Key Tips

What You Will Need

Fluid Types

Preparation Overview

Fluid Preparation


Fluid Administration Sets

Preparing Your Cat (Includes the Clothes Pin Trick)

The Big Moment!


Re-use and Disposal of Needles and Administration Sets




Site Overview

What You Need to Know First

Alphabetical Index


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What Happens in CKD

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Is There Any Hope?

Acute Kidney Injury



Nausea, Vomiting, Appetite Loss and Excess Stomach Acid

Maintaining Hydration

The Importance of Phosphorus Control

All About Hypertension

All About Anaemia

All About Constipation

Potassium Imbalances

Metabolic Acidosis

Kidney Stones



Coping with CKD

Tanya's Support Group

Success Stories



Alphabetical List of Symptoms and Treatments

Fluid and Urinary  Imbalances (Dehydration, Overhydration and Urinary Issues)

Waste Product Regulation Imbalances (Vomiting, Appetite Loss, Excess Stomach Acid, Gastro-intestinal Problems, Mouth Ulcers Etc.)

Phosphorus and Calcium Imbalances

Miscellaneous Symptoms (Pain, Hiding Etc.)



Blood Chemistry: Kidney Function, Potassium, Other Tests (ALT, Amylase, (Cholesterol, Etc.)

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Complete Blood Count (CBC): Red and White Blood Cells: Anaemia and Infection

Urinalysis (Urine Tests)

Other Tests: Ultrasound, Biopsy, X-rays etc.

Renomegaly (Enlarged Kidneys)

Which Tests to Have and Frequency of Testing

Factors that Affect Test Results

Normal Ranges

International and US Measuring Systems



Which Treatments are Essential

Fluid and Urinary Issues (Fluid Retention, Infections, Incontinence, Proteinuria)

Waste Product Regulation (Mouth Ulcers, GI Bleeding, Antioxidants, Adsorbents, Azodyl, Astro's CRF Oil)

Phosphorus, Calcium and Secondary Hyperparathyroidism (Calcitriol)

Miscellaneous Treatments: Stem Cell Transplants, ACE Inhibitors - Fortekor, Steroids, Kidney Transplants)

Antibiotics and Painkillers

Holistic Treatments (Including Slippery Elm Bark)

ESAs (Aranesp, Epogen etc.) for Severe Anaemia

General Health Issues in a CKD Cat: Fleas, Arthritis, Dementia, Vaccinations

Tips on Medicating Your Cat

Obtaining Supplies Cheaply in the UK, USA and Canada

Working with Your Vet and Recordkeeping



Nutritional Requirements of CKD Cats

The B Vitamins (Including Methylcobalamin)

What to Feed (and What to Avoid)

Persuading Your Cat to Eat

Food Data Tables

USA Canned Food Data

USA Dry Food Data

USA Cat Food Manufacturers

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UK Cat Food Manufacturers

2007 Food Recall USA



Intravenous Fluids

Subcutaneous Fluids

Tips on Giving Subcutaneous Fluids

How to Give Subcutaneous Fluids with a Giving Set

How to Give Subcutaneous Fluids with a Syringe

Subcutaneous Fluids - Winning Your Vet's Support




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Home > Fluid Therapy > Subcutaneous Fluids Tips



  • The very idea of giving subcutaneous fluids to your cat be pretty scary at first, but there are ways to make it easier for both you and your cat.

  • The type of fluid you use can make a lot of difference to your cat's comfort levels. This page explains more about the different types of fluids that are available.

  • It also discusses the best type of needles (Terumo), how to prepare and calm your cat (including the famous clothes pin trick) and what to expect both during and after the procedure.

Key Tips

Giving sub-Qs for the first time is scary! It may never be something you look forward to, but there are ways to make the process go more smoothly which not all vets are aware of, so they may not tell you about them. If you follow these tips, you and your cat still may not necessarily enjoy the process (although some cats realise that sub-Qs make them feel better and actually remind their human if they are late giving them!), but it should make it tolerable for you both.


Remember, you're doing this to help your cat. Sub-Qs do help!


The key tips:

  1. Warm the fluids. Cold fluids can be very uncomfortable.

  2. Use Terumo UTW (ultra thin walled needles) if possible. These can make an incredible difference to your cat's comfort level yet few vets use them. 

  3. You don't have to only use the scruff of the neck. You can use the area that would be covered by a saddle.

  4. Try to get into a routine. Most cats like routine. Even if your cat never grows to like sub-Qs, if s/he knows you always do them at 6 p.m., s/he will remain relaxed around you the rest of the time (yes, of course cats can tell the time!).

  5. Is your cat the demon cat from hell? Try the clothes peg (clothes pin) trick! It can often make even the wildest cat co-operate.

What You Will Need


You will need several items in order to give your cat sub-Qs. Vets can normally supply these items, and it is worth obtaining them from your vet the first time or two and being shown how to give sub-Qs by your vet or vet tech. Most people do eventually start sourcing their own supplies in order to save money. See the Obtaining Supplies Cheaply section for information on where to buy fluids, needles and administration sets in the USA, UK and Canada.


Essential Supplies When Using the Giving Set Method

This is the most common way of giving fluids in the USA.

  • Fluid bags

  • Most people use a type of fluid called lactated ringers solution (LRS) but sometimes other types of fluid are appropriate. See below for more on this.

  • Needles

  • You have to insert the needle into your cat to allow the fluids to flow into him or her. Ideally you want Terumo ultra thin wall needles.

  • Fluid administration set (giving set or venoset)

  • This enables you to attach the bag of fluid to the needle. The fluid flows from the bag through the administration set and into the needle and then into your cat.

Optional Supplies When Using the Giving Set Method

  • IV pole

  • Some people find these helpful to speed up the process.

  • Weighing scales

  • Some people find these helpful for measuring the amount of fluid they are giving.

  • Burette or buretrol

  • These items are used by some people to measure accurately how much fluid they are giving.

  • Calming or restraint method

  • Some cats do better when these are used. See below for options.

