Why Cat Poop Can be Dangerous (Toxoplasmosis)

By Melissa Brett, Guest Blogger

Welcome to my first blog post. I thought I’d take a stab at a topic that came up when I was pregnant that seems to have a lot of misconceptions surrounding it. Specifically, what is toxoplasmosis, who is at risk of contracting it, and how can I protect myself? Read on for answers to these questions, and more!

So what is toxoplasmosis, you ask? It’s a parasite. According to the Centre for Disease Control (CDC), Toxoplasmosis is the leading cause of death in the United States from food borne illness (as of 2014). For the Immunocompetent (ie. people with a normal immune system), it is possible to carry the parasite and not suffer any ill effects other than the possibility of short-term, flu-like symptoms that resolve without treatment. Not so lucky are those who are pregnant, and/or immunocompromised (as in those living with AIDS or organ recipients). For these subjects, toxoplasmosis can result in severe consequences, including death.

There are several different ways to “catch” Toxoplasmosis. Human infection is usually a result of ingestion of undercooked or raw meats. Lamb and pork are the most likely sources, but in some instances beef and game meats have also been identified. These meats must contain cysts, or carry little things called oocytes that are excreted in the feces of infected cats. So if you own a housecat, odds are, you have likely come in contact with the parasite. How does Mittens the friendly cat get Toxoplasmosis? She roams around outside and eats a yummy field mouse who is the definitive host of the parasite, then, voila! Now Mittens has been infected (likely without any symptoms) and will start shedding the oocytes into the litter box for you to scoop out. You breathe in these tiny organisms that might be floating in the air while you scoop, or you neglect to wash your hands after, and now you’re infected as well. As mentioned, you might feel unwell for a couple of days if you are a healthy person, and then symptoms will disappear on their own. If you were to get a blood test done, it would show that you have been exposed to the little critters and are now colonized.

In some countries where cats are allowed to roam freely around farms where consumable livestock are raised, the rates of toxoplasmosis are high if meats are served less than well-cooked as in Mexico and Brazil. Drinking unfiltered water or consuming unwashed vegetables may also lead to infection by ingestion if cat-shed oocytes are present.

So how will this affect you if you’re pregnant? In the case of congenital transmission (mother-to-baby in utero), little risk is posed to the fetus if the mother is a carrier of toxoplasma. If the mother contracts toxoplasmosis infection during pregnancy, or within 3 months of conception, the parasite can cross the placental barrier and infect the fetus. Early infection can result in severe toxoplasmosis causing death of the fetus and spontaneous abortion.

It has been suggested that cooking meats for longer duration at higher temperatures will decrease the spread of toxoplasma, as well as keeping the barn cats away from the livestock. If you are looking to adopt a cat (which I highly recommend!), and you’re pregnant, have someone else scoop the litter box for now.

About the Author: Melissa Brett is a Registered Nurse working in Infection Control in Ottawa, Canada. She is currently doing her Master’s in Global Health and Infectious Disease. A lover of animals – Siamese cats especially – she is a champion for animal and human preventative health.