After 50 Canada geese were found dead floating in the St. Lawrence River outside Montreal earlier this week, veterinarians are saying they may have died from a lightning strike.

A local fisherman came across the geese near Contrecoeur, Que., Thursday and veterinarians were called in from Université de Montréal to examine the bodies.

A video of the dead birds was distributed on social media and has been shared more than 19,000 times.

Veterinarian Stéphane Lair said that the geese had small lesions in their hearts that indicated a possible lightning strike.

He said the level of decomposition indicates that they all died at the same time, which rules out disease or malnutrition.

Following the discovery, both the provincial and federal flora and fauna ministries were alerted.

Lair told the Canadian Press that while this kind of event has been recorded before, it's rare to see animals killed en masse on the water.

In this case, the water conducted electricity over a wide area, causing the birds to die without any localized burns.

"It's been described, reported, but I can't remember having seeing it before,'' he said.

Geese are protected under the Migratory Birds Convention Act.