Monk seal deaths on Oahu linked to parasite found in cats

HONOLULU (AP) — The three monk seals found dead on Oahu last month were killed by the parasite found in cat feces, Hawaii officials said.

National Oceanographic and Atmospheric Administration veterinarians determined that toxoplasmosis caused the deaths of two adult female seals and a female pup that were found dead in the span of a week on Oahu in mid-May, officials said.

Cats are the only known host of the parasite, which reproduces in the animal’s digestive system, according to the state Department of Land and Natural Resources and the state Department of Health. The parasite can infect other species, including humans.

“In addition to impacting marine mammals and wildlife, toxoplasmosis is a risk to humans,” said Bruce Anderson, the state health director. “It is known to cause serious problems for pregnant women and their unborn children.”

The parasitic disease can create cysts in muscles and organs and can cause inflammation of vital organs. During pregnancy, the toxoplasmosis can cause miscarriages or birth defects.

“The only thing certain about toxoplasmosis is that there are far more cases in humans and more deaths in seals, dolphins, native birds and other animals today than are recognized and reported,” Anderson said.

Feeding feral cats, especially in state parks and coastal areas, increases the chances of the parasite spreading, said Suzanne Case, the chair of land and natural resources.

“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,” Case said.

NOAA officials have attributed at least 11 deaths of endangered monk seals in Hawaii to toxoplasmosis infections since 2001.