You literally just summed up the article I linked.

Here's a great PDF highlighting the environmental damage toxoplasmosis causes. Again, 200 million cats in the US alone is why this is such a problem.

Toxoplasmosis is a disease spread by parasites in the feces of cats. It is one of the top threats to the Hawaiian monk seal, killing eight of the remaining 1,400 since 2001

If we're taking conservation seriously, we need to take this problem seriously. Here in the pacific northwest, we are down to seventy four southern resident killer whales. What if we lost five or six whales due to these parasites? What if one or two of those were breeding whales?

It's difficult to determine an exact cause of death with other pollutants in our waterways, but the NOAA considered taxoplasmosis a threat to the endangered southern resident killer whales. Source.