How does my horse get infected with the equine arteritis virus?
 EAV infection can be transmitted among horses in four different ways: via respiratory secretions from acutely infected horses, in the semen of infected stallions to mares, indirectly through contaminated tack/equipment shared between horses, and occasionally from an infected pregnant mare to her unborn foal.  

What are the signs of equine viral arteritis?
The majority of horses that become infected with the virus show no signs of  illness!  Horses that are suffering from equine viral arteritis present with general signs of illness including fever (near 40.5 degree celcius) for 1-5 days, anorexia, depression, serous nasal discharge, lacrimation (tearing), coughing, edema of limbs, skin rash and swelling of eyelids.  EVA can cause abortions in pregnant mares, and can become a chronic infection in breeding stallions.

How long will my horse be sick?
The incubation period is 1 to 6 days, and clinical signs usually persist for 3 to 8 days.  Some horses may require a couple of weeks to return to normal.  As previously mentioned, recovery is usually full and uneventful. 

Can I vaccinate my horses against the equine arteritis virus?
Yes, there is an effective vaccine licensed for use in horses in Canada.  Consult your veterinarian for more information. 

Can I breed my mare to a carrier stallion?
You can choose to breed to your mare to a carrier stallion.  You should ensure that your mare is vaccinated at least 3 weeks prior to breeding.  It is also recommended to isolate your mare for three weeks after breeding to an EAV carrier stallion.

Is EVA a big concern for horse owners in western Canada?
Equine viral arteritis is a disease the horse owners should be aware of but not lose sleep over!  Many horses infected with EAV don't exhibit clinical signs.  Those that do develop clinical signs typically have an uneventful recovery.  The biggest concern is for those with pregnant mares.  Owners should ensure that the stallions they breed to (or have semen collected from) are EAV free, and take proper precautions if they elect to breed to a carrier stallion.  It is important to differentiate disease caused by EAV from other infectious agents such as equine herpes virus or Streptococcus equi (the causative organism of strangles). 


Reference:   Constable, P. D, Gay, C.C., Hinchcliff, K.W., Radostits, O.M. (2007). Veterinary Medicine A Textbook of the diseases of cattle, sheep, pigs, goats, and horses. Saunders Elsevier Company, Ltd. Toronto. Tenth edn. Pps. 1320-1322.