Hylenex Injectable

Giving your pet an injection might feel intimidating at first, but with practice, it becomes routine. Follow these steps for safe and stress-free injections.

Get Your Supplies Ready

1. Medication vial or pre-filled syringe
2. Alcohol swabs
3. Sterile syringe & needle (if not pre-filled)
4. Sharps container for safe needle disposal

Drawing Up the Dose (if needed)

1. Clean the vial top with an alcohol swab
2. Attach needle to syringe
3. Pull in air equal to the dose
4. Insert needle into vial, push air in
5. Draw out the correct dose
6. Tap out air bubbles

Pick the Injection Site

1. Subcutaneous (under the skin): Loose skin between shoulder blades or side
2. Intramuscular (into muscle): As directed by your vet

Prep the Area

1. Pinch a fold of skin to form a “tent” (for subcutaneous). Wipe with alcohol if recommended.

Inject the Medication

1. Hold the syringe like a pencil
2. Insert the needle into the base of the skin tent at a 45° angle
3. Push the plunger slowly to inject

After the Injection

1. Remove the needle smoothly
2. Place it immediately in the sharps container (don’t recap)
3. Pat the area and give your pet praise or a treat

Safety Tips

1. Never reuse needles
2. Always dispose of used needles properly
3. Ask your vet for help if unsure

The uses and pharmacology described below reflect the FDA-approved labeling for this active ingredient; your veterinarian determines whether and how they apply to your animal's treatment plan.

Hyaluronidase is an enzyme that breaks down hyaluronic acid, a component of connective tissue, which temporarily increases tissue permeability. On the FDA-approved label, it is used as an adjuvant to increase the absorption and dispersion of other injected drugs, to facilitate subcutaneous fluid administration, and to improve resorption of radiopaque contrast agents in certain imaging procedures.

In veterinary medicine, this same tissue-dispersing effect has led to off-label use in dogs and cats to help distribute subcutaneous fluids or other injected medications, and — in a more limited, less-established application — as a rescue treatment injected around the site of certain chemotherapy drugs that have leaked into surrounding tissue. Evidence for this latter use in veterinary patients is limited: a recent retrospective review found the severity of injuries in a small number of cases treated with hyaluronidase was similar to cases that weren't treated with it, so its benefit in that setting hasn't been clearly established. Prescription only. Use only under the direction of a licensed veterinarian. This information is not a substitute for veterinary diagnosis, prescribing, or monitoring. Compounded drugs are not approved by the FDA for safety or effectiveness.

Do not inject into areas of active infection or acute inflammation, and never apply directly to the eye. This product is not for intravenous administration — it is inactivated rapidly in the bloodstream and is intended for local, subcutaneous use. Hypersensitivity reactions are possible; discontinue use and contact your veterinarian if signs of an allergic reaction occur. When used to aid absorption of other injected drugs, be aware this product is reported to be incompatible with certain medications, including furosemide, benzodiazepines, phenytoin, dopamine, and alpha-adrenergic agonists — these should not be combined with it in the same injection. Use in an emergency or time-sensitive setting (such as a suspected drug extravasation) should be directed and supervised by your veterinary team.