An animal rights group have discovered a testing lab where puppies and monkeys are force-fed chemicals.

A distressing undercover video has revealed test animals being force-fed drugs inside a laboratory.

Animal rights group, Humane Society of the United States spent seven months investigating the Inotiv Inc’s testing lab in Mount Vernon, Indiana of US.

Workers were assigned to work on more than 70 toxicity studies, commissioned by more than 12 pharmaceutical companies, with more than 6,000 animals including beagle puppies and monkeys.

The bodyworn footage shows workers putting a feeding tube down a puppy’s mouth and feeding it drugs before they release it back to the kennel for observation.

The poor canine whimpers and shakes before it collapses on the floor.

A statement from the investigation report noted: “The investigator witnessed dogs continuing to be given doses of substances even when they were vomiting, shaking and had high fevers and laboured breathing.”

In another part of the video shows a grim side of drug testing on monkeys.

The macaques, all locked up in separate boxes with hands and feet tied and held by the neck in restraint chairs, have feeding tubes inserted into their mouth as the workers shove the liquid down their throats.

The monkeys wail in pain and one worker can be heard saying to one of them: “I’m so sorry, lady, maybe this will be your final dose.

“I kind of hope it is because it’s torture at this point.”

The investigator claimed that during the investigation, which took place from August 2021 and March 2022, at least two monkeys accidentally hanged themselves in the restraint chairs.

At the end of the tests, the animals are killed and cut open to examine any toxic effects on their body.

The Humane Society are urging Inotiv Inc to release the beagles immediately and put them up for adoption – as they fear 82 are set to be euthanized.

Kitty Block, CEO and president of the Humane Society of the United States said: “The disturbing findings at this facility cannot be ignored.

“We are calling for the release of beagles we know are suffering in the lab today and soon to be euthanized, but that is just the start of our work.”

Inotiv said that their research is legally required in the US in order to develop lifesaving medicines.

They wrote in a statement to the Journal and Courier that their mission is to “help our clients realise the full potential of their scientific and medical research”.