"It was a very distressing and incredibly sad event for them, and we regret that it happened."
The pond has since been drained, with all ponds in Ryman Healthcare villages checked for similar problems.
The incident has been put down as a one-off incident, but the fountain involved has since been drained and turned into a garden.
The health and safety investigation found that the current was enough to be fatal for the dog, but not large enough to cause a human fatality.
But Master Electricians Wellington Operations Manager Bernie McLaughlin said any current in water had the potential to kill a person.
"The fact is, milliamps can kill a person.
"If it can kill a dog, it can kill a person or a child, it's as simple as that."
Mr McLaughlin said some situations were just tragic accidents, while he'd seen others that were preventable.
He said fountains with electric pumps weren't a problem by nature, but anyone who was worried should be aware of some safety advice.
Licensed professionals should always be used over DIY, as they could spot dodgy equipment and make sure everything was installed correctly.
"Because it's such a dangerous area, with water and electricity, you've got to have equipment that is safe and proper to use in damp situations.
"There's an awful lot of equipment that's being brought in by property developers and entrepreneurs who want to make a quick buck.
"But a huge amount of this product doesn't comply with the safety rules for this country."