This is totally normal. Maintaining a vacuum by continuing to pull on the plunger while you disconnect it from the port at the end of the catheter helps ensure that the spent antibiotics are removed.

If at the time of the pouch emptying there is no fluid being removed or if there is no resistance at the time of filling the pouch, the integrity of the pouch may be compromised.

If your animal has disrupted the catheter and caused the port to fall off the end, cut < 1 cm of the tube, wipe with alcohol and replace the white barbed connector and needleless port. If the connector/port have been lost or are otherwise not usable, you should have replacement parts in your owner kit provided by your veterinarian. If this does not work or you do not have replacement parts, protect the end of the catheter under the bandage and contact your veterinarian.

Please contact your veterinarian.