- Lake County News reports
- Posted On
County receives final test results on dog that became ill after swimming in lake
LAKEPORT, Calif. – Lake County Public Health has received final reports of testing done to investigate the cause of an illness developed by a dog after swimming in the Konocti Bay area of Clear Lake at the end of July.
The dog later had to be euthanized and local officials arranged for a state lab to test several types of tissue specimens for microcystins (a type of cyanotoxin), leptospirosis and amanita mushroom poisoning.
Public Health Officer Dr. Karen Tait said the tests did not confirm any of the above to be the cause of the illness which led to the dog’s death.
“The recent tests show that while we can't affirmatively prove that toxins caused this dog's disease, we have an association of an unsafe level of toxin in the water where the exposure occurred and a clinically compatible illness consistent with cyanotoxin illness without another explanation,” Tait said.
Many if not most species of cyanobacteria – often referred to as blue-green algae – do not produce toxins and some produce toxin only intermittently and unpredictably, according to Tait's report.
In addition, laboratory test methods are readily available for only a few of the possible cyanotoxins, she said.
Tait said these scenarios make study of cyanotoxins and direct linkages to related illnesses difficult and illustrate the necessity for an increased awareness by the public, health care providers, veterinarians and local officials related to potential dangers to toxin exposure from cyanobacteria.
The high level of microcystins in the area where the dog was swimming gives rise to continued concerns about exposure to cyanotoxins leading to illness, according to county officials.
The sample taken from the area where the dog played detected elevations of several types of microcystins totaling 395 ppb, which was well into the range (20 – 2,2000 ppb) considered by the World Health Organization to be unsafe for recreational water, the county reported.
Officials said extreme care should be taken when the potential for exposure to humans or pets exist.
The elevated microcystin level in the water sampled from the area where the dog played was far in excess of any other measurements taken to date in Clear Lake, Tait reported.
Although this appears to be an isolated and unusual elevation, more information is needed to determine what conditions might have led to the increased toxin and whether the high level will persist or could be found under similar conditions elsewhere, according to the report.
The county reported that samples of water from the area have been submitted for repeat testing and other sites around the lake were recently sampled.
Public areas that meet recommended criteria for posting of health advisories or warnings will continue to be posted, but certain guidelines should be followed regardless, officials said.
A few recommended precautions include:
- Avoid contact with water in areas with surface foam, scum, or a pea soup appearance, especially in areas with little current or wave action. This is particularly important for small children and pets.
- Avoid generating aerosols (water skiing, jet skiing, etc.) in areas of the lake where there are signs of blue-green algae.
- After swimming, towel off promptly. Even better, shower with fresh water. After pets swim, rinse with fresh water and towel them dry to prevent them from ingesting the blue-green algae while self-cleaning.
- Never drink untreated lake or other surface water. Boiling water does not guarantee that it is safe to drink. If your household water system draws water from a lake, bee sure that it is properly maintained.
- If unexplained illness develops following direct exposure to water in a lake, pond, or stream, see a doctor (or bring your pet to a veterinarian) promptly and be sure to mention the exposure that occurred.
For more information, see http://www.co.lake.ca.us/Government/Directory/Environmental_Health/Blue-Green_Algae.htm or http://www.cdph.ca.gov/healthinfo/environhealth/water/pages/bluegreenalgae.aspx .