EHV-1 – Disinfection 101

Friday, May 20, 2011
Posted by Tanis MacDonald, DVM

Tanis MacDonald, DVM mantains a blog that is both well-written and informative  and we are excited to be featuring many of her articles on our Horse Health section in the weeks and months to come.  She has a natural ability to take a seemingly complicated topic and break it down into easy to understand pieces suitable for equine enthusiasts of all ages and experience levels.  Today's article is Part Three of a series of posts in relation to the EHV-1 Virus so be sure to check back often!!

Part Three - I am getting a ton of questions concerning disinfection procedures for the EHV-1 virus. People want to know how and what to use in their barns, trailers, equipment, etc to kill the virus.
For such a contagious virus, EHV-1 is actually easily killed on surfaces by common disinfectants. The most common choices are household bleach, Nolvasan or iodine. There are others out there as well, but these are the most commonly available and easily accessed.

The most common disinfectant to use is diluted bleach. Mixing 1 part bleach to 9 or 10 parts water will make a solution that will kill EHV-1. Spray it liberally over stall walls, trailers, buckets, etc and allow it to DRY completely. If it is a bucket or other item that needs rinsed before it is used, you can do so after the dilute bleach solution has dried on the item.

You can also spray diluted bleach on dirt floors in stalls. One caveat - be careful of the mixing of bleach with urine in stalls – the chlorine-ammonia reaction can make some noxious fumes that are dangerous to horses and humans. Please use the utmost care if you are spraying bleach in areas where horses have urinated.

For an example, add 3 ounces of bleach to a 32 ounce sprayer and fill the rest with water. Spray surfaces and allow to dry.

If you need to use a disinfectant that is not going to ruin/bleach something, Nolvasan (chlorhexidine) solution is a good choice. Again, dilute according to the bottle directions and spray liberally and allow to dry. You can also add some to your laundry if you are washing human or horse clothes. Washing laundry in hot water and regular laundry soap is enough to kill the EHV-1 virus, however.

Nolvasan is also good for things like spraying farrier tools between appointments, spraying down tires on vehicles before leaving a farm, etc.

You want to buy Nolvasan or chlorhexidine SOLUTION and not scrub (which contains soap) for this. Not that scrub won’t work, you just really don’t need the soap.

Iodine will work too – again the solution version, not the scrub with soap. Dilute with water to the color of weak iced tea, and spray liberally on surfaces. Iodine is more likely to stain everything it contacts yellow, so is a good choice for things like dirt surfaces or as a boot dip.

For people, alcohol based hand santitizers will kill EHV-1. I would suggest anyone coming into your horse property at least use hand sanitizer before and after they visit with horses to help prevent the spread. Normal showering with hot water and soap will kill the virus as well.