"The most dangerous thing to your horse's health is another horse," says Dr. Chris Clark, a large animal internal medicine specialist at the Western College of Veterinary Medicine (WCVM). He also led the development of biosecurity manuals for the college's Veterinary Medical Centre.
Biosecurity is the practice of minimizing the chance of horses getting sick. As Clark points out, it's much easier to prevent a horse from becoming ill versus "trying to figure out how to treat it."
But accomplishing this goal can be more difficult than it sounds, especially when a horse appears healthy even though it's ill.
"It's easy to diagnose a clinical case where the horse looks sick, but a subclinical case can shed bacteria into the environment and infect other horses without us knowing it," says Clark.
Talking to your veterinarian and doing your own research can help you to improve the biosecurity at your own barn and as you travel with your horses. There are also a few basic principles that every owner can follow to protect their horses' health.
• Plan. Plan for horses to get sick: create a designated quarantine space. By working with healthy animals before feeding or treating the sick animal, you can also prevent the spread of disease on your property.
"Look online, talk to your veterinarian and think about what you can do. The key is to create a workable plan," says Clark.
• Assess your risk. Determine the amount of risk you're comfortable living with. For example, Clark says if you operate a high-end breeding operation with valuable horses, biosecurity should be paramount. With good biosecurity in place, stables and arenas can be completely functional even with high horse traffic.
• Vaccinate.Talking to your veterinarian to determine which diseases you should vaccinate your horse against is one of the most important things you can do.
• Properly clean and disinfect. The first step of disinfection is to remove visible dirt and feces until the surface looks clean — but that's only the beginning.
"You've taken all the heavy stuff, but the biofilm is left behind. It's a tough, microscopic layer of fat and protein, and the bacteria hide underneath it," says Clark.
To remove biofilm, scrub the surface with soap before disinfecting. Follow the instructions on the disinfectant's label to create the right concentration and to maximize its effectiveness.
"Apply the solution to the things you need to disinfect and leave it on for 10 minutes," says Clark. He adds that some disinfectants need to be rinsed while others can be left on the surface.
• Wash your hands. Touching a horse's muzzle is a correct way to introduce yourself, but it's also a way to smear your hands with viruses and bacteria from the horse. When you go from one horse to the next without washing your hands, you're acting as a disease transmission system.
• Don't share tack and equipment. This is an important rule in your own barn, at a boarding barn and at shows. Each horse should have its own feed and water buckets, tack and grooming equipment, and all equipment should be labelled to prevent shared equipment use between horses.
• Be proactive at horse shows or events. Clark recommends choosing horse shows or competitions that ask for proof of a negative equine infectious anemia (EIA) certificate because this requirement shows that the organizers have given consideration to infection control.
Using your own equipment and tying your horse to your trailer versus stabling with other horses can help prevent illness. Never allow your horse to drink from a shared trough; instead, opt for filling your own bucket using a faucet or hose.
And although it seems obvious, Clark has one final, simple piece of advice: if your horse is showing any signs of illness, don't transport it to a horse show or public event — no matter how much you lose in entry fees.