Sonoma County public health officials are weighing the extraordinary step of urging people and their pets to avoid the Russian River after a dog that died moments after swimming in the water last Saturday preliminarily tested positive for a lethal toxin produced by blue-green algae.
Such an advisory, which likely is without precedent, could come on the eve of one of the busiest weekends of the year at the river, when thousands from across the Bay Area and beyond are expected to take advantage of a late-summer heat blast to enjoy leisure time at beaches and hotels, restaurants and other establishments catering to visitors.
Officials have been monitoring the Russian River for about a month after the discovery of potentially toxic blue-green algae in the river, found almost exclusively along shoreline areas in shallow and slow-moving water. The discovery prompted the Sonoma County Division of Public Health to issue a public warning Aug. 21 urging people to take precautions, including avoiding the algae and washing after exposure to river water. Warning signs were posted at several beaches.
But the rapidly evolving situation took a dramatic turn late Thursday after officials received preliminary results of tests on a 3-year-old golden retriever that died while on a floating trip north of Wohler Bridge. The preliminary results indicate the dog, which suffered symptoms that included seizures and foaming at the mouth, was infected with a toxin produced by blue-green algae.
Officials say they don’t know where the dog may have come into contact with the algae, whether it was in the river or another water source. But they also acknowledged Thursday that their monitoring efforts to date have been focused on a different toxin than the one found in tissue samples of the dog. Virtually no water testing has occurred in the area where the dog died.
Officials are now scrambling to revamp the testing process, taking additional water samples at points along the river Thursday and sending the samples to labs outside Sonoma County. Those results are not expected until after the holiday weekend.
“Here we’ve been sampling for the presence of this very lethal toxin, and it turns out that it wasn’t the one that did in this poor dog,” said Clayton Creager, watershed stewardship coordinator with the North Coast Regional Water Quality Control Board. “We’re left without a lot of information and a lot of uncertainty related to something that potentially could be worrisome for pet owners and even children.”
He said, based on the new findings, officials are considering advising people to avoid getting in the river. Creager was planning to confer Friday morning with officials from county public health, the lead agency responding to the algae outbreak.
Dr. Karen Holbrook, the county’s deputy health officer, said late Thursday that she would be awaiting final test results on the deceased dog before deciding what her recommendation will be for people and animals interacting with the river, if at all.
“We want to protect the health of animals and people using the river, but we also don’t want to act on information that’s incorrect or preliminary,” she said.
She said the next steps beyond issuing advisories could include the county restricting access to the river, including beach closures. Holbrook called those actions “extreme measures.”
“Typically we like to get people the information and have them make an informed decision. It’s a pretty big deal to close beaches and close the river,” she said.
Should officials decide upon new actions, they would have to move quickly to inform people arriving in the river area for the holiday weekend. Creager acknowledged the potential ramifications to the local economy should the county advise people to avoid the river.
“It’s a very difficult situation to be in,” he said.
County officials did not publicize news of the dog’s death, nor the fact they are investigating the circumstances surrounding it. The news has been circulating widely via word-of-mouth and on social media sites.
The golden retriever was on a float trip Saturday with its owners hosted by Russian River Adventures, according to Don McEnhill, executive director of Russian Riverkeeper.
He said the owner of the company contacted him Saturday to report the dog’s death, which occurred on the river between the city of Healdsburg and Wohler Bridge.
“The dog started panting, foaming at the mouth and shaking like it had some muscle tremors. Then it stopped breathing. It sounded like it was a very rapid death, unfortunately,” McEnhill said.
McEnhill said he contacted county health officials to urge them to take custody of the animal for the purposes of having it tested. Healdsburg Animal Control stored the dog’s body over the weekend. It was then transported on Monday to the California Animal Health and Food Safety Lab at UC Davis, which has been conducting the tests.
Creager said the test results showed the presence of Anatoxin-a, which attacks the central nervous system of mammals. The toxin can be so lethal that it’s earned the scary moniker “VFDF” — short for “Very Fast Death Factor.”
The most common toxin produced by blue-green algae is microcystin, which attacks the liver. Creager said the monitoring program on the Russian River has been focused on that toxin because the algae that supports its production was found along the river, in algal mats hugging the shoreline.
