Sick pets can be annoying, but they're practically IMPOSSIBLE in rotational play

I don't even see why it's a thing, the game will auto-generate brand new illnesses on pets when you're playing as a vet. So to make so many pets in the world sick when not playing on a vet clinic lot is mind-boggling.

What use is that from a gameplay pov ? To level up your vet skill, so every single sim in Brindeton Bay can have access to fresh test subjects just in case they feel like experimenting on that feral cat that was passing by ? Yikes.