Much of the focus and effort put forth on breeding farms this spring will center on mares and the various reproductive problems
that they experience. Stallions are often given minimal attention other than bacterial cultures and examination of early season
ejaculates unless there are unusually high numbers of return "open" mares or evidence of serious problems.
But it takes two to tango, and stallions also are affected by any number of conditions that can impact their ability to mount,
ejaculate or "settle" mares. A look at the most common causes of lesions of the penis and testicles of the stallion may alert
practitioners to potential problems that can be addressed at an early stage and possibly deal with aggressively. This knowledge
and early management can save potential fertility in some stallions and might help make this season a successful one.
Relatively early stages of penile squamous cell carcinoma will show up as red to whitish raised areas on the penis and prepuce.
Lesions of this type and stage might cause little to no clinical problems with either collection or natural service but the
sooner these areas are noticed and biopsied, the sooner treatment can be started.
Paraphimosis, or swelling of the penis, is one of the most commonly seen problems in breeding stallions.
"Breeding injuries and trauma from phantom (artificial collection mounts) accidents cause the majority of stallion injuries
that we see," says Dr. Charles Love, a member of the Department of Reproduction at the College of Veterinary Medicine at Texas
Aggressive Thoroughbred stallions often charge mares, and aggressive mares occasionally kick stallions. Either of these scenarios
can result in blunt-force trauma to the penis of the stallion, "essentially a smashed penis", Love says. "Breeding managers
have become so comfortable collecting stallions off a phantom that they tend to think that all of the potential risk has been
removed. Yet charging the phantom or misalignment, especially with an aggressive breeder, can result in significant trauma,
penile hematoma and paraphimosis."
Dr. William Ley, an equine reproductive specialist in private practice in Virginia, concurs that a kick from a mare before,
during or after breeding is the most common cause of injury to the stallion and can result in scrotal contusion, testicular
hematoma or penile paraphimosis. These stallions usually will present with a slight elevation in temperature due to a pain
response and with very obvious swelling of the affected area. Ultrasound examination will confirm the presence of edema. If
an acute testicular hematoma is present, it might be hypo-echoic or anechoic (areas of reduced or absent ultrasound signal
that appear as black spaces) due to an accumulation of blood within the tissue. Chronic lesions will appear hyper-echoic (areas
of whiter ultrasound shading) due to fibrosis. Prognosis for these types of injuries is guarded, but quick recognition of
the problem and aggressive treatment may preserve acceptable stallion performance and fertility.
Treatment for traumatic swelling or paraphimosis requires aggressive measures to reduce edema. Love recommends vigorous massage
of the penis and periodic cold hydrotherapy during the initial 24-hour period.
"And I do mean massage as often as possible over that initial period requiring that the stallion be in a location offering
24-hour care," he says.
The goal is to be able to retract the penis into the prepuce, which then greatly increases the chances of a successful outcome.
Anti-inflammatory medications, such as flunixin and dexamethasone, can be used along with topical antibiotics to reduce the
chances of infection. Salix and Naquasone (trichlormethiazide and dexamethasone combination) also can be used to reduce edema,
but there is no substitute for hydrotherapy and massage. Caution must be used, though, with the application of cold water
because reduced blood flow to the penis can result in tissue trauma if the cold is excessive or used continuously for too
long. Short (eight to 10 minute) applications every hour are best. The use of compression bandages or various slings designed
to help hold the penis up against the ventral abdomen can be very beneficial as it helps offset gravity and allow easier reduction
of edema. Still, the primary goal is to replace the penis within the prepuce as quickly following trauma as possible.