CO2 laser correction of closed sheath on puppy

    By William E. Schultz, DVM For The Education Center
    Originally Published In Veterinary Practice News, October 2019 – Download as a PDF

    Overly aggressive licking of a puppy’s sheath by the dam or other puppies trying to nurse a littermate’s sheath may cause an inflammatory response in the skin and underlying tissue, resulting in the sheath’s opening to close completely. In large litters or those with low milk production from the dam, pups may search for fluid and nurse on the sheath of male pups. The case described here involved a single-puppy litter and a dam that continually cleaned the pup. The sheath became irritated and the puppy was taken away from the dam. The severe inflammation of the sheath’s skin was controlled with topical medication; however, the healing response caused full closure of the sheath opening.

    The problem

    On presentation to the local veterinarian, the sheath was distended with urine. The veterinarian opened the sheath several times with blunt pressure (using a metal urinary catheter), and the trapped urine drained. The sheath, however, continued to close every few days. The retained urine caused the sheath’s mucosal layer to thicken dramatically. Compounded with the skin healing, inflammation of the mucosal layer caused rapid closure of the sheath opening each time.

    The patient

    Guinness, a six-week-old German shepherd dog, was presented to our clinic for surgical repair following full closure of his sheath (Figure 1).

    Anesthesia and procedure preparation

    Preanesthetic blood was normal for a puppy of his age, and he was given preanesthetic pain meds. Induction was performed with propofol 28 and he was maintained on sevoflurane anesthesia. The patient was placed in dorsal recumbency, with the area surgically prepped with chloroxylenol (Figure 1). In very young patients, anesthesia must be monitored especially carefully.

    Laser equipment and settings

    The VetScalpel CO2 laser (by Aesculight of Bothell, Wash.) with a tipless handpiece was utilized for this procedure. The laser was set to 15 watts SuperPulse, with a 0.25-mm focal spot size.

    The procedure

    The sheath was opened with a blunt metal urinary catheter (Figure 2). The laser incision was made following the catheter for 1 to 1.5 cm on the central ventral aspect of the sheath (Figure 3A to 3C). The catheter served as a backstop, protecting the penis from inadvertent damage. The opening had to be large enough for the penis to be exteriorized (Figure 4). It should be noted that when this procedure is performed on a very young puppy, the opening must be monitored as the dog grows to ensure it is large enough to allow the penis to be exteriorized.

    After the initial incision was made, the penis was examined to rule out anatomical damage. The mucosal layer was then sutured to the skin using an interrupted cruciate pattern. In this case, 4-0 Monocryl was utilized (Figures 5A to 5D). Note that minor bleeding occurred only during suturing.

    Watch the Entire Procedure

    The video of the entire procedure, with the surgeon’s explanations, can be watched here.

    To watch this procedure on YouTube, click here.

    Postoperative care

    An e-collar was used for one to two weeks post-op to prevent the puppy self-trauma during healing. The patient was sent home on NSAID therapy for one week.

    Follow-up examination

    The surgical site after suture removal at two weeks. Note excellent healing.

    The surgical site after suture removal at two weeks. Note excellent healing.

    Guinness returned two weeks postoperatively for suture removal. He did not have problems urinating. The penis was unaffected and could be exteriorized easily (Figure 6).


    Without surgery, Guinness could have had permanent damage due to obstructive urinary outflow, so timely surgical intervention was crucial. One of the challenges of this procedure in very young patients is the necessity to ensure the opening is large enough for the penis to exteriorize as the animal ages.

    The affected area of the sheath has increased vasculature secondary to the trauma, making hemostasis very difficult when a scalpel is used for the procedure. The ability of a CO2 laser to control bleeding during surgery is imperative for making a correct incision that is not occluded by hemorrhage. The use of a laser dramatically controls intraoperative hemorrhage, significantly shortening the procedure time. (Shorter surgery time is especially beneficial in very young patients, as it means less time under anesthesia.) With very little collateral tissue damage, recovery is rapid and smooth, and the pain level is low.

    William E. Schultz, DVM, graduated from Michigan State University in 1973, went into private practice, and opened his companion animal practice in the fall of 1974. Dr. Schultz has been a board member on the Synbiotics Reproductive Advisory Panel, The Society for Theriogenology, and The Theriogenology Foundation. He has spoken at veterinary conferences, veterinary associations, and national specialties due to a special interest in canine reproduction with transcervical and surgical inseminations using fresh, chilled, and frozen semen. Schultz was given the Dr. John Steiner Practice of Excellence Award by the Society of Theriogenology in 2014. He also has a special interest in laser surgery, having spoken at veterinary conferences and published many related articles. Schultz has more than 20 years of soft tissue laser experience using flexible fiber CO2 lasers and focused-beam handpieces.

    This Education Center article was underwritten by Aesculight of Bothell, Wash., manufacturer of the only American-made CO2 laser.