Allergy testing

[MissShapesMissStakes]

My dog is about 1 and a half. He’s pretty healthy (so far!). We have been to the vets a few times - mostly anal glands and an ear infection he got when he was wearing a cone. The vet has said to me a couple of times that he thinks he has allergies but that he’s not really affected enough (yet) to do tests. He’s saying this because 1. Most dogs don’t get ear infections from wearing a cone 2. He has had anal gland issues a few times 3. He thinks his paws are quite pink 4. He can be a bit itchy at times (but not massively so and it doesn’t seem to bother him other than enjoying a good scratch sometimes.

I’m pretty sure he needs his anal glands doing again which the veterinary nurse does.

My questions are
Do I take him off grains entirely? His food is grain free and most of his treats. But not cut them out entirely.

Do I need to get him allergy tested? The vet has only mentioned it in passing. Is it blood tests? How expensive is it? (Insurance will pay anyway though I suppose?)

Does it matter so much if he’s not hugely effected? He really doesn’t seem bothered by anything other than if his anal glands get full - and that could just be his anal glands anyway couldn’t it?

Obviously I will talk to the nurse tomorrow. But just wondered if anyone had any experience?