The parasitic blackhead disease causes considerable economic damage in poultry farming due to loss of performance and animal losses. Unfortunately, oregano oil alone is not a miracle cure for blackhead disease, but it can be used as a supplementary feeding measure to support the health of the animals.

Devastating consequences of blackhead disease

Blackhead disease, also known as histomonosis, is caused by the single-celled parasite Histomonas meleagridis. Infection usually occurs via intermediate hosts such as nematodes or earthworms. Free-range animals are particularly at risk due to the high infection pressure. If animals ingest Histomonas pathogens, they settle in the intestine and appendix and spread from there to the liver. This leads to massive inflammation of these organs. The consequences are devastating:

  • Poorer feed conversion
  • diarrhea
  • emaciation
  • Loss of performance
  • In severe cases death

Oregano oil: natural and effective support

Oregano oil has been shown in various trials to improve gastrointestinal function.

In 2019, the Department of Poultry Science at North Carolina State University found in an in vitro experiment with oregano oil and Histomonas meleagridis that a concentration of 0.02% oregano oil reduced the number of histomonads by around 95%.

Oregano oil is known to have anti-inflammatory properties, among other things. In the case of a histomonas infection, data and studies show that there is a reduction in liver and appendix lesions. Less intestinal inflammation also means that the body can better absorb and utilize the nutrients from the feed. The combination of anti-inflammatory properties and improved feed conversion, also due to the appetizing effect of oregano oil, can contribute to an overall stronger immune system and an associated lower mortality rate*.

* Department of Poultry Science, North Carolina State University, 2022, trial with Histomonas meleagridis infected turkeys, duration from day 0 to 28 of life. The animals were infected with Histomonas on day 14 of life. Non-infected animals were compared with infected turkeys and with infected turkeys that received either 45 g, 75 g or 300 g oregano oil per ton of feed.


Oregano oil alone is not a miracle cure for blackhead disease, but can be used as a complementary measure to stabilize feed intake and thus support animal health. It therefore also contributes to sustainable and economical production.

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