She needs to see a vet.
The hole if its by her anal area is probably from an anal gland infection abcessing through the skin. If its down on a mammary gland this could be a mastitis infection.
I don't think putting poisons in her are going to help her get better.
She could be in kidney failure if she is not urinating.
She might be having a uterine infection.
I don't think its something you can cure at home. I think she needs fluids and antibiotics and a vet exam.
Hope this helps you!
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