My dog, a 10 year old female bichon frise, Daisy, was diagnosed with a kidney problem about 8 weeks ago. After having blood tests and a urine protein screen my vet explained that the kidneys were functioning, but that too much protein was passing thru holes in the kidneys. The vet put her on a low protein diet (Hill's Prescription Diet U/D, canned), prescribed 1/2 tablet of 5 mg. Enalapril twice daily and instructed me not to give her anything high in protein. The explanation was that more protein would make the holes in the kidneys larger, therefore they would lose more protein.
The first check-up 4 weeks later revealed that things were going fairly well, the levels of protein in the blood and urine were midway between what may be expected and there was nothing alarming.
The next check-up was 3 weeks later, last week. Daisy was already looking poor at times, low energy, drinking more water, stopped eating her favorite treats (marrow treats) or milk bones, etc. And she goes through shaking spells, like she's cold, sort of shivering.
The vet had also prescribed Remadyl for pain during the 8 weeks, switching to prednisone for a week because the shivering was felt to be due to a previously treated ailment - pain due to a pinched nerve or strain of the spinal cord.
Anyway, now the vet and I wonder if the kidney problem could cause the off and on shivering. Sometimes the shaking is worse just before a meal and would seem to fade after she ate.
There could be a lot of things wrong with her. Her teeth missing is no big deal, dogs lose teeth but if her mouth is really bad it could be painful for her to eat. You may want to try a soft canned food. Her shaking could be pain as well. Her abdomen being "bloated" could be ascites (fluid in her abdomen). This can be caused by many things including tumors, liver failure, etc. Vets are expensive but I think you should call around and get her in somewhere. Tell them you are tight on money and they will try to work with you. Either way you should do something because it sounds like she is suffering because she isn't eating.
Good Luck