Hematoma of the uterine artery

Keywords: uterine, middle, artery, hematoma, injury, equine

Hemorrhage during foaling can involve the utero-ovarian arteries, external iliac arteries or uterine (middle uterine) arteries. Of these, rupture of the uterine arteries is most likely.

The location of the uterine arteries is shown below. In the left inset image, these vessels have been left in color to accentuate their location. In the right inset, the location of the right uterine artery within the mesometrium is indicated by the red arrow. Note its relationship to the ovaries (colored purple), the uterus (colored pink) and the bladder (colored yellow). A phantom hand is shown, examining the tract as though it would during transrectal palpation. One can appreciate how readily a hematoma in the mesometrium can be palpated during that examination. 

Image size: 1023 x 480px. Right inset image highly modified from an unknown source.

During parturition, the foal's movement may draw the uterine artery in a caudal direction, trapping it against the shaft of the ilium. It is probable that direct tension or local vascular hypoxia exacerbated by tension, causes rupture of the vessel. Age-related degeneration processes  are probably important as well because data suggests strongly that vascular rupture is more more common in older than younger mares. Although copper deficiency has been implicated in vascular rupture, it is relatively unimportant in most cases because balanced rations are available to well managed horses.

Although it is possible, most mares do not exsanguinate after rupturing the uterine artery. Instead, blood escapes into the mesometrial ligament, accumulating between its dorsal and ventral surfaces. The discomfort of normal parturition and placental expulsion probably masks the pain as hemorrhage. It is usually at foal heat breeding that a hematoma is discovered by chance while one is examining the uterus and ovaries. Once the large mass is discovered, ultrasonography will confirm the diagnosis. The typical ultrasonographic appearance of a mesometrial hematoma is illustrated elsewhere.

In the image below, a large hematoma has been removed from its position in the left mesometrial ligament.

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The following image provides a ventral view of the tract shown above. The location of the hematoma in the left mesometrial ligament is clearly visible. This mare also has a large urolith in her bladder. A detailed view of that urolith is given elsewhere in LORI.

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On rare occasions bleeding can dissect the mesometrium until it ruptures, with fatal results. A description of  the potentially life saving treatment used in those cases is beyond the scope of this entry.

It is often suggested that mares with mesometrial hematomas should not be re-bred because of the threat of fatal hemorrhage during subsequent foalings. However, the purpose of mares on many stud farms is only to produce foals. Therefore some breeders continue to use affected mares notwithstanding. In the author's experience over many years, this practice has not led to the subsequent death of a broodmare through fatal hemorrhage. Therefore it is tempting to suggest that mesometrial hematomas are one-time accidents and once recovered, affected broodmares can again be used for breeding, with little fear of repeated hemorrhage. This philosophy is probably not suitable when there is a substantial emotional attachment to a mare.

In many mares, a palpable mass may remain in the mesometrium for months after foaling.

References: 
Pascoe, R. R. Rupture of the utero-ovarian or middle uterine artery in the mare at or near parturition. Vet. Rec., 104:77, 1979.

Rooney, J. R. Internal hemorrhage related to gestation in the mare. Cornell Vet., 54:11, 1964.

Stowe, H. D.: Effects of age and impending parturition upon serum copper of Thoroughbred mares. J. Nutrition., 95:179, 1968.

Third-degree perineal lacerations

Keywords: laceration, degree, mare, foaling, injury

First and second degree perineal lacerations are seldom of importance, the first being laceration of the vaginal mucosa and the second, laceration of the vaginal mucosa and the tissue between the vagina and rectum.

Third degree lacerations involve the vaginal mucosa, rectal mucosa, and the interposing tissue.  They may take the form of fistulas or more commonly, complete destruction of the perineal body. As mentioned in an entry on evisceration after foaling these accidents appear to be more common in maiden mares than pluriparous mares.  These old but valuable images illustrate the problem well.

In the top right inset of the image below, a third degree laceration is being examined several days after foaling. A large hematoma is present in the left wall of the vestibule and there is considerable fecal contamination over the lacerated tissue between the vagina and rectum.  These injuries are almost never fatal and hemorrhage is seldom severe because of the blunt nature of this trauma.

The author estimates that the main image was obtained perhaps ten days later, when the hematoma had resolved and secondary intention healing of the torn tissue was well underway.

Image size: 840 x 767px  Modified. Original copyright Dept. Theriogenology, ISU. Ames, Iowa.

Although the value of antibiotic treatment is debatable in these cases, immediately tetanus prophylaxis is suggested. Although there is some disagreement on when surgery should occur, the author suggests that one should resist the temptation to repair these injuries surgically until second intention healing is complete. If that is done, the wound margins and viable tissue can be clearly delineated for surgery.

In practice, the foal is also weaned before surgical repair is attempted because dietary restrictions imposed on the mare (to decrease fecal production) will retard the growth of the foal.

