I apologize that no one has responded to your question sooner. Different experts come online at various times. I just came online and saw your question. My name is XXXXX XXXXX I'm a biologist with a special interest in small animal health. I have raised rabbits and guinea pigs for over 30 years. I'm sorry to hear of Princess' problem.
A guinea pig and a rabbit cannot breed. A guinea pig has 64 chromosomes, while a rabbit has 44. They don't even belong to the same genus. There is simply no way a rabbit could get a guinea pig pregnant.
That means Princess has a more serious problem. She may have a tumor in her reproductive organs, which could lead to all the symptoms you are seeing. So could a serious infection or a rupture. Ovarian cysts are common in females, and can also produce such symptoms.I know you would like a home remedy, and I would like to give you one, but unfortunately, this is a situation where there isn't one. Princess needs to be seen by a vet as soon as possible. Any of these potential causes could be fatal if not treated promptly. She is already critically ill. This link will take you to a directory of vets who treat guinea pigs:
Vets who treat rabbits also treat guinea pigs, so here is another directory. Scroll down on the page for Canadian vets.
In the meantime, I would not give her any more baths. It is not recommended to bathe guinea pigs. It is very stressful for them, and they easily become chilled, leading to more health problems. Their own grooming, along with some brushing from you will keep them clean. It's usually only recommended to bathe guinea pigs if they have parasites or a skin infection for which the vet has prescribed special baths. If their back ends become dirty with feces or urine, wash only the soiled area. You can read more about guinea pigs and baths here:
If you have more questions, let me know by clicking on REPLY. I hope Princess will be fine.
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