Coenurosis is a parasitic infection that results when humans ingest the eggs of dog tapeworm species Taenia multiceps, T. serialis, T. brauni, or T. glomerata.

This means that these species can develop into full grown, reproductively capable adult worms within the human body.

In contrast, the four species that cause human coenurosis can only grow into mature, reproductively capable worms inside their definitive hosts, canids such as dogs, wolves, foxes and coyotes.

[1][3] When the cyst occurs in the brain, as it often does, the infected individual may experience neurological symptoms of headaches, seizures, vomiting, ataxia, paralysis affecting one side of the body (hemiplegia), paralysis involving one limb (monoplegia), and loss of ability to coordinate muscles and muscle movements.

[5] When the cyst occurs in the spinal cord, it can cause severe pain and inflammation, and loss of feeling in some nerves (arachnoiditis).

Intermediate hosts such as rabbits, goats, sheep, horses, cattle and sometimes humans get the disease by inadvertently ingesting tapeworm eggs (gravid proglottids) that have been passed in the feces of an infected canid.

The disease cannot be transmitted from one intermediate host to another, but it is still not a good idea to eat meat that presents with cystic nodules from coenurosis.

Many animals may serve as intermediate hosts, including rodents, rabbits, cattle, sheep, goats and humans.

[7] Some other clinical findings that can be used for diagnosis include papilledemas, hypoglycorrhacia, and high intracranial pressure caused by obstruction of the ventricles.

[7] Some serological and microscopic tests can confirm the presence of Taenia larvae once surgery has taken place and a portion of the cyst can be removed to undergo examination and biopsy.

Because of the lack of specificity in diagnostic technique, coenurosis can be misdiagnosed as neurocysticercosis or echinococcosis, other parasitic diseases affecting nervous system tissue.

If the person presenting symptoms lives in an area with poor sanitation, high wild dog population, or known endemic tapeworm, his chance of having coenurosis is much higher.

Most human cases occur in developing countries such as India and Sub Saharan Africa where the dog population is not controlled or treated for tapeworm, and in areas lacking proper sanitation.

T. multiceps has been reported in regions all over the world (both human and animal infections) and is the most common coenurosis causing species.

[8][16][5][17] Because this disease so rarely occurs in humans, it took a long time for it to become recognized within the population, and species differentiation among the four different types is still somewhat difficult.

(9) In 1983, a 4-year-old girl in the USA was admitted to the hospital with progressive, generalized muscle weakness, inability to walk, rash, abdominal pain and deteriorating neurological ability.

[2] The most recent North American case took place in 1994 in Los Angeles, CA, when a 39-year-old man presented an enlarging mass on his back.

In all of these recent cases, the infected individuals had been exposed to wild dogs in regions where canid tapeworm is considered endemic, and probably ingested the parasite accidentally through contact with contaminated food or water.