Neo-predef topical contains neomycin sulfate, isoflupredone acetate and tetracaine hydrochloride. It is useful for minor skin irritation that itches. I would not expect it to have any effect on a growth on a foot pad. It is unlikely to penetrate the cornified pad. Steroids can reduce inflammation, but don't help growths.
Lidocaine and other -caines can be injected locally. They should not be injected into foot pads. It is very painful and the density of the tissue prevents distribution. It can be injected under the pad and/or under the skin around the pad.
How big is the growth and what does it look like?
Hyperkeratosis and zinc responsive dermatosis increase the cornified layer of the pads. The thick pad will crack and form fissures that are painful. The cut surface of lacerated pads can heal without the parts reuniting resulting in a divided pad that can look like a mass. There are a number of tumors that can affect the pad. Mast cell tumors, malignant melanoma and sweat gland tumors are examples. Diagnosis requires analysis of a biopsy. Treatment can be difficult and often requires removing wide area around the mass. The foot has a large blood supply and bleeding can be hard to control. Healing can take a long time and infection is an issue.
Are you able to take your girl to a vet to get a diagnosis and treatment options? Surgery may not be the best treatment.
Let me know if you have other or follow up questions.
Does it have a well defined base? How broad is the base (size and narrower, the same as or broader than the free end of the growth?
If you press on the pad away from and over the bump, do you get a pain response?
You may be able to tie it off without numbing.
Lidocaine patches might work. If you try to lidocaine use a very small needle 25g or smaller and go into skin and under the pad. You shouldn't need much (<1cc). Cardiac effects are seen at high doses (less than 1 cc of 1% lidocaine /10 lbs is relatively safe).
My bias is to use a vet for the expertise particularly if the unexpected occurs, but I understant the $$ issue.
Scrub first with a surgical scrub and soak. Feet are very dirty.
If the base is small, 1/4-1/2 inch, an antibiotic ointment with a high bandage would be OK. You can use a Telfa pad under gauze. Wrap with cling (not tight), pad with a sock or cast padding and cover with vetwrap. Use duct take on the foot to protect from wear and dampness. Use white adhesive tape at the top and tape to fur.
Antibiotics are OK, but probably not necessary. Dose for Amoxi is 10 mg/lb bid.
If you do this, make sure you have a couple competent helper who can restrain your girl and pass you stuff. Please be careful of your dog and yourself.