Hello, my dog eats vegetarian kibble as she has suspected allergies, to what we aren't sure but the vet believes it could be an animal protein, whenever she is on meat based kibble we get loose stools, diarrhoea, paw biting, flank chewing, she scratches her neck and ears although I know she doesn't have fleas.

She eats ami vegetarian dog kibble which i really feel is the best one.
All the other brands I have seen contain soya (Penelope is definately allergic to this) which is a common allergen and also wheat which is a common allergen.
Ami has l carnitine added but no taurine, all the other foods have no l carnitine and no taurine.
If your going to feed vegetarian, you need to add veggiedog supplement by harbingers of a new age for the taurine.

It's worth noting though, Penelope has no reaction to meat that's not in kibble, we give her sausages, bacon, chicken etc and she's fine but as soon as you feed her meat kibble she reacts.

Your dog might be okay on a raw diet perhaps?
Or a mostly vegetarian with plain cooked meat added which is what Penelope has.

I have been getting mixed messages in terms of feeding vegetables. Am I supposed to give them raw or steamed? Liquefied or chopped?

When Tonks had anal gland issues the vet suggested that, because modern day dog food was so easily digestible, she would benefit from some raw vegetables in her diet as they would be non digestible and pass through in chunks and help to express her anal glands on the way out. So, if you wee using them as their source of nutrition I presume that they would need to be cooked. Maybe steamed and add the water left to their food to retain as much nutrition as possible.

I too have one very lean dog due to having intolerances to so many food substances. After trial and error he has now been on Orijen 6 Fish kibble which is Canadian so very expensive here but worth every penny as both my dogs flourish on it. My dog in question can't eat grains, beef, chicken, turkey or lamb. Good luck but I would try the Orijen if I were you as its made in your home country and has won so many awards.