I am so glad that you were able to get a hold of your vet, as it would have been terrible to have the injury develop into something worse. If you need help getting your Springer to the vet in the future, some pet-sitters offer transportation to and from the veterinarian. Phoenix Pet Sitting and Boarding Services Here is a link that might be useful: Pet Sitting Services

If it's a pus-y lump then it's likely to be an abscess where she has cut her foot or something like a sharp grass seed has gone in and caused an infection. Get to the vet asap because if it's small enough it might be ok with lancing and antibiotics but once it grows larger it will need surgery to clean it out and put a drain in it.

There are a couple other major differentials for furuncles of the feet- demodex mites (easy to skin scrape and diagnose, hard to treat), fungal infection (need a fungal culture; treatment is antifungal meds almost always need systemic and topical), pedal pemphigus (need biopsy to diagnose; treatment is high dose steroids), lupus (need biopsy with steroids for Tx), metabolic problems (Cushing's disease, liver disease, etc.)- bloodwork may be suggestive or you may need specific testing) or a bacterial infection resistant to cephalexin (need culture and sensitivity). Basically you need the appropriate diagnostics. Throwing misc. meds at the problem is not helping your dog and is wasting your money. I have a patient with similar issues, but have just started on the diagnostic pathway. So far, I did cytology of the puss that comes out of the furuncles and didn't see any evidence of fungal or bacterial infection. I also did several skin scrapes and found no evidence of demodex. So far I've spent less than $100 of the client's money of diagnostics. This is a Great Dane though, so her 6 weeks of Abx for empirical treatment was another $85. It's extremely important to rule out infections before treating any immune disease such as pemphigus or lupus because immunosuppressive steroids will worsen any infection- demodex, bacterial, and fungal- so much that you may NEVER get a cure. But the owner knows that if this Abx course doesn't help, she's getting biopsy, bacterial culture and sensitivity, and fungal culture at the 6 week check up. Unless your vet is willing to do the appropriate diagnostics and recommend appropriate follow up, I'd go ahead and get the dermatologist. Shar Peis are prone to many dermatologic problems that some vets may not be familiar with. In the meantime, Musher's wax is safe and may provide some relief to your dog.

That's great news about your dog, so glad to hear he's doing better. I'm wondering if the itchiness you mentioned after he's given the Apoquel could be a negative reaction to it. I read a little bit about it on Drugs.com and it seems it could be (maybe?). If it doesn't stop doing that soon, you may want to speak to the Vet about it, especially since it's a newer drug. Also, I'm so glad you "get" his need to burn energy. Our lab acts as if she's in pain if she has energy to burn. We use a doggie day care called Camp Bow Wow, it's a franchise with a couple of centers in your area. The only reason I bring this up is I know they offer 1/2 day rates and believe me 6 hours will exhaust him! But since it's indoors in a clean and controlled area, his feet will heal easier. They're also really good at watching them and stop him from chewing his feet.