Given that it's mosquito season, what better than to post on Medical Monday about West Nile Disease.  (I imagine that if this was being narrated aloud, "West Nile Disease" would be all echo-y and have ominous tones playing in the background - da da daaaa.)

Symptoms (can include):

• listlessness, change in behaviour
• muscle twitches 
• lack of coordination
• limb weakness
• partial paralysis, inability to get up.

Treatment:

• Currently there is no treatment available for horses

Prevention:
 While there is a vaccine available for horses, it is not a guarantee that your horse will not contract the disease.  The best preventative measure, currently, is to do your best to reduce the mosquito population at your barn by reducing the number of areas with stagnant water - ie. clogged rain gutters, ceramic pots, recycle boxes (drill holes in the bottom to allow better drainage).  Keep wheelbarrows overturned to prevent them from collecting water.  Fly sprays containing mosquito repellent are available and may help keep them away.

The good news:
There is currently no evidence that the disease is transmitted any other way than by mosquito.  So if you do have an infected horse at your barn, he or she will not be able to pass the disease on to your horse.

I hope that helps - for more information on mosquito prevention and population reduction, check out google, they're a wealth of information!