When is a foot bath effective and when does it lose its punch? When it no longer keeps organic material from spreading from one pen or building to another.

Foot baths can be a useful part of a biosecurity program, but they're only one part of that program, says Jim McKean, Iowa State University extension veterinarian. To make a foot bath an effective tool, you first need to come to a realistic expectation of its benefits and limitations.

"You can't just place foot baths outside buildings and do nothing else," McKean says. Develop protocols for going from building to building. Make sure workers know when to clean their boots, how to clean their boots or when to change into new ones.

McKean notes that foot baths are an expense: It takes time and effort to maintain them. The question is whether they are an effective use of that time and effort.

Are there other, simpler ways to achieve the same goals? For instance, using a garden hose to wash boots may do more than simply stepping into and out of a foot bath. That's especially true if the foot bath is dirty.

Washing boots before stepping into a foot bath does two things. It lets the foot bath do its job of neutralizing any matter left on the boot, and it avoids contaminating the bath with excessive amounts of organic matter.

"You want to keep organic material from moving from one location to another," McKean notes. "Too many foot baths look like they're actually transferring more matter onto your boots than they're taking off."

Proper maintenance is critical. If the foot bath turns dark, you're losing efficacy. McKean suggests avoiding products that dissipate and lose strength quickly such as bleach. Try a more stable product such as a phenol compound.

Foot baths can help keep pathogens from migrating between pigs. But use them wisely and don't expect them to curtail all your herd health woes.