Tuesdays with Tony – Those Pesky Mosquitos

Well, we are into that time of year when I don’t know whether to prepare for a monsoon or to park myself directly in front of the fan all day. As I’m sure you know, cats hate water. We also hate tropical storms, flooding, hurricanes, and basically anything that causes puddles of water which we are then forced to tread through with our delicate paws. Thus it was no surprise to me that tropical storm Colin, that jerk, caused a bunch of flooding that is going to bring on even more mosquitos than usual this summer!

   As the self-proclaimed manager of a veterinary practice, mosquitos of course make me think of diseases, which make me think of vaccinations! Many of the core diseases that we vaccinate against here at Springhill Equine, namely West Nile Virus and Eastern Equine Encephalitis, are transmitted by those nasty mosquitos. How does that work, you ask?

     The simplest way to understand it is to look at it from the virus’ point of view. If I am a virus, my goal is to replicate, and to spread myself to as many individuals as possible. One way to do that is to live in the bloodstream of birds. When a mosquito bites an infected bird, it will ingest blood laden with me (the virus). I will replicate inside the mosquito and get into the mosquito’s saliva. Then, when it goes to bite another bird, I (the virus) will infect that bird through the mosquito’s saliva.

   So, what does all this stuff about birds and mosquitos have to do with horses? Well, nothing really. Horses are an accidental, or “dead end” host for the virus. The virus cannot replicate within horses (or humans for that matter). Thus it cannot spread from an infected horse to any other individual. That stinks for the virus. But unfortunately for horses, when an infected mosquito bites an unvaccinated horse instead of a bird, the horse will still show symptoms of the disease, which are often fatal.

   So, horses and my other mammalian followers, make sure to lather yourselves up with Mosquito Halt this summer! Oh, and don’t forget to have our docs out to catch you up on your West Nile virus and Eastern Equine Encephalitis vaccines! Stay dry, stay cool, stay classy.

http://www.cdc.gov/westnile/resources/pdfs/13_240124_west_nile_lifecycle_birds_plainlanguage_508.pdf