Blue-Green Algae Toxic to Animals Found In Hudson Bend Area of Lake Travis


Cyanotoxin, a toxin produced in blue-green algae, has been found in water samples taken from Lake Travis. Officials are urging dog owners to keep their pets away from the Hudson Bend area of Lake Travis.

According to media reports, the Lower Colorado River Authority received lab results following reports that four dogs became ill after swimming in the Hudson Bend region of Lake Travis earlier this week.

Dog Passed Away After Swimming

Solid organic material was taken for testing from the edge of Travis Landing, located on the east side of Hudson Bend. Those samples indicated the presence of algae and decaying algae containing cyanotoxin, which is fatal to dogs and other animals. LCRA received an additional report made in late January 2021 from a pet owner whose dog passed away after swimming in the lake’s Comanche Point area, which sits directly across from Hudson Bend.

While reports have not surfaced from other areas of Lake Travis, LCRA noted algae could be present. As a result, pet owners should always use their best judgment in determining whether to let their dogs play in Lake Travis, according to LCRA. Pet owners should avoid stagnant water and any area with visible algae or decaying matter.

At this time, no reports have been made in other bodies of water throughout Austin, including Lady Bird Lake, which experienced toxic algae bloom in 2019 that resulted in the deaths of five dogs. LCRA is obtaining additional water samples from the lake and will update the community upon receiving results.

Drinking or Bathing In Contaminated Water

When people are exposed to cyanotoxins, adverse health effects may range from a mild skin rash to severe illness or, in rare circumstances, death. Acute diseases caused by short-term exposure to cyanobacteria and cyanotoxins during recreational activities include hay fever-like symptoms, skin rashes, respiratory and gastrointestinal distress. 

Cyanobacteria or blue-green algae occur worldwide, especially in calm, nutrient-rich waters. Some species of cyanobacteria produce toxins that affect animals and humans. People may be exposed to cyanobacterial toxins by drinking or bathing in contaminated water. The most frequent and severe health effects are caused by drinking water containing the toxins (cyanobacteria) or ingestion during recreational water contact.

Exposure to drinking water contaminated with elevated concentrations of microcystin and cylindrospermopsin could cause liver and kidney damage. The table below summarizes the health effects caused by the most common toxin-producing cyanobacteria.

Reduced Growth and Reproductive Rates

High biomass blooms, whether of toxic or nontoxic species, can lead to deficient oxygen levels in the water column (hypoxia), resulting in higher mortality rates in local fish and shellfish invertebrate and plant populations. The blooms may also affect benthic flora and fauna due to decreased light penetration. Toxic blooms from some cyanobacteria genera may lead to inhibition of other phytoplankton and suppression of zooplankton grazing, leading to reduced growth and reproductive rates and community structure changes composition.

CyanoHABs can also harm pets, wildlife, and livestock. Pets and other animals can be poisoned by drinking toxin-contaminated water or swimming in waters with a cyanoHAB. Several dog and livestock deaths have been reported after exposure to cyanotoxins in water. Symptoms of exposure to HABs in pets can include excessive salivation, fatigue, difficulty breathing, vomiting, diarrhea, and seizures. Death can occur within hours to days of exposure.

People are mainly exposed to cyanobacterial toxins by drinking or bathing in contaminated water. Other sources include algal food tablets. Some species form a scum on the water, but high concentrations may also be present throughout the affected water. Surface scums, where they occur, represent a specific hazard to human health because of their exceptionally high toxin contact. Contact, especially by children, should be avoided.

Cause Poisoning In Animals and Humans

The organisms can increase in favorable conditions, such as calm nutrient-rich fresh or marine waters in warm climates or during the late summer months in cooler parts of the world. Blooms of cyanobacteria repeatedly occur in the same water, posing a risk of repeated exposure to some human populations. Cyanobacterial toxins in lakes, ponds, and dugouts in various parts of the world have long been known to cause poisoning in animals and humans.

Cyanobacteria have been linked to illness in various regions throughout the world, including North and South America, Africa, Australia, Europe, Scandinavia, and China. There are no reliable figures for the number of people affected worldwide. The only documented and scientifically substantiated human deaths due to cyanobacterial toxins have been exposed during dialysis. People exposed to drinking-water and recreational-water have required intensive hospital care.


Please enter your comment!
Please enter your name here