Scrotal Hematoma in Dogs After Castration: Why does it happen and how to prevent it.

Scrotal hematoma, the accumulation of blood in the scrotal sac, is a common postoperative complication of castration in dogs. (Fig. 1) 

Fig. 1: Scrotal hematoma that developed after castration in this golden retriever

Postoperative bleeding from one or both testicular arteries or veins is the most likely cause. Bleeding from these vessels can also accumulate in the abdominal cavity and be unrecognized until the dog becomes hypovolemic and develops shock. Bleeding from subcutaneous tissues could also result in a scrotal hematoma but is less likely, particularly in cases where bleeding is severe and the scrotal hematoma is large.

Etiology

Insecure ligatures are probably the cause of bleeding from testicular vessels. Ligature failure during castration may be due to a number of technical problems, such as loose ligature, improper suture material, or ligature slippage. Improper location of the suture ligature can also predispose to failure. If the spermatic cord is not adequately exteriorized the ligatures will be placed too close to the testicle. (Fig. 2) 

Fig. 2: The red dotted line indicates ligation of the spermatic cord too close to the testicle (T)
The ligatures in the figure are placed in the proper location.
(Modified from: Boothe, HW. Surgery of the testicles and scrotum. Saunders Manual of Small Animal Practice, Birchard and Sherding editors,  Figure 87-1, Elesevier, 2006, pg. 970.)

This causes excessive tissue to be incorporated in the ligatures. Insufficient stripping of the adipose tissue from the cord also predisposes the ligature to slippage.

Treatment

Scrotal hematomas can be managed medically with compresses (ice packs for the first 24 hours postoperatively, followed by warm compresses), Elizabethan collar, restricted exercise, analgesics such as NSAIDS, and antibiotics. In severe cases or those not responding to medical therapy, scrotal ablation is necessary to remove the entire scrotum and its contents.

Prevention

To prevent scrotal hematoma when performing castration, adhere to the following technical principles:

- After incising over the testicle and exposing it, break down the gubernaculum testis and place traction on the testicle to allow several centimeters of the spermatic cord to be exposed. (Fig. 3)

Fig. 3: Proper exposure and clamping of the spermatic cord during routine canine castration.

- Carefully and thoroughly strip the adipose tissue from the spermatic cord with a moistened surgical sponge.

- Triple clamp the cord with Carmalt clamps, cut between the 2 clamps closest to the testicle and perform routine ligatures with Monocryl or PDS suture (transfixing and full ligatures). The full ligature is placed in the crush area of the most proximal clamp after it is removed, the transfixing ligature is placed just distal to the full ligature. (Fig. 4)

Fig. 4: Proper ligature technique in a closed canine castration. (T=testicle)
(Modified from: Boothe, HW. Surgery of the testicles and scrotum. Saunders Manual of Small Animal Practice, Birchard and Sherding editors, Elesevier, 2006, Figure 87-1, pg. 970.)

- Check the vascular stump for bleeding prior to replacing it into the incision. Repeat the same procedure on the opposite side.  

I prefer closed castration, even on large dogs, because it allows excision of the testicular tunics along with the testicle. (Fig. 5)

Fig. 5: Closed castration allows removal of the parietal vaginal tunic with the testicle

Close the subcutaneous tissue routinely (3-0 or 4-0 absorbable suture in a simple continuous pattern). Although skin sutures can be used on the skin incision, I prefer do an intradermal closure in lieu of skin sutures. Fewer complications occur with an intradermal closure of castration incisions. In an unpublished study performed at Ohio State several years ago, dogs with intradermal skin closure had fewer incisional problems and even fewer scrotal hematomas postoperatively. Less self-trauma to the incision and scrotum were thought to be the reason for this finding.

