Is your cat controlling your mind?

Understanding toxoplasma's effect on humans

- DR. EDSEL MAURICE T. SALVANA

Everybody loves cats. For centuries, man's love affair with these furry felines has gone beyond their utility as a means of eliminating vermin.

In our modern age, the most popular videos that people waste countless hours on are of cats doing silly things. The most beloved memes often involve cats, including one that shows an angry cat in front of a salad. Undoubtedly, cats are beautiful, furry, and affectionate creatures with which most people are more than happy to share their homes. However, unlike dogs, which are loyal and love their owners to a fault, cats can be fickle, temperamental, and act like they own the owner and not the other way around. Despite this, people cling to their cats fiercely, despite all the bite marks and scratches, not to mention the insufferable yowling at night. Is it really their personalities we are in love with, or is there something else going on?

As it turns out, your cat may be controlling your mind through a sophisticated form of biological warfare. It does this by infecting you with a microscopic brain parasite called Toxoplasma gondii. Toxoplasma, or toxo for short, is a protozoan (one-celled organism) that reproduces in the gastrointestinal tract of cats and can infect many animal hosts, including humans. Only cats and related felines are toxo's definitive hosts where it can reproduce and form oocysts, the infectious form of the parasite. Almost all other mammals are just intermediate hosts. Oocysts are subsequently shed in the cat's stool. When a hapless owner cleans the cat's litterbox or said cat rubs its behind on its owner's face, some of these oocysts are ingested or inhaled and infect the human host. These oocysts germinate in the gut of the intermediate host and invade tissues, including the muscles and the brain, where they form cysts.