Strangles can be transmitted by infected horses or from the organism persisting in the environment after an outbreak. During an outbreak, the disease can also be linked to carrier horses. A carrier is a horse that does not demonstrate any clinical signs but is still able to infect other horses.
Reports of the viability of the organism in the environment vary widely. Aggressive cleaning and disinfection, with special attention to the cleaning and disinfection of water containers, feeders, fences, stall walls, and trailers, is indicated. It is our recommendation that pastures and paddocks be rested at least 30 days. The best way to decrease the risk of infection is to ensure your horse is properly vaccinated for strangles especially before such a move.