endoparasitic

from WordNet (r) 3.0 (2006)

endoparasitic
    adj 1: of or relating to parasites that live in the internal
           organs of animals

from The Collaborative International Dictionary of English v.0.48

Endoparasite \En`do*par"a*site\, n. [Endo- + parasite.]
   (Zo["o]l.)
   Any parasite which lives in the internal organs of an animal,
   as the tapeworms, Trichina, etc.; -- opposed to
   {ectoparasite}. See {Entozo["o]n}. -- {En`do*par`a*sit"ic},
   a.
   [1913 Webster]