How to Diagnose and Treat Hemospermia: A Review and Case Series

1. Introduction

Disorders of breeding stallions have severe ramifications for not only the economics of the equine industry but also the welfare of affected animals. Hemospermia in particular is challenging to diagnose and manage, as there are many etiologies and treatment options. Importantly, one of the mainstays of treatment for all cases is sexual rest, which has severe economic consequences on the stallion’s reproductive performance. Because hemospermia is associated with heavy breeding or collection schedules, the disease is often diagnosed in the beginning or height of the breeding season. Therefore, timely identification of the disorder, diagnosis of the pathophysiology, and implementation of a treatment protocol will provide the best opportunity to return the stallion to breeding function, albeit most often for the following season. Some causes of hemospermia are life-threatening, such as squamous cell carcinoma, and early diagnosis and treatment may improve survival rates.

Often, the first indication of hemospermia, especially in live-cover breeding operations, is infertility. Presence of erythrocytes within the ejaculate may dramatically reduce pregnancy rates as the result of effects of an unknown factor of the erythrocytes on spermatozoa. Alternatively, blood may be noted at the mare’s vulva or stallion’s penis on dismount. Stallions that are collected by means of an artificial vagina may be identified by blood-contaminated ejaculates. External lesions may be observed during washing before collection. Stallions may demonstrate normal libido but pain on erection, dilation of the glans, or ejaculation. Pain may also be observed in association with masturbation behavior or urination. 

The objectives of this paper are 1) to provide an overview of the diagnostic evaluation of stallions that present for hemospermia; 2) to review the major causes of hemospermia and their treatment options; 3) to present a case series of stallions with hemospermia that represent cases that veterinarians commonly see in practice.

2. Diagnostic Protocol

Signalment

Hemospermia has been reported in stallions of variable ages and breeds; however, in one report of 18 cases, 15 were Quarter Horses (83.3%). Of the 18 horses, the average age at onset of hemospermia was 7.1 years (range, 3–18) and the number of seasons at stud was 3.7 (range, 0–13).¹

History

Hemorrhage may be noted during washing of the penis, from the penis after breeding or collection, on the phantom after collection, from the mare after live-cover mating, or associated with urination. The horse may have a history of pain during urination, masturbation, erection, or ejaculation. Self-mutilation behavior and colic have been described in a stallion with hemospermia caused by seminal vesiculitis.² Important history to acquire from the owner includes the following:

• Any previous episodes of hemospermia
• Any change in stallion body weight or condition
• Any change in stallion collection frequency
• Any recent adjustments to the collection phantom, such as height, type, and so forth (stallion use: collection only, live-cover mating, or both)
• On observation of hemospermia, was the blood expelled as large clots or progressive from blood-tinged to frank blood?
• Any observations of bleeding in the stall, such as associated with urination
• Any observations of bleeding when the penis is washed during erection

Physical Examination

Evaluation of the stallion that presents for hemospermia begins with a thorough physical examination. The horse may require sedation to facilitate examination of the external genitalia. The epithelium of the prepuce and penis should be evaluated for any lesions, including papules, pustules, erosions, ulcers, proliferative lesions, or lacerations. Special attention should be paid to the urethral process and urethral fossa because these are common sites of injury and neoplasia, although some lesions of the glans are not apparent until erection occurs. The epididymis should be palpated and imaged for enlargement or an increase in firmness. Transrectal ultrasonography may demonstrate abnormalities of the ampullae, seminal vesicles, bladder, or inguinal lymph nodes, which would indicate further diagnostic testing.

Semen Collection

The stallion is teased and washed, and semen is collected through the use of an artificial vagina. Some practitioners prefer to use an open-ended Colorado-style artificial vagina to fractionate the ejaculate, although in most cases this is not necessary to obtain a diagnosis.³ Stallions with painful lesions of the glans penis or urethral process may not ejaculate because of pain associated with the lesion at the time of dilation of the glans. These stallions demonstrate normal libido but become acutely painful and dismount the phantom without ejaculating. Repeated collection attempts may result in frustration of the stallion. Often, examination of the penis after dismount will demonstrate the source of hemorrhage on the glans or urethral process. Stallions that ejaculate grossly hemorrhagic semen but do not display external lesions should be submitted for endoscopy within 20 minutes to identify the origin of hemorrhage. Stallions with a history of hemospermia that have had a period of sexual rest may not hemorrhage during initial collections but may do so after repeated collections over days to weeks.

Collected semen with hemospermia on gross or macroscopic inspection may appear pink to red in color. On gross inspection, semen with microscopic hemospermia may appear to be normal; the use of cytology is imperative to the diagnosis. Cytology that demonstrates the presence of large numbers of leukocytes and erythrocytes should direct the clinician to evaluate the urogenital tract for inflammatory or infectious processes of the bladder, epididymis, seminal vesicles, or urethra.

Endoscopy

In the absence of lesions of the glans penis and urethral process, endoscopy should be performed within 20 minutes of collection to examine the urethra, colliculus seminalis, seminal vesicles, and urinary bladder. The horse is sedated, often with α-anadrenergic agonist such as xylazine or detomidine and butorphanol intravenously. The penis is washed with warm water and non-irritating soap. Any accumulation of smegma in the urethral fossa should be removed. The penis is then dried. Endoscopic examination requires the use of three personnel: one to aseptically insert the endoscope into the urethra and hold the extended penis; one to operate the endoscope; and one to restrain the horse. Most adult light-breed horses can be examined with a sterilized flexible endoscope of 100-cm length and 10-mm diameter.⁴ Small ponies and miniature horses require the use of a pediatric gastroscope of 8-to 9-mm diameter.⁴ Large horses may require the use of a longer endoscope. Smaller-diameter endoscopes are easier to introduce into the seminal vesicles.

The endoscope is inserted into the urethra with a small amount of sterile lidocaine-containing lubricant by an operator who maintains one hand around the glans and one hand to advance or retract the depth of the endoscope, while wearing sterile examination gloves. The endoscope is advanced slowly to observe for signs of pathology. Small volumes of air may be applied to facilitate examination. Dilation of the urethra results in hyperemia of the underlying corpus spongiosum vasculature, which should not be confused with urethritis.⁴ At the level of the ischial arch, the convex surface of the urethra should be closely examined for hemorrhage caused by idiopathic urethral rent formation. [...]