Coccidia and Worms

Worms are one of the commonest cause of poor performance. A simple screen will confirm whether or not you are controlling them.


Pigeon hairworm egg – Capillaria sp.
Pigeon roundworm egg – Ascaridia columbae
Pigeon coccidial oocysts – E.labbeana

Last Revision: 06/04/13

Hairworm egg

They can be brown or green. Usually you cannot see the cells dividing inside to form the worm larva.

Round worm egg.

You can see the thick smooth wall. Sometimes, as in this case it has faecal material stuck to it. Usually they are brick shaped with curved corners but occasionally, I have seen a spherical roundworm egg.

Pigeon coccidial oocysts.

You can see one or two that have sporulated.

About David Parsons 19 Articles
David Parsons began his veterinary career in mixed practice which triggered his 39-year passion for poultry. Following positions as a veterinary research officer in the Poultry Department at the government’s Central Veterinary Laboratory and then as a poultry company veterinarian, he set up his own poultry veterinary practice in the southwest of England in 1985. He obtained his MSc in Applied Immunology in 1981, Certificate in Poultry Medicine and Production in 1989 and a Nuffield Farming Scholarship Trust to study the“Status of diseases specific to poultry and their control in Europe” in 1991.

He has been an Honorary External Lecturer at the University of Bristol Veterinary School on poultry medicine and production since 1999,a lecturer on the Institute of Animal Health’s poultry disease course since 2000 and is a regular monthly contributor of veterinary articles for backyard poultry keepers in the Practical Poultry magazine.