A Staffordshire Bull Terrier mauled its owner to death after eating crack cocaine, an inquest heard.
Major was the equivalent of eight times the human drug drive limit when he latched onto Mario Perivoitos's face and neck moments after his owner took part in a BBC documentary.
Mario, 41, had been filming with a camera crew for the BBC program Drugs Map Britain when he fell into an epileptic fit and attacked on his bed.
Nicholas Carmichael, an expert in veterinary toxicology, revealed that samples of cocaine and morphine had been discovered in Major's urine.
The exact reading and measurement of cocaine was not stated but Carmichael said: "We undertook two analysis of blood and we did not find any toxins but we also received a urine sample and identified a cocaine metabolite and also morphine.
"It is very likely that this dog had consumed drugs, probably eaten them.
"It is almost impossible to say whether that will make the dog attack but it does make them respond abnormally.
"They become very excited and agitated, it is highly more likely that this attack happened because this dog had taken cocaine.
"In my experience with Staffordshire Bull Terriers if they think they are in a dominant position its response must have been to attack.
"The dog was eight times the drug drive limit.
"The dog had clearly taken it and, whether it had eaten it or taken it in by smoke, it is likely to have been a factor in the dog's behavior."
Before becoming a vet pathologist he spent over a decade as a veterinary surgeon.
He added: "The drug is very quickly excreted from the dogs body it must have been ingested up to 48 hours before, but it may have been much shorter than that.
"The combination of these events together with the fact that there were drugs in the dog's system made it behave in the way that it did.
"In our opinion the dogs behavior was as a result of the intoxication of cocaine."
Pathologist Dr Julie Higgins said: "The body included injuries to the neck and face with extensive hemorrhaging and the larynx was crushed."
Peter Roe, a London Ambulance Service paramedic said: "I arrived at the scene at 10:42 pm the front door was locked upstairs in a tower block, it was clad in heavy locks.
"Approximately nine minutes were required for the police to open the door.
"Mario has a laceration to the neck about four or five centimeters long, I could observe his trachea, it was a large deep wound to the left had side of his neck."
Senior Coroner Andrew Walker recorded a conclusion of death as a consequence of injuries received from a dog.
In his conclusion he said: "Mr. Perivoitos was taking part in a documentary about illegal drugs, having returned to his home at 10:17 pm consumed a quantity of cocaine before becoming unwell.
"It is likely that he was experiencing an epileptic shock which caused the dog to nip his face before biting his neck.
"The film crew telephoned an ambulance whilst attempting to get the dog off Perivoitos.
"It is likely that the dog had consumed cocaine by eating it and it is likely that this was an additional factor in the dog's behavior."
"Mr. Perivoitos suffered serious injuries and was taken to a major trauma hospital and died shortly after midnight."
He added: "I would like to thank the witness personally for their actions at the scene and that of the colleague who was there helping and following advice from the London Ambulance Service, it is to be commended."
The officer in the case detective chief inspector Luke Marks, who brought no criminal charges in the case, told the court that Major was due to be destroyed.
He said: "The dog was taken to a secure police storage facility, it was due to be destroyed but I do not know if it has been."