The shelter officials had noted the stenotic preputial orifice and preputial swelling when the dog was initially presented to them. Fine-needle aspiration of the swelling had revealed suppurative fluid and urine pooling in the prepuce. Repeatedly aspirating fluid from the prepuce had not resolved the problem.
PRESURGICAL TESTING AND PREPARATION
Before surgery, the results of the dog's packed cell volume, blood glucose concentration (measured by using a glucometer), total solids concentration (measured by refractometry), and rapid estimation of blood urea nitrogen concentration (by using a dipstick) were normal.
Oral nitenpyram (Capstar—Novartis Animal Health) was administered to treat the flea infestation. The patient was premedicated with subcutaneous acepromazine and hydromorphone. The preputial swelling was aspirated, and 78 ml of purulent fluid was obtained. Since previous analysis showed a nonseptic suppurative fluid, the shelter officials declined fluid analysis, cytologic examination, and bacterial culture and antimicrobial sensitivity testing. Anesthesia was induced with intravenous propofol, an endotracheal tube was placed, and anesthesia was maintained with isoflurane. Carprofen (4 mg/kg) was also administered subcutaneously.
The dog was placed in dorsal recumbency. Its ventral abdomen and prepuce were clipped, aseptically prepared, and draped in the standard fashion. Perioperative antibiotic therapy consisted of intravenous cefazolin (22 mg/kg every two hours). Plasmalyte A (Baxter Healthcare) was administered intravenously at 10 ml/kg/hr for the first hour and at 5 ml/kg/hr every hour thereafter throughout the procedures.
The right testicle was palpable in the subcutaneous tissues of the inguinal region. A right inguinal castration was performed, and a routine closed castration was performed to remove the left testicle. The right testicle was submitted for histologic examination.
Further examination of the preputial orifice revealed that the penile mucosa was adhered circumferentially to the preputial orifice. A 5-F red rubber catheter was placed in the urethra, and an incision was made with a No. 10 blade on the ventral prepuce starting 2 cm caudal to the preputial orifice and extending 9 cm caudally. On entry into the prepuce, fibrous connective tissue between the parietal preputial mucosa and the visceral penile mucosa was present dorsally and caudally (Figure 3). The fibrotic tissue attachments were separated from normal tissue by using a No. 15 blade and Metzenbaum scissors (Figure 4). Hemostasis was maintained by using unipolar electrocautery.
The preputial orifice was reconstructed by removing a triangular wedge of tissue from the dorsal aspect of the orifice. The triangular wedge resection was oriented with the base at the mucocutaneous junction to create a larger preputial opening. Care was taken to not excise too much tissue, which may result in paraphimosis (an inability to retract the penis into the prepuce).1
The subcutaneous tissue along the ventral aspect of the prepuce was closed by using 3-0 polydioxanone (PDS II—Ethicon) in a simple continuous pattern. The skin was closed by using 3-0 monofilament nylon in a cruciate pattern. The red rubber catheter was removed.
Immediately after closure, the patient received morphine (0.05 mg/kg) and bupivacaine (0.02 mg/kg) epidurally. An indwelling urinary catheter was placed, and the catheter passed freely. The patient recovered from anesthesia without complications.
The dog recovered in the intermediate nursing-care unit, and a fentanyl patch (50 µg/hr) was immediately applied. The patient was given subcutaneous hydromorphone (0.01 mg/kg every four hours) for the initial 12 hours after surgery to provide pain relief until the fentanyl patch took effect. Cold packs were placed on the incision sites every four hours for the remainder of the dog's time in the hospital. The dog wore an Elizabethan collar for the next two weeks.
The day after surgery, the dog was bright and alert but in pain, and the indwelling urinary catheter was removed. The dog's prepuce was slightly swollen, and the patient was passing bloody urine with difficulty. The dog was not interested in food. Because of patient discomfort, the penis could only be extruded and lubricated with sterile jelly once or twice a day, instead of every four to six hours. Amoxicillin trihydrate-clavulanate potassium (22 mg/kg given orally twice a day for 14 days) was started that morning, and carprofen (1.7 mg/kg given orally twice a day for seven days) was started that evening. Topical 2% lidocaine jelly was used instead of sterile lubricating ointment to provide additional local pain relief during the extrusion of the penis.
Two days after surgery, the patient's prepuce appeared more swollen and painful, although the incisions were intact. When urinating, the patient would extrude its penis from its sheath and produce a normal urine stream, but after finishing the main stream, the dog would occasionally strain to produce a few drops of bloody urine. Often the dog would whimper as its penis receded into the prepuce.
