Rabbit Intraductal Injection: Localized Delivery of Solution of Interest into the Rabbit Mammary Gland

An intraductal injection is used to provide localized treatments through the ducts to the mammary glands. First, place an anesthetized rabbit facing the ventral side up on a table for the procedure. Locate the teats to be injected and wipe the area with alcohol.

Load a syringe with an appropriate amount of sterile saline solution and insert the needle, bevel side up, into the side of the teat. Inject the saline for better visualization of the ductal openings. Next, lift the teat and carefully insert the blunt-tip needle to cannulate the duct. Load the syringe with a solution of interest to be injected.

Now, gently lock the syringe on the needle's hub and slowly inject the solution to avoid any damage due to pressure. Injection in the teat would directly deliver the solution to the rabbit mammary gland. In the following protocol, we will administer a contrast agent for visualizing the mammary gland's ducts using the intraductal injection technique in a rabbit model.

To begin this procedure, carefully shave the caudal abdomen of an anesthetized rabbit in the area around the third and fourth pairs of inguinal teats. With the majority of the hair removed, apply the hair removal cream to the shaved areas, and 10 minutes after application remove the cream using a damp paper towel wetted with warm water. Then wipe the area with alcohol-soaked gauze pads to clean the injection site. Place the rabbit on its dorsum in a V-shaped trough lined with a recirculating warm water blanket and an absorbent pad.

To prepare the contrast agent, reconstitute it according to the manufacturer's instructions, Then gently rock the vial to mix. The contrast agent used here is stable at room temperature for four to six hours after reconstitution. Locate the third and fourth pairs of inguinal teats to be injected. Then load 0.2 milliliters of sterile 0.9% saline into a 1 milliliter Luer-lock tuberculin syringe with a 22 gauge needle. Dispose off the 22 gauge needle once the saline is in the syringe and replace it with a sterile 25 gauge needle.

Next, gently wipe the area with 85% isopropyl alcohol on a gauze pad. With the bevel of the needle up and the syringe parallel to the body of the animal, insert the needle into the side of the teat and slowly inject 0.1 to 0.2 milliliters of saline, to allow for a better visualization of the ductal openings. Afterward, load 0.2 milliliters of injection solution into a 1 milliliter luer lock tuberculin syringe.

Hold the teat gently with the thumb and index finger and lift it slightly for the intraductal injection. While maintaining the lifted position of the teat, carefully cannulate the duct of interest using a 25 gauge blunt-tip needle. After cannulation, gently twist the Luer-lock syringe on the hub of the blunt-tip infusion needle until it is locked in place. Lift the teat and inject the solution slowly to minimize potential damage caused by rapidly moving fluids within the duct.