So You Have to Give Your Cat Subq Fluids: Here’s How


You might be accustomed to the idea of wrestling a pill down your cat’s throat, but it’s a lot more intimidating when you leave the vet’s office with a bag of fluids, a drip set, and a packet of needles. Watering the cat, as we like to call it around this house, can be intimidating if you’ve never done it before — and some vets don’t provide much training or reassurance to scared pet guardians beyond “make a tent, stick a needle in, pay at the counter on the way out.”

Don’t blame the vets. They’re used to giving fluids (it’s in the first line of treatment for many conditions and typical in surgical settings as well) and it doesn’t occur to them that a freaked-out guardian who’s already upset at a scary diagnosis might be even more intimidated by sticking a needle into their beloved feline friend. What if you do it wrong? Will your cat hate you? What should you expect? If you’re squeamish around needles, can you even handle this?

Vets usually prescribe fluids because cats are dehydrated or they have kidney problems. In both cases, they’re trying to save you money and your cat stress — the alternative would be coming into the office for every fluid treatment. Dehydration can happen with old or very sick cats who aren’t drinking or eating enough because they don’t feel good, or they’re stressed out and frightened. Cats with kidney problems, on the other hand, are unwell because their kidneys get increasingly inefficient, which allows toxins to build up in their bloodstreams. Ultimately, their kidneys just can’t keep up — but if you give fluids, it can help flush those toxins out.

A cat receiving fluids.
Leila kindly modeled because Loki was feeling shy. Believe it or not, this is all the restraint I need. Your mileage may vary.

Typically, your vet will send you home with a bag of something called lactated Ringer’s. You’ll also get what’s known as a drip set — a set of plastic tubing that plugs into the bottom of the bag of fluids and ends with an attachment for the needle. The tubing also has lines where you can directly inject medication, but you probably won’t need those. Often, vets or the technicians will connect the drip set for you, so you don’t have to worry about wrestling it onto the bottom of the Ringer’s.

You’ll also get a packet of needles, usually 18 gauge: Big enough to let the fluid flow, but small enough that they don’t irritate your cat. Too much. Usually the vet’s office will connect the first needle for you.

Be safe: Keep your needles capped unless they’re in use, and store them out of reach of paws of all species.

As a standard, vets usually recommend 100-150 ML per sitting, and these markings are easy to find on the bag. When you’re ready to water your cat, take the time to get set up. It’s a good idea to pick a time when your feline is calm and unsuspecting (like if she takes naps in the afternoon) and a place where she’s comfortable — like the bed or a couch. Find something to suspend the bag, or put in a hook temporarily, and make sure it’s firmly in place. (Trust me, you don’t want the bag falling on you or the cat.) Grab some treats and a towel, along with a few alcohol wipes. Depending on your cat’s demeanor, you may also want a few band-aids and a shot of scotch.


Loki sits relatively calmly while I give him his fluids. It’s a good thing that it’s a one person job, because there’s only one person in my household, and Leila won’t help much. Many people find that they need two people: one to hold the cat, sometimes in burrito form, and the other to give the fluids. In either case, make sure to stay mellow, and don’t fight your cat. If your cat starts to associate fluids with stress, it will get increasingly difficult to give them, which is frustrating for both of you. You can always stop and pick up later, and remember to deploy treats every time so she’ll associate fluids with something she enjoys.

Scoop up your pal, talk reassuringly, and see if she’ll sit calmly on a towel for you before deploying the big guns. If this is your first time, try just sitting for a while, letting your cat sniff the tubing, and draping it across her back — without delivering fluids. Give your cat a few treats and let her saunter away when she feels like it. Go back for another try in an hour or so for the real deal: Just like the vet showed you, make a little tent between your cat’s shoulderblades by pinching up gently, wipe her skin with alcohol, uncap the needle, slide it in just under your fingers, and open the line to let fluids start pouring. When you’re done, close the line, pull the needle out, immediately recap, and give your cat a few treats.

Twisting a needle cap off.
Used (and capped) needle on the table, new needle in hand — I’m twisting the endcap off so I can attach it to the drip set.