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Caserean Section in Dogs and Cats: Surgical Technique

Indications

Cesarian section (C-section) in dogs and cats is indicated for a variety of reasons such as uterine inertia, oversized neonates, narrowed maternal pelvic canal, and others. Fetal dystocia is common in brachycephalic breeds such as Bulldogs, prompting some breeders or owners to schedule the C-section as an elective procedure in these kinds of dogs. Evidence fetal death or uterine infection would also warrant immediate C-section. The readers are referred to other publications for more information on dystocia in dogs and cats.(1)

Cesarian section is a safe surgical procedure and one study found fetal survival actually slightly higher with C-section than natural birth.(2) For information on pre-operative assessment and anesthesia for C-section see Veterinary Key Points blog by Dr. Lisa Ebner posted June 14, 2016.

Surgical Procedure

The abdomen is clipped and an initial scrub performed prior to beginning anesthesia. This minimizes the time spent under anesthesia helping to prevent depression of the puppies or kittens. Perform other pre-operative and anesthestic protocol as described in the Veterinary Key Points blog by Dr. Lisa Ebner posted June 14, 2016 on anesthesia for C-section.

Place the animal in dorsal recumbancy and perform a routine ventral abdominal midline approach. Be careful to avoid trauma to the enlarged uterus when entering the peritoneal cavity. Exteriorize the entire uterus including both uterine horns. (Fig. 1) This simple step is important to relieve pressure on the caudal vena cava by the very enlarged uterus and therefore improve venous return to the heart. Isolate the uterus from the peritoneal cavity with moistened abdominal sponges.

Fig. 1: Gravid uterus exteriorized from the abdominal cavity

Make an incision in the ventral aspect of the uterine body just proximal to the bifurcation of the horns.(3)  Take care to avoid trauma to the puppies inside the uterus. Once inside the uterine lumen, carefully begin removing puppies one by one.(Fig. 2)

Fig. 2: Begin removing puppies from the incision in the uterine body midline.
from: Sicard GK, Fingland RB. Surgery of the ovaries and uterus. In: Saunders Manual of Small Animal Practice, 3rd edition, Birchard SJ, Sherding RG, eds. Elsevier, St. Louis, 2006

Begin with puppies in the uterine body, then milk them down each horn to the incision and then remove. The uterine incision may have to be extended into the horns to reach and remove all puppies.

When each puppy is removed from the uterus, gently tear the placental membrane and remove it from the fetus.(Fig. 3) 

Fig. 3: After removing puppy from the uterus gently open and peel away placental membranes
from: Sicard GK, Fingland RB. Surgery of the ovaries and uterus. In: Saunders Manual of Small Animal Practice, 3rd edition, Birchard SJ, Sherding RG, eds. Elsevier, St. Louis, 2006

Take care to avoid spillage of fluids into the peritoneal cavity. A convenient area to perforate the thin membrane is at the ventral neck of the puppy. Once the membrane has been removed, place 2 small hemostatic forceps on the umbilical cord, transect the cord between the clamps, and hand the puppy off to an assistant.(Fig.4a, b ) 

Fig. 4a: After removing placental membranes from the puppy, double clamp
the umbilical cord with small hemostats, cut between them, and pass the
puppy off to an assistant.

Fig. 4b: Double clamp umbilical cord and cut between the clamps.
from: Sicard GK, Fingland RB. Surgery of the ovaries and uterus. In: Saunders Manual of Small Animal Practice, 3rd edition, Birchard SJ, Sherding RG, eds. Elsevier, St. Louis, 2006

The assistant will then ligate the cord with absorbable suture and begin routine care to stimulate respirations and assessment 
(see http://drstephenbirchard.blogspot.com/2016/06/anesthesia-for-cesarian-section-in-dogs.html).

Before uterine closure, be sure to check the entire uterus including the body and vagina for any remaining fetuses. Routine ovariohysterectomy can be performed now if requested by the owner. If the uterus is to be preserved, close the uterine incision with absorbable suture (Monocryl or PDS) in a Cushing pattern.  Lavage the abdomen with warm sterile saline if spillage of uterine contents has occurred into the peritoneal cavity. Close the abdominal incision routinely. Intradermal closure of the skin layer is preferred to avoid the irritation associated with skin sutures and nursing puppies.

