Blue Green Algae Facts You Should Know

Blue green algae

What is it?
  • Cyanobacteria – literally blue/green bacteria
  • Creates “blooms”
    • ​​​colonies that give the water a pea-soup appearance
    • ​​​​​​​​​​​​​​can also look like blue or green paint on the surface of the water
    • ​​​​​​​Very thick – mats can be blown to the shore
Where is it found?
  • How/why does it grow/what conditions are needed
    • Most abundant during hot weather – only grows in high water temps
      • ​​​​​​​​​​​​​​Spring/summer
      • Nutrient rich water – run-off from fertilized fields
      • Most actually don’t produce toxins, but all should be considered toxic
        • Don’t know w/o testing
    • What areas of the country/state are at risk?
      • EVERYWHERE!!!

How is it toxic?

  • What species are affected?
    • Cats, Dogs, Horses, Cows/sheep/goats/llamas, Birds
      • Ruminants and birds more susceptible
      • Dogs more sensitive to neurotoxins
      • Need to ingest it
      • Can lick it off the fur/hair too!
    • People – contact dermatitis
  • Types of toxins
    • Microcystins – harmful to liver
    • Anatoxins – harmful to nervous system
  • Not toxic unless dense surface bloom present

Clinical signs

  • Microcystins
    • Malaise/lethargy
    • Weakness
    • Inappetance
    • Vomiting
    • Diarrhea
    • Blood in stool or black, tarry stool
    • Pale mucous membranes
    • Jaundice
    • Seizures
    • Death
    • First signs in a few hours if microcystins
      • Hepatotoxicosis
      • Death within 12-24 hours
  • Anatoxins
    • Inability to walk
    • Disorientation
    • Coma
    • Shock
    • Excessive secretions (e.g., salivation, lacrimation, etc.)
    • Neurologic signs (including muscle tremors, muscle rigidity, paralysis, etc.)
    • Blue discoloration of the skin and mucous membranes
    • Difficulty breathing
    • Death
    • First signs w/in 30-60 min if anatoxin – neuro signs
      • Respiratory paralysis/arrest
      • Death can occur within 30 min, usually a few hours
Treatment
  • Limited and rarely effective
  • Supportive care only
    • IV fluids, electrolytes, control seizures/muscle tremors
    • Activated charcoal
    • Out of direct sunlight
Prevention of exposure is key!!
  • Can treat water supplies, water mixing techniques for livestock
Prognosis
  • Very poor for animals
  • Good for people, but need medical attention
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