Subcutaneous Fluids

By Marje Blaine

The ability for a caregiver to give his/her cat subcutaneous (subQ) fluids at home is an excellent tool to provide the cat support for myriad conditions such as acute or chronic kidney disease (AKD and CKD, respectively), IBD, pancreatitis, lymphoma, liver failure, triaditis, diabetes, and constipation to name a few. Subq fluids provide support through hydration and electrolytes. Subq fluids should never be given to a cat unless the caregiver’s veterinarian has prescribed them for that specific cat and has indicated the type of fluids, the amount, and the frequency at which they should be administered. Even if a caregiver is experienced at giving subq fluids and has them on hand for a different pet, it is imperative that the veterinarian first be consulted regarding administration of the fluids to each specific pet.

Please note there are other methods of providing hydration to your cat such as adding water to its food or using oral hydration sachets as your vet may indicate and you can discuss with him/her. However, if a cat needs supplemental hydration because it is not eating or cannot get enough through oral methods, then subq fluids can be extremely beneficial. Conversely, there are situations where the cat may have a more critical need for fluids that can only be provided by IV fluids administered by the vet.

Following is a brief overview of topics to discuss with the vet if he/she has prescribed subq fluids for your cat. Included is information on types of fluids available, supplies needed to support administering fluids, tips on giving fluids, and a video tutorial.

Conditions which May Benefit from the use of Subq Fluids

IBD, Pancreatitis, Liver Disease, Triaditis, Lymphoma, Constipation
For any of these conditions where the cat might be vomiting or have diarrhea, subq fluids can help with restoring hydration and electrolyte imbalances and provide general support to allow the kitty to feel better. Subq fluids can help cats with constipation by providing additional hydration although treating chronic constipation often requires a multi-tier approach.

Acute or Chronic Kidney Disease
Cats with acute or chronic kidney disease typically have difficulty concentrating their urine that puts them at risk of dehydration. Especially in CKD where the cat cannot drink enough water to stay adequately hydrated, there usually comes a point where supplemental fluids, in the form of subq fluids, are needed. Your vet should be consulted as to when subq fluids should be started for a cat with CKD but, in general, they would be started when the creatinine is around 3.5 (in the U.S.). There may be situations where the vet would start them sooner for a specific cat. Also, in general, it is better to give smaller amounts more frequently than to overwhelm the kitty with a larger amount given two or three times a week but, again, it’s important to consult your vet on this.

The most common use of subq fluids in diabetic cats is if ketones are present in trace amounts or for after-hospitalization, at-home continuing treatment of diabetic ketoacidosis (DKA) once the vet feels the cat is stable enough to be sent home. Please do not administer subq fluids at home for ketones without consulting with your vet. Even with “trace” ketones, your vet should be contacted immediately. Please see the more detailed Diabetes discussion on this site for specific information on diabetes.

Cautions When Administering Subq Fluids
It is very important to remember that cats can be overhydrated!! Do not listen to any person or vet that tells you that you cannot overhydrate a cat. The best form of hydration for a cat is drinking water followed by the caregiver adding a little extra water to its food, having extra water dishes around the house, and a water fountain.

While it may not be economically feasible to do so, if the caregiver can afford it, it is often a good option to have an echocardiogram, or at the very least an EKG, done before long-term administration of subq fluids at home. Not all heart conditions are apparent or detectable solely by the vet listening to the heart. Administration of fluids to a cat with a heart condition can potentially put the heart function at risk and result in fluid accumulation in the chest or abdominal cavity. If your vet is aware of any heart condition, he/she can determine if it is safe for you to give the cat subq fluids at home and define the amount and frequency of fluids that are safe.

If your vet has prescribed subq fluids, it is extremely important that the cat be checked every single time before administering them to ensure the previous fluids have been completely absorbed. Do not give fluids without talking to your vet if it appears there are any residual fluids or if the cat feels “squishy” anywhere (including under/around the chest, in the sides or abdominal cavity, behind or down the front paws). A good way to prevent over-hydration is to weigh the kitty regularly to ensure there is no sudden weight gain which could be attributable to fluid retention.

No matter what the caregiver does to make giving subq fluids as least stressful as possible, some cats will not adjust and the whole process will end up causing them much more stress than the potential benefit of giving fluids. It is hopeful this does not happen with your kitty and it typically does not because subq fluids can make a kitty feel so much better. But if you’ve tried it for several weeks and the situation is not improving, it’s also important that you listen to your cat and discuss with your vet if there are other options such as a mobile vet that can administer them at your home or a vet tech who is willing to assist you.

