Why do people love cats and what does parasites have to do with it?

Do you love cats? The inhabitants of ancient Egypt, for example, simply adored them. Along with hieroglyphs, obelisks, and geometric patterns, cats figured prominently in art and reflected their unique status: the animals helped control pests and eventually became a symbol of divine help and protection. This is confirmed archaeological finds of mummified animals – Egyptian rulers wrapped pets in golden costumes and allowed them to eat from their plates. It was believed that the souls of the dead moved into the bodies of mummified cats, and the gods often appeared to mortals in cat form.

But cats were loved not only in ancient Egypt, these animals were an integral part of the culture of Mesopotamia, Persia, India and Rome. Not much has changed these days: cats are still popular. And if you believe the statistics, most of all the mustachioed-striped people love the inhabitants of the United States, China and Russia. But what is the reason for this love? And why is suspicion increasingly falling on a microscopic parasite called Toxoplasma gondii?

Furry friends

If you love cats, then you know how much joy these four-legged creatures bring to everyday life. On social networks, videos and photos with cats collect thousands of views and likes, and users are increasingly creating Instagram and Tik Tok accounts for their pets. But what is the reason for such popularity? After all, modern cats do not catch mice, birds and snakes, and hunting is replaced by games with “candy wrapper on a string.”

The Indy100 portal (a project of The Independent newspaper) calculated the approximate number of cats in the world.

Let’s start with the fact that cats are good for health: a number of scientific studies show that their owners are less likely to die from a heart attack and stroke. Lowering blood pressure, reducing stress, and releasing oxytocin (the hormone associated with feelings of love) are also credited to purring pets. In addition, cats are unpretentious in their care and enjoy spending time alone with themselves.

But what about “crazy cat people”? Where do they come from? The best embodiment of this stereotype is Dr. Eleanor Abernathy from The Simpsons, who lives with 40 cats and constantly throws them at people. Alas, experts in the field of neurology confirm the grim reputation of cats: Toxoplasma affects the human brain.

The best cat lady in history

Why do we love cats

Scientists have been studying Toxoplasma gondii for years, a parasite that is hosted by all members of the cat family. Once in the body, it travels to the intestinal cells and forms oocysts, which enter the environment along with feces. Intermediate hosts are usually small rodents – Toxoplasma skillfully manipulates their behavior, forcing the unfortunate to do everything to be caught and eaten. The trick is that in infected mice, the reaction to the smell of cat urine changes – it begins to attract them.

The results of the studies also showed that the proximity of cats to other mammals changes the behavior of the latter. In the human population, Toxoplasma threatens pregnant women (causing congenital abnormalities of the fetus) and affects the brain, leading to the formation of abscesses in it. In persons with reduced immunity, toxoplasmosis acquires a severe course.

Researchers have also shown that the parasite can exacerbate schizophrenic patients.

Most often, infection occurs through contact with cat feces, but can also be transmitted through raw or undercooked meat (mainly pork). This parasite is so successful that those infected remain its carriers forever – to date, there is no cure for toxoplasmosis, as well as a vaccine.

The results of a study recently published in the journal Nature showed that the presence of Toxoplasma in humans is associated with diseases such as schizophrenia, depression, psychosis and BAD (bipolar affective disorder). More than four thousand people took part in the work.

Previously, researchers have found that the parasite likes the eyes (mainly the retina), and ophthalmologists have long been treating ocular toxoplasmosis, which reduces vision in more than 50% of cases, and threatens blindness in 25%. To diagnose the disease, a retinal examination and a detailed blood test are necessary (the diagnosis can be made on the basis of a thorough clinical examination and positive results of serological and allergic reactions).

Toxoplasmosis makes people beautiful

There is something else interesting in this story. It turned out that this single-celled parasite makes people beautiful . In a paper published in the journal Brain, Cognition and Mental Health , the researchers concluded that the parasite can directly alter the characteristics of the host’s face and body, increasing their chances of having offspring. It seems to be the worst beauty industry in history.

Composite images of ten infected men and women (left) compared to ten uninfected men and women (right).

Infected subjects turned out to be more attractive in almost everything: the faces of infected men and women are more symmetrical, and they have more sexual partners than those who have not encountered the parasite. According to available data, about a third of the world’s population is infected with toxoplamosis, but most are unlikely to ever know about it.

Where did the love for cats come from?

Researchers believe that whole cultures were formed under the influence of Toxoplasma: exposure to the parasite could explain the love of cats among the ancient Egyptians and the French passion for raw meat dishes. This is due to the increased synthesis of dopamine in the brain, the effect of which is comparable to that of a drug.

However, this should not be surprising: such parasites in nature are not an exception, but rather a pattern. So, in 2020, scientists announced the discovery of a new species of wasps that can turn their victims into zombies. Another example is the parasitic fungus Ophiocordyceps, which takes control of the ant’s muscles and controls its movements.

But even if the love of cats is indeed caused by a parasite, there is nothing we can do about it. It remains to be hoped that a couple of mutations will not cause a zombie apocalypse (yes, this is possible). In the meantime, it’s relatively calm around, let’s continue to enjoy communication with cats, friendship with which has lasted for more than 12,000 years.