species barrier

species barrier (plural species barriers)

1. (pathology, zoology) The inability of a disease to be transmitted from one species to a different one.
   • 2003 June 3, Sandra Blakeslee, “Mad Cows, Sane Cats: Making Sense of the 'Species Barrier'”, in The New York Times‎, →ISSN:

     The people had died because they ate meat from infected cows. A species barrier had crumbled.

   • 2004, W. Michael Scheld et al., editors, Infections of the Central Nervous System, Lippincott Williams & Wilkins, →ISBN, page 261:

     The species barrier often is not an absolute barrier and refers to the difficulties in the transfer from one species to the next.