Over 40 million Americans carry a parasite cats can spread. Your dog can bring two more.

CDC says dog and cat poop can carry roundworms and hookworms that infect people, and it tells families not to let children kiss pets. Your pet sleeps in your bed. Here is what can come with it.

The dog jumps up around eleven, turns twice, and settles against your legs with a long sigh. By morning she has worked her way up to the pillow, and her nose is an inch from your face. Last night she spent twenty minutes in the backyard with her nose in the grass, and the cat spent the afternoon in a litter box a few steps from the kitchen.

Most pet owners have never been told that the country's public health agency has specific advice about this. CDC's guidance for pet owners says dog and cat poop can contain parasites and germs that can be harmful to people, and it tells families: don't let children kiss pets or put their hands in their mouths after handling animals.

The cat parasite in 40 million Americans

Toxoplasma gondii is a single-celled parasite, and CDC says over 40 million people in the United States are infected with it. Cats are the animal it depends on. According to CDC, kittens and cats can shed millions of parasites in their feces for as long as three weeks after they are infected. People pick it up by cleaning a litter box and not washing their hands, by eating undercooked pork, lamb or venison, or by eating unwashed vegetables from a garden. Most people with a healthy immune system never notice symptoms, and CDC says the parasite can stay in the body for long periods, up to a lifetime. CDC singles out pregnant women and people with weakened immune systems as the groups who should take extra care.

The two worms dogs and cats carry

Toxocara is the roundworm of dogs and cats. CDC says it spreads to people through contact with the feces of dogs and cats with roundworm, usually by way of soil, and the eggs need one to four weeks in the environment before they can infect anyone. That delay is why a backyard, a sandbox or a garden bed can hold infective eggs long after the dog has moved on. When a person swallows one, CDC's lab manual explains, the larva hatches, goes through the intestinal wall and travels in the bloodstream to the liver, lungs, eyes or brain. Many people never develop symptoms, and the ones at greatest risk of serious illness are young children who play in dirt.

Zoonotic hookworms take a different route. They normally live in dogs and cats, and their larvae burrow into bare skin when someone walks barefoot or sits on soil or sand contaminated with animal feces, leaving itchy red tracks.

Pets are one route among several. The same household also eats rare steak, raw oysters and bagged salad, and CDC links those to beef tapeworm, Toxoplasma and Cyclospora.

What gut parasites do once they're in

Intestinal worms live off the person carrying them. WHO says soil-transmitted worms feed on host tissues, including blood, which leads to a loss of iron and protein, and that they make it harder to absorb nutrients from food. Hookworms attach to the intestines and feed on blood, and WHO links heavy hookworm infection to anemia. Light infections, CDC says, usually cause no symptoms, which is how they go unnoticed.

One clean test can still miss them

The standard check for gut parasites is a stool exam, and CDC's laboratory guidance asks for three specimens collected two to three days apart when possible, because parasites and their eggs don't turn up in every sample. Strongyloides is harder still: CDC's lab manual says even serial samples are not always sufficient, because the worm load is often low and stool microscopy has low sensitivity. Toxocara doesn't show up in stool at all in people, because the larvae never grow into adult worms; CDC's lab manual says it is diagnosed with a blood test. A single normal result tells you less than most people assume.

3 signs people link to gut parasites

If your pets share your bed, your couch and your kitchen floor, you may wonder what exposure would feel like. Each of these signs has many ordinary causes, and most people who have them do not have parasites. They are simply the signs CDC and WHO describe in their own fact sheets, and the ones people most often connect to a parasite.

If any of these has gone on for weeks, talk to your doctor. A doctor can order the right stool or blood test, and that is the only way to know what is actually going on.

Why a parasite cleanse runs for weeks, not a weekend

Pet parasites run on a slow clock: cats shed Toxoplasma for up to three weeks, and Toxocara eggs need one to four weeks in soil before they can infect.

Parasites reproduce on a calendar of weeks and years. According to CDC, a female Ascaris roundworm can produce about 200,000 eggs a day, the adults live one to two years, and the eggs need 18 days to several weeks in soil before they can infect anyone. A beef tapeworm sheds about six segments a day, each holding up to 100,000 eggs, and it can keep doing that for years. Cyclospora usually takes about a week to cause symptoms, and the illness can run past a month, fading and returning along the way.

Because the life cycle is measured in weeks, people who decide on a parasite cleanse plan it as a routine of several weeks, taken at the same time every day, rather than a two-day reset they forget about by Tuesday.

You don't have to wait for a diagnosis to think about your gut routine

Keep your pets' vet visits on schedule, pick up after the dog and scoop the litter box daily, wash your hands after both, and wear shoes in the yard. Those habits lower exposure. Plenty of owners also add a gut routine of their own without waiting for a lab result, since a family that shares a bed with its pets also shares the yard.

From the JevityRx team

The parasite cleanse we make

JevityRx makes a parasite cleanse called Para Cleanse, and since this journal is published by the company that sells it, you should know that before you read further.

Para Cleanse is a 10:1 liquid extract of seven botanicals: black walnut hull, wormwood, clove bud, pumpkin seed, pau d’arco, garlic and oregano, all named on the front of the vial. People who research herbal parasite cleanses tend to come across these names, and most of them end up ordering several products from different sellers, with different labels and no easy way to compare them. Para Cleanse combines all seven in one dropper from one company, sold as a dietary supplement.

How to take it: one full dropper (2 mL) in water once a day, at the same time every day so it becomes part of your morning instead of something you have to remember. Check with your doctor before you start if you are pregnant or nursing, take any prescription medication, or have a medical condition.

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