Postoperative Care

When the bitch is fully recovered from anesthesia the puppies can be placed with her and encouraged to nurse. Carefully monitor the puppies and bitch to be sure she does not accidentally injure the pups. Soon after anesthetic recovery is it usually best to discharge the dog and her puppies back to the home and educate the owner on care of the bitch and puppies. See blog on C-section anesthesia for postoperative analgesia of the mother.

References

1. Graves T. Diseases of the ovaries and uterus. In: Saunders Manual of Small Animal Practice, 3rd edition, Birchard SJ, Sherding RG, eds. Elsevier, St. Louis, 2006, pgs. 987-991.
2. Moon PF, Erb HN, Ludders JW, Gleed RD, Pascoe PJ Perioperative management and mortality rates of dogs undergoing cesarean section in the United States and Canada
JAVMA [1998, 213(3):365-369
3. Sicard GK, Fingland RB. Surgery of the ovaries and uterus. In: Saunders Manual of Small Animal Practice, 3rd edition, Birchard SJ, Sherding RG, eds. Elsevier, St. Louis, 2006, pgs. 996-999.

Urethral Prolapse in Dogs: Why it happens and how to fix it.

Prolapse of the urethral mucosa is a rare condition that occurs in male dogs.  Young, intact, brachycephalic dogs, such as bulldogs or Boston terriers, are commonly affected.  The cause of the prolapse in most cases is unknown, but may be related to excessive sexual excitement or underlying urogenital disorders such as urethritis or urethral calculi.  Some authors believe that the relationship between brachycephalic breeds and urethral prolapse may be due to abnormal urethral development or increased abdominal pressure secondary to upper airway obstruction that is typical for these breeds.(1)  Increased abdominal pressure could impair venous return and subsequently cause chronic engorgement of the corpus spongiosum tissue surrounding the distal urethra. (1)

Clinical signs

Clinical signs of prolapsed urethra are bleeding from the prepuce, discomfort, and in rare cases, stranguria.  Affected dogs may show excessive licking of the penis.  Examination of the penis by extruding it from the prepuce reveals the protruding mucosa as a characteristic round, donut-shaped mass at the tip of the penis. (Fig. 1a)

Fig. 1a: urethral prolapse in a dog (arrow)

The prolapsed mucosa is bright red to dark purple.  A urethral catheter usually can be passed through the center of the tissue.  Differential diagnosis would include neoplasia such as transmissable venereal tumor, or penile trauma.

Diagnosis

Dogs with urethral prolapse should be thoroughly examined and evaluated for underlying urogenital disease or other disorders. Perform rectal examination to evaluate the pelvic urethra for a mass or calculus. Catheterize the urethra to determine urethral patency and other possible problems such as calculi.  Obtain urine for analysis and culture to rule out bacterial infection of the urinary tract.  Plain film abdominal radiographs and abdominal ultrasonography should be obtained to evaluate the kidneys, urinary bladder, and prostate gland. Positive contrast studies of the urinary tract can be done if indicated.

When urethral prolapse affects in tact male dogs castration should be recommended to decrease sexual excitement, a possible factor in the pathophysiology of urethral prolapse.  Although medical management of urethral prolapse has been described, surgical treatment by either mucosal resection or urethropexy offers the most expeditious option to alleviate clinical signs and prevent recurrence.

Surgical Technique

The animal is anesthetized and placed in dorsal recumbency.  The prepuce and surrrounding area are clipped and aseptically prepared.  The penis and interior of the prepuce are also gently scrubbed and irrigated with antiseptic solution.  After prepping the prepuce for aseptic surgery, the surgical site is draped and the penis extruded using   assistant’s fingers or by placing a Penrose around the caudal aspect of the penis to hold the prepuce caudally. (Fig 1a,b)

Fig. 1b: surgical model of a penis and urethral prolapse

            Urethral mucosal resection

A lubricated, sterile urinary catheter is passed into the urethra.  A 180o incision is made at the base of the prolapsed mucosa, as close to the penile tunic as possible. (Fig 2a,b)

Fig. 2a: incision in urethral mucosa with a scalpel blade

Fig. 2b incising urethral mucosa

The incision can be started with a scalpel (#15 blade), and continued with Metzenbaum or tenotomy scissors. (Fig. 3)

