Vet Nigel Underwood of Janssen Animal Health believes there is a growing number of poultry hobbyists who know little or nothing about preventative healthcare.

"While it's great to see people getting interested in keeping livestock using natural systems and thinking about where their food comes from, we are worried that no one appears to be giving any thought to the measures that need to be taken to keep birds healthy outdoors. Parasitic worms are very common and a cycle of infection can quite quickly be set up, resulting in a drop in egg quality and quantity, ill birds and even death."

Worms may not be a terribly trendy topic at the moment but as free range and barn systems of rearing become more popular, small scale chicken owners are likely to be having more conversations around this subject. Worm eggs can live in the soil for years, are resistant to disinfectants and represent a source of infection. In some cases the parasitic worms infect beetles, earthworms and other insects and are consumed that way. Once inside the bird the adult worm lays more eggs which are again passed out into the environment.

Traditionally, spring sees a rise in worm egg numbers, which can have a big effect on egg production by the chickens.

In rare cases, worms can even be incorporated into the chicken egg.

Treatment does not have to mean compromising on the 'return to nature' values that have usually driven the acquisition of backyard poultry. Veterinary licensed poultry wormers available from vets, pharmacists and agricultural merchants can be safe and effective and leave no residue in the eggs, which can still be eaten during treatment.

Says Nigel Underwood, "We would really like poultry owners to find out more about worms. In most cases there is a restricted amount of space in the garden available to the chickens and once that gets infected it will be much harder to eliminate the problem."

A free leaflet about worms affecting chickens, geese and turkeys is available from vets, pharmacists or licensed agricultural merchants or by calling Janssen Animal Health on 01494 567555.