Parks Canada is warning visitors to Prince Albert National Park in northern Saskatchewan about the possible presence of blue-green algae in Waskesiu Lake.
The federal agency issued the advisory Friday, saying the algae may also be present in other areas of the park, which is about 200 kilometres north of Saskatoon.
Blue-green algae can produce toxins that are harmful to both people and animals. The toxins can cause serious illness if swallowed or if they come into contact with skin, the advisory warned.
Symptoms can include fever, headache, dizziness, stomach cramps, vomiting, diarrhea, irritated skin and eyes, sore throat and swollen lips. The symptoms usually last only a few days, but Parks Canada warns the toxin has been fatal to pets and livestock that have ingested it.
Visitors to the park are advised to avoid drinking or allowing pets to drink the affected water, swimming or wading in it, or coming into contact with algae that has dried on shorelines.
Parks Canada says anyone who suspects a health concern related to blue-green algae is urged to contact a health-care provider.