Do not need to worry about it effecting people or pets.
Why would that be? If mice can't stand it, I'd expect dogs and cats would react the same way. Young dogs have unusually good hearing; one of my dogs became quite deaf as she got older so I don't suppose she would have minded it.
On a more general note (yes, pun was intended) I wouldn't immediately dismiss the idea that we might be bothered by sounds we can't hear. It might have quite subtle effects, anxiety and blood pressure changes are 2 I'd immediately look for. But you'd have to do some fairly large "double blind" studies to find out.
[Double blind means that neither the subject nor the investigator knows whether a given "inaudible sound source" is real or fake. The placebo/nocebo effect is very large, maybe 15%. That's right, as much as 15% of the population feel much better on sugar pills, and a similar percent get all sorts of symptoms from sugar pills.]