Keeping chickens in your garden provides many joys beyond fresh eggs. These charming birds often form attachments to their keepers, following you hopefully for a tidbit. Yet, just like any pet, they can fall ill and may not show obvious signs early on.
One of the most common and damaging diseases affecting chickens is coccidiosis. This parasitic infection primarily targets the gut, causing severe discomfort and in some cases, fatal illness.
Coccidiosis is caused by microscopic parasites belonging to the genus Eimeria. Several species infect different parts of the chicken's intestinal tract, damaging the gut lining and impairing nutrient absorption. This results in symptoms like diarrhoea, weight loss, dehydration, and lethargy. The six main species affecting poultry are:
Usually, multiple species infect the flock simultaneously, compounding the damage. Young chicks between 3-6 weeks old are especially vulnerable, but coccidiosis can affect all ages.
The coccidia life cycle involves several stages, beginning with oocysts passed in chicken droppings. Initially, these oocysts are unsporulated (non-infectious), but within 24-48 hours, given warm, humid conditions, they sporulate and become infectious. Oocysts have a thick protective shell, allowing them to survive harsh environmental conditions, including disinfectants, for up to a year.
When ingested by a chicken, digestive enzymes break down this shell, releasing the infectious sporocysts which invade gut wall cells. They multiply and destroy these cells, releasing thousands of new oocysts back into the environment, continuing the infection cycle. This intestinal damage causes severe discomfort and impaired digestion in affected birds.
Affected chickens often become hunched, with feathers ruffled and tails down, preferring isolation. They may stop eating or drinking and suffer from watery or bloody diarrhoea. If gut damage is severe, blood may enter the gut, leading to anaemia, which manifests as pale combs and wattles. These signs signal urgent veterinary attention is needed.
Controlling coccidiosis relies heavily on good management practices. Keep chicken sheds clean, regularly remove soiled bedding and droppings, and disinfect with poultry-safe products like Interkokask (a Defra-approved disinfectant). Ensure housing is well-ventilated to avoid damp and humid conditions that favour parasite survival.
Note that battery hens are particularly at risk when re-homed, as they typically lack immunity due to their upbringing. Proper acclimatisation and monitoring are essential during this time.
Treatment usually involves three key approaches:
Prevention is preferable to cure. Vaccines are available to help chickens develop immunity, but their effectiveness depends on careful administration and optimal environmental conditions. For small backyard flocks, strict hygiene and environmental control often remain the best preventive measures.
Additionally, maintaining dry, well-ventilated coops and limiting overcrowding reduces infection risk. Regularly rotating bedding and avoiding dampness can significantly decrease oocyst survival.
If your chickens exhibit any of the symptoms described, act promptly. Isolate sick birds and consult your vet for diagnosis and treatment advice. Early intervention can prevent severe illness or death and helps protect the rest of your flock.
Caring for chickens with coccidiosis requires patience and compassion, along with practical steps to break the parasite's cycle. By maintaining excellent hygiene, providing supportive care, and using appropriate treatments, you can help your chickens stay healthy and enjoy many happy years in your garden.