The Colorado Department of Public Health and Environment has issued a warning to residents and visitors about the risks posed by toxic blue-green algae in state waters during the summer months.
Blue-green algae, also known as harmful algae blooms (HABs), occur naturally but can grow quickly in warm, nutrient-rich water. Under these conditions, they may produce toxins that are dangerous to humans and can be fatal to pets.
“People exposed to toxic algae may develop skin irritation, rashes, digestive system issues, low energy, fever, headache, or sore throat. People who think they may have come in contact with toxic algae should: Shower or rinse with fresh water immediately. Contact a healthcare provider if they experience symptoms.”
Pets are particularly at risk because they are more likely to drink contaminated water. “Pets are more likely to drink affected water. Symptoms can include drooling, diarrhea and vomiting, low energy, loss of appetite, stumbling, and tremors. If your pet is exposed, you should: Get the pet out of the water immediately. Keep the pet from licking their fur or paws until they are rinsed. Rinse the pet with clean, fresh tap water as soon as possible. Thoroughly remove all algae from their fur, skin, and paws. Watch for symptoms, and contact a veterinarian if your pet shows any symptoms or if you suspect they have swallowed toxic algae. For additional support, contact Poison Control at 1-800-222-1222.”
The department advises checking with local authorities for current water conditions before entering lakes or reservoirs and following posted signs regarding potential blooms or scum on the surface. Officials emphasize that only laboratory testing can confirm whether an algal bloom is toxic: “The only way to know whether algae is toxic is to test for it. When in doubt, stay out.”
A dashboard listing recently reported blooms is available online; however, officials caution that conditions can change rapidly and data may not always reflect real-time status.
To help prevent future outbreaks of toxic algae blooms throughout the year, residents are encouraged to pick up after pets promptly and dispose of waste properly; avoid overusing fertilizers; and limit use of de-icing products containing nitrogen or urea.
Suspected cases of toxic algae should be reported by contacting ToxCall at 303-692-2606 or emailing cdphe_toxcall@state.co.us.
Further information about blue-green algae risks in Colorado can be found at https://coepht.colorado.gov/toxic-algae.
