There are some rat fist aid kit guides online:
ratguide.com
NERS: First aid for rats (UK site. Not sure what the US equivalent of some of the products are)
Be sure to check the kit at least twice a year and discard anything that is expired especially prescription medicine you keep on hand "just in case". Sterile water and disinfectants have an expiration date, too. Sometimes things like gauze have expiration dates. Basically read all the tiny print on the package, both the wrapper the item comes in and the box / carton 🤪Maybe make a list of every item in the box and the expiration date and keep the list inside the box.
You may want to ask the vet about feeding the rat Oxbow Omnivore Care to ensure proper nutrition in addition to the mush you are feeding.
What curved syringes are you using? Syringes have expiration dates. It's printed on the wrapper or box the syringe comes in.
First Aid Supplies – Rat Guide

Be sure to check the kit at least twice a year and discard anything that is expired especially prescription medicine you keep on hand "just in case". Sterile water and disinfectants have an expiration date, too. Sometimes things like gauze have expiration dates. Basically read all the tiny print on the package, both the wrapper the item comes in and the box / carton 🤪Maybe make a list of every item in the box and the expiration date and keep the list inside the box.
You may want to ask the vet about feeding the rat Oxbow Omnivore Care to ensure proper nutrition in addition to the mush you are feeding.
1 ml straight and curved syringes
What curved syringes are you using? Syringes have expiration dates. It's printed on the wrapper or box the syringe comes in.