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.
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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.
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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.
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.
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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.).
