Fatal feline feces: Scientists discover cause for recent monk seal deaths

HAWAII (HawaiiNewsNow) - State officials are now blaming toxoplasmosis, a parasite carried in cat feces, for the deaths of three critically endangered Hawaiian monk seals on Oahu.

The diagnosis means that the recent monk seal deaths were completely preventable, according to officials from the state health and natural resources departments. In addition to being potentially fatal for sea creatures, the parasite is also known to cause serious symptoms in humans with weak immune systems.

Cats are the only known reproductive host of the toxoplasmosis parasite, and officials say a single cat can excrete 145 billion parasitic eggs into its feces a year.

Once released into the environment, toxoplasmosis parasites create cysts in muscle and organ tissues and can cause inflammation of the heart, liver, and brain.

"Feeding cats near water obviously increases the risk of transmission but, given the nature of the watersheds in Hawaii, cats almost anywhere are probably contributing to the problem," said DLNR Chair Suzanne Case, in a news release.

"The cysts can live for months in soil and can wash into streams and runoff and be carried into the ocean from almost anywhere. Feeding cats at state parks, boat harbors and other coastal areas increases the risk of transmission because the cysts don't need to travel very far to get into the ocean," Case said.

"Frankly, feeding cats anywhere where their feces can ultimately wash into the ocean is a problem," Case said.

One of the seals that was killed by toxoplasmosis, identified as RK60, gave birth to a pup on Moku Iki off shore from Lanikai in spring of last year, according to officials.

NOAA says there have been at least 11 documented deaths of the endangered Hawaiian monk seals since 2001. There are currently only 1,400 Hawaiian monk seals on the planet.

"We simply cannot afford to lose even one of these critically endangered mammals to a disease that is preventable," Case said. "We hope people will provide as much love to our few very special seals as they do to the hundreds of thousands of feral cats around our islands."