A technique for catheterization of ferrets for chronic intratracheal material administration

A method was needed for repeated administration of a liquid surfactant suspension into the lungs of nonrodent animals for the purpose of safety testing. Catheters were implanted surgically into the tracheas of 66 juvenile ferrets and exteriorized at the back of the neck. After the ferrets had recovered from surgery, liquid was administered via the catheters into the ferrets' tracheas multiple times, for periods up to 1 month. Ferrets were conscious and free-breathing during the intratracheal administration of the liquid. The ferrets tolerated the surgery, catheterizations, and dosings well, with few complications. Most ferrets had an occasional nonproductive reflex cough due to tracheal stimulation by the catheter but continued to gain weight, play, and otherwise behave normally. The catheters of two ferrets became displaced from the trachea into the subcutaneous space. Two other ferrets died acutely during administration of the liquid into their tracheas, as a result of airway obstruction. Relative to alternative methods, however, this procedure provides a safe and simple chronic nonrodent model for safety testing of materials introduced into the lungs.