OMG are there really people who flush cat poo down the toilet and into our drinking water system??? That's really not ok and as PP have said our sewerage system is not set up to remove Toxoplasmosis infection.
Toxoplasma gondii infects almost every single animal on the planet, including humans.
It can only reproduce in cats.
Therefore the parasite will already be in the sewage system, regardless of whether people flush their cat poo or not.
I don’t think you should flush cat poo, regardless of the whether you worm your cat as the litter can cause a blockage over time which is going to cost you a fortune to sort.
My grandads cat did this naturally and it was funny and much more hygienic than a litter tray (which can spread parasites too) but it was quite unnerving walking in on the cat in the toilet or queuing up to use the bathroom.
It also reminds me of ‘meet the parents’ 😂