Mosquito-Transmitted Disease Vaccines for Horses

March 20, 2006 (published) | May 2, 2016 (revised)

The numbers of mosquitos are sure to increase during rainy seasons or flooding, which also increases the chance of mosquito transmitted disease to your animals. The Texas Animal Health Commission sent out a press release recommending all horse owners contact their veterinarian and make sure their horses are up to date on equine encephalitis (sleeping sickness), and West Nile vaccines.

There are three strains of sleeping sickness and all are transmitted by mosquitos. Eastern and Western encephalitis are more commonly found in the United States. In Texas, the Venezuelan strain has not been seen in many years but many vets still vaccinate for it due to our close contact with Mexico and Mexico has had outbreaks. All of these strains cause nervous system signs including loss of coordination, lethargy, depression. Some horses will not survive. Almost all of the horses with the Eastern strain will not survive while less than 50% usually die with the Western strain. West Nile virus causes similar nervous system signs and can also be fatal in some cases. So you can see how serious these diseases can be for your horse and it is important to make sure that your horse is currently protected.

All of these mosquito-transmitted diseases can infect humans, so mosquito control is critical for people as there is no vaccine.

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