The prepuce and penis of an anesthetized 2-month-old sexually intact male pet degu (Octogon degus) were inadvertently traumatized during attempted removal of the right testicle for routine castration, and the procedure was aborted. When no urination was evident for several hours after anesthetic recovery, the degu was referred to the Washington State University Teaching Hospital for evaluation. The degu weighed 210 g (7.4 oz); was in good body condition with good hydration; and was bright, alert, and responsive. Physical examination findings were marked bruising and swelling of the prepuce and severe edema to the left of the prepuce. A skin incision to the right of the caudal portion of the prepuce was closed with tissue adhesive. The penis could not be extruded from or palpated in the prepuce.
General inhalant anesthesia with isoflurane and oxygen delivered by mask was used. Radiography revealed an enlarged urinary bladder and air in the subcutaneous tissues surrounding the castration site. A 25-gauge catheter was inserted into the preputial orifice, and 0.5 to 1 mL of ioxilana (300 mg/mL) was injected. The prepuce and surrounding subcutaneous tissue filled with contrast medium, but no contrast medium was seen in the urethra or urinary bladder.
The peripreputial area was explored through the previous right inguinal incision. A moderate amount of yellow fluid (presumed to be urine and serum) was detected. The penis, which was completely separated from its preputial attachments, was located in the subcutaneous tissue caudally and to the left of the prepuce. It was oriented at a 45° angle to the long axis of the prepuce and was freely moveable. The penis was maneuvered into the incision with gentle manipulation, including external finger pressure on the left inguinal area. The penile urethra was catheterized with a 25-gauge catheter, and urine flowed from the catheter. The urinary catheter was temporarily removed from the penile urethra, passed through the preputial orifice in a retrograde fashion, and replaced in the penile urethra. An attempt to lever the penis back into the prepuce with the catheter was unsuccessful. A mosquito forceps was then passed in a retrograde manner through the preputial orifice, the tip of the penis was gently grasped (avoiding the urethral orifice), and the penis was successfully placed back into the prepuce. A small amount of exposed erythematous tissue at the tip of the penis was removed with tenotomy scissors. The base of the penis was sutured to the base of the prepuce with a 4-0 polydiaxanoneb suture, and the surgery site was lavaged. The incision was closed with tissue glue. Castration was not performed at this time because of the already long duration of anesthesia. After surgery, the degu received replacement crystalloid fluids (19 mL/kg [8.6 mL/lb], SC, once), butorphanol (0.20 mg/kg [0.09 mg/lb], SC, once), and enrofloxacinc (4.4 mg/kg [2.0 mg/lb], SC, q 24 h for 7 days). An Elizabethan collar made from radiographic film was placed around the degu's neck. Recovery from anesthesia was without complications.
The following morning, the degu was bright, alert, and active. The Elizabethan collar was off. The caudal inguinal region was bruised and erythematous bilaterally, and a small piece of desiccated material was adhered to the preputial opening. The right caudal aspect of the prepuce was dark. Urine was leaking out of the incision, which had partially dehisced. It was unclear on palpation if the penis was still located in the prepuce.
The degu was anesthetized, and the previous surgery site was reentered. The penis was still in the prepuce but could not be exteriorized, even after removing the dried tissue that was adhered to the preputial opening. The suture placed from the base of the penis to the prepuce during the previous surgery was removed. A mosquito forceps was inserted into the preputial orifice, the tip of the penis was gently grasped, and the penis was positioned such that the tip protruded slightly beyond the preputial opening. The tip of the penis was sutured to the edge of the preputial orifice with 4 simple interrupted sutures of 4-0 polydiaxanone,b taking care to avoid the urethra. Orchiectomy was performed by exteriorizing the right testicle through the incision, placing 2 encircling ligatures of 3-0 polyglactin 910d on the spermatic cord, and transecting the cord distal to the ligatures. This procedure was repeated on the opposite side after making a left peripreputial incision. The left incision was closed with tissue adhesive. The right inguinal region was lavaged with 20 mL of sterile saline (0.9% NaCl) solution, and the caudal half was closed with tissue adhesive; the cranial half was left open to allow drainage. The Elizabethan collar was sutured to the neck. After surgery, the degu received fluids and butorphanol as before.
The degu was briefly anesthetized via mask administration of isoflurane and oxygen for daily evaluation until suture removal. During this time, the bladder was no longer palpable and the penis remained positioned as it had been at the conclusion of surgery. Daily treatments included lubrication of the tip of the penis with petrolatum ophthalmic ointmente and enrofloxacin injection. The right peripreputial incision closed 4 days after the last surgery. Preputial and inguinal swellings gradually resolved. The sutures at the tip of the penis were removed 6 days after surgery via general anesthesia. The Elizabethan collar was removed 1 day later. A 3 × 3-mm region of the right preputial skin sloughed 8 days after the initial surgery; this area was treated with topical collagen hydrolysatef and healed by second intention. The degu was urinating from the penis normally. Two years later, the degu underwent a routine examination (Figure 1). The prepuce and penis appeared healthy, although the penis could not be moved relative to the preputial orifice. The degu was urinating normally and did not require any treatment of the 1.5 mm of exposed penis.
Oxilan 300, Guerbet LLC, Bloomington, Ind.
PDS II, Ethicon Inc, Somerville, NJ.
Baytril, Bayer HealthCare LLC, Shawnee Mission, Kan.
Vicryl, Ethicon Inc, Somerville, NJ.
Paralube Vet Ointment, Pharmaderm, Melville, NY.
Collasate, PRN Pharmacal, Pensacola, Fla.
Inestrosa NC, Reyes AE, Chacon MA, et al. Human-like rodent amyloid-beta-peptide determines Alzheimer pathology in aged wild-type. Octodon degu. Neurobiol Aging 2005;26:1023–1028.
Bennett RA, Mullen HS. Guinea pigs, chinchillas, and prairie dogs: soft tissue surgery. In: Quesenberry KE, Carpenter JW, eds. Ferrets, rabbits, and rodents: clinical medicine and surgery. 2nd ed. St Louis: WB Saunders Co, 2003;274–284.
Johnson D. Small rodent husbandry, behavior and disease, in Proceedings. Atlantic Coast Vet Conf 2006. Available at www.vin.com/Members/Proceedings/Proceedings.plx?CID=ACVC2006&O=VIN. Accessed Jun 18, 2007.
Bennett RA, Mullen HS. Small rodents: soft tissue surgery. In: Quesenberry KE, Carpenter JW, eds. Ferrets, rabbits, and rodents: clinical medicine and surgery. 2nd ed. St Louis: WB Saunders Co, 2003;316–328.
Bellah JR, Spencer CP, Salmeri KR. Hemiprostatic urethral avulsion during cryptorchid orchiectomy in a dog. J Am Anim Hosp Assoc 1989;25:553–556.