Cindy and I were sitting in our hot tub the other night, talking with a couple of friends from England, when the topic of cat ladies came up. That was probably because my friend Daniel is the quintessential cat lady. I asked, “Do you know about the theory of toxoplasmosis being the cause of cat ladies?” Dan asked, “Toxo what?” After explaining it to them, I realized that not many people know about this, so here goes.
Toxoplasma gondii is a parasite that reproduces only in cats and gets distributed in cat poop as cysts. The lifecycle of the parasite depends on it getting ingested by, and thereby infecting, other warm-blooded creatures, where it wreaks various forms of neurological havoc. The parasite can be acquired by humans through undercooked food or through handling of cat poop (such as when cleaning a cat litter tray).
The parasite can also be passed from a human mother to her child during pregnancy. If an unborn fetus gets infected by the toxoplasma parasite then it may die or end up severely brain damaged. This is the reason that pregnant ladies are instructed by their doctors to not empty cat litter trays or dig around in flowers beds while doing gardening; cats like to poop in flower beds.
The natural life-cycle of the toxoplasma parasite includes a rat eating the poop of an infected cat. When the rat gets infected, the parasite…
