Fighting Barber Pole Worms in Goats and Sheep

Given their high adaptability and resistance to many commonly used dewormers, fighting barber pole worms in goats and sheep can be difficult. As a result, successful management tactics will come to play which will combine chemical and non-chemical techniques.

This article will discuss several preventative methods, pasture management strategies, and genetic selection for resistance that farmers can use to combat Barber Pole Worms in their flocks.

What is barber pole worm (Haemonchus Contortus)?

The barber pole worm (Haemonchus contortus) is a parasitic roundworm that infects the gastrointestinal tracts of sheep and goats. These worms get their name from their unique appearance, which resembles a barber pole with red and white stripes.

The barber pole worm is a big problem for livestock farmers since infected animals can suffer from severe disease and possibly death. Worms feed on the blood of their hosts, causing anemia and starvation. They can also clog the intestine, resulting in digestive issues and abdominal pain.

Reproduction Cycle of the Barber Pole Worm (Haemonchus Contortus?)

The reproduction cycle of the Barber Pole Worm begins when adult worms living in an infected animal’s gastrointestinal tract lay eggs. These eggs are excreted by the animal and fall to the ground. If the conditions are favorable, the eggs will hatch into larvae in a matter of days.

The larvae then burrow into the earth and molt multiple times over several weeks before becoming infective third-stage larvae. They are now capable of infecting a new host if consumed. This can happen if the animal consumes contaminated grass or other plants, or if the larvae are consumed by an intermediary host like a snail or slug.

When ingested by a new host, the infective larvae move to the small intestine, where they mature into adult worms and repeat the cycle by laying new eggs. Because mature worms can live for months and lay hundreds of eggs, the Barber Pole Worm is a particularly dangerous parasite for animals.

How do you diagnose barber pole worm Haemonchus Contortus?

A veterinarian or livestock producer may use a combination of the following approaches to diagnose barber pole worm infection:

Physical examination:

The veterinarian will look for signs of sickness in the animal, such as anemia, weight loss, or diarrhea.

Laboratory tests:

A blood sample may be collected and tested to see if the parasite’s eggs or larvae are present. A fecal sample may also be analyzed for the presence of eggs or larvae.


An ultrasound can be used to discover mature worms in the digestive system of an animal.

A post-mortem examination can be performed on an animal that has died from a suspected barber pole worm infection to confirm the diagnosis and establish the degree of the infection.

Symptoms of barber pole worm

Symptoms of barber pole worm infection can include:

  • Anemia (pale gums and mucous membranes)
  • Weakness and lethargy
  • Weight loss
  • Diarrhea
  • Bottle jaw (swelling under the jaw due to fluid accumulation)
  • Loss of appetite
  • Abdominal pain
  • Death (in severe cases)

Always remember that these symptoms can also be caused by other illnesses, thus it is critical to have the infection diagnosed and treated by a veterinarian. Barber pole worms can cause serious disease and death in animals if left untreated.

Several environmental and managerial factors have contributed to the prevalence of barber pole worms. High temperatures, humidity, and rainfall are all environmental influences. Excessive anthelmintic medicine use, poor forage management, an inadequate nutritional plan, and a lack of anthelmintic drugs approved by the Food and Drug Administration for small ruminant use are all management issues.

Can humans be infected with Haemonchus Contortus?

Haemonchus contortus lives in the abomasum (“fourth stomach”) of ruminant animals which humans do not have, however the abomasum resembles the stomach of humans and it was recorded that H. contortus has been found in humans in Brazil and Australia.

Are there Vaccines for barber pole worm?

Several vaccines are available to prevent H. contortus infections in small ruminants. These vaccinations, which often comprise a dead or inactivated form of the parasite, are given to animals via injection or orally. Among the vaccinations available for Haemonchus Contortus are:

Haemonchus contortus vaccine (Hce): This vaccine comprises an inactivated form of the parasite and is given to sheep and goats orally.

Barbers Pole (BP) vaccine: This vaccine comprises a dead form of the H. contortus parasite and is given to sheep and goats via injection.

Barbervax: This vaccine, which contains a dead form of the H. contortus parasite, is given to sheep and goats orally.

While these vaccines can assist to lower the severity and frequency of H. contortus infections in livestock, they are not always successful and may not give total protection against the parasite. To assist lower the likelihood of H. contortus infections in livestock, further control measures such as excellent pasture management, regular deworming, and the use of resistant breeds must be implemented.

Prevention of barber pole worm

You may avoid barber pole worm infections in your animals by taking the following steps:

Good pasture management:

This is essential for reducing barber pole worm infestations. Good pasture management includes rotating pasture to allow grasses to regenerate, frequently eliminating animal waste, and minimizing overgrazing.

Forage management:

90% of barber pole worms reside in the top 10 inches of ground soil. Maintaining a grazing height above five inches protects animals from several dangerous parasites.

Lower stocking density:

Lowering the stocking density reduces grazing pressure and fecal deposition in the same area. As a result, the parasite population per unit of land area will be lowered.

Rotational grazing:

Parasites can be avoided by dividing pastures into paddocks and allowing animals to rotate through them over time. In a heavily diseased location, the rest period should last three to six months, depending on the weather.

Use anthelmintic drugs:

Regularly administering anthelmintic medications can assist to avoid barber pole worm infections. Your veterinarian will be able to advise you on the best medication and dosing regimen for your animals.

Implement quarantine procedures:

When introducing new animals to your herd or flock, it is critical to quarantine them for a period of time to verify that they are free of parasites. This will allow you to deworm the new animals before they are introduced to the rest of the herd or flock.

Keep animals clean and dry:

Barber pole worms thrive in moist, warm environments. You can assist to lessen the chance of illness by keeping your animals in clean, dry environments.