  • Baby food or other treats

  • Some people use these to distract their cats during fluids, others use them as a reward afterwards.

Essential Supplies When Using the Syringe Method

This is the most common way of giving fluids in the UK and is also used by some people in the USA.

  • Fluid bags

  • Most people use a type of fluid called lactated ringers solution (LRS) but sometimes other types of fluid are appropriate. See below for more on this.

  • Syringes

  • You use these to measure out the fluid which you are going to inject into your cat.

  • Needles

  • You use these to draw the fluid out of the fluid bag into the syringe, ready to give to your cat.

  • Winged infusion sets

  • These are used to inject the fluid into your cat.

Optional Supplies When Using the Syringe Method

  • Calming or restraint method

  • Some cats do better when these are used. See below for options.

  • Baby food or other treats

  • Some people use these to distract their cats during fluids, others use them as a reward afterwards.

Choosing a Fluid


There are several different classes of fluid:

  • Isotonic - have the same sodium concentration as body tissues.

  • Hypotonic - have a lower salt concentration than that in body tissues.

  • Hypertonic - have a higher salt concentration than that in body tissues.


All the fluids discussed below (apart from dextrose, which is not recommended) are isotonic. However, ISFM consensus guidelines on the diagnosis and management of feline chronic kidney disease (2016) Sparkes AH, Caney S, Chalhoub S, Elliott J, Finch N, Gajanayake I, Langston C, Lefebvre H, White J & Quimby J Journal of Feline Medicine & Surgery 18 pp219-239 state "although a balanced electrolyte solution such as lactated Ringer's solution is often used, a hypotonic solution (half-strength lactated Ringer's or 0.45% saline, with added potassium as needed) may be preferable to reduce the sodium load."


There are a variety of fluid types available. The fluid most commonly used for CKD cats is Lactated Ringers Solution (LRS), but occasionally other fluid types are prescribed, usually because of other issues which need addressing. If your vet gives you another type of fluid, do check this is necessary because some other types can sting, plus some of them are more expensive than LRS. Please also always check the bag of fluid before you start to use it in case you have been given the wrong type: mistakes can happen.


International WIN shows the contents of commonly used fluids.

Introduction to fluid therapy (2008) Dr S DiBartola has information about different fluid types and explains why LRS is the best choice for sub-Qs for cats.


The DEHP Issue

The plastic of some fluid bags contain a chemical called diethylhexyl phthalate (DEHP), which softens the bags. Some people prefer not to use bags containing DEHP because they are concerned that some of the DEHP may leach into the fluids themselves, especially if the bag is warmed before use.


The Australian Government Department of Health mentions that studies into the effect of DEHP on mice and rats found that they developed liver tumours, but this was after they were fed DEHP in high doses. I am not aware of any studies into the effect of DEHP on cats. The US Food & Drug Administration has concluded that "there is little or no risk posed by patient exposure to the amount of DEHP released from PVC IV bags during the infusion of crystalloid fluids (e.g., normal saline, D5W, Ringer's Lactate)".


I would probably avoid DEHP bags myself if I could find an alternative. I understand that the B Braun, Baxter and Hospira brands in the USA offer DEHP-free bags which cost around $0.50 a bag more. As at July 2016 it was virtually impossible to obtain DEHP-free fluids in the USA because of supply problems, and I know some people are very concerned about this. Personally, if I couldn't find or afford DEHP-free bags, it is not something I would lose any sleep over - in my opinion, it is more important that a cat who needs fluids receives them.


Lactated Ringers Solution (LRS)

Human patients with kidney disease are given fluids containing a buffer such as lactate, and this is also the most common choice for CKD cats. The lactate is important for CKD cats because lactate is metabolised by the liver where it is converted to bicarbonate, and this aids in the correction of mild acidosis.


In the USA fluids with lactate as a buffer are known as Lactated Ringers Solution (LRS). The nearest British equivalent is called Aqupharm No. 11 Hartmann's solution, although you may also be offered Vetivex 11. These fluids may vary slightly, and there may also be small differences between human and veterinary formulations, but they are all broadly the same:

Fluid Sodium Potassium Chloride Calcium* pH Calories per litre Lactate
LRS         mEq/l 130 4 109 3 6.5 9 28
Aqupharm 11  mmol/l 131 5 111 2 6.5 9 29
Vetivex 11 mmol/l 131 5 111 2 6.5 9 29

MEq/l and mmol/L values are the same for the above ions apart from for calcium ions, where the mmol/L measurement is half that of the mEq/l measurement, so the Aqupharm and Vetivex fluids each have an mEq/l value of 4


Introduction to fluid therapy (2008) Dr S DiBartola discusses (penultimate question) why LRS is the best choice for most cats on sub-Qs. He states ""I am unaware of clinical situations in which small animal patients have been harmed by lactated Ringer’s solution."


Normosol-R/Plasma-Lyte A/Isolyte-S

This is a type of fluid which is sometimes used instead of Lactated Ringers when a cat has high calcium levels, liver problems or lymphoma (a form of cancer).


Normosol-R is the most commonly prescribed fluid in this category, but you may also be offered PlasmaLyte A, or occasionally Isolyte-S. They are all basically the same type of fluid, but different manufacturers use different trade names.


If you are using Normosol, you need Normosol-R, not Normosol-M: the latter contains dextrose (see below).


There are two versions of Normosol-R, one with a pH of 6.6 (similar to LRS, which has a pH of 6.5) and one with a pH of 7.4. Plasma-Lyte A also has a pH of 7.4. For cats with high calcium levels, the more alkaline varieties (pH of 7.4) may be a better choice.

