Well, I don't know much about cat and dog worms presentation in people....other than they are something we really don't want our pets having due to their zoonotic nature. Some people apparently can ingest the eggs, have an infection, have very few symptoms and it runs it course. However, in some people some more concerning outcomes are possible, and those are not something I will write here. You are right, It is VERY rare to get these toxicaris infections, really really rare...and very unlikely. I want to remind though, that there are articles that claim a long-term chronic infestation of pin/thread worms can mimic bowel disorders like Chron's. There are also many documented cases of hookworm infestations in human beings, and they definitely DO cause blood in stools, changing bowel habits that are like IBS. Also, very rare here it seems (just read) but WHY WOULD YOU BE TAKING the risk not to treat them?
Everyone else is probably bored senseless with this lonnnnggggg discussion of intestinal parasites....if they've even bothered to read it.