Owners may be concerned to wait for several month for repair because fecal contamination of the vagina continues during that period. Remarkably,this approach does not appear to have a detrimental effect on the future reproductive capacity of mares. This could be due to excellent uterine defense mechanisms in young mares,

Method of repair:

Image size: 743 x 824px  Modified. Original copyright Dept. Theriogenology, ISU. Ames, Iowa.

The author has used an Aanes two-stage technique modified by Dr. Tracy Clark at Iowa State University. The image at upper left shows how the perineum has been prepared for surgery. Pre-surgical starvation diminishes the amount of feces in the rectum (ringed in the lower left inset) at the time of surgery. After all feces have been removed by hand, fecal debris can be prevented from entering the surgical field by using a large tampon device made of rolled cotton, held together with half hitches of umbilical tape, complete with a tail of tape to withdraw it from the rectum after surgery.  Epidural anesthesia is used.

The inset image at lower right shows how the rectum, vagina and interposing tissue are repaired using a continuous, cranial-to-caudal suture pattern. No attempt is made to reconstruct the perineal body during first stage repair. Doing so will cause feces to exert pressure on the anus, breaking the suture line described above.

After the first stage has healed, the perineum is reconstructed.

Third degree lacerations of the perineal body may not involve the anus; after healing they take the form of  fistulas between the vagina and rectum. Sometimes these fistulas are large, allowing these animals to defecate through their vulva lips. Such a case is shown below.

Image size: 444 x 1050px  Modified. Original copyright Dept. Theriogenology, ISU. Ames, Iowa.

The lower image shows the area being prepared for surgery with a dramatic demonstration of the extent of the lesion to be repaired. The technique used is similar to the first stage described above.

Reference: 

Aanes, W.A. 1988. Surgical management of foaling injuries. Vet. Clin. North Am. Equine Pract. 4:417-438. 

Foaling injuries and pneumometra (wind sucking)

Keywords: pneumometra, wind-sucking, equine,injury, infertility

Injuries from foaling or other causes may result in mild to severe distortion of the vulvar lips after healing.  The result is essentially the same as if a mare had congenitally poor conformation i.e. affected mares becomes "wind suckers” and pneumometra develops.

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The cause of the injury in the mare at upper left was never determined but it was not due to foaling. This contributed to wind sucking. In the image below that, mild distortion of the left vulva lip was indeed a result of foaling. Surprisingly however, this did not appear to cause wind sucking.  When Caslick’s operations are not reversed prior to foaling, similar injuries can occur.

When pneumometra occurs, it is occasionally visible using transrectal ultrasonography. For example, in images A and B, (a separate case from the mares pictured at left) bubbles of air can be seen as highly echogenic structures in uterine cross-sections. This can cause long term infertility as discussed elsewhere in LORI.

Trans-luminal adhesions

Keywords: foaling, injury, obstetrics, adhesions

Purulent discharge seen on the floor (red ellipse) behind a mare. This mare discharged pus intermittently because of multiple draining abscesses that had formed in her vagina. These abscesses formed between trans-luminal adhesions caused by vaginal irritation. This followed prolonged intervention during dystocia.  This also caused obliteration of the cervix.

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This illustration also shows how the extent of trans-luminal adhesions can be evaluated using transrectal ultrasonography and an infusion of saline.  At the upper right corner, a green check mark shows the normal appearance of saline in a uterine lumen.  Its echogenicity is due to microscopic bubbles of air that are normally found in saline. This appearance makes saline an ideal contrast medium for the evaluation of the uterine and vaginal integrity using ultrasound.

In the red rectangle, one can see how poorly an infusion of saline had distributed itself within the uterine lumen of another mare. That mare had severe trans-luminal adhesions throughout her uterus, probably as a result of a foaling injury.

Trans-luminal vaginal adhesions arising from the management of dystocia are not uncommon. To prevent trans-luminal adhesions from forming, a lubricating substance such as oil-based mastitis ointment can be applied to the vaginal wall two or three times at 48 hrs intervals after relieving an equine dystocias. Similar adhesions are rare in other species following treatment for dystocia; the equine vaginal wall appears to be especially sensitive to abrasion and chemical irritation.

Penile injury

Keywords: stallion, equine, penis, injury, Gunn

An approximately five year old 500 kg Australian Stock Horse stallion was presented having been found in the paddock adjoining an “in season” mare, with a very large and swollen penis and prepuce.

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There was also an obvious wound on the left dorsal mid-shaft of the penis. The stallion appeared to have jumped into the paddock adjoining the mare, and attempted to serve her through the fence.

