OK, I have had enough of Tony this and Tony that. I’m taking over this week. Welcome to Tuesdays with Teannie. That’s right, I’m the cuter and smarter cat at Springhill Equine, and this week I’m writing about eyes. I should point out I don’t have any, but that story is what makes me qualified to write this week’s blog.
I started life with two normal eyes. Along the way I got infected with a Herpes virus. Herpes is the same virus that causes rhinopneumonitis in horses. In horses and cats this usually presents as a bit of a cold. Sometimes it goes elsewhere and causes all kinds of problems. In horses, it can also cause abortions in pregnant mares and a neurologic disease. In cats, it can cause the immune system to attack the eyes. This is what happened to me. It took years and years, and Dr. Lacher tried pretty much every treatment available, but eventually they couldn’t save my eyes. Along the way I have become an expert in eyes.
I’m going to start with the obvious. If there is redness, swelling, or a lot of tears, call Springhill Equine. These are pretty good indicators of a problem, and the earlier a problem is addressed, the better the outcome (I lived on the streets for a while just trying to keep a roof over my head, so don’t judge me that I didn’t get proper care). To start, our Docs are going to use a special device called an ophthalmoscope to look in the eye. They claim this is to get good light and magnification. Personally, I think they like shining a bright light in my eye to torture me. I get back at them by standing in front of computer screens and stepping on keyboards. Next a special stain called flourescein is put in the eye. This stain shows if any of the surface layer of cells is gone. You want a negative flourescein result. Negative here means all is good. Positive means you have long nights and days, or your horse has an all-expense-paid trip to Springhill Equine.
With their big bug eyes set on the side of their heads and their propensity to stick their heads where they don’t belong and then get scared, horses are very prone to ulcers. So that’s problem number one with horse eyes. Next, we live in Florida and we grow fungus here. Put bug eyes and fungus together and chaos follows. This is why if you call with a question about an eye, our Docs freak out a little bit and move the Earth to get you on the schedule that day. All eyes get treated like they have a bacterial and fungal infection, no matter what. They also get a wee bit obsessive-compulsive about rechecking the eye to make sure it’s going to the right direction. Treatments are sometimes done every hour!
Sometimes horses, and let’s be honest, cats, are… umm… difficult to treat. Eye treatments sting! The Docs have a few tricks up their sleeves to help. They always give horses (and this cat) treats with EVERY eye medication. They also have a device called a sub-palpebral lavage system. Using a really, really big needle, they put a long tube through the eyelid which lets you stand at the withers to inject medications which are then delivered to the eye.
If the worst happens and the eye can’t be saved, then a procedure called an enucleation is performed. This is the fancy word our Docs use for taking the eye out. Here’s where my experience comes in. Please do not worry about your horse missing an eye. I lost my left eye first and certainly didn’t miss it a lick. In fact, without the constant pain, I was loving life. I would run around and attack Tony, chase my tail, and knock papers off the desk. When my right eye began hurting, I was back to moping around the clinic. Dr. Lacher decided to let me slowly go fully blind so I could better adjust to life with no eyes. Once they removed my right eye, I was right back to running this joint. I still stalk Tony, I still stand directly in front of the computer screen, I know exactly where the escape key is on the keyboard, and I am loving life as the smart cat at Springhill Equine. Moral of this story: if you think something is wrong with your horse’s eye, call Springhill Equine!
There has been a bit of a kerfuffle around here about something called Herpes, or Rhinopneumonitis. A horse in Georgia was diagnosed with it and a bunch of horses in New Mexico at a racetrack are under quarantine. A few of the horses in New Mexico have even had to be euthanized. That got the curiosity of this cat piqued. Euthanasia seems pretty serious.
Herpes viruses are really good at hiding. Like time for the cat to go the vet, can’t find them anywhere hiding. This virus lays dormant in nerves until it feels the immune system is busy elsewhere. Then it pounces, again let’s go with a cat metaphor, like a cat on a toy mouse filled with catnip. Usually the horse experiences a snotty nose, maybe a cough, and sometimes a mild fever. This goes on for a few days before the immune system gets back to work and brings things under control.
Vaccination is really important for immune system control of Rhinopneumonitis. A well vaccinated immune system recognizes that the virus is out and about and attacks it faster. This means less virus is put out in the environment. It makes it a little complicated to understand, but essentially, by vaccinating a horse we don’t protect them, but we do protect every horse they come in contact with. For this reason horse shows, racetracks, and many horse events have started asking for proof of vaccination for entry.
Ok, I asked, I’m sure the horses at the racetrack were vaccinated, so why did they get it? I’m a really smart cat so I pick up on these sorts of details. It turns out Rhinopneumonitis has experienced a mutation which makes it harder for the immune system to see, makes it spread really quickly while the immune system is distracted, and causes havoc in the nervous system while it’s doing the first two things. Horses with this particular kind of Rhinopneumonitis (also called EHV-1) can go years without showing any symptoms. However, if a stressful event causes them to start shedding virus it passes like wildfire through a stable. Infected horses can keep shedding virus for weeks! Quarantining affected stables ends up being the only way to stop the spread since vaccination can’t help once horses have been exposed. The good news on this version is that once it is identified and quarantine procedures put it place it is often stopped quickly. Twice daily temperature-taking identifies affected horses quickly when treatment can still save them.
