Cats actually take a few parasites, a few fleas and some diseases and a few can turn serious however, not many. If pet cats were causing too much sickness they might not have invaded our lives as well as they may have. But there are still people out there who do not like cats. When I first went to China about twenty years ago there have been very few cats living with people and incredibly few wild pet cats. I was astonished because I've had cats all my life and I never thought people didn't like cats. But in China people said cats carried disease and this was it. I feel that may have something to do with that cat sick you get in your eyesight. Not serious just a moderate problem for a week In case you were pregnant you'd to keep away from cats. I think they were referring to toxoplasmosis, but if you get that when you are a kid it will not affect your baby. They also said cats were soiled but I don't think so. I think felines are one of the cleanest house animals you could have. I think that originated from the cats getting rid of the rats and mice. Because rats are extremely dirty pets then because the felines wiped out and ate them they will also be dirty. A dusty by connection kind of thing. Also there have been some big sewer rats running round throughout the day. Once I observed a rat and a cat face off one another and the pet cat wasn't much bigger than the rat. These were about a feet apart staring the other person out and the cat ran away. I'm not amazed the rat's pearly whites were bigger that the felines.
Then the nine lives of the humble feline who only wanted to help mankind by killing rodents that taken disease took a serious change for the worse during the dark ages. Where witch hunts and burning up at the stake were typical. A person who didn't like cats somehow connected those to witches plus they were burnt at the stake with there owners. How they made that connection I'll never know. It started off with Pope Gregory IX in the 1232 who regarded the common house kitten as diabolical. Then to make matters worse in1484 along came up the greatest kitty killer of all time, Pope Innocent VIII, who decreed something along the lines of all cats originated from hell and should returned to the fires of hell by fireplace. Felines were mercilessly prosecuted and were burnt so they might return to the fires of hell. It really is amazing any survived because if you were caught with a pet cat you were burnt mutually. I still go to cathedral and sometimes I simply wonder why. And of course the Black Death was in the background surviving and flourishing because there were no felines to eliminate the rats that carried the fleas that triggered the condition. Then along came the cat's savior Ruler Louis XIII of France, who in the 1630s repealed regulations and cats once again started to live. However they were still hated and killed for many generations from then on. I don't know if the Dark colored Loss of life subsided but cats once again covered mankind contrary to the diseases taken by rodents. And the famines brought on by mice plagues.