avian GI parasites SDL

Question 1

list avian intestinal parasites

Answer 1

• ascaridia galli
• heterakis gallinarum
• trichostrngylus tenuis
• capillaria spp
• amoebotaenia sphenoides
• choanotaenia infundibulum
• davainea proglottina

Question 2

outline the lifecycle of ascaridia galli

Answer 2

• Direct and simple, non-migratory
• Ascaridia worms produce oval, smooth-shelled eggs that are laid in the bird’s intestines and excreted through faeces
• The eggs embryonate in a week or more, after which they can be picked up by another bird, hatch in the intestine and develop into mature worms
• Earthworm may act as a transport/paratenic

Question 3

list clinical signs of ascaridia galli infection

Answer 3

• poor growth
• diarrhea
• body weight loss (mainly in young birds)

Question 4

how is ascaridia galli treated

Answer 4

• flubendazole
• piperazine

Question 5

outline the lifecycle of heterakis gallinarum

Answer 5

• Caecal worms have a direct life cycle
  Adult worms produce eggs inside the infected chicken, which pass in faeces
• Eggs in the soil or litter are ingested by another chicken
• Once inside the chicken, the larvae hatch in the upper intestine and move to the caecum
• The eggs can also be ingested by earthworms, which are then eaten by the chicken

Question 6

how is heterakis gallinarum transmitted

Answer 6

The worms can be transmitted to chickens through the ingestion of intermediate hosts (earthworms), or directly through contaminated water, food, bedding or soil

Question 7

what is blackhead disease

Answer 7

• The caecal worm (Heterakis gallinarum) serves as the main vector for the transmission of Histomonas meleagridis, a protozoan parasite known to cause blackhead disease that affects the caecum and liver
• Transmission occurs through the ingestion of embryonated eggs of Heterakis gallinarum containing trophozoites of H. meleagridis, or by the ingestion of earthworms that have ingested eggs of the caecum worm
• Blackhead disease is important for turkeys, but it can also affect chickens
• Chickens are often carriers of H. meleagridis and show no clinical signs
• It is important that chickens and turkeys are not raised together. It is also important not to raise turkeys in the same area that was previously used to raise chickens, as H. meleagridis can survive up to two years in its environment

Question 8

ouline the lifecycle of trichostrongylus tenuis

Answer 8

Question 9

outline the general life cycle of capillaria spp

Answer 9

• There are several species of Capillaria, each invading a specific area inside the chicken
• Some species (C. contorta and C. annulata) invade the crop and oesophagus, causing thickening and inflammation of the mucous membranes
• Others (C. bursata, C. caudinflata and C. obsignata) target the lower intestinal tract, causing inflammation, haemorrhage and erosion of the intestinal lining.
• When capillaries are present in high enough numbers, it can be fatal for the chicken

Question 10

list capillaria spp, the location they infect in the bird and what the intermediate host is

Answer 10

Question 11

compare the cysticercoid phase host in amoebotaenia sphenoides and choanotaenia infundibulum

Answer 11

amoebotaenia sphenoides: in earthworm
choanotaenia infundibulum: in house fly/beetle