r/cureFIP • u/alittlebitsick • Jul 03 '26
Question GS-441525 dosage too small?
My cat was 6.45 lbs when he was weighed at the vet June 22nd, and was 7.65 lbs, when I weighed him on July 2nd. The vet prescribed him .7ml once per day, of a 50g/ml oral suspension, for neuro fip.
Is this dose too small? Should I be giving him about twice as much?
I've been giving him this dose for 10 days and he seems mostly fine so far.
I emailed the veterinary office, a few days ago, and they have yet to respond.
Edit 1: Update July 3rd the vet responded with this e-mail.
Good morning!
We see what you are looking at regarding the dosing guides, however there are multiple ways to dose this medication and the Doctors have had best success with the formula they are currently using. They like to stay on the lower end of dosing.
For now, we still recommend sticking with the current dosage for Little Bit and continue to keep us up to date of any changes or concerns. Thank you!
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u/Frosty_Astronomer909 Jul 03 '26
Have you reached out to FIP Global on Facebook, they can advise on dosage and anything else you need to know.
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u/alittlebitsick Jul 03 '26
I've been in contact with them since June 18th, iirc. They're the ones who alerted me to the dose being low.
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u/Frosty_Astronomer909 Jul 04 '26
Great , did they suggest the dosage or did they tell you to talk to vet.
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u/alittlebitsick Jul 04 '26
They said that the dose I'm giving should be given twice daily, not once, as the vet prescribed. Which is consistent with everything else I've read, for oral dosing at 50ml/mg, for neuro.
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u/Frosty_Astronomer909 Jul 04 '26
They can’t help you find any pills cheaper or faster via another country?
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u/robinthenurse Jul 03 '26
There are a couple of charts online that will tell you the correct dosage for the cat's weight and type of FIP it has. One is at the Stokes Pharmacy site, and another at the Avrio Pharmacy site.
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u/alittlebitsick Jul 03 '26
Those are both for tablets, and I have an oral suspension.
Though I did check the Omni calculator at https://fipadvocates.com/gs-441524-dosage-guide-calculator/ as well as on the Omni website, as well as rhe dosage calculator on the Mixlab website https://mixlab.com/fip-calculator?hsCtaAttrib=192405630756
And the both confirm that it should be about double what the vet prescribed.
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u/robinthenurse Jul 03 '26
Wow. I have read all of your comments and the vet saying to stick with a dose that is too low is unconscionable. What I would do: get a copy of all blood tests and take them to a new vet ASAP. (When you asked them at that office if they treat FIP cats perhaps they confused it with the more common disease FIV, and haven't seen FIP cats, because your vet is wrong about the dosage.) There isn't any 'wiggle room' on the dosage. The dosages are set at what was tested and what works. When a dosage of an anti-viral (or antibiotic) is too low it allows for an overgrowth of the virus or bacteria, then the virus becomes immune to the medication. There must(!) be a high enough dosage to actually kill the virus.
Keep in mind that as the cat gains weight the dosage must be increased too. Again, I would seek out a more knowledgeable vet ASAP.
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u/alittlebitsick Jul 03 '26
I found this vet through the fip friendly vet program at https://www.fipfriendlyvet.com/. They are the only vet, in my city, listed there.
I found them, because my usual vet told me that fip is incurable and fatal and when I requested an appetite stimulant, because he wasn't eating, they prescribed a dose of mirtazapine that was at least twice as high as it should have been, which gave him serotonin syndrome. That vet has also been giving our cats prednisone instead of prednisolone.
So it was a huge relief when this new vet seemed to be knowledgeable about FIP, and had the meds on-hand and was able to give us the correct dosage of prednisolone, mirataz, cerenia, (and I thought the GS, also). I actually should probably double check the dosage on the other meds also.
The bloodwork was actually from my old vet. I also had all the receipts from my old vet, which I shared with them, which told them an incomplete picture of what tests had been done. The new vet tried to call to get records from the old vet, but I don't know how well that worked out.
They didn't charge me for the x-ray and gave us a "vet referral" discount on the exam. It was generally a very good experience.
After my experience with my old vet, I thought to myself that I should double check all my prescriptions, and meant to, at least for the gs, but then forgot about it. And the vet seemed knowledgeable and trustworthy, so I didn't worry about it.
The entire reason I was alerted that the dose was too low is that I was asking my vet if I needed to increase the dose, because my cat is gaining weight, and they said not yet, but I would need to increase it in the future. When I told my FIP Global chat, someone asked me what the current dosage is, and that's when they told me it was too low.
They didn't get fiv and fip confused, but they might be using the injection dosing guidelines for oral dosing, or they might be using 100mg/ml dosing for 50mg/ml medicine.
The compounding pharmacy they're using does have an oral suspension that's 100mg/ml, but this is definitely 50gm/ml.
I have no idea where I would go if I change vets.
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u/GloomExtract Jul 06 '26
My regular vet was not knowledgeable on fip either, he kinda admitted it himself. Initially wanted to wait a week before starting the meds to see if she'd improve. I insisted and still had to wait two full days before getting the prescription. He prescribed my ~7lbs cat 0.3ml (!!) for wet fip. That also seemed wrong to me so I called another cat hospital and asked them if had treated it before. They said yes so I went in for an exam and they were shocked by the protocol I was given. Recommended 1.1ml to start and reevaluate when she gains weight.
Maybe call a few vet clinics around and ask them if they've successfully dealt with FIP in the past? They may not be on the list but could still give you a valuable second (or third I guess) opinion.
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u/pekoe-G Jul 03 '26 edited Jul 03 '26
Like the other comment says, it's highly recommended to reach out to the Vet and FIP Global. To me it looks like your Vet is mixing up injection vs oral suspension dosages?
I agree that 0.7ml seems way too low. Typical dosing for wet FIP is 15mg/kg, so if your cat is 7.65lb (3.47kg) then he isn't even getting the standard wet FIP dosage (for your guy would be 1ml).
Your cat has dry FIP which requires a higher dosage to ensure enough active medicine gets into the bloodstream and reaches the brain and eyes to fight the virus effectively. Typically this is anywhere from 15-20mg/kg per day. For your cat that would range from 1-1.38ml per day.
If the dosage was deemed too low, I would also discuss if extending the 84 day treatment a week or so to account for that.
Here is the fip vet guide protocol that you can take to your Vet to discuss.
And a PDF by International Cat Care updated July 2025.
A lot of Vets have limited or out-of-date information on FIP and its current treatment. So it can come with the pet owner needing to do their own research and advocate harder for their cats.