a group of animal diseases caused by different species of parasitic tapeworms of the genus Avitellina. The developmental cycle of these parasites has not been studied.
Avitellina tapeworms parasitize in the small intestine of ruminants. They reach a length of 3.5 m and a width of 2.2 mm. In the USSR, avitellinosis occurs in sheep and camels in the Middle Asian republics, Kazakhstan, Transcaucasia, Moldavia, and the Southern Ukraine; it also occurs in reindeer in the Far North. Infection of lambs begins in the midsummer of the year they are born. Infections and loss of livestock from avitellinosis are most widespread in fall and spring. The symptoms of the disease appear suddenly. The diseased animals exhibit impaired coordination of movements, retraction of the head, leg spasms, gnashing of teeth, drastic inhibition, and sometimes diarrhea. The symptoms last several hours and end in the death of the animal. Treatment and preventive measures have not yet been developed. In farms with a history of avitellinosis, the lambs are dewormed on instruction of veterinary personnel.