Canines are the definitive hosts for adult T. multiceps, T. seralis, T. brauni, and T. glomeratus tapeworms; sheep, rabbits, and other herbivorous animals are intermediate hosts depending on the infecting tapeworm species. Unwitting ingestion of material contaminated by dog feces causes human disease. In humans, the larvae invade and form a cyst (coenurus) in the central nervous system, subcutaneous tissues, muscles, or eyes. Most cases occur in Africa, but some occur in sheep-raising areas of Europe and North and South America.
Symptoms of coenurosis require several years to develop and depend on the organ infected. Involvement of the brain can cause increased intracranial pressure, seizures, loss of consciousness, and focal neurologic deficits. A coenurus in subcutaneous tissue or muscle may manifest as a fluctuant, tender nodule. If the eyes are involved, vision may be impaired.
Diagnosis of coenurosis is typically made after surgical removal, which is also the primary treatment. Surgery is typically done for symptomatic, space-occupying lesions.
Praziquantel can be effective. Some patients are treated with a combination of surgery and anthelmintics. But praziquantel is not used in patients with intraocular coenurosis because dying parasites can trigger severe inflammation, resulting in loss of vision.