To ask if there's a reason vets do this

[Makido]

I have a cat that gets urine infections/cystitis every few years. She has special food and filtered bloody water but sometimes they still pop up.

The vet always gives an injection of both antibiotics and an anti-inflammatory, that last about a day or two, and then a prescription for both medications to give at home for a week (but I have to wait a couple of days to start for the injection to wear off). The cost of each injection is about the same as a weeks worth of the medication I give her myself.

Is this really necessary? A doctor wouldn't give me an antibiotics injection and then tell me to start the prescription in a couple of days. They would just give me a normal prescription to start asap.

AIBU to ask them next time to leave the injections (and therefore the double cost) and just give me meds to start giving her straight away?

I presume the injection is a stronger dose and works more quickly to get the treatment started immediately so that you pet doesn't suffer for longer than necessary.

98% of cystitis in cats is not caused by infection standard protocol is just to use anti-inflammatories unless culture proves an infections is present.

But in answer to your question sounds like the antibiotic injections is an LA formulation that will last probably three days. There is lots of evidence that many, many cats will respond to an injection of something.

They've always done this with my horse when he's needed antibiotics and pain relief.
I understand it to be a 'loading dose' which is faster acting as it's straight into the body via injection rather than waiting for the tablet (or powder in horses case) to be absorbed.
I've always been told to start the next day though, not wait a few days.

It’s a fast acting strong dose to get you started. Also sometimes cats are very difficult with taking medications (I’m not saying yours is but most of mine are horrific!) so the injection ensures that some medication is getting in to your cat even if he’s not totally compliant with the remaining prescription. If you’re really uncertain just ask your vet—a lot of people seem not to want to query things with their vets but it is perfectly acceptable to do so. They will be able to explain fully why it’s necessary and you can then make an informed decision if you want to accept that treatment.

It sounds like they are giving a long acting injection of antibiotics and anti-inflammatories so the next prescription is for when they have worn off.

You would do this in people - for example starting on intravenous treatment and then switching to oral.

However my vet has never given antibiotics for my 2 girls prone to cystitis saying as per Lonecatwithkitten that it is stones or stress, not infection. We have had diet, anti-inflammatories, Feliway, extra litter trays out and that has always done the trick.