SQ / SC (Subcutaneous / Sub-Q)
An injection route abbreviation designating administration into the subcutaneous connective tissue layer beneath the skin.
💬 In Plain English
SQ (also written as SC or Sub-Q) stands for "subcutaneous," meaning "under the skin." Dogs and cats have loose, flexible skin with a rich subcutaneous space, particularly along the scruff of the neck and over their shoulders and flanks. When a veterinarian or pet owner gives an SQ injection (such as routine vaccines, daily insulin injections, or home hydration fluids for kidney disease), a small needle is inserted into the tented fold of skin. The medication or fluid pools in the loose tissue and is gradually absorbed into the bloodstream.
🔬 Clinical & Technical Depth
For Vets & TechniciansFormal Clinical Definition
Parenteral route of administration delivering pharmaceuticals or isotonic fluids into the hypodermis/subcutis (the loose connective and adipose tissue layer deep to the dermis). Provides slower, more sustained vascular absorption than intramuscular or intravenous routes.
Why Veterinarians Use It
Veterinarians use SQ as the standard gentle injection route for vaccines, insulin, antiemetics, and outpatient subcutaneous fluid therapy.
Clinical Context Encountered
Encountered during in-clinic vaccination appointments, home insulin administration for diabetic pets, or home fluid therapy for feline kidney disease.
Clinical Reference Guide (Prescription / Chart Abbreviation)
Injecting medication or fluid into the loose connective tissue layer directly beneath the skin.
Where You Encounter It
- Core and non-core vaccination administration
- Twice-daily home insulin injections for diabetic dogs and cats
- Subcutaneous fluid rehydration for feline chronic kidney disease
- Injectable medications (Cerenia, Cytopoint, Adequan)
- •In cats, subcutaneous injections should follow AAFP Feline Vaccine Location Guidelines (lower limbs rather than the interscapular scruff) to minimize the risk and manage Feline Injection-Site Sarcomas (FISS).
❓ Questions to Ask Your Veterinarian
Take these actionable questions with you to your next clinic visit or appointment:
- 1How do I properly "tent" the skin to ensure the needle enters the subcutaneous space without poking through the other side?
- 2How do I draw back slightly on the syringe plunger (aspirate) to ensure I have not entered a blood vessel?
- 3How much fluid or medication volume can safely be given in a single subcutaneous injection site?
- 4Should injection sites be rotated to prevent tissue soreness?
Academic & Clinical References
- AAFP Feline Vaccination Advisory Panel Guidelines and Injection Site RecommendationsOrganization: American Association of Feline Practitioners (AAFP) • Accessed: 2026-01-10https://catvets.com