Parasite Control in Small Ruminants

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Parasite Control in Small Ruminants

With the end of summer nearing and the onset of warm, damp, fall weather, producers should be thinking about worm populations and control methods in their sheep flocks and goat herds.


Haemonchus Contortus, or Barber’s pole worm, is an internal parasite that lives in the stomach of the animal.The Barber’s pole worm is a blood-sucking worm that can remove large quantities of blood, which results in anemia. Anemic animals are characterized by the paleness of the gums and the linings of the eyelids. Sheep and goats infected with the Barber’s pole worm may become ill, have difficulty gaining weight well, losing weight, become lethargic, and may have diarrhea – death is possible. Adult Barber’s pole worms live in the stomach of the animal and lay eggs in large numbers that are then passed in the manure. The eggs develop into larvae and are ingested by sheep and goats. Once ingested, larvae go through a three-week development period to become an adult and produce eggs.

When & Why?

At the start of the grazing season, with lush grass growing, grazing animals often pick up larvae, becoming infested. However, larvae develop and survive best under warm, wet conditions, so Fall weather is prime for parasite infestations. If conditions are hot and dry, larvae numbers will decline as they are killed due to heat. If conditions remain suitable for development, large numbers of larvae can accumulate on the pasture.

The Barber’s pole worm can cause economic and production loss to both sheep and goat producers. To avoid such losses, producers should have control programs in place to reduce the worm population.


The most effective control programs require the use of antiparasitics (dewormers) as well as other management techniques, such as grazing management, fecal egg counts, and utilizing the FAMACHA system.

Grazing Management

As the Barber pole worm eggs are passed in the manure, and larvae are ingested through grazing on grass, it is wise to make smart decisions about grazing. Below are some recommendations to follow:

• Grazing pastures with multi-species animals, like horses, can reduce parasite loads as these animals are not impacted by the Barber’s pole worm.

Grazing pastures planted with plant tannin-rich forages, such as Sericea Lespedeza, will also provide some resistance to parasites.

Fecal Egg Counts

As a maintenance method for all livestock, monitoring an animal’s fecal egg count (FEC) is efficient in helping

limit parasite infestation. To conduct an FEC, fresh fecal samples are taken from each animal and viewed under a microscope to help identify and calculate how many of what parasite eggs are present in the animal’s digestive tract. Depending on the amount and type of parasites, it would be decided if the animal needed to be treated with an antiparasitic. Using this method helps avoid parasite resistance due to decreasing the unnecessary use of antiparasitics.


The FAMACHA system is a system used to detect anemia in sheep and goats. The FAMACHA system compares a color chart to the inner lower-eye membrane of each goat or sheep. A white color indicates anemia from a high parasite load. Dewormer resistance is prevented and money is saved because only the animals that really need treatment are receiving it. To properly utilize the FAMACHA system, producers should be trained on its usage. If you are interested in becoming FAMACHA certified, please contact the Avery County Cooperative Extension Center at (828) 733-8270.


It is always a good idea to weigh the goats or sheep, so you know exactly how much dewormer to give them. Dewormers should always be given orally. The pour-on cattle deworming products, which are poured on the animal’s back, do not work on goats and sheep because they have different hair follicles than cattle. It is important to work with a veterinarian when using dewormers.

For additional information, please contact Michelle South, Area Extension Agent, Agriculture – Livestock with North Carolina Cooperative Extension, Avery County Center, at (828) 733-8270, by e-mail at, or visit our website at https:/

Original Article Written by Taylor Chavis

Updated by Michelle South