Fluid Sodium Potassium Chloride Magnesium pH Calories per litre Buffer
Normosol- R 140 5 98 3 6.6 18 Acetate 27 Gluconate 23
Normosol- R 140 5 98   7.4 18 Acetate 27 Gluconate 23
Plasma-Lyte A 131 5 98 3 7.4 18 Acetate 27 Gluconate 23
Isolyte S 141 5 98 3 7.4 18 Acetate 27 Gluconate 23


These products contain magnesium, so may not be suitable if your cat has high magnesium levels. This type of fluid also seems to sting some cats or make them twitch when the fluids are administered (see Symptoms for other possible causes of more frequent twitching), so cats may resist being given this type of fluid. A lot of vets don't seem to be aware of this possibility but Managing fluid and electrolyte disorders in renal failure (2008) Langston CE Veterinary Clinics Small Animal Practice 38 pp677-697 states (page 11) "Plasmalyte is reported to sting when administered SC." Introduction to fluid therapy (2008) Dr S DiBartola states "The low pH and high acetate content of some Plasmalyte products and Normosol R may contribute to pain on subcutaneous injection."


There have also been quite a few reports of cats vomiting after being given this type of fluid. All of these products are also more expensive than Lactated Ringers and may be harder to find. I therefore recommend that, if at all possible, you should use lactated ringers instead.


Saline Solution (Sodium Chloride or NaCl) 0.9%

Saline solution (sometimes referred to in human medicine as "normal saline") may be suggested by some vets, but it tends not to be the best choice for a CKD cat because:

  • it is usually too acidic

  • it lacks the buffer contained in lactated ringers

  • it does not have added potassium, which many CKD cats need.

  • the higher sodium load is additional work for already damaged kidneys to process

  • it is not usually suitable for cats with hypertension or liver problems.

  • it can sting when injected subcutaneously which may make the cat resist sub-Qs

However, it is sometimes appropriate for:

  • cats with high calcium levels (though Normosol-R may be a better choice); or

  • cats with hyperkalaemia (high levels of potassium), who may initially be placed on intravenous sodium chloride in hospital

Fluid Sodium Chloride pH Buffer
Sodium Chloride 0.9% 154 154 4.5 - 7.0



One possible compromise would be to use half strength (0.45%) sodium chloride fluids. ISFM consensus guidelines on the diagnosis and management of feline chronic kidney disease (2016) Sparkes AH, Caney S, Chalhoub S, Elliott J, Finch N, Gajanayake I, Langston C, Lefebvre H, White J & Quimby J Journal of Feline Medicine & Surgery 18 pp219-239 state "although a balanced electrolyte solution such as lactated Ringer's solution is often used, a hypotonic solution (half-strength lactated Ringer's or 0.45% saline, with added potassium as needed) may be preferable to reduce the sodium load."



These fluids contain dextrose, a form of sugar. Therefore they do contain a few calories, though not enough to be of any real benefit (8.5 calories per 100ml of fluid). These fluids are sometimes used when appropriate as intravenous fluids in a hospital setting but they are not usually appropriate for home use because:

  • the sugar means that bacteria can easily grow in the fluid and cause infection at the injection site.

  • fluids containing dextrose may sting when administered via sub-Qs.

  • fluids containing dextrose also have a shorter lifespan than non-dextrose fluids.

Occasionally vets may dispense this sort of fluid in the form of 2.5% dextrose added to either 0.45% sodium chloride or to LRS, as a way to reduce the amount of sodium your cat is receiving. I don't really see much benefit from adding dextrose, which has few advantages for CKD cats.


Pet Place discusses the need to avoid giving sub-Qs with added dextrose.

Introduction to fluid therapy (2008) DiBartola S discusses why fluids containing dextrose are best avoided for sub-Qs for cats.

Managing fluid and electrolyte disorders in renal failure (2008) Langston CE Veterinary Clinics Small Animal Practice 38 pp677-697 states (page 11) "Dextrose-containing fluids increase the risk of abscess formation... when administered SC."




Preparation is the key with sub-Qs. You want to have the best equipment possible, and you want to have a system in place to increase your chances of success. It is fine to buy a few supplies from your vet to tide you over until you've read through this page and the Obtaining Supplies Cheaply page and sorted out your plans for which supplies to use and where to obtain them.


The first thing to do is to practice giving sub-Qs - on an orange. The feel of a needle going into an orange is similar to that of a needle going into a cat, so give it a go and see how it feels. Just use the needle, don't bother with the fluids. You just want to feel the sensation. You can also practice on a piece of raw chicken with skin. Try to inject the needle between the skin and the muscle.


If you don't have to start sub-Qs urgently, you can also get your cat used to the idea of injections. Training your cat to love injections without ruining your relationship (2011) is a helpful article with photos from Dr Sophia Yin.


If you give your first sub-Q to your cat at the vet's, you may well find your cat behaves better there, so don't be surprised if your cat is less co-operative at home, where s/he does not expect this sort of treatment and is probably less fearful and therefore less afraid of letting you know what s/he thinks! You may also find that your first few sessions at home go well, but then your cat starts to object. This is also normal.


Most people do find that their cat eventually accepts sub-Qs at home. If you don't succeed, don't beat yourself up but instead look into alternatives, such as having a vet nurse/tech come to your home to help you, or taking your cat to the vet for treatment.


Fluid Preparation

Fluid Storage and Lifespan

Fluid bags have an expiration date on them. Do not use them beyond this date.


Once you have opened a bag of fluids, you should ideally not use it for longer than ten days. If you are giving 100ml of fluid every day, this is not a problem, but if you are only giving fluids every other day or small amounts at one time, this means you will probably have to discard a 1 litre bag before you have finished it. It is possible to buy 500ml bags of fluid, but these tend to work out more expensive than buying 1 litre bags and discarding what you don't use. See Obtaining Supplies Cheaply for fluid purchasing options.


Some people do use opened bags for longer than ten days without problems. In fact, Assessment of sterility of fluid bags maintained for chronic use (2011) Matthews KA & Taylor DK Journal of the American Association for Laboratory Animal Science 50(5) pp708–712 did find that "fluid bags used chronically can be maintained in a sterile condition for a maximum of 30 days" but that study was using syringes to remove the fluid from the bags (see How to Give Subcutaneous Fluids: Syringe Method) rather than using giving sets. Personally, I would err on the side of caution because CKD cats are immune-compromised, but if you do decide (with your vet's approval) to keep an opened fluid bag for longer than ten days, I would not keep it beyond thirty days.


