The symptoms you describe sound like what my small breed dog had. I took him to the emergency veterinary clinic (open 24/7) and one x-ray showed he needed emergency surgery to remove stones (both types).
It was a life threatening condition (blocked urethra). Often the veterinary clinics have payment plans, or accept credit cards.
The supplements and special diets are for prevention, they won’t help an existing condition or cure a blockage or infection.
They are available online, example http://www.entirelypets.com/k-plus-potassium-citrate-plus-cranberry-300-tabs.html?cmp=nextag&mr:referralID=2b34b4bd-6c95-11e2-b779-001b2166c62d Once your dog has received the appropriate treatment and is stable, ask your vet if these are options.
