This sounds like allergies to me. One of the first (and most noticeable) signs of allergies is paw chewing/excessive licking. It could be something in the house (cleaning product, dust, synthetic fiber), it could be grass mites (although that would generally be more of a spring/summer problem, usually), or it could be something in the food you’re giving him to which he has an intolerance (as was the case with my own dog…anything with wheat makes him practically chew his paw pads off). It’s a hard thing to pin down, and usually your vet will suggest a series of allergy tests to try and figure out what is causing the problem, although these are not always 100% reliable and can be expensive if you don’t have insurance. I would start by switching to a hypo-allergenic food with a different protein source than you’re currently feeding him (i.e. if it’s a chicken based food, try lamb or fish) which does not contain any wheat. I’d also try washing his feet in warm water every time you come in from a walk. As far as cleaning products go, perhaps you can switch to low-chemical brands.

Acral Lick Granulomas (licking out of boredom/to pacify/compulsion) are usually localized (meaning your dog has one or two spots that he licks until it’s red raw and gross). It doesn’t sound or look like this is what your dog is doing. I’d try to rule out allergies.

good Luck!

Trinity use to do the same, had blood tests done and result was that she has house dust so now we just have to sweep floor/hoover every day instead general house cleaning once a week. Test was pricey (€160) but got it refunded through pet insurance. Anyways even if you don`t have one it`s worth it as at the end of the day with never ending visits to the vet plus medications it`s probably going to cost more altogether Hope Herbies mommy can find solution to her worries.

I would agree with stk that it COULD possibly be allergies. Your vet should be able to run a concise and detailed series of tests (usually via bloods) to check for common allergens, could be anything from dust (a big allergen with dogs) to scented plugs / candles or floor product or floor components. I would go back to my vet and ask for these tests for Herbie.
Saying that, one of our girls (dalmatian) got exactly the same thing, the photos look identical, only she got it round the front of her paws as well, as a reaction to stress. Dals, and colllies are both known as being a highly strung breed so stress is not good for their already hyper nature. In Lola’s case, she got it when unfortunately we had to kennel our dogs during a home rebuild. She did it partly from boredom but mainly stress. We got some fantastic aloe vera products via our vet, who is also a homeopath, which really helped her. We chose not to put socks or any kind of cover on her paws as we felt this would compound the problem. Lola adored us checking her paws regularly, massaging them and rubbing in her various aloe vera products! She really enjoyed it. Sorry I cant be of any more help unfortunately but I really would go back to the vet if I were you, and get the tests kickstarted. If anything, at least you will have eliminated many common allergens and you can then start looking at other possible alternatives. Also, if you arent getting answers from your vet, please dont be afraid to seek more specialist advice – your vet certainly wont be offended and is bound to be in the position to make a referral to a dermatology type person who will be expert in their field. We had this done for our other dog who had a problem with his heart. The whole process was extremely quick, efficient and painless and at the end of it, we had answers and a treatment plan in place which really did ease our minds. I can appreciate that seeing Herbie in this state must be very distressing for you, as his owners, especially when he sounds like he already had a hard life prior to you adopting him so lots of licks from our gang here (canine! being sent your way, to Herbie also! Good luck with getting to the bottom of it and keep us updated – you will find its a common enough problem!