Fluids may be kept in the fridge and removed shortly before use, but if you are going to use up the bag  within ten days of opening it, it is usually not necessary to refrigerate it - they are not usually refrigerated in hospitals. The US National Library of Medicine mentions that fluids should be stored at room temperature of 25° C (about 65° F). We stopped refrigerating our fluids and had no problems.


Regardless of how long each opened bag lasts, always check the bag before each use. In order to avoid any possible problems with infection or contamination, never use a bag of fluids if the contents look cloudy. Often the bag itself will look a bit misty with condensation, particularly if you have just removed it from the fridge, but if the contents themselves look cloudy, that is a red flag.


Fluid Warming

When used straight from the fridge or even at room temperature, many cats find the fluids uncomfortable and may twitch, so you should warm the fluids before use. Place the bag of fluids and the giving set (keep the port openings out) in a bowl full of hot water, ensuring that the entrance to the bag (where the marker is) is not immersed, and leave to warm for ten minutes. Some people have found that filling a cooler box with hot water works well. Alternatively, you could use a heatpad to warm the fluids.


When you connect the fluid bag to the fluid administration set, run a little fluid through the line before you give it to your cat to ensure your cat does not receive cold fluid remaining in the administration set.


Make sure the fluids are not so hot that they will burn your cat! You can buy an infrared digital thermometer to check the temperature - I bought one from Radio Shack which cost about US$10.


Warming fluids in the microwave is not recommended because it is hard to get the right temperature so you may find the fluids are too hot in places.


A small number of cats do prefer the fluids at room temperature so experiment to see what works best for you both.


If you take your cat to the vet for fluids, you may find they do not warm them. Discuss with them whether it would be possible to do so if you think it would make your cat more comfortable.


All About Needles

In order to give your cat sub-Q fluids, you will need hypodermic needles. All needles are universal, i.e. they will fit any administration set. Needles are widely available from a number of different manufacturers and are single use only (see below to understand why). If you don't get the needle in correctly the first time, throw it away and use a new one.


A needle is sterile and should be kept that way until use, so after you've given your cat fluids, remove the needle from the end of the line and place a new needle complete with cover on, ready for your next session. Only remove the protective covering or cap when you are about to use it.


Hands up, those with a needle phobia. Join the club! I did master the art of giving sub-Qs despite my own needle phobia. In sixteen years of running this site, I've only heard of one person who did not master giving sub-Qs herself because of a needle phobia. She never even tried to give them (in her case, her needle phobia was insurmountable). Please give it a try. It's much cheaper for you and less stressful for your cat if you learn to give sub-Qs yourself at home.


Choosing Needles: Terumos

Many vets routinely stock Monoject needles or needles from other manufacturers. Some people use these without any problem, and many people use them initially when they have not yet had time to shop around for supplies. However, the best needles for CKD cats are widely considered to be those made by Terumo.


Why are Terumo needles so good?

  1. They are extremely fine but still very sharp. Terumo states that its Sur-Vet veterinary needles are 18% sharper on average than those produced by the leading veterinary needle manufacturer. Ordinary needles are referred to as "kitty harpoons" on Tanya's CKD Support Group, but Terumos slide in like a knife through butter.

  2. Some of the smaller gauge Terumo needles (from size 20 upwards (see below for information on needle sizes) are ultra thin wall (UTW). This means the diameter of the inside bore is larger than another manufacturer's needle of equivalent size, allowing greater flow rate. Terumo Europe has a photo of how this works (click on Surflo Winged Infusion Sets Leaflet). This feature means it takes less time to give your cat sub-Qs.

If you haven't yet used Terumo needles, give them a try. I regularly hear from people who cannot believe the difference they make to their cat's comfort levels and their own stress levels!


Some people find it can be hard to take the covers off Terumo needles. There are various ways to do it, but one way that seems to work is to attach the needle to the IV tubing, then twist and tug the cover quickly. Alternatively you can rock the cap to and fro to loosen it, then pull up quickly. Terumo now makes a new style of needle with a guard which is easier to open, but most needles with this feature are not UTW.


Terumos in USA and Canada

Unfortunately Terumo has reduced the number of ultra thin wall needles that it produces but I am thoroughly confused by what they are actually producing at the moment because different links on their website give different information, as follows:

  • The Terumo Veterinary Products Catalog (May 2015) indicates that size 22 x ¾" and 25 x ¾" Sur-Vet needles along with some under the Terumo name (gauges 21-23 in varying lengths) are still ultra thin wall.

  • The website (July 2015) indicates that in fact the veterinary products are only thin wall, not ultra thin wall.

  • the website (Sept 2015) indicates that needles under the Terumo name gauges 21-23 are still available in ultra thin wall form but only in longer lengths and only in Canada, though they are available to US distributors, so in principle it should be possible to find them in the USA if you shop around.

  • Terumo conventional needles and syringes (Nov 2015) indicates that gauges 21-23 are still available in ultra thin wall form but only in longer lengths.

All these changes may be partly because Terumo have introduced a new guard on their needles (which you flick rather than pull off, as you had to do with the older needles) which apparently makes them safer to use. It will probably make them more expensive too. I would suggest you order the older, cheaper ultra thin wall needles while you can. You can obtain details of mail order suppliers for needles in Obtaining Supplies Cheaply - you can expect to pay around US$6-10 for 100 needles.


Nipro make an ultra thin walled needle called Flomax. I don't know anyone who has tried this type yet but you might want to consider them if you cannot obtain Terumo.


Terumos in UK and Europe

In the UK, Terumo needles used to be branded as Neolus, and ultra thin wall needles (sometimes referred to as ultra fine wall) were available. Neolus needles were rebranded as Agani and Cosanum has a table showing the old and new reference numbers. It appears that the Agani needles are also ultra thin wall.


Terumo in Europe also sells Surguard needles with the new guard, which are not ultra thin walled. The Obtaining Supplies Cheaply page has details of suppliers who can still provide UTW needles.


