Veterinary advice should be sought from your local veterinarian before applying any treatment or vaccine. Not sure who to use? Look up veterinarians who specialize in poultry using our directory listing. Find me a Vet

Intestinal Parasites

There are several different types of intestinal parasites which can infect chickens:
  • Cecal worms: Cecal worms (Heterakis gallinarum) serve as a main vector for the protozoan parasite, Histomonas meleagridis, known to cause blackhead disease.
  • Coccidi (Eimeria spp) are protozoan organisms known for causing Coccidiosis in chickens.
  • Tapeworms: Tapeworms are flat intestinal worms that are made up of several small segments. They attach themselves to the bird's small intestine using their hook-like mouthparts.
  • Roundworms : Roundworms, also known as nematodes, are parasitic worms that can grow to be quite large (up to 7 inches long). They live freely in the bird's intestine, feeding off of partially digested intestinal contents.
  • Capillaria: Capillaria are often referred to as hairworms or threadworms. These are a very thin type of nematode.

Complications from intestinal parasites

Without treatment, intestinal parasites can cause damage to the chicken's intestines and reduce their ability to absorb the nutrients from food. High loads can lead to intussusception and intestinal volvulus, which is fatal without prompt veterinary care. Intestinal parasite infections also lead to reduced immunity, increasing the birds risk of secondary infections.

Clinical Signs

Weight loss
Loss of appetite
Pale face and comb (anemia)
Abnormal droppings
Ruffled feathers


  • History
  • Fecal exam


Treatment depends on the underlying cause. There are a variety of different deworming options. ::



  • Conduct annual fecal exams for flocks and of new birds before introducing them into the existing flock of birds.
  • Regularly clean coop

Scientific References

    Risk Factors

    • Overcrowded living conditions (too many birds living together in one space)
    • Not cleaning the coop regularly