He said water tested in early August in the area where the dog died did not uncover the presence of algae more commonly associated with Anatoxin-a. More recent monitoring has focused further south and west on the river, particularly in the Monte Rio area after reports of dogs taking ill after swimming there.
Dogs are particularly susceptible to the toxins because they tend to ingest water while swimming and also through grooming. They often slurp up algae while playing in the water.
But officials acknowledged the challenges of how to advise river users given evolving standards on what constitutes an actual threat from blue-green algae, which is widely present in rivers, lakes and reservoirs. This is the first time that so-called “nuisance” algae has ever been detected in the Russian River, further underscoring those challenges.
Blue-green algae tends to collect in mats or scums near the water’s edge, mixing with other, harmless green algae. Ingesting the algae can release toxins that can cause a variety of symptoms, including irritation of the eyes, nose, mouth and skin, gastrointestinal symptoms, muscle tremors, seizures and difficulty breathing.
So far, the blue-green algae in the Russian River containing potentially harmful levels of toxins have been confined to algal mats along the shoreline. Tests of water drawn from deeper river locations has not uncovered potentially harmful levels of toxins.
Blue-green algae toxicity is an inexact science based largely on tests of dried algae and factors such as water temperature and nutrient levels. Experts believe California’s lingering drought has exacerbated conditions ideal for nurturing problem algae, including in the Russian River.
“This is a natural phenomenon made worse by global warming,” Creager said. “As temperatures rise, we are going to see more blue-green algae. I guarantee you this is going to be a problem throughout the country.”
He said the regional water quality board also is investigating whether managed water flows on the Russian River to protect Coho salmon might also be contributing to the growth of toxic blue-green algae.
On Thursday, two biologists with the Sonoma County Water Agency took water samples of brackish water near the Monte Rio beach to measure the amount of blue-green algae cells. But nothing they found was cause for alarm.
“They are ancient, ancient organisms,” said Keenan Foster, a principal environmental specialist for the water agency, who waded into the water in shorts and sandals and handled green algae with his bare hands. “We don’t totally understand how they work.”
It’s that uncertainty that is sparking anxiety among people who monitor the river’s health, and for those who enjoy it recreationally.
Staff at a Santa Rosa veterinary clinic this week reported that a dog treated there died in late July under “highly suspicious” circumstances possibly tied to exposure with blue-green algae. The death apparently was not reported to county officials.
A third dog that was treated at Memorial Beach Veterinary Hospital in Healdsburg for possible exposure to toxins was transferred to another facility, where it died, according to Marty Shafer, a veterinarian and the owner of the Healdsburg clinic.
Shafer said she doesn’t know if the cause of the dog’s death was ever definitively determined. Nevertheless, she is advising dog owners to not let their pets go into the river if they know the dog will consume water — a fact she acknowledged pretty much applies to all dogs.
“As a veterinarian, we’re usually hyper-protective of our pets,” she said.
Other veterinarians echoed those concerns.
“I would not be taking them (dogs) swimming in the river right now even if it looks clear because it’s potentially deadly. I just wouldn’t take the risk,” said Rhonda Savage, a veterinarian and vice president of the Redwood Empire Veterinary Medical Association.
A warning posted on the website for Russian River Adventures this week stated the company was “highly discouraging” people from bringing dogs with them on trips. An employee who answered the phone Thursday declined comment.
McEnhill said he, too, will be leaving his dogs behind during excursions to the river.
“I don’t want to have to look my kids in the eye and tell them their dog died,” he said.
At the river Thursday, a number of dogs frolicked in the water at beaches in the Guerneville and Monte Rio area. None of their owners said they were aware of the algae outbreak, despite warning signs posted by the county near pay stations in beach parking lots.
Jill Castrella, who recently moved to Santa Rosa from Carson City, Nev., said she chose Sunset Beach Thursday to exercise her chocolate labrador retriever, Hershey, over an ocean alternative because drinking seawater tends to make the dog sick.
“I didn’t think I’d be handing her a death sentence,” said Castrella, as she wiped the dog off with a towel.
But at Monte Rio beach, John Reimann of Oakland did not let news of the algae stop him from going in the water with his dog, Sugar.
“There must be hundreds of dogs that come down here. I’d hate to not let her in the water,” he said.