Change the needle every time, because even one use blunts the edge, and being poked with a blunt needle hurts. I recommend changing the needle immediately after use, because that way you don’t have to ask yourself if you need to put a fresh one on every time you give your cat fluids. To change the needle, unscrew the part that keeps it anchored to the drip set, twist it off, and slide a new needle on. You’ll notice that your needles probably come with an endcap that keeps them sterile until they’re used: Don’t pull on it. Twist it gently and it will snap right off — if you pull on it, you’ll likely uncap the needle and stab yourself.


  • Help, my cat has a big bulge on her back! It’s normal — your cat can’t absorb 150 ML of fluid that quickly, and the bulge will subside. Tip: Make sure your fluids are room temperature, because the sensation of cold fluids running under your skin isn’t pleasant.
  • Help, there’s fluid leaking out! (And maybe it’s tinged pink!) Also normal — sometimes a few drops squeeze out, and occasionally a drop or two of blood comes out too. If your cat starts freely bleeding and it doesn’t stop, call the vet.
  • Help, pee! All those fluids had to go somewhere. Your cat will use the litter box more and you’ll notice a higher volume of pee than usual. Make sure to clean and change it more frequently than usual. Check for changes in color or smell that might indicate a problem. If your cat starts peeing outside the box, it may be because the box isn’t getting changed enough or it could be the return of a behavioral problem.
  • Help, my cat runs every time I hang the bag! Try leaving it out. It’s not pretty, but eventually it will blend into the background and your cat will ignore it.
  • Help, I stabbed myself! Needlestick injuries happen, and they can be unexpectedly painful. If you prick yourself before giving fluids, recap the needle, flush the injury, and apply a bandage. Then change the needle. If you stick yourself after your cat has had her fluids, recap it, flush the injury well, and bandage it. In either case, your finger might be irritated and swollen, with some bruising. If you notice red streaks, an unpleasant odor, extreme stiffness, or swelling that doesn’t go down in a day or so, call an advice nurse.
  • Help, my vet gave me injectable medication! Many medications — like anti-nausea drugs, painkillers, and tranquilizers — are delivered subcutaneously, and if your cat is already getting fluids, you may as well give them their medications at the same time. Your vet will usually give you a set of filled syringes with instructions on when to give the medications. To use them, uncap the needle, insert it into the port on the drip set, and slowly depress the plunger. Some medications sting, even when diluted with fluid, so your cat might be startled. In some cases you may need to draw up medication from a vial, and your vet will show you how.
  • Help, what do I do with all these needles! In most regions, throwing sharps (used or not) away is illegal and dangerous. Instead, you’ll need a sharps container. They’re available at pharmacies, often for free, and you can keep it tucked away in a safe spot out of reach of paws. If you’re only giving fluids temporarily, you can get a travel or mini size. Bring the container to a pharmacy for safe disposal. Tip: If you have injectable medications, the whole syringe likely won’t fit in the container. Instead, follow the directions on the container for inserting a syringe and withdrawing it while leaving the needle behind.
A vet examines a cat by Shutterstock

Whatever the reason your cat needs fluids, keep up with your vet’s recommendations. You may need to bring your friend in regularly for checkups and weigh-ins, and for cats with kidney function problems, your vet usually needs a quarterly blood panel. In addition, you should call your vet if you see new symptoms or your cat is behaving oddly, and if you just can’t get fluids in at all — you may need to start bringing her in if you can’t manage it yourself, but give it a few tries before you give up, because sometimes you and your cat alike have to get used to it.

For kidney cats, fluids can radically extend lifespan and comfort. When caught early, kidney disease is often quite manageable with diet, but as it progresses, fluids can keep it at bay. They won’t cure chronic kidney disease, but they will make your cat more comfortable and reduce the load on the kidneys. After a few months, you’ll be an old hand, I promise.

About the author: s.e. smith is a cat-owned writer, editor, and agitator living in Northern California with felines Loki and Leila. While not mediating cat fights, s.e. explores a wide variety of subjects in writing and elsewhere, in addition to enjoying reading like a fiend and baking like an angel. Follow smith on Instagram, Facebook, and Twitter.

1 thought on “So You Have to Give Your Cat Subq Fluids: Here’s How”

  1. Pingback: Life With a Cat Living With Kidney Disease • Calvin & Susie

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