CHAPTER 36Trauma to the Penis

EARL M. GAUGHAN, PHILIP D. van HARREVELD

Traumatic injury of the penis in horses is not common.^1,² Kick-related injury to the penis and prepuce of stallions and aggressive geldings by seasonal mares is likely the most frequent origin of trauma to this region.^1,² Horses can also experience blunt trauma from obstacles or objects either in competitive pursuits or during playful activity. Lacerations and penetrating injury can also occur from a variety of sources.

Initial assessment of a horse with penile and/or preputial injury should include a complete physical examination, noting vital signs and detection of any systemic repercussions. Clinical signs of shock should be addressed with complete diagnostic efforts and aggressive medical treatment. Most commonly, penile/preputial trauma does not require exaggerated systemic support but concentrated local and systemic management of the local tissue lesions.

Close attention and observation should be directed at assessment of penile function and the horse’s ability to position and maintain the penis in the normal preputial location. This may not be possible due to local tissue swelling; however, early signs of retraction efforts are encouraging for ultimate return to normal. It should be noted that an absence of obvious penile retraction does not rule out the final ability to return to normal function, especially when substantial penile and preputial swelling are present. Skin and deep tissues should be manually palpated and evaluated for warmth and possible sensation. Ultrasonographic examination may provide some information in regard to vascular blood flow and the nature of tissue swelling. Thermographic examination can also provide useful information relative to tissue perfusion and to establish a baseline from which to detect changes over the time of treatment.

TRAUMA WITHOUT OPEN WOUNDS

Blunt trauma to the penis/prepuce is likely the most common reason a veterinarian is asked to examine this region in an adult male horse. A complete physical examination should be performed with obvious attention to the external genitalia. Swelling that is marked in the acute phases after injury should be closely evaluated for the presence of a hematoma in which the hemorrhage is ongoing. The best detection method for this instance is likely ultrasonography.³ It is not recommended to perform needle aspirates at this time due to the possibility of inoculating microorganisms into a potentially sterile site. Ultrasonography may also assist in the evaluation of established swelling because edema fluid will typically have a more echo-dense appearance than free fluid/blood.³

Acute hematoma formation should be treated as for any other episode of substantial hemorrhage.^1,^2,⁴ Local tissue cooling with ice packs, cold running water, and local tissue pressure should be initiated at the earliest possible opportunity. The penis and prepuce should be compressed and elevated with a bandage or sling to approximate these tissues to the ventral body wall. If swelling is confined to the glans, a circumferential pressure bandage can assist in the reduction and resolution of bleeding and swelling. This should be maintained at all times other than when local, topical treatment is applied. The application of topical ointments, salves, and astringent agents should be approached carefully so that the skin is not irritated, which can exacerbate local swelling. Emollient ointments can assist some horses. Preparations with dimethyl sulfoxide (DMSO), lanolin, Furacin, petroleum jelly, and formulas for topical udder treatment in cattle can help keep penile and preputial skin protected from desiccation when retraction to normal position is not possible.¹

Horses with penile and preputial hematomas should be treated with systemic antibiotics and nonsteroidal antiinflammatory drugs (NSAIDs). Substantial swelling may be more rapidly resolved with the administration of systemic DMSO (100 mg to 1.0 g/kg PO or IV once to twice per day for 3 days). Medication can be discontinued when swelling is reduced and normal function is resumed.

Blunt trauma can result in permanent penile dysfunction. Paraphimosis and priapism can both result from trauma to the penis and prepuce (Figure 36-1). Repositioning of the penis into the prepuce and return to normal function are the obvious goals of treatment for these disorders.^1,⁵^–⁷