Wally Conron, the man who created the Labradoodle cross-breed has said he inadvertently unleashed a "Frankenstein's monster."

The 90-year-old, who worked for Guide Dogs Victoria in Australia when her first bred the Labrador-Poodle cross breeds in 1989 spoke of his regret at having begun a trend for breeders opting for designer breeds on an ABC podcast. "I opened a Pandora's box and released a Frankenstein ('s) monster," he said during the broadcast.

While they may be cute, cuddly and loveable, the creator of the first ever labrador-poodle crossover feels they are "crazy" with major health problems.

One of Conron's biggest regrets is that his invention paved the way for "unethical, ruthless people" to breed the dogs without considering the health of their offspring.

According to Conron, the majority of Labradoodles bred since then are "either crazy" or have a "hereditary problem," with healthy examples of the breed being few and far in between.

According to Conron, people have gone too far with cross breeding, increasing the dog's risk of congenital diseases. He laid particular scorn on the new Rottweiler-Poodle hybrid, known as a Rottle or a Rottie-Poo on the podcast.

Conron had originally crossed a Labrador and a standard Poodle to provide a guide dog for a blind woman in Hawaii whose husband was allergic to dogs. The resulting litter was of three pups and when one of them did not trigger the husband's allergies, it was sent to Hawaii to be her guide dog.

Since no one wanted the two remaining labradoodle pups, he asked the PR department at his work to spread the message of the new breed, with labradoodles becoming popular in Australia and the world thereafter.

However, with designer breeds becoming rampant, there has been consequences with labradoodles, for example, being prone to diseases of the eye and hip dysplasia.

Speaking to CNN, Colin Tennant, a British expert on dog behaviour said that breeders are blindly breeding and altering genetics of the line without knowing what would happen next. While Tennant said he doesn't have a problem with cross-breeding, breeders need to pay more attention to dog's health.