Fig. 3: continuing incision in urethral mucosa with scissors

The mucosa is not initially completely excised all the way around the urethral lumen since this will result in retraction of the mucosa and difficulty in suturing. The incised mucosa is then sutured to the penile tunic with 4-0 or 5-0 Monocryl or PDS in a simple continuous pattern with a small taper needle. (Fig. 4)

Fig. 4: suturing normal mucosa to penile tunic, simple continuous pattern. Note
inside out direction of needle placement (arrow)

Sutures are placed about 2-3 mm apart and the suture bites are made from inside the urethral lumen to the outside.  A recent study found that the simple continuous suture pattern resulted in a decreased incidence of recurrence of urethral prolapse.(2)

Fig. 5: half of the mucosa has been sutured and the pattern ended

Handle the healthy mucosa gently and avoid excessive manipulation with thumb forceps.  After the initial sutures are placed, the remainder of the prolapsed mucosa is resected and then sutured. (Fig. 6) 

Fig. 6: the remainder of the prolapse mucosa is resected and sutured.

Submit the excised tissue for histopathology to definitively rule out neoplasia.

            Urethropexy

An alternative to mucosal resection is urethropexy (3). In this technique, after prepping the site as described above, the prolapsed mucosa is pushed to the inside of the penis using a red rubber catheter. This catheter is modified by removing a portion of the tip lengthwise.  Sutures (4-0 PDS) are placed starting at the outer surface of the penis, then guiding it to the groove in the catheter and then exiting through the mucosa and to the urethral lumen. The suture needle is then redirected to enter the urethral lumen, again within the groove of the catheter, and exits the penis adjacent to the original entry point (mattress pattern). Three or four of these sutures are placed to secure the mucosa to the urethral lumen. 

Postoperative Care

Remove the urinary catheter after the procedure.  Place an Elizabethan collar on the dog to prevent licking of the surgical site.  Intermittent bleeding from the penis may persist postoperatively for a few days.  Tranquilization with acepromazine (0.05 mg/kg subcutaneous or IM, not exceeding a total dose of 3 mg) often is beneficial in reducing bleeding.  Excercise is limited for 7-10 days to leash walking only.  Treatment of underlying urinary problems, such as cystitis or prostatitis, should also be treated appropriately. The absorbable sutures do not need to be removed.

The prognosis for these animals is usually good although recurrence is common; 57% of dogs recurred in one recent study. (2) The treatment of recurrence is to repeat the surgical treatment as described above. Continue to be diligent in looking for an underlying etiology.  Penile amputation combined with scrotal urethrostomy may be necessary in the rare case that does not respond to repeated resection of the prolapsed tissue.

 References

1. Osborne CA, Sanderson SL. Medical management of urethral prolapse in male dogs. In Bonagura and Kirk, eds. Kirk’s Current Veterinary Therapy XII, Philadelphia: WB Saunders, 1995:1027-1029.

       2. Urethral Prolapse in Dogs: A Retrospective Study. Jennifer G. Carr1, DVM, Karen M. Tobias, DVM, MS, Diplomate ACVS, and Laura Smith3, BVMS. Veterinary Surgery 43 (2014) 574–580.

      3. Kirsch JA, Hauptman JG, Walshaw R. A urethropexy technique for surgical treatment of urethral prolapse in the male dog. Journal of the American Animal Hospital Association [2002, 38(4):381-384]

Blog update: Dr. Birchard has published a new book: "Their Tails Kept Wagging", a collection of moving stories about pets with serious illness who survived.  Click here for more information. 

