Actually it is not Sparganum that causes tumors in dogs, it is
Spirocerca lupi. Wil Bailey et al at Auburn showed that Spirocerca
lupi is associated with sarcomas of the esophagus of dogs that were
infected with this parasite. This syndrome is rarely seen, and it is
my impression that tumors/cancers associated with parasites are rare.
Schistosoma haematobium may be an exception. This parasite causes
egg granulomas in various parts of the body, and chronic irritation
by the eggs might cause cancerous conditions, albeit rarely. The
parasite causes sterility and problems in urination, among other
things, and according to an article published in a medical history
journal, it may have been in Jerico. In fact, that author
essentially said that Joshua destroyed the city and the well
to prevent spread of schistosomiasis into other parts of the mideast.
I have seen the book which is under discussion, and based on my
knowledge of parasites and parasitic diseases of domestic animals, I
think that her "bubble is a little off center."