A healthy, indoor domestic cat is not very likely to be actively shedding Toxoplasma gondii, but many cats have been infected at some point. The key distinction is between having antibodies (past exposure) and shedding oocysts (actively contagious).
🐱 How common is toxoplasmosis in domestic cats?
Different studies show wide variation depending on region, lifestyle, and testing method:
- Seroprevalence (past infection):
Many cats worldwide have antibodies, meaning they were infected at some point. Global estimates range from 20–50% in domestic cats, depending on the country.
Example: A study from China found 20.3% of pet cats had antibodies. - Active oocyst shedding (the contagious stage):
This is rare. Cats typically shed oocysts only once in their lifetime, for 10–14 days, after their first infection.
A global estimate puts active shedding at around 2–3% of cats at any given time. - Indoor cats:
Indoor-only cats that do not hunt and do not eat raw meat are unlikely to ever become infected.
🧪 Why “infection” doesn’t equal “risk”
Cats can test positive for antibodies (meaning they were infected before) but are not shedding and therefore not a risk to humans.
- High IgG = past infection, not shedding.
- High IgM = recent infection, possible shedding.
Most household cats with past exposure are not dangerous to owners.
🧍♀️ What increases a cat’s chance of infection?
- Outdoor access (hunting rodents or birds)
- Eating raw meat
- Contact with other cats
- Poor nutrition or immune suppression
Indoor cats without these exposures have very low risk.
🧑⚕️ What this means for you
If your cat is healthy, lives indoors, and eats commercial food, the chance it currently has active toxoplasmosis is low. If you’re pregnant or immunocompromised, it’s still wise to:
- Clean the litter box daily (oocysts need 1–5 days to become infectious)
- Wash hands after handling litter
- Avoid feeding raw meat
If you’re concerned, a veterinarian can run IgG/IgM blood tests to check your cat’s status.