Blue-Green Algae in Missisquoi Bay Suspected in Dog Deaths

For immediate release:
September 10, 2002

News Media Contact:
Dr. Ann Fingar, State Epidemiologist
Vermont Department of Health

Burlington—The Vermont Department of Health has received word that two dogs died after ingesting water from Lake Champlain in the Missisquoi Bay area.

One dog had been swimming in the Canadian part of the lake, the other near Highgate Springs. Both deaths occurred in the last two weeks.

“Although we are not sure at this time whether the deaths were caused by blue-green algae, it is a strong possibility,” said Dr. Ann Fingar, state epidemiologist with the Vermont Department of Health.

High concentrations of blue-green algae have also been documented in St. Albans Bay and toxins are present there as well.

Based on this, health officials are again warning people to avoid swimming in areas where there is visible green or blue-green scum collected on the surface of the water and to keep dogs and other pets out of this water as well.

Small animals are at risk if they eat the algae or drink the water in an area where a toxic algae bloom is taking place. They might also ingest the algae by licking their fur after they have been in water that is thick with algae.

“Our advice to pet owners is to keep your dogs away from the algae,” said Dr. Bob Johnson, state public health veterinarian at the Health Department. “And, if your dog does get into the water in an area where you see the algae, wash the dog off with clean water.”

Hot, dry, calm weather conditions promote the growth of blue-green algae, which are commonly seen in Lake Champlain and other lakes and ponds throughout the state. The blue-green algae appears as a heavy greenish-blue scum on the water or shoreline.

In some cases, these algae blooms can release toxins such as microcystin or anatoxin.

People should avoid swimming in areas where there is visible green or blue-green scum collected on the surface of the water. Ingestion (drinking) of algae that are producing toxin can result in symptoms including nausea, vomiting, and diarrhea. Skin exposure can result in irritation or allergic reactions. Children should especially be kept from entering scummy water since they are more likely to ingest the water than adults.

In the hot summer of 1999, several dogs died after ingesting large quantities of blue-green algae in Lake Champlain.

Not all blue-green algae blooms produce toxin. However there is no way to tell just by looking at it. Most other algae lake plants do not produce any toxin.

When blue-green algae bloom, they look thick like pea soup or blue or green paint on the water. They are mostly blue-green, although they can also be brown or purple. When blue-green algae washes up on shore, it can form a thick mat or foam on the beach.

Generally, lots of wind, cooler weather, rainfall, and cloudy days will lead to the collapse of an algae bloom. Some blooms die off after a few days or weeks, while others persist for a few months.