The life cycle of Parelaphostrongylus tenuis in the white-tailed deer and the llama. In many other ruminant species, the parasite larvae migrate into places where they don't normally in the white-tailed deer. The snails are ingested and the larvae migrate up the spinal nerves to the spinal cord but then seem to get lost. This causes damage to the central nervous system which may be severe enough to result in death. Other species which have been affected by meningeal worm are sheep, goats, llamas, alpacas, camels, moose, caribou, reindeer, wapiti, fallow deer and mule deer.
Animals can become infected in the spring, summer or fall.
Disease is usually seen in the fall and winter about 3 to 4 months after infection. Often only one animal is infected at a time on a single farm. There may be more than one animal infected at once or more than one animal infected on a single farm over the years. Circling Abnormal Head Position Arching of the Neck Blindness Gradual Weight Loss Generally, animals with more severe symptoms have a worse prognosis. There is no way to definitively diagnose meningeal worm in a live animal.