Tanya's Comprehensive Guide to Feline Chronic Kidney Disease - Giving Subcutaneous Fluids with a Syringe

This section shows how to give subcutaneous fluids using the syringe method.
Please be sure to read the Tips on Giving Subcutaneous Fluids page as well, to help you prepare your needles, fluid and cat so that the process is as simple as possible for both of you.
If you are in the USA, you will probably be using the giving set method instead, whereby the fluids drip out of a bag rather like into human patients on an IV drip. Please visit the How to Give Subcutaneous Fluids: Giving Set Method page for more information.

When Not to Give Subcutaneous Fluids Back to Page Index

Sub-Qs are not always appropriate and in fact in certain circumstances can do more harm than good. Do NOT give sub-cutaneous fluids to your cat if:

Your cat is so severely dehydrated that your vet considers intravenous fluid therapy (IV) more appropriate. In certain circumstances IV is the only correct treatment. If your cat has high bloodwork levels (creatinine over 7), s/he might benefit more from IV fluids initially, with sub-Qs provided once s/he returns home as needed.

Your cat has a heart condition. Fluid therapy may still be possible but your vet must decide if it is appropriate for your cat, and determine the amounts and frequencies to be administered.

Your vet has refused to agree to the procedure on other medical grounds.
fluids from the previous session have not yet been absorbed.
your cat is over-hydrated. This may be obvious, or your cat may feel "squishy", the way water in a plastic bag feels - squishiness sometimes happens if a little air gets in with the fluids, and is not normally a problem, but if it happens consistently, your cat may need less fluid. Other symptoms of overhydration may include sudden weight gain, coughing and nasal discharge. See Symptoms for more information. Overhydration may be associated with a heart condition, but contrary to what some vets claim it can still happen in a cat with a perfectly normal heart. It is a good idea to weigh your cat regularly, to check for sudden or continous weight gain which may give early warning of a problem; or
Processing the extra fluids in itself places an additional workload on the kidneys which can make the CKD progress faster; plus it can flush out certain nutrients, and giving fluids when they are not needed may increase blood pressure; so it is best not to begin fluids until the advantages are likely to outweigh the disadvantages. Dr Katherine James of the Veterinary Information Network believes that most CKD cats will benefit from sub-cutaneous therapy once creatinine levels are consistently over 300 -350 (US: 3.5-4). If your vet thinks your cat's CKD is less advanced than this, then it is probably safer to hold off on sub-Qs for the moment;
My vet agreed to us doing fluids in part because she felt Thomas would not find them too distressing. You and your vet do need to take your cat's personality into account in deciding whether to go this route; but do not necessarily assume your cat cannot cope, many cats who ordinarily hate medication of any kind tolerate sub-Qs because they make them feel so much better. I would suggest trying them for a few weeks at least.
Many cats appear happier (more active and alert, with a better appetite) after sub-Qs. However, some may become lethargic for an hour or so afterwards. This is probably nothing to worry about, but if it happens frequently it may be that your cat is not processing the fluid very well, so I would ask your vet to check your cat for possible heart problems or fluid retention.

The Syringe Method Back to Page Index

The syringe method has the advantages of speed plus precision regarding the amount administered. This can be particularly important for a cat with a concurrent heart condition where you need to be extremely cautious. The main disadvantage of this method is that it can be difficult for one person to do alone if the cat is the type to fidget.

If you are in the UK, if you are offered sub-Qs at all (they are not routinely offered in the UK), you will probably be offered this method of administration. However, some vets will ask you to give only 10ml of fluid in one spot, then 10ml in another etc., sticking the cat anew each time. This is extra work for you and much more invasive and less comfortable for your cat, so if your vet is recommending frequent sticks, see how we did it below and ask about doing it this way. Colorado State University College of Veterinary Medicine states "no more than 5 to 10 ml/lb should be given at each injection site" so giving 100ml in one place should not be a problem for a 10lb cat.

If you wish to learn how to give fluids using a giving set, please visit How to Give Sub-Cutaneous Fluids: Giving Set Method instead.

Below we show how we gave Thomas his fluids. As you can see, whilst it was not exactly the highlight of his day, it certainly did not distress him in any way. Some CKD cats like the fluids so much that they come and remind their humans if they are a little late giving them!

