Health issue What is it External parasites External parasitic infestations include ticks, lice and mites which can live on the birds or in the hen house and feed off the chickens when they roost. Sour crop Sour crop describes a yeast infection of the crop (found at the base of the chicken’s neck and forms part of the oesophagus). Vent problem A problem with the vent (the area where the egg, urine, faeces and urates pass) due to Infection (Vent Gleet), being egg bound or a prolapse. Worms The presence of parasitic worms such as roundworms (Ascaridia spp), tapeworms (Raillientina and Davainea spp), hairworms (Capillaria spp) and caecal worms (Heterakis spp). Worm infections usually occur after wet periods during the warmer months. Wounds Wounds can range from small scratches to severe open cuts caused by objects in the environment, the action of parasites or aggression from other birds. TABLE 1: COMMON HEALTH PROBLEMS (CONTINUED) PART 4 KEEPING YOUR HOME FLOCK HEALTHY 42 | THE CHOOK BOOK