Large Stomach Worm, Twisted wire worm, Barber pole worm
The adult female worm lays 5,000 to 10,000 eggs a day which pass out with the feces.
The egg is already in the early stage of cleavage. (cleavage means that the cells have started to divide)
Eggs continue to develop in the feces in moist conditions, then hatch as first stage larvae.
This takes 4 to 6 days at a temperature of 75° to 85° F.
Second stage larva emerges from the cuticle.
First and second stage larvae both have the rhabditiform type of esophagus.
Larvae eat and develope to the third stage infective larvae which crawl up blades of wet grass.
Larvae retain the protective cuticle but they do not survive long if temperatures
are high and conditions are dry.
Infective larvae are swallowed by the goat.
As the larvae pass through the first three stomachs to the abomasum the cuticle is shed.
The larva will molt and form a fourth stage larva within 48 hours after reaching the abomasum.
They will then penetrate the lining of the abomasum and begin to feed.
Droplets of blood form around the larva surrounding it with a clot.
Enlargement of the worm's head shows spicules which pierce the lining of the abomasum.
The worm then sucks blood through the mouth cavity.
In about 3 days the worm matures, emerges from the clot, and molts for a
fourth time into the adult stage.
The adult attaches to the mucosa of the abomasum and begins producing eggs in about two weeks.
yellowish in color
in early stage of cleavage with 16 to 32 cells
size: 70 to 85 µm long by 44 µm wide
Young animals who receive acute infections develop anemia quickly and die
showing few other signs of infection.
Adult animals with chronic infections are anemic, frequently with swellings under the jaw (bottle jaw).
Diarrhea is rare, the feces instead is harder and drier than normal.
Later the goat becomes weak, has a swaying gait and pale skin.
Shortly before death the goat will become very weak and not be able to get up.