All the above x4

but only one seems to vomit regularly and I reckon she just stuffs her face with catfood even after munching however many mice/birds she's caught and doesn't know when enough is enough

Most of the cat vomit appears to have mouse coloured bits in

I tend to shout "out!" very loudly when the pre-vomit noise starts, or when I hear a certain kind of "look what I've brought" miaow is heard in the kitchen, let alone if I see something being played with in the hall

They get the picture and pickup and leave with the dead thing, but I've had to capture a few live ones and sadly missed a few too so now I have unwanted lodgers which is why I got cats in the first place

I sometimes wonder whether worming cats is worth the hassle and cost - mine are forever hunting mice, rabbits etc and seem to show signs of shedding at least every month

so at what point does the chemical input start to become a health hazard to their innards?

Are injected wormers the answer and would they last longer?