Samantha the gorilla was euthanized Monday at the Toronto Zoo after suffering her second stroke in a month. (Toronto Zoo)

A 37-year-old Western Lowland gorilla described as the dominant female of the Toronto Zoo's seven-member troupe has died.

Samantha, living at the zoo since 1974, was euthanized Monday after suffering her second stroke in a matter of weeks, the zoo said in a release.

The gorilla was paralyzed on her right side after a stroke in mid-July. She made some progress in her recovery, but Monday's stroke put her in critical condition.

Zoo officials then decided to euthanize her.

She was the favourite mating partner of Charles, a male silverback gorilla at the zoo and father of her five offspring.

Charles paid extra attention to her after her first stroke, "coaxing her, or encouraging her or communicating with her because he was obviously very concerned about her situation," said Chris Dutton, a veterinarian at the zoo.

"So of course, now that she's passed away, I'm sure that there will be some upset within the group. There'll be some changes in the group dynamics most certainly."

The gorilla was born in Gabon in 1972 and came to the Toronto Zoo two years later.

Two of her offspring — Shalia and Sadiki — are still at the zoo.

"Over the years, I have spent a lot of one-on-one time with Samantha," said gorilla keeper Matt Stephenson in a statement.

"I will particularly miss her 'singing' at breakfast and dinner, and those purrs and rumbles she made that were like music to the soul and which always brought a smile to my face."

The Western Lowland gorilla is an endangered species found in western Africa. The average lifespan of the gorilla in the wild is about 35 years, although in captivity it can live up to 50 years.