Insulin Syringes for Cats

Always use the insulin syringes specified by your veterinarian when injecting insulin. Using any other syringe can be dangerous and potentially fatal to your cat.

U-100 Syringes for Human Insulin

If you use human insulin for your cat, use a U-100 insulin syringe with an orange cap.


Capacity: Use a 3/10cc insulin syringe with whole or half-unit scale
Insulin syringe capacity is measured in cubic centimeters (cc), which are the same as milliliters (mL). These measurements are interchangeable. A 1 cc syringe equals a 1 mL syringe in capacity. One unit of insulin is equal to one one-hundredth of a cubic centimeter or milliliter. So, a 1 cc/1 mL syringe holds 100 units of insulin.

Most cats on human insulin are taking 1 to 3 units of insulin twice a day. For these very small doses, a 3/10 cc insulin syringe is recommended. Because it only holds up to 30 units of insulin, it has a wider-spaced scale that is easier to read.

If your cat takes ½ unit insulin doses, for example 2 ½ units per meal, BD offers a 3/10 cc syringe with a half-unit scale. The half-unit marks on the syringe make it easier to draw an accurate dose.

Needle Length: shorter is easier to control

A ½” long needle (12.7mm) might be too long for very thin cats, making it more likely that the needle will go right through the pinched skin and out the other side.

Many cats do well with a syringe needle that is just 5/16” (8 mm) long. This shorter needle makes it easier for you to get the insulin into the fat layer just below the skin.

Needle Gauge: thinner is more comfortable

The word “gauge” rhymes with “cage”, and describes how thick a needle is. When describing gauge, the higher the number, the thinner the needle. For example, a 31-gauge needle is thinner than a 29-gauge needle.

The needle length that you have chosen for your cat may or may not come in a choice of gauge.

The latest U-100 syringes have very thin needles (30 and 31 gauge) that glide easily into the skin, for a more comfortable injection. However, some pet owners prefer a lower-gauge, thicker needle because it is more rigid. Talk to your veterinarian about which needle length and gauge may work best for your pet.

Insulin Pens
If you find it hard to handle an insulin syringe, it might be easier for you to use an insulin pen. These pens use pre-filled insulin cartridges. You dial the correct dose on the pen, and then press on the plunger.

Some people find that an insulin pen helps them keep the doses more accurate and makes it easier to inject the insulin into the cat. However, you will pay for that convenience. Insulin pens with cartridges may cost more than syringes and insulin vials.

BD pen needles fit all insulin pens that are sold in the U.S. The pen needles are available in several lengths and gauges; your veterinarian can suggest which length is best for your pet.

U-40 Syringes for PZI Insulin
If your cat takes PZI U-40 insulin, use a red-capped U-40 insulin syringe.

U-40 insulin syringes are available in ½ mL and 1 mL capacities. You can buy U-40 syringes with a ½” long needle in 28 or 29 gauge thickness.

The thinnest U-40 needle available in the U.S. at this time is a 29-gauge size.


BD™ INJECT-EASE® Automatic Injector
Automatic InjectorAfraid of needles? Not to worry... you can still inject your pet. Designed specifically for people who fear needles or have difficulty reaching some injection sites, the BD™ INJECT-EASE® Automatic Injector holds and conceals a filled insulin syringe. The needle is inserted into the skin at the touch of a button.

With the BD™ INJECT-EASE® Automatic Injector, the insulin syringe is more stable, which allows a more precise injection. The mouth of the automatic injector has more contact with the skin around the injection site, contributing to a reduced pain sensation for your cat.