Cryptorchidism in Dogs: 5 ways to make surgery easier

1. Determine which testicle is retained

Perform a thorough physical examination.(1) Carefully evaluate the scrotum, prescrotal area, inguinal canals, and abdominal cavity. If only 1 testicle is present in the scrotum, push it dorsally and cranially into the inguinal canal to determine whether it is the right or left testicle. After determining which testicle is retained, carefully palpate the prescrotal area and inguinal canal on the affected side. Palpation of the testicle in the inguinal region may be difficult since it can be confused with inguinal fat or lymph node. Ultrasound examination may be helpful to identify the testicle since it has a characteristic appearance (See recent paper on ultrasonography for retained testicles by Felumlee, Reichle, Hecht, et.al. http://onlinelibrary.wiley.com/.../j.1740-8261.../abstract)

Fig. 1: Ultrasound of a cryptorchid dog with a retained testicle found in the abdomen (arrow)

Also perform abdominal palpation, but unless the retained testicle is severely enlarged it will be difficult to palpate.

2. Begin with an incision over the pre-scrotal or inguinal region

Testicles located just cranial to the scrotum can be removed either by pushing the testicle caudally and exposing it through a standard pre-scrotal midline incision, or by simply incising directly over the testicle. Retained testicles in the inguinal area require incision directly over the inguinal canal. (Fig. 2a)

Fig. 2a: Inguinal incision for removal of right sided retained testicle
(Figs 2a through 2f are from: Birchard SJ, Nappier M. Cryptorchidism.
Compend Contin Educ Vet. 2008 Jun;30(6):325-36; quiz 336-7.)

Meticulous and thorough dissection may be required to expose the testicle. Be careful not to injure the pudendoepigastric artery and vein and its branches. It is possible to confuse the inguinal lymph node with the testicle. However, careful dissection and gross examination of the structure should allow differentiation before proceeding with the excision. Once the testicle and associated structures are exposed, remove them as described for prescrotal or normal testicles.

3. For an abdominal testicle, perform a paramedian approach

If one testicle is retained in the abdominal cavity, the paramedian approach to the abdomen offers the advantages of avoiding dissection around the prepuce, which necessitates ligation of the caudal superficial epigastric artery and vein, and not creating dead space in the subcutaneous tissues adjacent to the prepuce. Although the paramedian approach can allow removal of the testicle through a smaller incision than the ventral midline approach, the surgeon should not compromise the exposure of the intra-abdominal structures. Carefully identify the caudal abdominal structures, and expose and remove the testicle only after verifying that the correct structures have been identified. In one clinical study, the prostate gland was inadvertently removed in 3 dogs when insufficient exposure had been obtained while attempting to remove an abdominal testicle.(2) If additional exposure is needed to identify key structures, enlarge the abdominal incision and use appropriate retractors to find the testicle and surrounding organs.

For the paramedian caudal abdominal approach, place the dog in dorsal recumbency, and prepare the ventral abdomen for aseptic surgery. Depending upon the size of dog, make a 6-10 cm incision in the ventral abdomen, approximately 3-4cm lateral to the prepuce. (Fig. 2a)  Incise the subcutaneous tissue to expose the fascia of the rectus abdominus muscle using a scalpel, make a nick incision in the fascia, and sharply incise the fascia with Mayo scissors (not the muscle). (Fig. 2b) 

Fig. 2b: Sharply incise the rectus abdominus fascia with Mayo scissors

Bluntly separate the fibers of the rectus abdominus muscle, beginning with Mayo scissors, then continuing with the index finger of both hands. (Fig. 2c) 

Fig. 2c: Bluntly separate the muscle fibers of the rectus abdominus with fingers

Sharply incise the peritoneum. (Fig. 2d) 

Fig. 2d: Sharply incise the peritoneum with scissors

Place moistened laparotomy sponges on both sides of the body wall, and place a Balfour retractor or hand held retractors to retract the abdominal wall and expose the viscera.

4. Exteriorize the urinary bladder and palpate the prostate gland

If the retained testicle is not immediately seen in the abdominal cavity after making the paramedian approach, exteriorize the urinary bladder and retract it caudally. Identify the prostate gland, and the vas deferens entering the prostate.

Fig. 2e: Exteriorize the urinary bladder and identify the prostate gland and vas deferens

5. Find the vas deferens and follow it to the testicle

Follow the vas deferens cranially until the testicle is located. (Fig. 2e) Triple ligate the vas deferens and the vessels with absorbable suture, cut between the distal 2 ligatures, and remove the testicle.

