"We have seen a dramatic increase in the number of dogs where the bone gets stuck in the oesophagus... Some can't be saved by any means and they die as a result of the raw food diet.
"It is 100 per cent fatal if we can't get the bone out."
Robson said it cost around $4000 to get a piece of bone out with an endoscope. If that was not possible surgery, with a price tag upwards of $10,000, was needed.
Lack of nutrition is the other reason Robson does not endorse the diet. His hospital is seeing a phenomenon of puppies with inadequate bone development for the first time in 25 years. He said a solely raw food diet doesn't have enough minerals including calcium.
"It's ironic, these owners are feeding their pet a diet because of perceived negative aspects of commercial dog foods, then dogs are dying because of this diet.
"These diets are dangerous. It's been good for my bank balance but it is stressful work and I would much rather not do another one."
Ponsonby Vets' lead veterinarian Gareth Dunkerley agreed. He sees around seven cases a year, with severe constipation being the most common. Enemas to release the blockage could cost up to $2500.
Dunkerley saw a kitten die when a dagger of bone pierced its diaphragm. Gastroenteritis and food poisoning with salmonella or campylobacter were also possible hazards of the diet, he said.
"If you crush up bone into a powder it becomes like cement and the animal's stools become very hard. It causes a lot of problems with constipation.
"These diets are not produced to the same human health standards we see for meat in the supermarkets, so they can harbour bugs."
Dunkerley, who has been a vet for 18 years, had seen some suspected cases of food poisoning.
People commonly argue that the raw food diet is what pets would eat if they lived in the wild. But cats and dogs only live five or six years in the wild, Dunkerley said.
"Animals looked after by us on premium diets tend to live much longer, healthier, happier lives.
"While raw diets seem more natural, the big factor there is the animals don't live that long. I don't take that argument too well."
Robson would not endorse any diet as the perfect one for all dogs. Robson thought a mix of raw and dry food was usually best.
"Anyone who tells you their product is the right food for all dogs is deluded."
Raw Essentials founder Dr Lyn Thomson admitted that animals could run into health hazards, but this was primarily due to people not doing raw feeding properly.
"Raw feeding isn't a biscuit-fed dog who's fed a cannon bone on the weekend.
"You need to raw feed without mixing it in with processed, dry pet food. This increases an animal's ability to digest raw food."
Thomson also believed that the veterinary profession wasn't well educated in raw feeding, which made them more likely to blame health complications on the diet.
"Raw feeding is controversial, we're very much about educating so that if you are raw feeding you do it properly.
"There are thousands of raw feeders out there who are happy with the increased health once they start raw feeding."
