For Wolf: Uveitis and Horner’s Syndrome

This is one of the stranger entries I’ve made. I started with the intention of making this a comment in Wolf’s journal, but it just got way too big.

By the way, what do you know about Uveitis or honer’s syndrome? Both eye related problems.. and it would have been bilateral. If it’s alright that I pick your brain. -Wolf

Of course it’s alright if you pick my brain. I actually find it flattering that someone would ask me a professional question, and it’s nice to be able to use some of that veterinary education that I don’t get to tap into that often in my current job.

You say that this was a bilateral problem? Right off that tells me that the problem is more likely to be uveitis than it is to be Horner’s Syndrome. I’ll give you a brief run down on each though.

Let’s start off with Uveitis. The uvea of the eye is made up of the iris (the colored part of the eye), the choroid plexus (a very thin membrane of blood vessels between the sclera –white of the eye– and the retina) and the ciliary body (some extra stuff inside the eye, including the little muscles that control the lens of the eye). These three parts of the eye are interconnected with each other, and when one of these gets inflamed for any reason, all three tend to get inflamed. When all three are inflamed, it’s called “uveitis”.

Keep in mind that uveitis is a symptom, and not a disease. There are a lot of reasons for uveitis to happen. In animals, the one I’ve most commonly seen is uveitis from trauma. If the eye gets poked, or if something really irritating gets into the eye, then it can cause the eye to get red, teary, and painful. If this reaction happens in the iris, choroid plexus and ciliary body (the uvea) then it’s called uveitis. Other reasons for uveitis in dogs can be lymphoma, bleeding disorders, ehrlichiosis, Rocky Mountain Spotted fever, Lyme’s disease, brucellosis, bacterial infection, immune mediated (autoimmune) diseases, cancers other than lymphoma and parasitic diseases. Because so many different disease conditions can cause uveitis, you’d need a veterinarian to give a look at your dog to tell you what the cause is and what the proper treatment should be.

OK, onto Horner’s Syndrome. Like Uveitis, this is a symptom, not a disease. It can look like uveitis, because both cause the pupil to constrict down to a little dot and make the eye look “droopy”. Unlike Uveitis (which is inflammation), Horner’s Syndrome is caused by nerve damage. The following four things happening all at the same time in a patient indicate Horner’s Syndrome:

1. Constricted pupil (miosis)
2. Droopy upper eyelid (ptoptosis)
3. Sunken eye (enophthalmia)
4. Increased warmth on the side of the face that has the affected eye.

Like uveitis, there can be many different reasons for an animal to exhibit Horner’s Syndrome. Damage to the spinal cord in the upper chest, problems in the animal’s brainstem, injections of certain drugs, trauma to the neck (choke collars used improperly can do this), inner ear infection, other infections, and (in dogs, especially Golden Retrievers and Cocker Spaniels) it can happen “just because”. These cases that have no known reason in dogs usually are transient, and go away just as mysteriously as they came.