What It Is:
Subcutaneous fluids (also called SQ fluids or sub-Q fluids) are fluids administered under the skin to help treat or prevent dehydration. They’re often given at home for cats with chronic kidney disease (CKD), but also used for other conditions like vomiting, diarrhea, or recovery from illness.
It may sound intimidating, but with the right guidance, giving subcutaneous fluids can be safe, simple, and lifesaving.
🐾 When Sub-Q Fluids Are Used
Your vet may prescribe subcutaneous fluids if your cat:
- Has chronic kidney disease and needs hydration support
- Is recovering from vomiting or diarrhea
- Has low appetite or poor water intake
- Needs short-term fluid support outside the hospital
- Can’t tolerate IV fluids but needs rehydration
- Has mild dehydration that doesn’t require hospitalization
Sub-Q fluids help maintain electrolyte balance, support organ function, and improve energy and comfort, especially in aging cats.
💉 What’s in Subcutaneous Fluids?
Most commonly, it’s Lactated Ringer’s Solution (LRS), a sterile fluid containing water, electrolytes (sodium, potassium, calcium), and lactate to support hydration and acid-base balance.
Your vet may prescribe additives (like potassium or B vitamins) in some cases.
🔍 How It Works
Sub-Q fluids are injected into the space under the skin, typically between the shoulder blades. From there, the body gradually absorbs the fluid into the bloodstream like a slow IV.
It’s not painful for most cats, and many tolerate it well, especially with treats, a calm setup, and a little patience.
🧪 What You Need
Your vet will provide:
- A bag of fluids
- IV drip line
- Needles (typically 18–20 gauge)
- Instructions on dosage and frequency (e.g., 100 mL every 2–3 days)
Optional helpful items:
- Hanging hook or coat rack (to elevate the bag)
- Blanket or towel to keep your cat still
- A partner to help hold or distract your cat (at first)
🩺 At-Home Instructions (Simplified)
- Warm the fluids to body temperature (place the bag in warm water; don’t microwave).
- Hang the bag above your cat to allow gravity flow.
- Attach the needle to the line and remove air bubbles.
- Gently pinch the loose skin between the shoulder blades.
- Insert the needle under the skin, not into muscle.
- Open the clamp and allow fluids to flow until the prescribed volume is reached.
- Remove the needle and gently pinch the skin for a few seconds.
- Praise your cat and offer a reward!
😿 What to Watch For
Mild swelling or a “bubble” at the injection site is normal. It absorbs over a few hours.
Call your vet if you notice:
- Bleeding or fluid leakage
- Signs of infection (redness, heat, swelling)
- Limping, pain, or strong resistance
- Vomiting or lethargy after fluids
- Difficulty administering the fluids
💡 Cat Owner Note
The first few times can feel overwhelming, but most cat owners report that it gets easier very quickly. And many cats feel noticeably better after fluids. It’s one of the most impactful things you can do to improve your cat’s comfort and quality of life.
❓ Frequently Asked Questions About Subcutaneous Fluids
Are subcutaneous fluids painful for cats?
No. Most cats tolerate them well. The needle is small, and once in place, there’s little discomfort.
How long does it take to give sub-Q fluids?
Usually about 5–10 minutes, including prep and cleanup. The fluid drip itself may take 3–5 minutes.
How often should my cat get fluids?
Your vet will guide you. It could be daily, every other day, or weekly, depending on your cat’s condition.
Can I reuse needles?
No. Always use a new, sterile needle each time to prevent infection and reduce pain.
Why is there a lump under my cat’s skin after fluids?
That’s normal. It’s the fluid bubble and will be absorbed by the body over several hours.
What if I give too much?
A little overage is usually okay, but don’t exceed the prescribed volume without vet guidance. Too much fluid can stress the heart or lungs.
Can sub-Q fluids help with vomiting or dehydration from illness?
Yes, in some cases. Your vet may recommend short-term sub-Q fluids to support recovery.