Dog & Cat HospitalCalabasas

Patient Education

Fluid Therapy

Intravenous and subcutaneous fluid support to correct dehydration, maintain blood pressure, and help sick or recovering pets through illness.

Fluid therapy is one of the most fundamental supportive treatments in veterinary medicine — it is part of almost every hospitalization protocol and a mainstay of management for many chronic conditions. Dehydration impairs organ function, reduces drug effectiveness, slows healing, and makes pets feel markedly worse. The goal of fluid therapy is to restore and maintain normal hydration and electrolyte balance, support kidney perfusion, and provide a vehicle for intravenous medications when needed. Dog & Cat Hospital Calabasas administers intravenous (IV) fluids to inpatients and acutely ill pets, and trains owners of chronically dehydrated pets — those with kidney disease, for example — to give subcutaneous (SQ) fluids at home on a schedule prescribed by the veterinarian.

How It Works

Fluid therapy is tailored to the clinical situation:

  • Intravenous (IV) fluids — administered through a catheter placed in a leg vein; allows precise volume control, rapid delivery, and concurrent IV medication administration; used for hospitalized patients, surgical cases, and any pet who is too ill or too dehydrated to absorb fluids through the tissue. The type of fluid (balanced crystalloids such as lactated Ringer's, 0.9% saline, or colloids) and the rate are chosen based on the pet's electrolyte status, kidney function, heart function, and clinical condition
  • Subcutaneous (SQ) fluids — a volume of sterile isotonic fluid is injected under the skin, typically at the scruff of the neck, where it forms a fluid pocket that is gradually absorbed over several hours; used for mild-to-moderate dehydration and for at-home maintenance therapy in chronically ill pets (most commonly cats with kidney disease). SQ fluids are not appropriate for severely dehydrated or shocked pets, where IV delivery is necessary
  • Electrolyte supplementation — potassium is commonly added to IV fluids for pets with hypokalemia (low potassium), which is common in cats with kidney disease or prolonged vomiting; sodium and other electrolytes are adjusted based on serial bloodwork

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What to Expect

For hospitalized patients, an IV catheter is placed on admission; most dogs and cats tolerate catheters well once placed and settled. The fluid rate is monitored continuously and adjusted as the patient responds — an improvement in mucous membrane moisture, improved mentation, and stabilizing vital signs are the early signs that fluid therapy is working. For owners learning to give SQ fluids at home, the team demonstrates the technique (typically at the cat's scruff), specifies the volume and frequency, and sends home the necessary supplies. Most owners report that the learning curve is short and that the process is straightforward once they have done it a few times with guidance. Regular rechecks allow the fluid prescription to be adjusted as the pet's condition changes.

Good Candidates

  • Hospitalized pets with moderate to severe dehydration, regardless of the underlying cause
  • Pets with acute kidney injury (AKI), where aggressive IV fluid diuresis supports kidney recovery
  • Patients undergoing anesthesia and surgery, where IV fluid support maintains blood pressure throughout the procedure
  • Pets with severe vomiting, diarrhea, or both, who are losing fluids faster than they can drink
  • Cats with chronic kidney disease (CKD) who are mildly and chronically dehydrated — a twice- or three-times-weekly SQ fluid routine at home can dramatically improve quality of life
  • Pets receiving certain medications or treatments (including chemotherapy) where fluid support reduces the risk of adverse effects on the kidneys
  • Diabetic ketoacidosis (DKA) patients, where IV fluid and electrolyte correction is a central part of stabilization before insulin management begins

Frequently Asked Questions

1How can I tell if my cat or dog is dehydrated?
The skin tent test — gently pinching the skin at the scruff and watching how quickly it returns to flat — is a rough guide; slow return suggests dehydration. Tacky or dry gums, sunken eyes, lethargy, and reduced urine output are additional signs. Mild dehydration can be hard to detect at home; the veterinarian can assess hydration status on examination.
2What fluids are given to dogs and cats in the hospital?
Balanced crystalloid solutions — most commonly lactated Ringer's solution or Normosol — are the standard for routine hydration and maintenance. Saline (0.9% NaCl) is used for specific electrolyte imbalances. Colloids or other specialty fluids are reserved for pets with low blood protein or severe circulatory compromise.
3Can I give my cat fluids at home?
Yes — subcutaneous fluid administration is commonly taught to owners of cats with chronic kidney disease. With the right supplies (sterile fluid bag, IV line, needle) and the veterinarian's prescribed volume and frequency, most owners become comfortable with the procedure quickly. It is one of the most impactful things an owner can do for a CKD cat's quality of life.
4Does giving fluids hurt my pet?
IV catheter placement involves a brief needle stick that most pets tolerate well; once placed, the catheter is generally not bothersome. Subcutaneous fluid administration causes mild pressure as the fluid volume fills the tissue — most cats are calm during the process and many do not react noticeably.
5How long does a pet need IV fluids in the hospital?
Duration depends entirely on the underlying condition — a pet treated for vomiting and dehydration may need fluids for 24–48 hours; a pet with acute kidney injury may need several days of intensive IV diuresis; a post-surgical patient typically receives fluids only during and briefly after the procedure. The veterinarian updates the plan as the pet responds.
6Why does my vet want to give my dog fluids before surgery?
Anesthesia causes peripheral vasodilation and can drop blood pressure; IV fluids counteract this by maintaining circulating volume and supporting blood pressure throughout the procedure. Fluid support during anesthesia is a standard safety measure that reduces stress on the kidneys and cardiovascular system.
7What is the difference between IV and subcutaneous fluids?
IV fluids are delivered directly into the bloodstream and take effect immediately — they are used for severely ill or dehydrated patients who need rapid correction. Subcutaneous fluids are deposited under the skin and are absorbed gradually over a few hours — they are appropriate for mild dehydration and for maintenance support in chronically ill pets like those with kidney disease.

Talk to us about fluid support for your pet

Whether your pet needs in-hospital IV therapy or you want to learn home SQ fluids for a chronically ill cat, we'll walk you through every step.

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