If you are giving sub-Qs with a syringe, you will normally need winged infusion sets. These help you when inserting the needle and give you something to hold when you are switching syringes over. Terumo Europe sells these under the Surflo name, and these are ultra thin wall.


Choosing Needles: Size and Speed

The size of needle used can make a tremendous difference to your and your cat's comfort and stress levels. On the packet it will say something like 21G x 5/8". The first number with the G is the gauge, i.e. the needle size. The second number is the length of the needle in inches, so this needle is 5/8 inches long.


The higher the number (gauge) of the needle, the finer - smaller - the needle. If you choose a needle below size 18, it can be rather big and uncomfortable for the cat (size 16, for example, is often used on goats and sheep). On the other hand, a needle above size 23 can mean it takes too long to give the fluids.


Needles also come in different lengths, the most common being 5/8 inch or 1 inch. You are less likely to accidentally poke the shorter needle into your cat and out the other side, but on the other hand, it is harder to adjust the smaller needle (for example, if the fluid isn't flowing properly and you wish to move the needle a little). The length of the needle is a personal choice, but most people seem to like the 1 inch length.


If your cat dislikes fluids, you need to decide if it is the actual sticking that bothers him/her, or if it's the length of time it takes. If it is the sticking that is an issue, opt for size 20 or above ultra thin wall Terumo needles.  If it's the length of time it takes to give the fluids, opt for a size 18 or 19 which will get the job done quicker. Most Tanya's CKD Support Group members use size 19 or 20 because these give a balance between size of needle and speed of fluid flow. Those using a size 20 or above usually opt for Terumo ultra thin wall needles if possible.


Rad, whose lovely cat, Purr Box, is the model in How to Give Subcutaneous Fluids: Giving Set Method, ran an experiment regarding the flow rate of various needles. Here are the results of his experiment, which he has kindly given me permission to publish here. The flow rates (all for 100ml of fluid) are in minutes and seconds.


Needle Details

Speed of Flow in Minutes and Seconds

Brand and Size

Length (inches)


First Flow Test

Second Flow Test

Average Flow Rate

Terumo 18

1 TW




Monoject 19

1 n/a




Becton Dickinson 18

1 n/a




Terumo 19

1 TW




Monoject 18

1 n/a




Terumo 20





Becton Dickinson 20

1 n/a




Monoject 20

1 n/a




Terumo 21 1 UTW




Terumo 22





Terumo 21 (Sur-Vet Label)

1 TW




Monoject 22

0.75 n/a




Monoject 22

1 n/a




Terumo 23





Monoject 22

1.5 n/a




Terumo 25





TW Thin Wall

UTW Ultra Thin Wall


Freezing Needles

Some people freeze needles before using them. This is because of a study, Pain associated with injection using frozen versus room-temperature needles (2001) Denkler K Journal of the American Medical Association 286 p1578, where a plastic surgeon who froze needles before using them on his (human! - what cat needs plastic surgery?) patients found that 76.6% of the patients found the frozen needles less painful. Freezing the needles doesn't always seem to make a difference for cats, but it might be worth a try. If you decide to try this, do not freeze the needles for longer than a few days in case it adversely affects the sterile packaging.


IV Administration Sets (Venosets or Giving Sets)

If you are giving sub-Qs by letting the fluid drip out of the bag (giving set method), you need a venoset, also known as an IV administration set. You usually need a prescription (it depends which state you live in). As with fluid bags, you may wish to use a DEHP-free set (Hospira makes one, among others).


There are two factors to consider with administration sets, the flow rate and the length. In terms of length, these sets come in a variety of lengths but most people seem to like 72, 80 or 100 inches long sets.


In terms of flow rate, you will see a drop/ml reference, for example 10 drop/ml. 10 drop/ml means that 10 drops provide 1 ml, so if you are giving 100ml, you would be giving 1000 drops. Thus you want a 10 drop/ml or at most a 15 drop/ml administration set, because higher numbers/slower flow rate administration sets would take too long. One thousand drops sounds like a lot, but it will only take you about 3-4 mins to give your cat fluids with this size, depending upon how much fluid you are giving and what size needle you are using. Obviously a 15 drop/ml set takes 50% longer to give the fluids than the 10 drop/ml set but on the other hand the slower flow rate may suit some cats and mean they tolerate fluids better. You will have to experiment to see which works better for your cat.


Some venosets have a luer lock to lock the needle in place, which most people find helpful. Some venosets have a port which you can use to add certain medications. If you do this, make sure you only use medications in a form suitable for this purpose.


Most people use the administration set for 2-3 bags of fluid, as long as the end to which the needle is attached is kept sterile. When you want to remove the needle from the administration set, it can be rather difficult. Using pliers or a pair of rubber gloves can help.


See the Obtaining Supplies Cheaply page for stockists.


Mar Vista Vet has a helpful video about preparing for giving fluids.

Dr Mike Ontiveros has a video which shows how to prepare a venoset for sub-Q fluids.


IV Pole

Since giving fluids via a fluid administration set relies on gravity to deliver the fluids, many people try to hang the fluid bag high up so as to speed up the process. You can use a coathanger, but some people decide to buy an IV pole. This can be wheeled to your cat, which can be helpful if your cat copes better with fluids while sleepy.


Amazon sells a suitable pole for less than $30 including shipping.

Dr C Wladis explains how the height of the fluid bag affects the speed of delivery.


Preparing Your Cat


It often helps both you and your cat if you set up a routine and stick to it. Speak to your cat during the procedure and reassure him/her, but don't overdo it or s/he may think s/he is right to be frightened. Try not to be nervous yourself or your cat will sense it; aim to be very matter-of-fact about it all. Tell him/her what you are doing and why - many people find this seems to help. You can also choose a special word or phrase that tells them you are about to give them medication and/or fluids - the cat will soon learn what this means, and will then not be stressed when you approach him/her at other times.


Some cats tolerate sub-Qs better if they are sleepy.


