Animal rights investigators are probing a Snapchat video that appears to show a drug-addled teenager blowing marijuana into an already-stoned kitten's face.

The Australian RSPCA are concerned about the clip, which captures the youth inhaling large amounts of smoke from a bong device before gently exhaling the fumes inches from the young cat's nose and mouth.

The animal welfare campaigners believe that creature may already have been feeling the effects of the illegal drug because its body was limp and it did not try to escape the highly potent vapour.

The boy's face has been blocked out in video footage released to the media. He appears to be caucasian.

Experts warn that the cat's life was put in danger by the abuse, no matter how harmless or funny it may have seemed to the dopey teen.

"It's not struggling like you think it may so I am concerned that the kitten may already be under the effects of marijuana," said RSPCA spokeswoman Cheryl Doudle.

Marijuana is now being used to treat pets for physical and mental disorders in the US, where the drug has been legalised in 29 states.

One such pet is black labrador Cayley, who gets high each morning and evening to help her with a recently developed separation anxiety.

Owner Brett Hartmann also administers cannabidiol drops to his elderly dachshund Brutus, who has trouble with his (anatomical) joints.

However, providing pets with medical marijuana supplements to treat diagnosed conditions in no way justifies the practice of blowing bong smoke into a kitten's face.