Paragonimiasis in Animals
Paragonimus westermani and P kellicotti, the lung flukes, have been reported to migrate aberrantly and produce cysts in the brain and spinal cord of pigs, dogs, cats, rats, and humans. Flukes in these extrapulmonary sites in dead-end hosts do not produce patent infections.
Schistosomiasis in Animals
Schistosomes, or blood flukes, typically deposit their eggs in the small vessels of the gastrointestinal tract and urinary bladder, from which they pass into the external environment via the feces or urine. Some eggs, however, may reach the general circulation and the CNS, where they become encapsulated. This condition has been reported in domestic animals and humans.
Troglotremiasis in Animals
Troglotrema acutum inhabits the frontal and ethmoidal sinuses of foxes and mustelids in Europe. Flukes live in pairs in cysts in these sinuses. These parasites cause decalcification and atrophy of the bony sinus walls eventually resulting in penetration of the cribriform plate. Microorganisms enter the cranial vault, leading to fatal, purulent meningitis. No treatment is available.
