The Gape Worm also called Syngamus Trachea mainly affects chickens, turkeys and game birds, especially pheasants but can affect other wild birds as well which makes eradication difficult.
Infestation often occurs when there are wild pheasants close to your birds. Gapeworm infestation can occur either directly by birds eating eggs that have been swallowed or coughed up by infested birds, or indirectly by intermediate hosts such as earthworms or snails. Young birds up to 8 weeks of age are particularly susceptible to gape worm. Gapeworms normally live in the trachea (windpipe) but are also found in the bronchi and lungs.
Typically, eggs are picked up from the ground or intermediate hosts such as worms or snails. The eggs hatch and the larvae penetrate the intestine walls and move to the lungs and bronchi. It is here they go through a larval moult, before travelling up to the trachea. Male and female gapeworms attach to one another once they arrive here. This process takes around 7 days. Gapeworm lay eggs that get coughed up onto the ground or swallowed and passed out in the faeces.
Infestation causes respiratory distress. Gasping for breath or 'gaping' as it is known is the biggest sign of gapeworm. Shaking of the head and neck stretching are common. When birds are held, gurgling or a 'tracheal rattle' can often be heard. This can often be confused with respiratory infection, if in doubt, check for other signs of respiratory disease. If a heavy infestation occurs, death by suffocation will occur. Fully grown gapeworms are 'Y' shaped and vary in size between 1 and 2cm long.
Chickens are particularly prone to respiratory diseases so it is important to ensure you have a good worming schedule to eliminate the possibility of a respiratory problem being confused with a gapeworm infestation. Gurgling noises that come from the throat of the bird can be caused by gapeworm and can be confused with a respiratory problem.
As with all internal parasites, there are many treatments that will kill these worms but rotating the grazing area will help to stop birds becoming re-infected. Worming Chickens provides some ideas for worming poultry. Flubenvet is licenced for use in chickens and will kill gape worms.
Photo right: Gape worms in the Trachea. All photos on this page are courtesy of Janssen Animal Health.