Use resistant breeds:

Some livestock breeds are inherently more resistant to barber pole worm infections. Consult your veterinarian or a livestock professional to decide which breeds are most suited to your needs.

Treatment for barber pole worm

Barber pole worms can be treated using a variety of methods, including:

Anthelmintic drugs: These are medications that are specifically developed to kill worms. Barber pole worms can be treated with a variety of anthelmintic drugs, including avermectins, benzimidazoles, and levamisole. Your veterinarian will be able to recommend the best medication for your pet.

Pasture management: Managing pasture wisely is one of the most effective approaches to reduce barber pole worm infections. This includes rotating pasture to allow grasses to regenerate, frequently eliminating animal waste, and minimizing overgrazing.

Deworming: Deworming on a regular basis can assist to prevent barber pole worm infestations. This entails regularly providing an anthelmintic medicine, often every several months.

What is Antiparasitic Resistance?

According to the FDA, antiparasitic resistance is the genetic ability of parasites to withstand treatment with an antiparasitic medicine that was previously successful against those parasites. After an antiparasitic medicine is administered to an animal, the susceptible parasites die but the resistant parasites remain to pass on resistance genes to their offspring. (Parasites are frequently referred to as “worms,” and antiparasitic medications are sometimes referred to as “dewormers.”)

Antiparasitic resistance is rising in sheep and goats both globally and in the United States. Since you are constantly grazing your goats and sheep, they continue to be infected with parasites after ingesting the infective immature stage of the parasites, such as the larval, so your goats and sheep will have repeated parasitic infection and you will have to treat them with dewormers on a regular basis.

Grazing species become found to be infected after swallowing infective immature stages of parasites from the pasture, such as eggs or early larval stages. Since these animals are constantly exposed to worms, they might develop recurring parasitic infections and be treated with dewormers, resulting in antiparasitic resistance in your goats and sheep.

How to deal with Antiparasitic Resistance?

Here are a few techniques for dealing with antiparasitic resistance:

  • Use proper dosing: To guarantee that antiparasitic medications are effective, it is critical to use the exact dosage. Parasites may be able to survive exposure and develop resistance if the medications are not handled correctly.
  • Antiparasitic drug rotation: Using the same antiparasitic drug again and over can increase the likelihood of resistance. Consider cycling between antiparasitic medications to limit the chance of resistance. This will help to prevent the development of medication resistance in general.
  • Good management measures: such as good hygiene, quarantine protocols, and good pasture management, can help to lower the risk of parasite infections and the requirement for antiparasitic medications.
  • Monitor for resistance: Monitoring for antiparasitic resistance on a regular basis can assist determine when resistance is developing. This will help you to solve the issue before it becomes a serious issue.
  • Collaboration with a veterinarian is essential for developing a plan for dealing with antiparasitic resistance. Based on the individual demands of your animals and operation, your veterinarian will be able to offer the best techniques.

FDA Approved Good Management Practices Help to fight against Antiparasitic Resistance

  • Identify and then avoid management practices that contribute to antiparasitic resistance, such as treating every animal in the flock or herd and frequent routine deworming without performing diagnostic tests or determining if treatment is necessary;
  • Preserve refugia by not treating all animals at the same time. Refugia is the proportion of the total parasite population that is not selected for antiparasitic drug treatment—essentially, those parasites that are in “refuge” from the drug. Therefore, there’s no selection pressure on these parasites to develop resistance. Preserving refugia maintains a proportion of drug-sensitive (susceptible) parasites on the farm. The presence of some drug-sensitive parasites decreases (dilutes) the proportion of resistant parasites within the parasite population on a farm.
  • Choose antiparasitic drugs wisely. Use only those that are effective based on recent diagnostic test results and approved for the particular parasites present on the farm. Always follow the directions on the drug’s label; and
  • Quarantine new livestock. Before introducing new animals into a flock or herd, examine them for roundworm infections and treat accordingly.

The way forward

Small ruminant antiparasitic resistance is a global and developing issue that can only be slowed, not stopped. Random genetic mutations cause parasites to develop resistance to antiparasitic drugs. Resistant parasites survive treatment and reproduce, passing on their resistance genes to the following generation, producing even more resistant parasites. This trend is accelerated by poor management techniques. However, by collaborating and focusing on the long-term use of antiparasitic medications, the FDA, pharmaceutical companies, veterinarians, and producers can greatly decrease the development of antiparasitic resistance in small ruminants.

FDA-approved antiparasitic drugs for sheep and goats

Active IngredientProprietary (Brand) NameSpecies
ThiabendazoleThibenzole®Sheep and goats
Omnizole®Sheep and goats
E-Z-EX Wormer Pellets®Sheep and goats
Equizole®Sheep and goats
TBZ 200 Medicated Feed PremixSheep and goats
Morantel tartateRumatel® 88goats
AlbendazoleValbazen®Sheep and goats
Safe-Guard®Goats and wild sheep (Rocky mountain bighorn sheep) Not approved for use in domestic sheep.      
LevamisoleRipercol L®  Sheep
MoxidectinCydectin® Oral DrenchSheep

This list is current as of April 19, 2021


Barber Pole Worms are a significant threat to goat and sheep health and productivity, and appropriate management measures are critical for the success of any farming enterprise. Farmers may dramatically reduce the burden of these parasites on their flocks by using a comprehensive approach that involves targeted deworming, pasture management, and genetic selection for resistance, no single solution is a panacea, and that a combination of several methods suited to the individual demands of each farm is frequently the most successful way to tackle these worms. Finally, farmers can assist maintain the health and well-being of their animals, as well as the long-term viability of their companies, by being informed and proactive.