans do. It’s called Straight from the Horse Doctor’s Mouth, and they have several in-depth episodes on eyes. You can find them here on the Podcast Page, or subscribe wherever you get your podcasts. Every horse owner should be listening to this fantastic free resource! In addition to reading my cat wisdoms, of course. Goes without saying.