Thank you for telling me about heart problems! I have done so much reading and never read about that before. My vet is an exotic vet for sure. I truly believe she knows her stuff. She told me that she told them when Aubrey was first brought in that she wanted to do Xrays and a culture but they refused to pay for it. I emailed the company and they told me that they were going to look into this for me because they should have never sold me a sick piggie in the first place. I want to say again that I see now why pet stores are bad places. I got my other two girls from a girl who rescued a pregnant guinea.
It's good that she is an exotic vet, it does sound like she will need xrays and tests etc. to figure out if there is a more serious problem. Those will be quite expensive.... It doesn't surprise me that the pet store refuses to pay for more expensive tests like that. Usually they will cull any more severely sick animals before they put them in the pet store display but that's rarely a guarantee that they aren't sick as it doesn't always show up right away. They are usually willing to pay for cheap treatments but if they don't work they encourage people to return the pets so they can euthanize them although they obviously won't say that. I very much doubt they will heal it and put it back up for sale but I'm sure there are some rare exceptions to that.
Often animals in pet stores come from breeding mills where they will get rid of the sick or deformed animals before they go to the pet store, or they will only keep the better specimens for sale and use the lesser animals for breeding. Pet store pigs are also often pregnant because they don't generally separate them by gender properly, pregnancies are very tough on guinea pigs and of course there's the whole issue of inbreeding. If you read through these forums you will find thousands of topics of people who brought home a pig who was sick, pregnant, or has genetic problems. Pet stores just don't care, they are there to sell a product... it's not just apparent by how they treat their live animals it's also apparent by what they sell for those animals like bad treats
(yoghurt drops, seed sticks), bad pellets
(with little seeds and bits in it, they can choke on the seeds), and of course too small cages. Some will even sell hamster balls or wheels to guinea pig owners even though these can easily kill the pig.
To be fair, plenty of employees at those pet stores do genuinely care about the animals but simply don't know better because they've not been trained properly or given the wrong information during training and so they think they are doing the right thing. Also, not ALL pet stores treat their animals badly
(for example, some will only have rescues on display and work together with a shelter rather than a breeding mill, that or they won't sell any animals at all), this however is less common for sure.
So your only realistic options here are to either return it to the store where it will likely be euthanized, pay for the treatment yourself, or find someone willing to adopt her and who will pay for her treatment... but unfortunately it'll be unlikely that you will find someone willing to invest that much money into a pig they don't know well and neither of those two options guarantee that the pig will even survive or become healthy. If she has a heart condition she might require a lot of medical care for most of her life. Who knows though, maybe if you're lucky she might only have an allergy or something that can be cleared up with cheaper treatment but you won't know that for sure until you do those preliminary tests.
It's a difficult decision for sure, I don't envy you for having to make this call and that pet store is
absolutely in the wrong. I'm not sure if there is much you can do about that other than to complain and not give them your money in the future. I wish you the best of luck with this, I hope things turn out okay.