The dog was discharged to a foster home with an Elizabethan collar in place, the medications described above, and instructions to extrude the penis from the prepuce every six to eight hours or as much as possible for one to two weeks. The caregiver was also instructed to remove and dispose of the fentanyl patch five days after placement.
The shelter reported that the dog was able to urinate normally. The dog was adopted about a month after its surgical wounds had completely healed.
Phimosis has been recorded in most domestic species.2 Some sources define it as an inability to protrude the penis from the prepuce because of a stenotic or an absent preputial orifice1-3 ; however, another definition is simply the inability to protrude the penis from the prepuce.4-7 This latter definition is preferable because an inability to protrude the penis has many causes, both acquired and congenital, and may even be species-dependent.
Acquired phimosis in dogs most commonly results from lacerations after trauma, preputial sucking by littermates, or licking by the dam. In addition, neoplasia such as mast cell tumors, transmissible venereal tumors, squamous cell carcinoma, and perianal gland adenomas accounts for many cases.1
Congenital phimosis has been described in young dogs, cats, and stallions4 and can result from a developmental anomaly of the penis or prepuce. Such anomalies include a short penis or retractor penis muscle, persistent adhesions connecting the prepuce to the penis, or stenosis or absence of the preputial orifice.2 Congenital stenosis of the preputial orifice has been reported to be breed-related in German shepherds, golden retrievers, Bouvier des Flandres, and Labrador retrievers.1,2
In normal dogs, cats, bulls, or horses, the penis is fused with the prepuce throughout its length at birth. During prepubertal development, the penis grows and the relationship between the penis and the peripenile tissues changes.2 In addition, the connective tissue joining the penis and prepuce breaks down.2 This breakdown is mediated by androgens produced by the testis, which are also responsible for sexual differentiation of the male genitalia, the descent of the testis into the scrotum, and keratinization of the preputial epithelium.4 For this reason, it is important to fully evaluate a patient with suspected congenital phimosis for additional congenital problems.
The clinical severity of disease can vary from no clinical signs in a nonbreeding animal to complete obstruction of urinary flow leading to death, which may be seen with an absent preputial orifice.8 The most common presenting signs are abnormal urination and preputial swelling. Abnormal urination can include a small stream or dribble due to urine accumulating in the preputial cavity. This collection of fluid can lead to preputial irritation and secondary balanoposthitis.5 Another clinical sign is the inability to copulate in breeding animals.4
Only minimal laboratory tests were performed in this case because of monetary constraints; however, a complete blood count, serum chemistry profile, and urinalysis should be included in a comprehensive work-up.7,8 Other presurgical diagnostic procedures that might be valuable but that were not performed in this case are positive contrast radiographic examination and cytologic examination, fluid analysis, and bacterial culture and antimicrobial sensitivity testing of the fluid accumulating in the prepuce.
Phimosis caused by inflammatory or infectious disease can be treated with antibiotics and supportive care such as a warm compress, urine diversion through a catheter, or saline lavage to prevent urine scalding.5 Surgery is often indicated to correct a developmental anomaly or an acquired preputial stricture and usually leads to a successful outcome.1 In cases of uncomplicated phimosis (no adhesions), a simple wedge tissue resection is usually adequate. However, in this patient, the adhesions required a more aggressive procedure.
Postoperative complications may include either paraphimosis or postsurgical fibrosis and scar tissue formation. Multiple surgeries may be needed to correct fibrosis or paraphimosis. Additional surgeries may be required once the animal reaches sexual maturity. To avoid these complications, the surgical plan should be as aggressive as possible without creating paraphimosis.9 Additionally, especially in patients in which surgical breakdown of adhesions is required, mucosal layers must be reapposed to avoid postoperative adhesions from forming. To avoid adhesion formation, postoperative manual extrusion of the penis should be included in all recovery plans.
In this case, the pain management protocol included preoperative carprofen, postoperative epidural analgesia, hydromorphone for the first 12 hours after surgery, a fentanyl patch, and topical lidocaine jelly. It is questionable whether the lidocaine jelly provided marked relief; however, in theory, it should have provided more comfort than sterile lubricating jelly alone. Pain management in dogs undergoing surgery to correct phimosis has not traditionally been described in the veterinary medical literature. However, in this case, pain management was a particular challenge despite an aggressive approach and should be an important consideration in any case of phimosis that requires surgical intervention.
Kelly Saporito, DVM*
Hospital for Animals
College of Veterinary Medicine
Ithaca, NY 14853
*Dr. Saporito's current address is Coral Springs Animal Hospital, 1730 N. University Road, Coral Springs, FL 33071.
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