Types of Subq Fluids
Subq fluids are broken down into isotonic (same salinity as body tissues), hypotonic (lower salinity than body tissues), and hypertonic (higher salinity than body tissues). In general, isotonic solutions are the best to use as subq fluids. Some of the specific types of subq fluids are described below. If at all possible, it is best to use subq fluids which come in DEHP-free bags and tubing. DEHP is a chemical used to soften the fluid bags but there is concern that the DEHP can leach into the solution. While there are no cat-specific studies regarding this, a cautious approach is the best one if DEHP-free bags (like BBraun) are available.

Lactated Ringers Solution (LRS)
LRS is the most common type of subq fluids used for cats with AKD or CKD. In cats with CKD, the lactate in the LRS is metabolized in the liver and converted to bicarbonate that can help those CKD cats that have mild metabolic acidosis. LRS also contains potassium and is a good choice for those CKD cats with lower potassium levels; however, there is a point that low potassium cannot be corrected solely with LRS and your vet may need to prescribe supplemental potassium.

Saline Solution (NaCl or Sodium Chloride)
Use of saline solution is extremely dependent on why the subq fluids are needed. Saline solution can sting and may cause the cat to become resistant to allowing the administration of fluids. It is not the best choice for cats with CKD (as it is too acidic), liver issues, or hypertension (due to the salt content). It may be beneficial for cats with high potassium levels since it does not contain potassium, as does LRS.

Normosol-R, Plasmalyte A, Isolyte S
These subq fluids are generally the same but have different manufacturers. If a cat has high calcium levels, liver problems, or lymphoma, your vet might prescribe one of these fluids. Normosol-R is provided in two different pHs (6.6, similar to LRS, and 7.4). The more alkaline version (pH 7.4) is more indicated for cats with higher calcium levels, liver problems, or lymphoma. It has been noted that these fluids may cause cats to vomit after administration of them. They also tend to sting the cat and can cause twitching at the needle insertion site. In addition, these subq fluids contain magnesium and may be contraindicated in cats with high magnesium levels.

Normosol-M and other fluids with Dextrose
Fluids with dextrose are usually more beneficial on a short-term basis to diabetic cats with low blood glucose as these fluids contain sugar. They have a shorter “shelf-life” and can grow bacteria due to the presence of sugar. These fluids are not the subq fluids of choice for the majority of conditions where the caregiver would be administering subq fluids at home.

Methods to Administer Subq Fluids

Giving Set Method
This is one of the more common methods in which to give subq fluids at home and resembles how IV fluids are given with the exception that the fluids are given subcutaneously instead of intravenously. It requires a bag of subq fluids, an IV administration line, something from which to hang the bag (such as an IV pole), and needles. This is typically the best way to give a larger amount of fluids.
Pictorial on How to Give Subcutaneous Fluids Using a Giving Set:

How to Give Subcutaneous Fluids to your Cat at Home
(Includes a detailed description of supplies needed and a list of resources)


The Syringe Method
For administering smaller amounts of fluid, for speed of administration, or for finer control (e.g. in the instance of a kitty with a heart condition where the amount of fluid given must be very precise), the syringe method offers advantages over the Giving Set Method. However, it is more likely that this method will require two people if the cat is particularly fidgety. This method requires the bag of fluid, needles, several large capacity syringes (e.g. 20 ml), and a winged infusion set (a.k.a. butterfly needle). The fluids are drawn directly from the bag into the required number of syringes. The cat is usually held on a lap and the butterfly needle is inserted into the cat subcutaneously. The fluids are administered from the syringes into the winged infusion set.
Pictorial on How to Give Subcutaneous Fluids Using the Syringe Method:


Location, Location, Location
It’s best to find a good location which can always be used to give fluids and where there is good lighting, a comfortable spot for the cat to lay, easy access to all equipment, and a good place from which to hang the fluids as the more “drop” between the bag and the needle, the better the fluid flow. IV stands can be purchased quite reasonably from medical supply stores. Fluids can also be hung from the top of a door or shower rod using a coat hanger. The ideal setup is when the cat is lying on a flat, cushioned surface, at caregiver waist to breast height with the fluids hanging proximal to and above the cat.

