I have searching information about how to fix this, but no luck so far, only temporary solutions ( like clean up them via master controller....). My game spawn them like crazy, I have to clean up those every few sim hours, cuz it make my game unbearable to play - it lags and often crashes if I forget to do this. So I was wondering if you guys know things better or even can make something to it - like automatic clean up in owerwatch

I've never heard of this issue.  Most jig spam is caused by scripting not finishing due to errors. What kind of pets do you have on the lot? Are you using ErrorTrap? Encountering any errors about idles?

In addition to what Chain mentions, this was a huge issue as I recall when Pets was first released but quite a lot of the incessant by the hour pet jig spawning was later fixed by an EA patch. Is your game all patched up to current levels, meaning 1.67 or 1.69?

My game patched to 1.67
As I remember I always get errors about unroutable sim (usually pet) and I don't know what to do, cuz I get those notifications no matter what I do or where I play. I have tried a lot of different type of worlds and lots, and problems with pets everytime the same....
As for pets,I usually choose small cats or dogs, cuz horse routing is just simply horrible. But even that cause, a lot of problems like routing issues and...those god damn pet social jigs...

There is another reason for incessant pet routing errors I realize we hadn't mentioned, although this won't always be relevant. If your world has many baby animals (puppies and kittens), they can tend to get stuck in places where they shouldn't be because of their inability to use stairs. When I find this happening, I go around using MC to age the baby animals up to get this kind of thing to stop.

Currently no baby animals.
I rarely use them, my pets do not reproduce. So this is not a case in this matter ((