Worms in Chickens: Symptoms, Types and Treatment

Worms are the quiet thief of poultry farming. They rarely kill a flock overnight, but they steadily rob birds of the nutrition they eat — leaving you with slow growth, thin birds and a bigger feed bill. Here's what to watch for and how to get on top of them.

1. The common types of chicken worms

• Roundworms — the most common; large, visible worms in the gut.
• Tapeworms — flat, segmented worms that attach to the gut wall.
• Caecal worms — live in the caecum (a pouch in the gut); usually mild on their own.
• Gapeworms — live in the windpipe and cause the bird to "gape" and gasp.

2. How chickens pick up worms

Birds eat worm eggs from contaminated litter (the bedding on the floor), soil or droppings. Some worms need another creature to carry them partway (an intermediate host) — earthworms, beetles, slugs or flies — so free-ranging and wet, muddy ground both increase the risk. Worm eggs survive a long time in the environment, which is why birds so easily pick up worms again.

3. Symptoms to watch for

• Weight loss and poor growth despite normal feeding
• Pale comb and wattles
• Diarrhoea, sometimes with visible worms in the droppings
• Dull, ruffled feathers and listlessness (low energy)
• Reduced egg production in layers
• Gasping or "gaping" (gapeworm)

4. Treatment

Deworming is the answer, but the product and dose matter. Common dewormers include piperazine, levamisole and fenbendazole — confirm the right product, dose and withdrawal period with a vet or poultry specialist, because the withdrawal time (how long before you can sell birds or eggs) varies. Repeat according to your deworming schedule, not once and forget.

5. Prevention

• Keep litter dry and clean — worm eggs thrive in damp conditions.
• Rotate free-range areas to break the life cycle.
• Avoid overcrowding.
• Deworm on a routine schedule, not only when birds look sick.
• Keep new birds separate for a while (quarantine) before adding them to the flock.

Worm damage often shows up as poor growth that looks like a feed problem. If your birds are eating well but not gaining, check worms alongside your feed — and see the symptoms of a sick chicken to rule out other causes.