• Subq fluids will need to be acquired from the vet or a pharmacy. Vets will typically add a substantial markup (50-100%) for the cost of a bag. A prescription is needed to purchase subq fluids at a pharmacy but buying by the case through a pharmacy is much more cost efficient.

• With careful handling, it is acceptable to use a specific bag of subq fluids (other than dextrose) for 10-14 consecutive days after “opening”. Any fluid remaining in the bag after this timeframe should be discarded.

• Fluids do not need to be refrigerated after opening.

• Fluid in the bags may be “gently” warmed (never microwave a bag of fluid!) in the sink in a warm pan of water. If the caregiver elects to do this, it is wise to buy an infrared digital thermometer which will indicate the temperature of the fluids within the bag. Fluids should never be warmer than the cat’s body temperature (usually around 95 degrees F works just fine). Some cats tolerate the fluids at room temperature but many are more comfortable if the fluids are warmed slightly in a pan of warm water.

• Some States require that you have a prescription to obtain needles. If you are ordering them online, if your state is one that requires a prescription, you will need to provide it to the online company.

• Needles should be kept sterile so don’t remove the packaging until you are ready to attach it to the line and insert it in the kitty. Needles should not be used more than once so if the needle should fall out of the kitty during fluid administration, put a new needle on the line. Never reuse a needle, even if an insertion fails the first time. This is for comfort but also, more importantly, to maintain sterility and not risk introducing any bacteria into the process.

• The smaller the gauge of the needle, the more comfortable it is for your cat especially at insertion. Most vets use Monoject 18g needles to administer subq fluids because the process, even with 100-200 mls of fluids, goes quickly. However, for administering subq fluids at home, it is much better to go with a smaller gauge needle like 20-21g. It will take slightly longer but will be more comfortable for the cat and if fluids are going to be given long term, will result in less scar tissue accumulating.

• The best needles to use at home are the Terumo Ultra Thin Wall (UTW) needles. Although Terumo is discontinuing production of these needles, they make a “Sur-Vet” needle which has a thin wall and which may be an acceptable substitute if the caregiver cannot still find the UTW needles. Many caregivers find storing a few needles at a time in the freezer prior to use helps to numb the discomfort as the needle is inserted into the subcutaneous layer of the cat.

IV Administration Sets
This is the tubing that connects to the subq fluids bag on one end and then the needle on the other.

• In some States, you will need a prescription to purchase IV administration sets. If you are ordering them online, if your state is one that requires a prescription, you will need to provide it to the online company.

• The sets typically come in either approximately 80” or 100” long and many caregivers opt for the 80” line. They are also available in 10 drops/ml or 15 drops/ml. Most caregivers also opt for the 15 drops/ml sets as it allows faster administration of fluids.

• Other options to select would be DEHP-free lines, lines with a luer lock to ensure the needle does not easily separate from the line, and lines which have ports if kitty needs other medications (as prescribed by the vet) which can be given at the time of fluids.

The Cat
While some cats are very relaxed and administering subq fluids does not disturb them, the majority will need to become accustomed to the process. It’s very important for the caregiver to breathe and stay calm. It usually helps if two people can be involved in the process initially….one to keep the cat calm and the other to insert the needle and hold it during the fluid administration. There are several methods that can be used to calm a cat including Rescue Remedy or Feliway sprayed on the caregiver’s hands and then smoothing the hands over the fur. Feliway plug-ins can also be kept in the room where the fluids will be given.

Having favorite treats handy are also a good method for distracting the cat; the treats should be placed in front of the cat immediately before the needle is inserted so the cat is distracted by enjoying the treats. Treats should also be given as a reward or have a plate of food ready as some cats are hungry after receiving fluids.

Cats do not typically like restraint although a soft hand resting on their body as the needle is held in place is a comfort. For cats that are more nervous or fractious, the Thundershirt or EZ IV Harness will help with the process. You can also use Green Hope Farm flower essences (all alcohol free), or a calming collar. (All links are included below)

In Summary
It takes time and patience to learn to give subq fluids at home but the potential benefits to your cat outweigh the learning curve or the stress you and your cat may initially feel. Approach it with a positive attitude, tell your cat what every step will be and that he/she will feel so much better afterwards, reward him/her with treats and lots of love. And pat yourself on the back for helping your kitty.


Introduction to Fluid Therapy



EZ IV Harness

The Animal Wellness Collection from Green Hope Farm

Calming Collars (use coupon code IBDKITTIES for 10% off)

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