There’s another version of Rhinopneumonitis that very rarely causes a severe pneumonia that leads to scar tissue in the lungs. This version, EHV-5, is usually responsible for what we lovingly refer to as the yearling snots. As young horses get out and see more horses, experience some training, and are introduced to life, they often catch colds. I’m told human children experience a similar phenomenon. Most babies experience a few of these on their way to adulthood with only minor hiccups. Sometimes though, the body wildly overreacts to the virus. Another cat metaphor: Like a cat reacts to water-very badly. In these horses the body attacks the lungs and turns them into scar tissue. Unfortunately, I’m told the humans don’t have great treatment options for this form.
Turns out Rhinopneumonitis is just plain tricky. Vaccination is good, but not a cure-all. I’m told being cat-like is the best prevention. Don’t take life too seriously and stay well rested.
Why Vaccines are SO Important for your horse!
“Do I really need to vaccinate my horse?” YES. Absolutely. In an era where more and more people are turning to a more holistic approach to health care for both themselves and their horses, it is important to remember that vaccines are still an extremely important part of protecting your horse from harm.
All horses in Florida need at minimum to be vaccinated against Rabies, West Nile Virus, Eastern Encephalitis, and Tetanus. These are called ‘core’ vaccines because ALL horses should have them, regardless of their age, use, travel, or geographic location. The list of core vaccines and recommended vaccine schedule is put together by experts in immunology and equine medicine within the American Association of Equine Practitioners, the nationwide organization of horse vets. Why these four, and not others? Here’s the criteria used to qualify a vaccine as ‘core’, or a ‘MUST have’:
The disease causes severe symptoms or death.
- Rabies: A variety of neurologic symptoms leading to certain death.
- West Nile: Muscle twitching, hyper excitability, in-coordination, sometimes inability to stand or death.
- Eastern Encephalitis: Fever, severe in-coordination, inability to stand, seizures, coma, death.
- Tetanus: Muscle spasms/rigidity, inability to eat or drink, inability to rise, death.
The disease is difficult or impossible to treat.
- Rabies: 100% fatal regardless of treatment.
- West Nile: Supportive care only. Up to 1/3 of horses die despite treatment, and others have lasting neurological problems.
- Eastern Encephalitis: Supportive care only. Up to 90% of horses die despite treatment.
- Tetanus: Antibiotics, muscle relaxants and supportive care are used. 50-75% of horses die despite treatment.
The way the disease is spread puts all horses at risk, regardless of the horse’s lifestyle.
- Rabies: Through bites from rabid animals.
- West Nile: Spread by mosquitoes.
- Eastern Encephalitis: Spread by mosquitoes.
- Tetanus: Bacteria lives in the soil, horses exposed through wounds or hoof abscesses.
The vaccine is safe and effective.
- Rabies vaccine: 99% effective in preventing disease
- West Nile vaccine: 95-99% effective in preventing disease
- Eastern Encephalitis vaccine: 95-99% effective in preventing disease
- Tetanus vaccine: 95-99% effective in preventing disease
“But my horse doesn’t ever leave the property or interact with other horses.” Doesn’t matter. Your horse doesn’t have to go anywhere to get bit by a raccoon, a mosquito, or injure himself.
“But I’ve never heard of a horse getting Rabies.” Yes, Rabies in horses is rare. But when it does, there’s always a long list of people who get exposed in the process of diagnosing and caring for the horse prior to its death. Those people then have to go through the expensive and painful process of post-exposure therapy. Vaccinating your horse is a $20 insurance policy to protect you and your family from the possibility of exposure.
“But there haven’t been any cases of West Nile/Eastern Equine Encephalitis in my area recently. Those diseases are not here anymore.” WRONG. Just this year there have been 10 cases of EEE in horses in central Florida (Alachua, Gilcrest, and Levy counties). Our practice personally diagnosed 3 cases of EEE this season, all of course in un-vaccinated animals. The reason there haven’t been even MORE cases is because we have done a good job protecting horses by vaccinating them.
“But I’m worried about vaccine reactions.” This is a valid concern. Like all decisions in veterinary medicine, the decision to vaccinate should be one of risks-versus-benefits. For most horses the benefits of vaccination far outweigh the risks of vaccine reactions. The most common form of vaccine reactions are very mild – either a brief fever or local swellings, easily controlled by a few days of anti-inflammatories. If your horse has a history of a more severe reaction, then it may be safer to withhold that vaccine from that individual horse.
“My horse has had vaccines plenty of times before. He doesn’t need any more. My small animal vet says we only need to vaccinate my dog every 3 years.” Horses are not dogs. Unfortunately horses do not mount the same level of an immune response to vaccination as people or dogs. The scientists who did the research on extending the time between vaccines for small animals are clear that this won’t work in horses because of the different way their immune systems function. To be properly protected, horses in Florida should be vaccinated yearly against Rabies and West Nile Virus, and every 6 months against Eastern Equine Encephalitis.