Ascaridia galli
A. galli is a nematode (roundworm) that is the common roundworm of chickens. The turkey counterpart to this parasite is Ascaridia dissimilis.
The more parasites that infect a chicken at one time, the lower the percent of the worms "take" to the host and the longer the prepatency period (time between infection and reproduction of an individual). The rate of development of the parasite varies depending on the host's age, nutrition, individual and species genetics, gender, and degree of resistance. The larvae located in the mucosa causes the greatest damage and can include all of the following:
Mucosal edema, protein loss, and hemorrhage
Anemia and leukocytosis
Diarrhea, lowered bird weight, dehydration
Anorexia and lowered feed efficiency
Decreased blood sugar
Increased gut weight
The adult A. galli feeds only on mucosal filtrates and debris. Ascaridiasis magnifies and aids debilitations induced by pathogens present. An A. galli worm is found most commonly in young chickens due to immune response to the parasite increasing with the age of the chicken.
Life Cycle of A. galli:
1) Eggs are found in droppings. The eggs are very resistant to their environment and are sticky allowing them to attach to most surfaces.
2) Eggs contain the infective 2nd stage larvae in 30 days depending on conditions. Needs to be about 32 degrees Celsius with plenty of moisture and oxygen.
3) The egg containing the infective larvae is ingested by a chicken where it hatches in either the proventriculus, gizzard, or small intestine. The hatching is stimulated by unique chemical and conditional signals of the intestines.
4) The larva gets close to the mucosa which is within the mucus where it molts to the 3rd stage after about 7-17 days after infection. Some of this larvae enters the mucosal epithelium of the small intestine while the rest will stay in the mucus. Eventually, all of the histotropic 3rd stage larvae emerge from the mucosa or else die in it, here in the mucus the 3rd stage molts to the 4th stage. After about 10 days the 4th stage molts to the adult stage.
5) The prepatency is about 30 days at the earliest and the patency period for a female is about a few months.
The drug of choice for dealing with A. galli is piperazine, although very little effort is put into treating poultry for parasites, especially on the commercial level.
