If a dog has food or inhaled allergies, then clipping can still help but not as much as if it is because of contact allergies. For you see that food allergies can still manifest themselves on the feet of dogs. And yes itchiness on the feet of dogs is a classic sign of dog allergies..
If hair is allowed to continually grow on a dog’s feet, anytime it gets wet, it will
1 encourage fungal and bacteria growth.
2 If that growth compromises the dogs health and white blood cells go to aid the infected area
3 Both a dogs ears can get infected (because immunity is fighting off infection on the feet) and increased dog allergies can result, because their immune system is over taxed.
Note there is a tipping point for most dogs and their allergies. A highly allergic dog will always be activated easily by many allergens, and so their immune system will always be fighting to get on top of allergies, let alone secondary infections.
what about dogs coats over their bodies and dog allergies?
If you allow a dogs coat to get too long over the rest of its body, it will also trap dirt and irritate the skin. Then if you wash your dog too often you may remove too much oil from their skin increasing allergies.
A long coat when it gets when is also likely to tangle, unless you brush it after washing. When it tangles and dries it will often tighten up on the dog (into dreadlocks) and cause local skin irritation. Not only will it cause immediate pain to a dog, but it will reduce the warmth of the coat – which is the excuse a lot of people have for keeping their dogs coats absurdly long in winter.
There are many reasons why keeping your dog’s long growing coat to less than an inch, often half an inch can be very helpful in controlling dog allergy and allergic reactions.
ps , if you live in a really cold climate then keep it at an inch, but any extra isn’t insulating the dog any more, gravity will separate the weave on top of the dog. if you have groomed your dog too far, or the weather changes, let them sleep inside or put a coat on them as needed.