Posted by on February 23, 2005 at 16:54:08:
In Reply to: Sea otter may be first in Alaska infected with harmful parasite posted by on February 22, 2005 at 21:50:42:
TOXOPLASMA: Lethal disease linked to feline feces turns up in a Resurrection Bay otter.
By DOUG O'HARRA
Anchorage Daily News
Published: February 23rd, 2005
Last Modified: February 23rd, 2005 at 03:53 AM
A sea otter found injured in Resurrection Bay last month tested positive for a lethal parasite that has infected or killed hundreds of California sea otters in an outbreak blamed on domestic cats.
This appears to be Alaska's first confirmed case of an otter sick with Toxoplasma gondii, a protozoan that matures only inside cats and spreads through their feces.
The otter is under care at the Alaska SeaLife Center in Seward.
The parasite generally doesn't threaten healthy adult people and doesn't appear to spread otter to otter, say scientists and health officials involved in the case. But pregnant women are urged to avoid cleaning cat litter boxes because exposure to the parasite could harm a developing fetus.
"A large percentage of cats either have it or have been exposed to it," said veterinarian Carrie Goertz, rehabilitation manager at the SeaLife Center. "Up to about 50 percent of people, if you test them, will have antibodies to the disease."
How an otter caught the bug in the ocean near Seward isn't known, but scientists and local people have some guesses.
While birds and rodents can temporarily carry the parasite, only cats shed its immature eggs in feces.
The disease in California has been linked to places with rivers and storm drains, where cat poop gets washed into runoff and inserts the parasite into the food chain.
The same thing could have happened in Seward, especially if someone disposed of cat litter improperly on the beach, said W.C. Casey, Seward public works director.
The parasite can then concentrate inside clams and other bivalves, favorite food for otters. Once inside an otter, the parasite can lead to a deadly infection in the brain, Goertz said.
"We hope it's a localized case, but the fact that toxoplasmosis has appeared here in Alaska is just one more hit for Alaskan sea otters," Goertz said.
Biologists don't think the disease is likely to appear along remote coasts without a ready source of domestic cat droppings, said sea otter biologist Angela Doroff with the U.S. Fish and Wildlife Service: "It's more like a point-source contaminant. It's not necessarily that we're concerned about sea otters Alaska-wide."
Sea otters along the Alaska Peninsula and Aleutian Chain have crashed in number over the past few years and may soon be listed as threatened under the federal Endangered Species Act. But Gulf of Alaska otters appear stable, Doroff said. Probably fewer than 100 sea otters forage in Resurrection Bay near Seward.
State health officials don't plan to issue special warnings for shellfish in Resurrection Bay, but testing might be a good idea, said Kristin Ryan, director of the state Division of Environmental Health.
"It would be very difficult to determine at this point if there is any level of concern, because we don't know how the otter got the toxoplasmosis," she added. "We need to do some further investigation to see what's going on."
The otter, an adult male nicknamed Uno for the popular card game, was found on Jan. 29 on the shore near Seward's skate park with a broken rib, plus puncture wounds and broken bones in its right front paw.
What hurt the otter isn't known, Goertz said. But the animal was recovering from the injuries at the SeaLife Center when rehab staff noticed it would "zone out" into a stupor while floating in its tank, a symptom of neurological problems that could be caused by the parasite.
Multiple tests by experts at the University of California Davis confirmed the presence of antibodies to Toxoplasma, she said.
The animal could recover after treatment with antimicrobial drugs, but the danger of a relapse might prevent its return to the sea.
A sick otter would quickly die in the wild.
"We can clinically get him better, but there's always the chance he could still have it," Goertz said.