Initial treatment was cold hydrotherapy for approximately 20 minutes. When examined approximately three hours later, the stallion was bright, alert and responsive with obvious balanoposthitis resulting in paraphimosis. Clinical examination was otherwise unremarkable. The stallion was sedated with 20 mg romifidine and 20 mg butorphanol, and 750 mg flunixin meglumine was administered intravenously. Procaine penicillin (10,500,000 IU) was administered intramuscularly. The penis was extended with manual traction, palpated, examined visually, and scanned ultrasonographically. This suggested that the penile tunica albuginea was intact but as shown below (note cursors) there was substantial edema between the tunica albuginea and the skin.

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There was an obvious full-thickness wound on the left dorso-lateral aspect of the internal preputial lamina at the level of the internal preputial ring. The wound was left to heal by second intention. Massage was instigated to decrease the edema and assist in returning the penis to the prepuce. The penis was cleaned with water and very dilute  iodine surgical scrub, rinsed and dried. Emollient antibiotic ointment was applied to the swollen area.

The “underpants support mechanism” was applied to this horse, similar to other described by Gunn. A.J. et al 2013). He was hand walked four times daily and treatment was similar to that in the cases described above. The support was deviated to the side twice daily for hydrotherapy and application of antibiotic ointment. The support was changed daily for three days. On the fourth day, the stallion was able to retract his penis and prepuce into the preputial cavity. The support was removed as it was no longer required.

Daily hydrotherapy of the penis and prepuce, and antibiotic ointment application continued for seven days. Then stallion was then able obtain an erection and after erection, to retract his penis into the preputial cavity. The wound had granulated, epithelialization was occurring, and contraction of the area was evident.

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The stallion was exposed to mares daily to induce frequent erections for a period of two weeks. The penile wound had healed substantially by that time (see inset) allowing the stallion to serve a mare successfully. The mare became pregnant.

Copyright: Dr Allan. BSc.Agric, BVM&S, MANZCVS (horse med; repro), DACT, MRCVS
Lecturer; School of Animal and Veterinary Science Charles Sturt University, Wagga Wagga, NSW 2678, Australia. (algunn@csu.edu.au).

Reference: Gunn. A.J. et al 2013. Balanoposthitis and paraphimosis in the stallion. A novel support for an inflamed penis and prepuce Clinical Theriogenology • Volume 5:45-55 • March 2013

This material has been reproduced courtesy of Dr R.Youngquist, Editor.Clinical Theriogenology

An innovative method for suspending the penis

Keywords: underwear, penis, injury, stallion, equine

Injuries to the penis are common in stallions. These are most often sustained during breeding or teasing Usually a sophisticated sling and suspensory system is not available. Instead, a pair of men's underwear can be used suspended through the hind legs and over the flanks using baling twine or a bandage. The basic method is shown here. Additional details are described in the accompanying reference.

Image size: 2000 x 1551px

With appropriate modifications to prevent abrasions, the system can even used for extended periods of time.

Copyright: Dr A. Gunn. BSc.Agric, BVM&S, MANZCVS (horse med; repro), DACT, MRCVS
Lecturer; School of Animal and Veterinary Science Charles Sturt University, Wagga Wagga, NSW 2678, Australia. (algunn@csu.edu.au).

Photographic credit: Katrina Partidge http://www.katrinapartridgephotography.com

Reference: Gunn. A.J. et al 2013. Balanoposthitis and paraphimosis in the stallion. A novel support for an inflamed penis and prepuce Clinical Theriogenology • Volume 5:45-55 • March 2013

This material has been reproduced courtesy of Dr R.Youngquist, Editor.Clinical Theriogenology

Penile injury

Keywords: penis, injury, stallion, Monroe

Image size: 608 x 478px

This stallion ran  into a steel fence post, traumatizing its lower abdomen (see scrape marks) and inguinal area. Initially no other damage was evident but ovet the next few days, this prolapse developed.

Annotation on treatment and recovery pending. See these other entries in LORI for approaches to treating these injuries:

Kicking injuries to the penis

&

Approaches to penile prolapse in a stallion

Note: Low resolution image. Copyright: Dr Brian Monroe (lvh@dragnet.com.au)

 Approaches to penile prolapse in a stallion

Keywords: stallion, equine, penis, injury

A mature Icelandic stallion sustained an injury to his penis that resulted  in partial prolapse. The stallion had not been in contact with mares so this was not the result of a kicking injury (a common cause of penile injuries in stallions). Instead,  it was thought that he had been traumatized while attempting to tease mares across a paddock fence.

Image size: 2000 x 2667px

Because trauma to the penis was not severe, it was though sufficient to apply a purse-string suture around the prepuce to retain the penis; similar to the principle occasionally used in bulls with penile prolapse. As will become evident, this was an error in judgement by the author. The purse-string suture was difficult to place because the circumference for suture placement was not as easy to define as that in a bull.  Nevertheless, the penis was well retained after suture placement. An aperture of approximately 2.5 cm was left for the passage of urine. Zinc oxide ointment was applied to prevent excoriation because the stallion would not be able to exteriorize his penis during urination.

