A spurious parasite, according to Maruice C. Hall (1), is anything which is not a true parasite, at least in the host in which it is found. For example intestinal parasite ova of chickens can often be demonstrated in the feces of farm dogs who have been eating entrails of infested birds.
Sloss, M. W.
"Spurious Parasites in a Dog,"
Iowa State University Veterinarian: Vol. 1
, Article 8.
Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol1/iss2/8