Rarely, the abdominal approach and identification of the vas deferens may reveal that the testicle is in the inguinal canal. Remove the testicle as previously described in the inguinal approach.

Close the abdominal incision by first closing the external rectus fascia with absorbable suture (e.g. polydioxanone) in either a simple interrupted or simple continuous pattern.(Fig. 2f) Close the subcutaneous tissue and skin routinely.

Fig. 2f: Close the external rectus fascia, subcutaneous tissue, and skin routinely

Fig. 3: Testicular torsion of an abdominal testicle in a 5 month old Boxer
(same dog as in Figure 1) removed by the paramedian approach. 

References

1. Birchard SJ, Nappier M. Cryptorchidism. Compend Contin Educ Vet. 2008 Jun;30(6):325-36; quiz 336-7.
2. Schulz KS, Waldron DR, Smith MM, et al: Inadvertent prostatectomy as a complication of cryptorchidectomy in four dogs. J Am An Hosp Assoc 32: 211-214, 1996.

Blog Update: Dr. Birchard has published a new book: "Their Tails Kept Wagging", a collection of moving stories about pets with serious illness who survived. Click here for more information. 

Case Outcome on Betty: The pit bull with a vaginal mass

 This is the case outcome on Betty, a 2 year old in tact pit bull that presented with an acute onset of a vaginal mass. 

The appearance and palpation of the mass was characteristic of a vaginal prolapse. Betty was likely in estrus at the time of presentation. She was not having difficulty urinating. Some areas of mucosal necrosis were evident on the prolapsed tissue. (Fig. 1) 

Fig. 1: Vaginal prolapse in the 2 year old pit bull

We advised the owner to have Betty spayed as soon as possible. In the meantime, we recommended that they keep the tissue clean and lubricated, and place an Elizabethan collar on her to prevent self trauma of the area. 

Within a few days of having her spayed, Betty's prolapse was significantly improved. (Fig. 2)

Fig. 2: Appearance of the vaginal prolapse on Betty a few days after
ovariohysterectomy

The superficial necrosis had sloughed and completely healed, and Betty was doing well otherwise. Approximately 2 weeks later, the vaginal prolapse had completely resolved. (Fig. 3)

Fig. 3: Complete resolution of vaginal prolapse on Betty after
ovariohysterectomy

This case exemplifies the rapid resolution of vaginal prolapse after ovariohysterectomy without the need for resection of the vaginal tissue. A key element of this case is that there were only very focal areas of mucosal necrosis, not severe full thickness vaginal necrosis that would require removal. Resection of vaginal tissue with either hyperplasia or prolapse is rare in my experience. 

Etiology

Vaginal prolapse usually occurs during estrus due to estrogen stimulation of the tissues. Other causes are exogenous estrogens or prolapse during parturition. 

Diagnosis

Vaginal prolapse is suspected when a doughnut shaped mass has protruded from the vagina in an in tact female dog. It can appear similar to vaginal hyperplasia (edema); both usually occur during estrus. Vaginal neoplasia is a differential diagnosis.

Treatment

Keep the prolapsed tissue clean and well lubricated. On initial presentation, hyperosmotic solutions of dextrose or granulated sugar can be used to reduce swelling and possibly permit reduction of the tissue back into the vagina. If necessary, temporary sutures across the labia can be placed to cover the tissue and keep it moist until the swelling reduces. Recommend ovariohysterectomy to allow prompt reduction of tissue swelling and resolution of the prolapse. In breeding animals, warn owners that recurrence of the prolapse is possible in subsequent estrus cycles.

What is Your Diagnosis and Treatment? Acute onset of a vaginal mass in a pit bull.

Betty, a 2 year old in tact female pit bull.

"Betty" is a 2 year old in tact female pit bull with an acute onset of a vaginal mass. The owners just noticed the problem today and presented her to the emergency service. She had a small amount of pinkish vaginal discharge for a few days before her owners discovered the mass. They do not remember when she was in heat last. She had no other history of any medical problems.

