The '13 Reasons Why' cast had therapy dogs on set with them "every hour" during filming.

Dylan Minnette and Katherine Langford

Dylan Minnette and Katherine Langford

The gripping drama series has had viewers sitting on the edge of their seats, weeping into their tissues and hiding behind their cushions, but it wasn't just fans that were emotionally disturbed by the suicidal plot of the show as producers had adorable puppies brought in for the main stars to pat in between takes to ensure they didn't become depressed by the scenes.

Dylan Minnette, who plays Clay Jensen in the series, explained: "They had therapy dogs on set. There was a puppy per hour. They really tried to help out. The puppies helped."

And Katherine Langford no doubt benefited from the pooches the most as her scenes as suicidal teenager Hannah Baker, who killed herself in the bath, were the most "emotional."

He explained "She [Katherine] had the brunt of the emotional stuff. I mean, we all have very emotional parts, but this is about her character."

Although they tough to film at times, the 20-year-old actress - who was born and raised in Australia - is proud of the way the producers and cast handled the heavy topics.

She explained: "We cover so many intense issues. I feel like so much of Hannah's life, especially the last five episodes, is so tragic that you just have to put that shock aside and get through it. It's only been after the show and after wrapping that I've gone, wow, we really did handle some really heavy stuff. I'm really proud of how we handle it."

'13 Reasons Why', which hit Netflix on March 31, is based on the 2007 novel 'Thirteen Reasons Why' by Jay Asher and resolves around Hannah who kills herself following a series of heartbreaking failures brought on by a number of students within her school in California.

After Hannah's death, those individuals who contributed to her death received a box of tapes in which the troubled teen describes in detail how their actions led to her ending her life.