Hello I too am a newbie. I have a lovely little patter jack pup coming up to 4 months old. When I first got him he was on a supermarket brand of tinned puppy puppy food which I gradually changed over to wainwrights wet puppy food in trays (lamb, duck, chicken).
He seemed ok and then started scratching and dragging his chest along the floor…I then found out he had been fed all sorts of puppy food, treats etc by family as he is so cute and loves his food!
Long story short I ended up with ‘psycho pup’ scratchy hyper, overheating - off we went to the vet who gave him a cortisone shot, emptied his anal glands and advised to put him on an exclusion diet of white fish, potato, carrot, brown rice etc.
After nearly two weeks I took him back as he was miserable, lethargic and was advised to put him on Hills. I didn’t but put him on Barking Heads grain free puppy last week.
Its been a week now and he is still scratching his smelly ears, his anal glands were emptied yesterday - I was advised to keep him on this food as a week is not long enough - I am really worried and would welcome some friendly advice please - I hate to see my pup like this…thank you 
Hello and welcome to the forum. It sounds like you are having a bad time with your puppy right now. You did the right thing by putting him on a better diet than the supermarket one. Exclusion diets have to be carried out very carefully and methodically, preferably with the support of a vet. Having just checked the formula of Barking Heads puppy food it looks quite suitable and as it is grain free it is a good choice. I assume it is this one:
Composition* Freshly Prepared Deboned Salmon 20%, Sweet Potato, Dried Salmon 16%, Freshly Prepared Deboned Trout 11%, Potato, Lentils, Peas, Sunflower Oil, Salmon Oil 3.5%, Pea Protein, Salmon Stock 2%, Lucerne, Seaweed, Prebiotic MOS, Prebiotic FOS
Analytical Constituents Crude Protein 28%, Fat Content 18%, Inorganic Matter 8.5%, Crude Fibre 2.5%, Moisture 8%, Calcium 1.8%, Phosphorus 1.4%, Omega-6 (4%), Omega-3 (2.7%), DHA 0.3%
Nutritional Additives (Per kg) Vitamin A 25,000 IU, Vitamin D3 2,222 IU, Vitamin E 694 IU
Trace Elements as Compounds Ferrous sulphate monohydrate 956mg, zinc sulphate monohydrate 772mg, manganous sulphate monohydrate 152mg, cupric sulphate pentahydrate 56mg, calcium iodate anhydrous 6.80mg, sodium selenite 0.77mg
Link
Assuming that your dog hasn’t got mites or has been bitten by anything then I am at a loss to know why he is scratching and so irritable. What you describe does sound like allergy but I take the point that your vet is making in that one week is not a long time to get established on a different food. Of course it is possible that his diet has nothing to do with it. There are dogs that are sensitive to pollen and there is a lot of it around right now. I recall that my youngest dog had a touch of hay fever when she was a puppy and it was this time of year.
You can give Chlorpheniramine (Piriton) to dogs but you really need to ask your vet first because yours is just a baby and you need to be sure it is safe and that you have the correct dose.
The other thing that might help is to clean your pup’s feet and undercarriage when you come in from a walk. You can do this using plain warm water or purchase special wipes for dogs.
With the ears you can just use a small piece of damp cotton wool and wipe around the external ear twice a day (I assume your dog has dropped ears). However, I am just wondering if he has an ear infection as well - did the vet look down with an auroscope? I know that you have seen the vet but without knowing the full details, I think that it sounds as if some extra treatment might be necessary just to get him comfortable.
If you really feel that this is diet related then the only thing I can think of right now is to give him some home cooked food for the next few days. When mine are poorly I usually give well cooked brown rice, chicken and steamed white fish. It is not very well balanced but as a stop gap for a few days it seems to help.
Please let us know how you get on with him. I hope that he is soon better.
Bless his little heart. There is no other helpless feeling when they can’t tell you the problem and your doing your best to relieve his itching.
As a pup when allergy’s just started on mine, the vet put him on a antihistamine X2 a day for a few months…much like benedril and the tablet Dottie mentioned.
It made him sleepy and mellow but it stopped the cycle of itching and scratching himself raw and gave us time to pin point his irritant.
As the vet and I worked out by trial and error what was irritating him and he was able to come off the antihitimines and hasn’t itched and scratched as before.
Ask your vet for a trail of them…he won’t be on them a few months and the perscription didn’t cost very much. I forgot the name but it’s the same version as humans take for allergy’s.
Keep us informed how he gets along.
((((Hugs))))
aah thank you for your replies - he’s a patter jack and yes the vet did look down his ears and said they were a bit inflamed and crusty in one - he put a ‘wash’ down the bad one which made pup scratch even more but that was due to his wee ear being full of liquid. its now afternoon and am glad to say he seems to not be scratching anywhere near as much as he did before - happy !
I previously under vets advice have given him piriton - which I did last night…yup theres a lot of pollen around and I do give him a good wipe down when he comes in.
He has two meals a day now of BH as per guidelines so I will keep him on this as he only eaten this since last Saturday and see how he goes…