Some cats feel happier if they are given fluids in a familiar place, whereas others may be more co-operative if the fluids are given in a strange place, perhaps a room they are not normally allowed to enter. Experiment and see what works best.


Here are some methods which people have found makes the process easier.


Calming Methods - Feliway or Zylkène



Feliway is a copy of the pheromones naturally present on a cat's face. When a cat rubs his face on something, s/he is marking it with these pheromones, which make the cat feel more relaxed. Some people find Feliway can be helpful when giving sub-Qs. You can buy Feliway plug-ins and simply leave them on in the room where you usually give fluids, or you can use the spray version.


Entirely Pets also sells Feliway for US$28.99, with refills costing US$10.99.

Petguys sells plug-in Feliway for US$27.99 in USA, with refills costing US$15.99.

Vet UK sells Feliway in the UK.



Zylkène is a natural product derived from casein, the protein in milk. Life Extension Magazine has an article about why bioactive milk peptides can be calming. Effect of alpha-casozepine (Zylkene) on anxiety in cats (2007) Beata C, Beaumont-Graff E, Coll V, Cordel J, Marion M, Massal N, Marlois N & Tauzin J Journal of Veterinary Behavior: Clinical Applications and Research 2(2), pp40–46 found that it seems to be effective, and it does seem to help some cats to accept sub-Qs.


Zylkène is often available from vets in Europe. In the USA you can find it on Amazon. You can open the capsule and mix its contents with food.


Distraction and Bribery

Some cats can be distracted with a little food during sub-Qs. Cookie on the left was the sort of cat who needed to be sedated for blood draws, yet as you can see he had no problems receiving sub-Qs, and could easily be distracted during the procedure with food, so no restraint was necessary. I think this is a great photo for showing sceptical vets that many cats can tolerate sub-Qs very well.


Even if you prefer not to feed your cat during the procedure, many cats feel hungry after fluids so take the opportunity to offer your cat some food afterwards - we always fed Thomas as his reward for being a good boy. 



Some cats do better if they are restrained during sub-Qs, either by hand or by a cat restraint bag, or in a carrying basket with a top opening. However, others are more likely to co-operate if they are not restrained and feel they have some kind of control. If your cat tends not to like being held generally, s/he probably won't like to be held during the sub-Q process either. You know your cat best so decide which would be better. 


The Thundershirt is not a restraint device but rather a coat that provides gentle, constant pressure which is supposed to reduce anxiety.  It is intended for dogs, and The effect of a pressure wrap (Thundershirt) on heart rate and behavior in canines diagnosed with anxiety disorder (2014) King C, Buffington L, Smith TJ, Grandin T Journal of Veterinary Behavior 9(5) pp215-221 found that it appears to be effective. I don't know if it would be effective for giving sub-Qs (I'm not sure you'd be able to access the injection area) but I have heard of people using one successfully to calm their cats in other situations. Please do not use without your vet's approval.


Comfort cats in a towel wrap is a video by Dr Yin on how to handle a difficult cat simply using a couple of blankets.

Feline Friendly Handling (22015) Scherk M is a helpful article on reducing stress for your cat.


Restraint Products

Four Flags in the USA sells the Cat Sack, for holding your cat while you medicate him/her or administer sub-Qs. It can help with wriggly cats, and most cats do not seem to mind it. I put this on my cat and was surprised to see that she didn't mind it at all.


Amazon also sells the Cat Sack in various sizes at various prices (be sure to buy the correct size for your cat).


DVM News Magazine shows you how to make a restraint bag from an old pair of jeans.


EZ IV Harness has been used by some members of Tanya's CKD Support Group. This can be shipped internationally. It allows the cat to wander a little, which can be better for cats who do not like restraint. It helps hold the needle in place, so you don't need to.


The Clothes Peg (Clothes Pin) Trick


If your cat wriggles or gets stressed during sub-Qs, you can try the clothes peg (clothes pin) trick: this is a form of acupressure recommended by an acupuncturist vet back in 2000 to a lady called Lori. Here, Joan's Sassy models this trick. Sassy, left, was not a particularly placid cat, but this method enabled Joan to give Sassy fluids successfully and with much less stress for either of them. As usual, please check with your vet before trying this.


Be sure to "clip the kitty" when he or she is calm, and before you begin the sub-Qs. It won't work once the cat is upset and squirming to get away. 


You take standard wooden clothes pegs (clothes pins), and clip the scruff of the cat's neck starting at the back of the skull where the skin is loose. 








You attach three clothes pegs side-by-side to form a "ridge" down the centre of the back of the neck. Some cats might need to have as many as six clothes pegs placed there for it to be effective. It looks just like a "kitty mohawk" when done properly.






This is what it looks like from the side. The clothes pegs can pinch if you don't clip enough skin in the teeth, so make sure you have enough skin in them to create pressure, but not to hurt the cat. Most cats should relax quite a bit within a few minutes - some even lie on their side.


You can then give the sub-Qs lower down. Once you've finished the sub-Qs, you can remove the clips, and the cat should be fully alert within a few minutes. 


Eight years after I first mentioned this technique, a study was published, Pinch-induced behavioral inhibition ('clipnosis') in domestic cats (2008) Pozza ME, Stella JL, Chappuis-Gagnon AC, Wagner SO, Buffington CA Journal of Feline Medicine & Surgery 10(1) pp82-7 which concluded that "PIBI was useful for gentle restraint in most cats."

You can buy special clips for this purpose now but they work in exactly the same way as clothes pegs, and clothes pegs are much cheaper and easier to obtain quickly.

In 2011 I was concerned to learn that several members of the Association for Pet Behaviour Counsellors have reservations about the use of this technique. They believe that whilst the cat may appear calm and submissive, s/he is actually very stressed. In this sense it would be very similar to the way rabbits trance when you flip them on their backs which is extremely stressful for rabbits. I am investigating this further. Ohio State University College of Veterinary Medicine reports on the rationale for the above study and their interpretation of the behaviour of the cats in the trial, whom they consider were not stressed.


