#1. Sign up for Pawp. The service is $20/month and you get 24/7 access to vets. Additionally, every calendar year you have access to a one time emergency coverage of $3k USD (there may be a waiting period associated, not 100% sure). Depending on the vet/facility you go to, Pawp will be able to disburse this to the practice directly, meaning none of that irritating "you pay up front and we reimburse you later" bs. This is not an ideal solution as it doesn't cover any kind of preventative or less-serious interventional care, but if something goes wrong sooner than your insurance kicks in, this is a safety net you can have.

Side note: If you have a subscribe and save membership with Chewy, you also at least get access to a similar 24/7 chat line with vets, so if you want to talk to one sooner rather than later to ease your mind or to verify your suspicions, then that may be a way to go.

#2. Per Progressive's own site: To check for pre-existing conditions (which aren't usually covered), some insurers require a checkup and waiting period before your coverage begins. The waiting period may be a few weeks for illness coverage; for accident coverage, it's usually a few days. Note that Progressive's Pet Insurance by Pets Best does not require a checkup, but it does require waiting periods: three days for accident coverage and 14 days for illness coverage

So you may end up in the clear, especially if you're going to a new vet who doesn't have her old records.

I am a very anxious pet parent, and Pawp has come in handy more times than I would care to admit. Full disclosure I have only utilized the vet chat function to date, but I primarily signed up for it for the emergency fund. I have read over the emergency fund usage policy quite recently though (Puppy ate some fabric on Friday...still waiting for it to pass....) and it is really quite straightforward to use if necessary.

Urgh... IANAL but if they don't require a vet precheckup before signing up, there is little they can do to prove that those conditions were preexisting conditions. That being said, putting in a claim right after signing up is sus and will likely flag an investigator on the matter. As long as you claim to the investigator you have never gone to any vet before or used any veterinary products you can probably get away on a technicality. Also not going back to the same vet is a must just in case they interview the vet. Because patient confidentiality doesn't apply to animals, it is likely they will try to find a history, but idk exactly how hard they will look, depending on how much mney it is going to cost them. Idk though, it would be a tricky navigation. Easier with people because you have to subpoena medical records, which is a pain in the ass.

On a side note, it sounds like your cat just has diarrhea which is common after changing brands of food.