The dog was bright and alert and her physical examination was unremarkable except for the vaginal mass. 

Vaginal mass on Betsy

What additional diagnostic tests would you do?

What is your diagnosis and how would you treat this problem?

Post answers either here or on Facebook.

Ovarian Remnant Syndrome in Dogs and Cats: Why does it happen and how to prevent it.

Ovarian remnant syndrome in dogs and cats: 

21 cases (2000–2007)

Rebecca L. Ball, Stephen J. Birchard, Lauren R. May, Walter R. Threlfall, Gregory S. Young

Journal of the American Veterinary Medical Association Mar 2010, Vol. 236, No. 5, Pages 548-553

Summary

The authors of this paper looked at clinical cases of dogs and cats with ovarian remnant syndrome (ORS) after ovariohysterectomy. The cases were from the veterinary teaching hospitals at The Ohio State University and University of California - Davis. Here are some key points of the study:

• The most common clinical signs were those of proestrus and estrus;
• Clinical signs in some cases took years to develop, even up to 9-10 years in 3 animals (Fig 1);
• Results of abdominal ultrasonography were suspicious for an ovarian remnant in 11 of 12 animals; 
• All residual ovarian tissues were in normal locations, not ectopic;
• Retained right ovaries were more common than left;
• Long term follow up on 18 cases showed resolution of clinical signs after surgical removal of the retained ovary.

The authors concluded from the study that the results indicated surgical error was the most likely cause of ovarian remnant syndrome. 

Commentary

Ovarian remnant may be more common than we think, especially considering the length of time that clinical signs can develop after ovariohysterectomy. In our experience the entire ovary is usually found, not a small fragment of it. Possible causes could be: separation of the ovary from the uterine horn during tugging of the uterus to exteriorize the ovary, or incorrect placement of hemostatic clamps when preparing it for removal. 

Ovarian remnant syndrome should be suspected in any dog or cat with signs of estrus or estrus-related disorders like vaginal hyperplasia or prolapse. Diagnosis can be substantiated via vaginal cytology, ultrasonography, and hormonal assays.

Key Point: Perform abdominal exploratory on dogs and cats with ovarian remnant syndrome while they are in heat. The ovary and associated vasculature will be easier to identify during this phase of the reproductive cycle.

Prevention

The ovaries, especially in obese animals, can be difficult to identify. Careful palpation of the firm, bean like structure is necessary in many animals to be sure that clamp placement is proximal to the ovary and on the vessels in the ovarian pedicle. Adequate surgical exposure is a key element in removal of the entire ovary. After removal of the ovaries and uterus, opening the ovarian bursa will confirm that the entire ovary has been removed.

Have you seen any cases of ovarian remnant syndrome in dogs or cats? Post comments or questions here or on Facebook. 

Case Outcome on Lucky: F/S dog with a vaginal mass (Did you get it right?)

Case outcome on "Lucky", a 4 year old female spayed dog with a large vaginal mass. (Fig. 1)

Fig. 1

Because of Lucky's history of intermittent blood tinged vaginal discharge, and the appearance of the mass, our clinical impression was that the mass was vaginal hyperplasia (also called vaginal edema). There was no history of the owners using any estrogen products on Lucky.  Vaginal hyperplasia would be more common in an intact dog, so we were suspicious that Lucky had an ovarian remnant. 

Abominal exploratory was performed and a left sided ovarian remnant was found. (Fig. 2) 

Fig. 2: ovarian remnant found on Lucky (arrow).
The left kidney (K) is just cranial to the ovary.

A uterine stump mass was also found. (Fig. 3) 

Fig 3: Uterine stump mass (arrow) on Lucky.
The urinary bladder (B) has been retracted caudally.

Both the ovary and uterine mass were excised. Histopathology confirmed a normal ovary and a uterine granuloma.

Postoperatively Lucky had an uneventful recovery and her vaginal hyperplasia gradually resolved over a period of a few weeks. 

Ovarian remnant syndrome (ORS) is more common than you might think. We will discuss the syndrome in more depth in the next blog.

Many of you made the correct diagnosis on this case.

Nice job!