Poor girl. I'd consider asking whether bladder support supplements - things like cranberry extract for dogs - are appropriate to help her get through until she has a heat and/or surgery down the line. These are definitely NOT a replacement for medical treatment when it comes to an active UTI, but may help prevent them from reoccurring. It's one of those things where the scientific evidence is shaky, but it can't hurt and so may be worth it just in case it does help her.
I feel you on the medicated diets being expensive. We've had to use them once or twice for digestive episodes with our older dog. But if they're keeping your dog healthy and reducing/eliminating the symptoms they're meant to target, it's absolutely the right call. While they may have 'substandard' ingredients, they are formulated to be extremely effective at what they do, and if your dog isn't able to handle the dog foods with 'good' ingredients, then that isn't a good food for her right now. It sounds like once you get her past this rough period where she's having bad UTIs you'll likely be able to transition her to a more affordable diet, but it's important to do whatever supports her best right now.
And I'll defer to your vet on long-term antibiotic use. It's of course not ideal, but neither is letting an infection go and have it potentially spread to the kidneys (absolutely a possibility with a UTI). You can (and should) get a second opinion with another vet or request a referral to a specialist if you feel like your current vet isn't handling things well or taking your concerns seriously, but my understanding is that UTIs can be very tricky to get a handle on, so it's very possible that there's not much more anyone can do for her than what you're doing now.
Good luck, and keep us updated!
I feel you on the medicated diets being expensive. We've had to use them once or twice for digestive episodes with our older dog. But if they're keeping your dog healthy and reducing/eliminating the symptoms they're meant to target, it's absolutely the right call. While they may have 'substandard' ingredients, they are formulated to be extremely effective at what they do, and if your dog isn't able to handle the dog foods with 'good' ingredients, then that isn't a good food for her right now. It sounds like once you get her past this rough period where she's having bad UTIs you'll likely be able to transition her to a more affordable diet, but it's important to do whatever supports her best right now.
And I'll defer to your vet on long-term antibiotic use. It's of course not ideal, but neither is letting an infection go and have it potentially spread to the kidneys (absolutely a possibility with a UTI). You can (and should) get a second opinion with another vet or request a referral to a specialist if you feel like your current vet isn't handling things well or taking your concerns seriously, but my understanding is that UTIs can be very tricky to get a handle on, so it's very possible that there's not much more anyone can do for her than what you're doing now.
Good luck, and keep us updated!