WORMS and REFUGIA

Trying to keep goats as stomach worm-free as possible is the biggest challenge facing most goat producers. Further complicating the matter is that many folks raise goats in areas so wet that goats are constantly exposed to reinfection by worms. Repeated deworming only makes the situation worse by creating dewormer-resistant stomach worms.

A new and somewhat confusing concept has recently appeared in the fight against Haemonchus contortus, commonly called the Barberpole stomach worm: REFUGIA. Refugia refers to stomach worm larvae in your pasture that are still susceptible to being killed by dewormers. Personally I think its name is confusing. Sounds to me like it might refer to resistant worms or worms in refuge from dewormers, but the meaning is precisely the opposite. Refugia refers to stomach worm larvae that remain susceptible to being killed by dewormers. If you can wrap your mind around this concept (tough for me to do), then here is how you handle deworming your goats to try to increase Refugia in your goats and their pastures:

1) Always use the FAMACHA field test of checking coloration of inner lower eye membranes every time you handle a goat.

2) Deworm goats individually and only when necessary.

3) Perform your own fecal counts on a regular basis to both verify your FAMACHA readings and stay ahead of the curve on worm development.

4) Deworm orally. Never as a back drench. Even those dewormers that say "injectible" should be used orally. Don't use feed medicated with dewormers. Deworm each goat individually.

5) Cull all worm-susceptible goats in your herd. That means sending them to slaughter and getting them out of the breeding chain. Caveat: If your goats are over-crowded or living in filthy conditions, no amount of culling is going to help and being wormy isn't the goats' fault; it is a management problem (you).

6) Select for worm-tolerant and worm-resistant goats. There are no breeds of goats that are worm resistant but there are goats within breeds that develop resistance to worms. These are the ones that you want to select for keeping and breeding.

Relying on repeated deworming requires that there be a steady development of new dewormers. This is not happening. New dewormers are not being formulated fast enough for producers to be able to rely solely on anthelmintics (dewormers). Much more detailed information can be found in my article titled DEWORMING AND VACCINATION SCHEDULING on the Articles page at www.tennesseemeatgoats.com.

Suzanne W. Gasparotto, Onion Creek Ranch, Texas 6/4/13