Scots c ouncil bosses have warned the public after toxic scum has been found in several waterways.
People in Fife have been urged to avoid swimming or letting their pets into the waters at Beveridge Park, Kirkcaldy, Clatto Reservoir, Cupar and Lochore Meadows as suspected blue-green algae has been detected.
Contact with the poisonous substance can lead to skin rashes, eye irritation, vomiting, diarrhoea and pains in muscles and joints and dogs and other pets dying.
Earlier this summer horrific stories of painful rashes were reported after people swam in Loch Lomond and other waters.
And in June a dog nearly died after taking a dip in River Fillan, near Crianlarich but was saved by quick thinking vets.
Fife Council have announced the poisonous algae around the county and have urged locals to take proper precautions.
In a statement, the local authority said: "Blue-green algae pose risks to public and animal health when they form blooms and scums in freshwater in warm summer months.
"In people, exposure to the blue-green algae toxins may cause skin rashes and more severe symptoms if swallowed.
"Dogs are also at risk if they drink the water, or lick their coats after swimming; exposure may be fatal or lead to severe symptoms requiring very rapid vet treatment.
"Please keep yourselves and your dogs away from affected water bodies."
Blue-green algae is usually sparked by hot weather in waters which have been polluted by agricultural, domestic or industrial discharges.
In still waters the algae can multiply during the summer months to such an extent that they discolour the water which then appears green, blue-green or greenish brown.
Further advice from Fife Council adds: "Some, but not all, the blue-green algae release poisons into the water. It is not possible to tell which algae do or do not produce poisons without detailed examination in a laboratory; therefore it is advisable to regard all algal scums as poisonous.
"The toxins of blue-green algae can cause death to animals either through drinking contaminated water or swallowing quantities of the scum. Dogs have died after going into the water at the shores of affected lochs.
"Canoeists, wind surfers and swimmers who have either swum through algal scum or swallowed it have suffered from skin rashes, eye irritation, vomiting, diarrhoea and pains in muscles and joints.
"There have been no reports of long-term illness or death in human beings. However, illnesses were sometimes severe.
"Drinking water supplies are treated to prevent any harmful effects to health from blue-green algae.
"Avoid all contact with affected or suspect water and ensure that children and pets are kept away.
"Farmers should ensure that their animals do not have access to contaminated water."
