Prevent Illness from Blue Green Algae Toxins
Published: August 4, 2016
TO: SONOMA COUNTY VETERINARIANS
FROM: KAREN MILMAN, MD, MPH, HEALTH OFFICER
QUESTIONS: DISEASE CONTROL UNIT – PUBLIC HEALTH (565-4566)
CC: PLEASE SHARE WITH ALL STAFF
During the summer of 2016, the Department of Health Services (DHS) and our partners have been monitoring the Russian River for conditions that could support algal blooms, which may include blue-green algae. We have been looking at water temperature as well as information from visual monitoring (e.g., algal mats, stagnation,
changes in wildlife, etc.). Beginning the week of August 1, DHS began quantitative testing for blue-green algae toxins. The results indicate that low levels of blue-green algae toxins (specifically anatoxin-a) are present in certain areas of the river. In accordance with state guidance, these low levels are enough to
trigger the posting of “Caution” signs. Although there are currently no restrictions for recreational use of the Russian River, potentially harmful algae may be present. Care should be taken to keep children and pets away from algae, and prevent them from drinking river water. Dogs like to eat things and
are known to preferentially seek out blue-green algae. Dog owners should be aware of this in deciding how they supervise their dogs. Veterinarians are requested to promote awareness and healthy water habits and to be alert for possible cases of toxin mediated illness in pets that are exposed to the river.
Actions Requested of Veterinarians
1. Be alert for and evaluate potential cases of blue-green algae toxin mediated illness:
- See clinical description below, and
- Ask about exposure to the Russian River or other bodies of water known to have blue-green algae.
2. Promote awareness and prevention as outlined below.
3. For pets with a high suspicion of illness or death due to cyanobacteria toxin exposure, pursue testing:
- See options for testing below.
4. Notify Sonoma County Disease Control via phone (707) 565-4566 or fax (707) 565-4565 of pets with illness proven to be toxin mediated.
Algae, including blue-green algae, is a normal inhabitant in many water environments. Warm water, low flows and abundant nutrients can cause algae to grow more rapidly than usual and create algal mats or “blooms”. Most algae, including blue-green algae, do not produce toxins. Some species of blue-green algae have the ability
to produce toxins, including neurotoxins, hepatotoxins and dermatologic toxins, which can create health affects for humans and animals. It is important to note that although some blue-green algae can produce toxins, they do not do so all the time.
Algal blooms can look like green, blue-green, white, or brown foam, scum or mats floating on the water or along the shore. Within the Russian River cyanobacteria have been embedded in otherwise harmless filamentous algae. If toxin is present, dogs and
children are most likely to be affected. Dogs are especially vulnerable because they tend to drink more water and lick algae off their fur.
Toxins can cause a variety of symptoms including contact irritation (e.g., eye, nose, mouth and skin), gastro-intestinal symptoms (e.g., abdominal pain, nausea, vomiting, diarrhea, hepatic inflammation) and neurologic symptoms (e.g., numbness, muscle
tremors, seizures, difficulty breathing).
There are no widely available rapid diagnostics for confirmation of cyanotoxin poisoning. If you are interested in pursuing testing, the California Animal Health and Food Safety Laboratory in Davis is able to provide clinical testing. For information
on specimen collection, laboratory testing contact Drs. Robert Poppenga or Arya Sobhkumari, 530-752-6322.
Treatment is generally supportive care.
Please notify Sonoma County Disease Control via phone (707) 565-4566 or fax (707) 565-4565 of pets with proven cyanobacteria toxin mediated illness. Please provide this information: your name and contact information, type of animal, location and extent of water exposure, illness onset date, symptom
category (dermatologic, gastrointestinal, hepatic, neurologic), and if animal died.
Healthy water habits can prevent illness. Please encourage recreational water users of the Russian River to follow these healthy water habits with their pets:
- Avoid all algal scums or mats, which are found most often along the shore line;
- Do not let pets drink the water, swim through scums or mats, play near scums or mats on shore, nor lick their fur after contact with scums or mats;
- Wash your pets with clean water after river play;
- Get medical attention for your pet if you think it have been poisoned by blue-green algae toxins. Be sure to tell the medical professional about possible contact with blue-green algae.
For questions regarding the status of the Russian River go to the website listed below or call the recorded beach hotline at (707) 565-6552.
The following websites provide more information on blue-green algae and harmful algal blooms: