Alison Colville-Hyde of Chicken Vet explains the importance of worming your chickens.

Animals and birds are capable of hosting various internal parasites, including worms. Chickens are no different, therefore worming is part of caring for your pet chicken’s health plan to implement prevention and control. Some species of worm can affect your chicken’s health if not treated.

There are four species which can be found in chickens:

Ascaridia (round worm) is the largest (up to 7cm long), inhabiting the small intestine. It burrows into the gut and large burdens may cause a blockage, resulting in damage, inflammation and a reduction in the absorption of nutrients. This leads to weight loss, diarrhoea, fewer eggs and anaemia if left untreated. These worms are very common.

Capillaria (hairworm), the smallest worm, about 1.5mm, can be particularly damaging and commonly colonise in the crop. These worms use earth worms in part of their life cycle. Hairworms typically cause diarrhoea, anaemia, weight loss, loss of appetite and the birds can look depressed and dull.

Heterakis gallinarum, or the caecal worm, is found in the caecum of chickens. The worm is relatively harmless, however it can carry ‘blackhead’, another parasite, which normally affects turkeys but can occasionally affect chickens. Blackhead burrows into the caeca, leading to inflammation and yellow droppings. The parasite migrates to the liver causing damage which can result in death. Unfortunately there is no specific licensed treatment for blackhead, so worming is the preventative option.

Syngamus trachea, the gape worm, lives in the trachea (windpipe) causing gasping and head shaking. Because of the clinical signs, gape worms are the most commonly thought of worms affecting chickens. However, they are quite rare and the cause is usually respiratory disease.

Tape worms rarely affect chickens but if you do suspect them consult your vet.

It is easy to assume your birds have worms, so one way to check is to get the chickens droppings tested. This avoids over-worming and will advise you of the species present. Vets can supply special kits to collect a sample and includes packaging to send to the laboratory.

For treatment, the only licensed poultry wormer is Flubenvet 1%, suitable for chickens, turkeys and geese, but not ducks. Flubenvet 1% is available only through outlets that employ suitably qualified persons (SQP’s) or through a veterinary practice. Flubenvet is administered in feed over seven days and comes in a 60g pot, which is enough to treat a 20kg bag of feed. Eggs can safely be consumed during treatment. Testing and treatment for worms should ideally be carried out every three months, for a preventative measure as well as a treatment.

It is best practice to clean out the coop during worming and use a disinfectant which destroys worm eggs, such as Interkokask, to destroy worm eggs in the environment. If your chickens are confined to a run, it helps to reduce worm burdens by moving the run regularly or changing the surface material every so often.