Thanks to Lori for providing this helpful tip back in February 2000 and giving me permission to share it here, and thanks to Joan and Sassy for the photos.


The Big Moment!


So you've got your supplies and your cat, and you're all ready to go. It can be worth doing a trial run without your cat to ensure you have all the supplies that you need at the ready. But eventually it will be time to stick a needle in your cat. And you're terrified. Don't worry, that is completely normal. The first time might go well or it might not. Don't worry if it's a bit of a disaster, if you don't get all (or even any) of the fluid in - many people only get 30ml or so in the first time. You are going to get better at this!


Having said that, do try to think positive. Your cat will sense if you are fearful, and may react to this, creating a vicious circle. So think positive, and remember, you will both adapt, especially once you and your cat realise how much better s/he feels afterwards.


Remember, cats can be good at giving you a guilt trip. Some cats make a fuss even if the needle is not in! But if it does turn into a bad session, let it go and try again later or the next day.

The website most people find most helpful when they are getting started is Sophia gets her subcutaneous fluids. You can also visit these pages with photos of giving sub-Qs to see the two different ways of giving sub-Qs:

The Saddle Area

You do not need to restrict your injections to the neck area, in fact it is better to move around the body in order to minimise the possibility of scar tissue forming. Roughly speaking, you can inject your cat anywhere which would be covered by a saddle (as Sophia models here; scroll to near the end of the page). Experiment a little because some cats have preferences - Thomas much preferred being injected on his right side to his left. Be careful to avoid the spine though.


Numbing or Cleaning the Area

Some people use lidocaine but it is not recommended because it can be toxic to cats. Pet Place states "Caution should be used whenever lidocaine is given to cats since they tend to be especially sensitive to the drug." Local anesthetic toxicosis (2000) Welch LS Toxicology Brief says "Cats are sensitive to the CNS effects of lidocaine, however, so monitor them for seizures when you give lidocaine as an antiarrythmic or local anesthetic." In Topical creams and pets: a dangerous -combination the ASPCA includes lidocaine on its watch list. In any event, if you use sharp needles, sub-Qs are really not that painful.


You also don't need to wipe with alcohol first. It needs time to work, about 30 minutes, and since most people don't wait that long, it's a bit pointless. Critical Care DVM says "It is not necessary to “sterilize” the skin with alcohol prior to inserting the needle. In reality, wiping a little alcohol on the skin does not sterilize it, and the odor and feel of alcohol may aggravate your pet." If you are keen to clean the area, ask your vet about using chlorhexidine (hibiscrub). You only need to wait 30 seconds for chlorhexidine to take effect but it should not be removed until you've finished giving the sub-Qs.


The Tent

You will find it easier to inject your cat if you form a good tent (pouch) with the skin. On the left you can see us making a tent on Thomas.


One reader asked me to mention that if your cat wears a collar and you give fluids nearby, you need to make sure the collar does not become uncomfortably tight as a result.



Inserting the Needle

Before you insert the needle, check to see it is smooth and sharp - on rare occasions needles are faulty and have a little barb which makes inserting it uncomfortable. If your cat normally doesn't flinch when you insert the needle, but suddenly does so, this might be the cause.


Another reason why your cat might flinch when you insert the needle is that you hit a muscle. Just withdraw the needle, reassure your cat, and try again in another spot (with a new needle).


Flinching only happens very rarely, but if it seems to happen regularly, you may be using a type of fluid (such as saline or Normosol) which stings, in which case you may wish to speak to your vet about changing to another type of fluid. Incidentally, some cats flinch even when you are only pretending to insert a needle!


You need to insert the needle the right way up. The needle will look like this from the side: ______\ 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.


I used to hold the needle gently in place (which is easier to do with a winged infusion set). If the needle does slip out, try again with another needle. However, I would not stick a cat more than twice in one session, so if the needle slips out more than once, I would give up and try again another time.


Some vets in the UK recommend using multiple needle sticks, e.g. only giving 20ml in one place, so a cat receiving 100ml would receive five sticks. This is completely unnecessary. International Cat Care states "Generally around 10-20 ml/kg of fluid can be given at a single SQ injection site (around 60-100 ml for an average sized cat)."


Trouble Inserting the Needle - Thick Skin

Sometimes the skin may feel tough so it is hard to get the needle in. There are a number of possible reasons for this. Firstly, perhaps surprisingly, it can indicate dehydration, in which case your cat definitely needs the fluids. Secondly, it may indicate scar tissue. This is actually not that common, and usually doesn't happen for a long time (months to years) but one way to avoid it is to rotate where you give fluids (see above).


Stabbing Yourself with the Needle

At some point you will almost certainly accidentally stab yourself with a needle. This is usually nothing to worry about, it happens to virtually everyone and is not usually cause for concern. However, if you have a compromised immune system or if the area becomes red or sore, or if you are worried, seek medical advice - if you're not up to date on your tetanus shots, you may be advised to have one.


Giving the Fluids

The actual process should only take 2-5 minutes. If it's taking longer than this, you need to review the rest of this page to work out why.


If your cat fights the process, don't panic, but try to find the cause. Certain types of fluid can sting, see above for more information. Not warming the fluids can be uncomfortable for some cats. Occasionally a needle can be barbed.


If your cat is calm initially but then fights you after a minute or two, it might be because you are giving too much fluid in one spot and it is becoming uncomfortable - generally speaking, you should not give more than 100ml in one spot. Also make sure you are holding the needle in place, so it does not move and irritate your cat.


Pressure Infusor

Some people with fidgety cats use a pressure infusor to help the fluids flow more quickly. A pressure infusor is a special bag into which a bag of fluid is placed, and a pump is used to squeeze the fluid out of the fluid bag more quickly. The Society of Critical Care Medicine explains more about how these work. Bay Medical has a good photo showing what they look like. You will need a prescription from your vet.


In principle you can give 100ml of fluids in under a minute using a pressure infusor, though you have to be careful not to make them flow so quickly that it is uncomfortable for the cat. Because the fluids flow so quickly, you also have to be very careful not to give too much fluid to your cat.


