My IBD dog: Hypoallergenic wet food or hydrolyzed protein diet?

Hello, and thank you for your question. Dogs with IBD should definitely be on a hypoallergenic diet of some sort. The good news is that there are a wide variety of hypoallergenic diet options.

Hill's i/d is actually NOT a hypoallergenic diet. It is a bland diet designed for sensitive stomachs, but not for food allergies. There are two main categories of hypoallergenic diets:

1) Novel protein diets, which consist of protein sources that most dogs have never been exposed to before. This includes venison, duck, kangaroo, rabbit, etc. You would choose the novel protein that you are sure Toby has never eaten before, including through treats or table scraps.
2) Hydrolyzed protein diets most often consist of hydrolyzed soy protein, where the molecule is broken down in such a way that the body does not recognize it as an allergen. These are a good option as well, but it is not guaranteed to work in all dogs.

Both types of diets come in wet and dry options (e.g. Hill's z/d comes in wet and dry). I would talk to your vet about trying a brand with a wet option. Once he is weaned onto the new diet, he should be kept on it for a minimum of 8 weeks with no other treats or table scraps.

I hope this helps, and that Toby gets better soon!