Poop in compost. Why the danger?

I have been making some compost and it contains some sheep, cat and dog poop. I understand that these substances can contain pathogens, but how can this contaminate my tomatoes? The plant grows above ground. Can the pathogens travel up the plant and into the food? What is the vector?

There’s some info here.

Most sources suggest that herbivore poop is okay to use, though. We toss our guinea pigs’ droppings into the compost with no problems.

So why doesn’t every cat owner that changes the litterbox come down with this? Dog and cat poop are everywhere!

They probably do. Toxoplasmosis symptoms resemble mild flu symptoms in people with normal immune systems. But it can be pretty dangerous for people with weakened immune systems, and can cause birth defects in fetuses. This is why pregnant women are advised to avoid changing the cat litter for the duration of the pregnancy.

Is that the same sickness that that the woo crowd thinks makes us into slaves of our feline masters?

Drives certain sufferers to become circus performers, where they stick their heads’ into the lions mouth.

Toxoplasmosis certainly influences rat behaviour, making some rats actively seek out cat urine (uninfected rats avoid cat urine).

Given that toxoplasmosis infection rates are high (possibly up to 50% of the worlds population) and the disease is generally only a health issue in the immuno-compromised, and has effects related to dopamine and testosterone, it seems likely that there may be some impact on human behavior.

Wiki has decent research-based cites, too. It is not all woo.


The toxoplasma oocysts (which are passed in the cat’s faeces) take around 2 or 3 days to sporulate and thus become infectious. As long as you change the litter on a daily basis (and presumably disinfect the litter tray itself), there is no infection risk.

Not many people, I warrant, will be leaving cat faeces festering for 3 days indoors. At least, I hope so.

I was told by one of the big researchers in feline toxo that he had had plenty of pregnant women working in his lab over the years, and no infection problems - normal hygiene precautions (and not eating faeces) were sufficient.

Man, you really have no idea.

If I think I might be suffering from toxoplasmosis, how would I bring this up with my doctor? I do have a tendency toward hypochondria but I’ve had to deal with litter pans for years and my health is poor.

Ask for a test. However, it appears that toxoplasmosisis a one time infection, and once you’ve been infected, your body will produce antibodies to fight it off in the future. It doesn’t look like a chronic condition.