This is a small needle used for drawing up fluids: we used a Terumo size 21.

This is a syringe: we always used 20ml syringes because that is what we were originally given by our vet and we got used to them; you might prefer to use larger ones, particularly if you are giving fluids alone, though the bigger the syringe, the harder they are to squeeze. Thomas received 100ml of fluid at each session so we used five of these altogether.

Attach the opposite end of the needle to the end of the syringe.

Take the protective cover off the end of the Terumo needle so the needle is exposed.

Take the bag of fluids and find the entrance with the blue marker. Insert the needle into the clear cellophane as far as it will go (you only need to push gently).

Hold the fluids upright and gently pull on the end of the syringe, gradually drawing the fluids up into the syringe. Try not to pull up air - keeping the fluids upright can minimise this.

When the syringe is full, remove the needle and lay the syringe on its side on a clean cloth, ensuring the end where the needle was attached is not touching the cloth.

Continue drawing up fluids in this way (it is fine to use the same Terumo needle attached to each syringe) into syringes until you have as many syringes as you require.

Lay all the syringes on a clean cloth where you can reach them easily when you have your cat on your knee. Put the bag of fluid to one side until you are able to put it back in the fridge if that is where you store it - the valve on the bag of fluids is one-way, so you do not need to worry about the fluids spilling or leaking.

Next, take another needle: this one is a winged infusion set(also known as a butterfly needle), a needle with a narrow tube attached. We used size 23, which is a very fine needle. Winged infusion sets are more expensive than ordinary needles, so you might wish to use a normal needle with an extension set instead.

Attach the end of the needle to the end of one of the syringes. Take the cap off the end of the butterfly needle. Squeeze gently so the fluid begins to flow and clears the air out of the needle.

Place your cat comfortably on your knee. Pinch some of your cat's skin to form a tent, or pouch. There is no need to apply alcohol to the cat's skin first (Washington State University explains why this isn't necessary unless the cat has a poor immune system, e.g. also has cancer). ).

Hold the needle so the bottom end is the longer end - the needle looked at sideways will look like this: ______\ or this: l____ . Holding the needle parallel to your cat's back, insert the needle smoothly into the tent you have formed.

It can be helpful not only to move the needle towards the tent, but also to raise the skin slightly to meet the needle. Ensure you have not pushed the needle through the other end of the tent - the fluid will leak if so.

Hold your cat with one hand, and squeeze steadily on the syringe with the other. There will be slight resistance as you squeeze on the syringe, and if it seems to going in too easily, the chances are the needle is sticking out the other side of the tent.

Your cat may flinch slightly when the fluids first start going in - this may be because the fluids are too warm or too cold for the cat's liking, or as my vet says, the sensation can be a little bit of a shock to start with. Thomas never flinched at the needle but occasionally did at the first squeeze of the syringe. As you can see, he did not find sub-Qs distressing.

Steadily squeeze all the fluid contents of the syringe into your cat. If there is some air at the end of the syringe, stop squeezing before you reach the air so that you do not inject it into your cat.

When you have finished, remove the needle and pinch or massage the injection area for a minute or so - this will minimise the possibility of fluids leaking. Occasionally you will see a little blood when you withdraw the needle - this just means that you have nicked a small blood vessel and is usually nothing to worry about.

Put the sub-Q fluid back in your fridge or storage area until the next session. Replace the syringes in their containers - it is safe to use them again as long as the tips have not touched anything else apart from the needle that was attached to them. You can re-use them until they no longer run smoothly. Put the lids back on the needles and do not use them again. You must be careful about disposing of needles, which are clinical waste, so the safest thing is to keep them somewhere safe away from children and your pets and ask your vet to dispose of them permanently for you.

Please visit the Tips on Giving Subcutaneous Fluids page for more tips on how to give fluids and possible concerns that might arise during the process.

Additional Information Back to Page Index

Washington State University College of Veterinary Medicine has some clear photographs of how to give fluids using an extension set, a variant on the syringe method.

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This page last updated: 22 June 2011

Links on this page last checked: 14 December 2011