In theory the pressure infusor bags should only be used once but some people use them more than once. Be guided by your vet.


Sun Med produces pressure infusors to fit various fluid bag sizes.


Measuring the Fluid

It is important to try to give fluids accurately. Giving too much in one go can be risky, especially for cats with heart conditions. There are a number of ways to measure how much fluid you are giving, as outlined below.


If you do accidentally give too much fluid once, it will probably be fine, but check in with your vet and watch for signs of overhydration.


Never give any more fluid until the previous amount has been properly absorbed.


If you are using the Syringe Method, you can measure the amount you give very accurately.


Marking the Fluid Bag

In the USA, there are markings on the bag, often the numbers 1 to 9 or 10. These numbers represent 100ml, and when you hang the bag up, I am told you usually have the number 1 at the top. So, for example, if your fluid level is at 7, you have used 700ml of the bag and have 300ml remaining.


Fluid bags often aren't marked in the UK. Some people mark the bag with a permanent marker (sharpie) but this was not recommended because the ink can leach through to the fluids, though The contamination of intravenous fluids by writing on the infusion bag: fact or fiction (2014) Langston JD, Monaghan WP & Bush M International Journal of Advanced Nursing Studies 3(1) pp18-19 found that in fact this did not happen during their study.


Weighing the Fluid Bag

Hanging scales can help you work out how much fluid you have given if you are using a fluid administration set. 100ml of fluid weighs 100g, so it is not too difficult to do. Hanging scales are usually the best choice.


Pesola is a popular brand of hanging scale but is quite expensive.

Hanging scales are also available from Amazon here and here.

Amazon UK has scales which are not hanging scales but one member of  Tanya's CKD Support Group has used these scales successfully.



These terms are often used interchangeably. As far as I've been able to work out, a burette is a chamber which allows you to measure precise amounts of fluid. A buretrol is a device containing a burette which essentially does the same thing when you are giving fluids or other medications.


Buretrols can be useful for measuring the amount of fluid you are giving to your cat. Some of them (such as this Baxter set) come with an attached fluid administration set, which means that the speed of that set controls how quickly you can give fluids to your cat. Since buretrols are usually used for intravenous fluids, where a slow flow is normal, some of them are 60 drops/ml, which is too slow for giving fluids to a CKD cat (see above for more on drop speeds). Therefore most people use an add-on buretrol, as shown by The ABCs of IVs, which means the speed is determined as usual by your administration set drip rate and the size of your needle.


You attach the spike (pointy bit) on the end of your fluid administration set into the bottom of the cylinder. You then attach the spike on the end of the buretrol to the end of your fluid bag.


Another advantage of a buretrol is that you can simply warm the amount of fluid you are giving that day, rather than having to warm a bag multiple times.


Some stop automatically once empty


After Sub-Qs

Most cats feel better after receiving fluids, and are often more active, with a better appetite. If your cat becomes lethargic after receiving fluids, or loses appetite, this may be a sign of overhydration or heart problems. If your cat vomits, it may be because of the type of fluid you are using (see above). Speak to your vet about this.


Leaking Fluid

You may also see a bit of fluid leaking out on to your cat's fur after you remove the needle: again, this is normal. If you pinch or massage the injection area for a minute or so, this will minimise the possibility of fluids leaking.





Seeing Blood

Occasionally you may see a little blood when you withdraw the needle. This usually means you have simply nicked a small vein, and is not normally anything to worry about.


The Fluid Pouch

After a little while the pouch of fluid which you have injected will move around the cat's body. It may go down one of the front legs or just hang on the stomach. This is normal and is nothing to worry about - think of it like a camel's hump, to keep your cat hydrated. It should be absorbed gradually over 6-8 hours.


Still, it is better to avoid injecting in an area where the fluid consistently moves down to a front leg because this can be uncomfortable for the cat (try to move back slightly); and you should never give more fluid until the fluid in the pouch has been absorbed.


Crackling Noise Under the Skin (Subcutaneous Crepitus)

Occasionally you may hear a "crackling" noise under your cat's skin after giving sub-Qs and/or the cat may seem "squishy". This simply means that a little air has got under the skin (this is known as subcutaneous crepitus), and should go away on its own in a couple of days.


It is not usually anything to worry about unless it happens regularly. If it does, I would recommend that you discuss it with your vet because it may mean that your cat is overhydrated, in which case you need to reduce the amount of fluid which you are giving; or you may need to refine your technique so as to allow less air under the skin.


Re-Using Supplies


Re-using Venosets

Most people change the venoset every time they change the fluid bag, though some people use them for two fluid bags. If you do this, switch the line to the new bag as soon as you've finished the first bag, making sure not to contaminate it.


Re-using Needles

This is not recommended, because using a needle just once blunts and distorts the needle which means using it again makes it more painful for the cat. Children with Diabetes shows photographs of how a used needle looks - scary! Re-using a needle also increases the risk of infection, not a good idea with an immune-compromised cat.


You can obtain needles very cheaply (around US$6-10 for 100 online, see Obtaining Supplies Cheaply) so it's really best to use each needle only once.


Needle Disposal

Most countries have laws about putting used needles in the trash. If you are in the USA, you can check your state's laws at the Environmental Protection Agency website. You can usually buy a sharps disposal unit from your vet or local pharmacy for a few dollars or pounds, or some vets may allow you to return used needles to them for free.




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This page last updated: 23 July 2016


Links on this page last checked: 23 July 2016






I have tried very hard to ensure that the information provided in this website is accurate, but I am NOT a vet, just an ordinary person who has lived through CKD with three cats. This website is for educational purposes only, and is not intended to be used to diagnose or treat any cat. Before trying any of the treatments described herein, you MUST consult a qualified veterinarian and obtain professional advice on the correct regimen for your cat and his or her particular requirements; and you should only use any treatments described here with the full knowledge and approval of your vet. No responsibility can be accepted.


If your cat appears to be in pain or distress, do not waste time on the internet, contact your vet immediately.



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