Appropriate tetanus prophylaxis and antibiotic treatment was used.

Image size: 2000 x 1500px

Within 12 hours the penis had escaped the restraint of the purse-string suture. Fortunately this was discovered soon after that had occurred, so strangulation of the penis was not yet evident.

The purse-string suture was removed immediately....

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 ..... and the penis was suspended in a conventional sling (below) used for penile injuries in stallion. 

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The method used for suspending the sling was conventional as well. It is shown below.

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Soon after the application of this sling, it was noticed that pouch of that sling was not large enough to contain the prolapsing penis in this animal. This was replaced by the larger pouch seen below. Zinc oxide treatment continued to prevent excoriation because the pouch remained damp during during the support period.

Image size: 2000 x 1500px

Recovery was uneventful. 

This cases illustrates the caution that should be exercised if  the application of a purse string suture is contemplated. It also shows that a suspensory  system and several sizes of pouches should be on hand for penile injuries in stallions. 

A kicking injury after natural service

Keywords: injury, penis, stallion

Image size: 2441 x 1548px

This amalgum of two images shows the appearance of a stallion's penis and prepuce after a typical injury sustained during breeding. This topic is described in some detail elsewhere in LORI. Click here to reach that entry.

Kicking injuries to the penis

Keywords: stallion, equine, injury, penis

Damage to the penis of a stallion sustained by a kick from a mare during breeding. This is all too common and can be prevented by appropriate teasing and mare restraint. Alternatively and preferably one should use a phantom and AI.

On no account should inexperienced stallions be turned out into a group of mares to breed them, especially stallions that have been trained to serve a phantom or have been hand-bred to mares.

Image size: 500 x414px

In the lower image in this amalgum, note how the penis has curved to face caudally. This is due to damage of a major venous plexus on the dorsal aspect of the penis, forming a hematoma that induces this curvature of the penis. 

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This plexus is shown in the following image. An overview of the anatomy of a stallion's penis viewed from the lateral aspect and in the inset, from the dorsal aspect.

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Of particular interest here is the massive venous plexus that lies dorsal to the penis. Its function is unknown but it may serve as a temporary reservoir for blood as it is drained from the penis after an erection. As shown in the previous image, this plexus is often damaged when stallions are kicked on the dorsal aspect of their partially erect penises during mounting or dismounting.

A major priority in these cases is to catheterize the urethra to ensure normal urine flow. Also, as shown below, zinc oxide ointment should also be applied to protect the penile mucosa from urine scalding after the catheter has been removed.

Image size: 1000 x 890px

Hydrotherapy is a valuable part of treatment as well:

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When injuries such as this occur, the stallion often cannot be used again for the rest of the breeding season.

These images show the penis and prepuce of a three-year-old Appaloosa stallion. He stood in a pasture with a number of mares and was kicked whilst trying to serve one of them. Treatment included tetanus prophylaxis, antibiotics and pressure bandage placement on his penis.

Image size: 1200 x 1332px

The top two images in this amalgum show the state of the penis at presentation. The stallion was able to withdraw the penis into his prepuce but there was severe peri-penile edema. At lower left the penis is shown compressed with "Vetwrap" after being catheterized.  In this case, the wrap was only left in place for a period of approximately 3 hours and as shown at lower right, improvement was substantial. Some of the edema had however, been driven caudally and covered the scrotum. Examination of the scrotum using ultrasound suggested that there was very little effusion into the tunica vaginalis itself. However, local inflammation and insulation the testicles would probably have compromised spermatogenesis anyway. Owners should always be warned of this potential.

The image below shows some options for penile suspension after kicking injuries.

Image size: 1200 x 818px

The first is a crude truss made from netting, suspended with loops of surgical rubber tubing; two cranially and a single loop caudally. The single loop is passed up through the hind legs with tubing on either side of the tail. That loop is then joined to both of the cranial loops which are passed dorsally on the flanks of the stallion.  The inset shows how a similar effect can be achieved with a simple belly bandage.  Whichever system is used, it should allow for frequent bandage changes and access to the penis.

In general, treatment of penile kicking injuries should include catheterization of the urethra, compression of the penis and re-bandaging every few hours, suspension of the penis to prevent gravitational exacerbation of edema, tetanus prophylaxis, analgesia and prophylactic antibiotics.

It is important to realize that the dorsal nerves of  the penis can be damaged by kicking injuries as well. In such cases, sensitivity to the glans penis is lost and as is the case in bulls, the stallion may be unable to detect the vulva for intromission. Should this be suspected, a client can be convinced of the fact (after preliminary testing!) by placing a hemostat on the stallion's glans penis (personal communication, Dr John Cavalieri,  john.cavalieri@jcu.edu.au.).