The caecal worm (Heterakis gallinarum) from the pinworm family, can infect chickens, turkeys, ducks, geese, grouse, quails, pheasants, guinea fowls and other domestic and wild birds. It is a small whitish worm with a pointed tail, 1-2 cm long. Adult worms are visible to the naked eye in the host’s caecal contents.
The lifecycle of the caecal worm is is short, only 4 weeks from egg to adult, which means even after treating you can quickly get a reinfection occurring despite all great husbandry, and it can remain viable in the soil for 2–3 years!
These environmental factors make it hard to control. What we do know is that general disturbance of the ground is linked to outbreaks as this may recirculate buried caecal worm eggs.
Symptoms
While a cause of relatively mild disease in its own right, caecal worm is mainly of concern because it can transmit Histomonas meleagridis, a parasitic protozoan that causes blackhead.
DETECTION
The caecal worm infects the caecal pouches of the chicken; these are two blind pouches located where the small and large intestines join. They ferment food to aid digestion and are emptied every 24 hours or so, which can be seen, and smelt! as a light brown (mustard colour) dropping that is often covered with froth. Include some of this caecal poo in the composite sample taken for a worm egg count. Caecal worm eggs do show up on a worm egg count which is the primary route of detection. While a cause of relatively mild disease in its own right, caecal worm is mainly of concern because it can transmit Histomonas meleagridis, a parasitic protozoan that causes blackhead. Any presence of this parasite showing up on a worm egg count therefore warrants treatment.
TREATMENT
The priority is to reduce the presence of worm eggs and insects in the environment. Clean, disinfect and change litter, have a good insect and rodent control programme to minimise presence of E. coli. thought to exacerbate likelihood of infection. Ensure the hen house is well drained to reduce bacteria and likelihood of earthworms. Spreading a lime-based product can help destroy worm eggs. Use pre and probiotics, apple cider vinegar in water to strengthen hens.
Flubenvet is an effective treatment for caecal worm. We would recommend a reduction test worm egg count 10-14 days after treatment to ensure this has been effective. For heavy infections you may want to consider retreating again 3 weeks on with the aim of trying to break the lifecycle.