Thanks for your question, my name isXXXXX and hopefully I can be of some assistance.
I'm sorry to hear that your dog is not feeling well, but hopefully there is an underlying condition that can be treated medically.
Based on your description, it sounds like your dog may indeed be experiencing an abscess (pocket of infection) on her paw. Since she has been chewing at one paw consistently, my guess is that the site where the abscess is now erupting has been a source of pain and inflammation, which she has responded to as all dogs do by licking at the site constantly. In terms of the source of the abscess, I have seen this type of issue in dogs that step on something sharp that causes a deep puncture wound, or even dogs that are bitten by prey animals or another cat or dog in the house.
In terms of treatment, if you think the area is infected, it most likely needs some type of antibiotic to heal completely. Some of these abscesses also require surgical lancing in order to allow the region of infection to drain properly. I would recommend seeing a veterinarian so that they can properly treat the wound, as well as prescribe appropriate antibiotics and pain medications. Additionally, since your dog will continue to introduce infection into the wound by licking at it constantly, this needs to be stopped with the use of an Elizabethan (e-collar) collar, which can be purchased at any major pet supplier or through your veterinarian.
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