How Often to Deworm Goats

The skinny on worms in goats, and how to medicate for them.

Reader Contribution by Carrie Miller
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Liver fluke anatomy.

The growing resistance of parasites to medication can make goat deworming difficult. Learn how often to deworm goats, and about the different dewormers available.

When it comes to goats, worms are notorious for causing havoc amongst owners and their herds. Protocols and worming medications have changed a lot over the years –some good, some not. Once upon a time it was thought that staying ahead of the worms and preventing outbreaks with strategically thought-out scheduling was the preferred method. Due in huge part to this practice many worms have become resistant to several of the medications on the market.

I have been raising goats for about three years, as with any new species of animal I did a ton of research beforehand. The worm debate seems to be among the most confusing of discussions. What works for one farmer may not work for another when it comes to de-worming medications. Goats in certain regions have become resistant to some de-wormers, due in part to the over-use of the regiment in that area.

How often to deworm goats based on the FAMCHA System

The FAMACHA System is the method whereby only certain goats in a herd are selected for treatment. Goats are selected for treatment based on the degree of anemia they display in the color of their mucous membranes. “The brighter the red the better!”

With guidance from our amazing farm Veterinarian, Dr. Elizabeth, we choose to treat only when needed. We use the FAMACHA system which allows us to make de-worming decisions based on an estimate of the level of anemia in each goat. With the Famacha system only goats who show a definite level of anemia are wormed. However, we go one step above this practice and send a fecal sample to our Vet to determine which worms we are fighting against. Why? To make life more confusing, not all worms are treated with the same medications.

Lung worms irritate the bronchioles inside the lung and cause a local reaction with mucus and white blood cells. The irritation and pain cause the animal to cough on a routine basis.

Stomach worms are parasitic bloodsuckers that will destroy the lining of the stomach to access the bloodstream. The damaged lining of the stomach can cause anemia, colic, diarrhea, and weight loss.

Liver flukes burrow tunnels into the liver, causing extreme scarring and damage. Since scar tissue is not functional, the liver’s normal function can be hindered. The liver’s job is to filter the blood of toxins and waste. When the liver is compromised due to the damage from the flukes, other organs such as the brain may become damaged.

Classes of dewormers for goats

There are three classes of drugs that are used to treat internal parasites in goats:

1. Benzimidazoles-Fenbendazole, Albendazole, Oxybendazole, Thiabendazole
2. Nicotinics – Levamisole, Pyrantel, Moratel
3. MacrolyticLactones– Ivermectin, Doramectin, Moxidectin

The Benzimidazoles (Safeguard®, Panacur®, Valbazen®, Synanthic®), also called “white dewormers” are broad spectrum. They are all effective against tapeworms but have shown resistance towards other worms in some parts the U.S.A. Albendazole is effective against adult liver flukes, but cannot be used in pregnant or lactating females.

Nicotinics such as Levamisole (Tramisol®), also called a “clear dewormer” is broad spectrum and effective against larvae. Pyrantel (Strongid®) is only effective against adult worms. Moratel (Rumatel®) is an oral feed additive and is only effective against adult worms.

*Our Veterinarian has asked us to stay away from all pelletized feed additive de-wormers. She believes they do not work and further add to the resistance issues that plague goats.

Avermectins (Ivomec®, Dectomax®, Quest®, Cydectin®) are the newest family of drugs. They are broad spectrum and are also effective against external (biting) parasites, including nose bots, lice and mites.

When are goats more susceptible to worms?

During warm weather, moist conditions, and the summer months goats are at highest risk. Due partially to grazing upon pasture, when eaten from the ground parasites are easily ingested. Goats can go downhill rapidly when worm numbers are high. Checking their eyelids more often is a grand idea (every two weeks). Twenty-four hours after a doe gives birth it is recommended to de-worm. We choose to do this because of “worm bloom.” The stress of kidding can trigger a “worm bloom,” an outbreak occurs because the doe’s immune system is tired and depleted of energy. It is critical that when de-worming is called for, goats are never under-medicated. The wrong dosage will further help to build resistance to medications. Obtaining semi-annual fecal checks, no matter the FAMACHA score, helps solidify a healthy happy herd.


Carrie Miller grew up in a small rural town in Northwest Pennsylvania, married her high school sweetheart and had two amazing children. She spends her time raising chickens, pigs, beef cows, and Oberhasli dairy goats at Miller Microfarm. She raises vegetable gardens, fruits, and berry patches while never using herbicides, pesticides, or chemicals of any kind. She spends a lot of time preserving the bounties through canning and freezing methods. She recently added bees to the farm in hopes of producing fresh honey and beeswax products.

  • Updated on Jul 5, 2022
  • Originally Published on Jan 15, 2019
Tagged with: liver fluke, lung worms, parasites, Reader Contributions
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