The Truth About Pet Cancer (TAPC) is a slick bit of propaganda. Although it contains some interesting, even promising ideas, these are unfortunately served with a heavy seasoning of misinformation and fear-mongering. Hypotheses and opinions are presented as established facts, and anyone who disagrees is suggested to be ignorant at best, venal and corrupt at worst.
Every natural pet health website has their recommendations for flea treatments that don’t use harsh chemicals. The evidence for their claims is nonexistent. It’s appropriate that they’re talking about parasitic organisms, but I don’t think they see the irony.