Hi Ellie,
we own 2 young labs (nearly 10months old) and when I looked into the BARF method maybe 6 months ago, the main thing stopping me was the amount of preparation time. Additionally you can't just feed vegetables without pulverising them. Dogs digesive systems don't break down the cell walls in the vegetable matter which means that they won't get to absorb all the important vitamins and minerals.
quoting from [1] "In addition pulped vegetables and fruits are also added to mimic the stomach contents of prey animals that would have been eaten in the past."
quoting from [2] "Vegetables needs to be blended into a pulp so dogs can digest them. Dogs are carnivores and are incapable of breaking down the cellulose that makes up the cell wall of all plant cells. If they are not pureed then what goes in will come out the same way, completely undigested because the dog's body is unable to pull the nutrients from inside each cell. In the wild when carnivores would hunt and consume herbivores they would digest some of the contents of their preys stomach and intestines where the animals stomach enzymes had already broken down the cellulose making it digestable to the carnivore. This is why it is absolutely essential to puree all vegetables and fruits"
So be aware that just because you feed them lots of vegies, doesn't mean they are actually providing much more than fibre/roughage.
regards
Peter
[1] Parkvets Barf Diets - Goodness or Garbage
[2] BARF DIET