Health officials believe the dogs ingested too much of the water that had high counts of blue-green -- or "toxic" algae.
This incident prompted all bodies of water statewide to be tested for blue-green algae amounts.
Potato Creek State Park has the following warning posted on their web site following the findings:
Caution: Due to high blue-green algae counts, users and pets should avoid ingesting water, avoid contact with surface scums (mats of algae) when visible, and shower with soapy water after swimming.
Summer, with its sunlight, warmth and higher levels of lawn and agricultural fertilizer runoff, can bring blue-green algae blooms to some Indiana lakes. During these blooms, some types of algae produce toxins. It is especially important to limit access for dogs, horses and other animals in areas where algae may be found. Animals drink water and self-clean after they leave the water and can ingest large amounts of toxins which may result in serious illness or death. Consider carrying fresh water for your animals to drink.
There is much variability in the appearance of blue-green algae, but it is usually found in shallow water or in coves/bays where water movement is limited. However, algae may be producing toxins in one area of a lake or pond, and not in another.
Area state parks and lake access areas will notify residents as soon as the lakes are at a normal level.
These bodies of water are not off-limits at this point -- but bathers are urged to use caution when playing in the water.
You can see the entire list of lakes with high blue-green algae counts here:
http://www.in.gov/idem/algae/