LORI.ovine

Scrotal hematoma/seroma and scrotal abscessation

Case 1: Scrotal  hematoma

Keywords: ovine, ram, scrotum, hematoma, infertility, fertility

A Texel ram approximately 4 years of age was presented with a history of  weight loss and right scrotal enlargement of approximately 2 to 3 weeks duration. This enlargement was semi-firm and the ram resented palpation in this area. The owner had treated the ram with penicillin and trimethoprim-sulfa for five days before presentation.

Figure 1. Enlargement of the right half of the scrotum in a 4 year old Texel ram due to a hematoma. Aseptic tapping of the right side of the scrotum revealed clear serum. Image size: 1000 x 755px

Ultrasonography showed the presence of a large hematoma in the right side of the scrotum and an apparently normal testis in the left side of the scrotum. See figure 2.

Figure 2. A hematoma within the right half of the scrotum (lower insets). Fibrin clots had displaced the right testis dorso-medially making it difficult to image; only the hematoma and part of the seminiferous cord within the right half of the scrotum (lower right) were visible. Cross sections and longitudinal sections of the left testis (upper insets respectively) suggested that the left testis was normal. Image size: 1039 x 825 px

As shown in figure 1, aseptic tapping of the hematoma revealed the presence of serum, presumably the result of  blood clotting. The serum sample was smeared and stained; it was acellular and no bacteria were found. However, there was a substantial increase in the peripheral neutrophil count (approximately double normal values) but no other suggestion of septicemia. The animal was bright alert and responsive throughout its stay in the clinic therefore the origin of the neutrophilia remained an enigma.

Surprisingly, electro-ejaculation produced a semen sample that was normal in appearance, with excellent motility and morphology. The ram was discharged and the owner was told that the animal could be used for breeding as soon as required. The farmer was also advised of the risk of scrotal abcessation and the need to monitor the ram's scrotum and fertility.

It was surmised that this seroma was the result of trauma as several other rams were housed together with the ram.

Case 2: Scrotal abcessation. 

Keywords: scrotum, ram, ovine, abscess, peritoneum, omentum, infertility

A mature Texel ram of uncertain age was admitted with a a large abscess. This was substantiated by ultrasonography (figure 3)

Figure 3. Ultrasonography adjacent to the right testis showing pockets of fluid (presumed to be pus) in a fibrous mass surrounding the right testis. Image size: 767 x 484 px

Aseptic tapping of the the right half of the scrotum (figure 4) revealed large amounts of pus.

Figure 4.  Tapping of the enlarged mass over the right testis in a ram with an enlarged scrotum, revealing a mixture of blood and pus. Image size: 1200 x 931 px

The ram was euthanized and submitted for postmortem examination. There was inflammation and hemorrhage in the tunica dartos around the right testis. There was also substantial pus accumulation in the vaginal cavity, under the visceral surface of the parietal vaginal tunic, adjacent to  the right testis.  There were also accumulations of pus in abscesses around the spermatic cord. See figure 5.

Figure 5. Inflammation and edema within the right tunica dartos surrounding the right testis. The intact parietal vaginal tunic surrounding the right testis can be seen in the same image. In the image to  the right, the parietal vaginal  tunic has been incised, revealing a mass of interconnected abscesses. Image size: 1200 x 880 px

The abscesses and fibrous tissue formed a mass beneath the visceral tunic of the right testis had enlarged sufficiently to ablate most of the vaginal cavity around the right testis. The shallow remnant of the vaginal cavity viewed from the peritoneal cavity is shown in figure 6.

Figure 6. A shallow remnant of the right vaginal cavity. The vaginal cavity normally surround the entire testis and epididymus. Inflammation beneath the vaginal tunic resulted in inflammation that caused adhesions between the visceral and parietal vaginal surfaces, diminishing the capacity of the vaginal cavity. Image size: 2044 x 2504 px

In addition to the scrotal abscesses, numerous abscesses were found in the inguinal lymph nodes and mesentery (figure 7) suggesting that the scrotal abscesses were part of systemic disease.

Figure 7. One of many peritoneal abscesses present in a ram with peri-testis abscessation. Image size: 1267 x 1454 px

Budget constraints did not allow bacterial culturing. Although other bacteria are sometimes involved in scrotal abscessation (see the following case) literature suggests that Corynebacterium pseudotuberculosis was the likely pathogen in this case.

Case 3: Scrotal abcessation. 

Keywords: scrotum, ram, ovine, abscess, E.Coli, infertility

A 2 1/2 year old companion animal ram of mixed breed was presented for an enlarged scrotum. As seen in figure 8, the scrotum was so dependent that it dragged beneath the animal's legs, causing trauma and smearing the ground with blood.

Figure 8. A grossly enlarged scrotum in a mixed breed ram. Note how the scrotum was so heavy and dependent that it dragged on the ground. An outline of  the left testis is clearly visible. Image size: 1265 x 791 px

This ram had sired at least three lambs prior to the onset of the swelling which was first seen about nine months before presentation. There was no history of injury. The ram was eating normally and passing feces at the time of presentation but according to the owner, had been mildly obtund for the preceding three days. The rDVM had sampled the swollen mass by needle puncture, revealing pus. Culture of that pus revealed E. coli.

Ultrasonography of the scrotum revealed multiple pockets of fluid with small echogenic particles suggesting the presence of multiple abscesses in the scrotum. There was no evidence of intestinal contents in the scrotum and only the left testis could be seen on ultrasonography.

Figure 9. Ultrasonography of the right side of the scrotum of a mixed breed ram, showing two abscesses (of many). The left testis appeared to be normal. Image size: 798 486 px

Due to the value of the ram as a companion animal, it was not euthanized. Instead, the scrotum was removed under general anesthesia. Severe blood loss during surgery necessitated hospitalization for several days after removal of the scrotum.

The scrotum weighed 14 kg after removal:  The left testis appeared to be normal in size. An impression smear of the cut surface of that testis and its epididymis revealed the presence of spermatozoa. A histological section of the left testis also showed that spermatogenesis was progressing normally.

Numerous incisions into the right testicular mass revealed many compartmentalized abscesses.

Figure 10.  A collage of images showing the content of the scrotum of a mixed breed ram. All images are viewed from the cranial aspect of the scrotum. Image A shows the amputated scrotum. As in image B, all images show the presence of the left testis (large blue arrow) Image C shows pus flowing from an incision in the right side of the scrotum. Image D shows a collection of red arrows, indicating many of the interconnecting abscesses in the right side of the scrotum. The only possible remnants of the right testis are indicated by the black arrows. Image size: 1904 x 1615 px

As was the case for the rDVM, culture of the pus from one of these abscesses also revealed a pure culture of E. coli.

Although a thorough dissection of the right testicular mass was undertaken, no obvious remnant of the right testis seminiferous epithelium was seen. A small section of what may have been seminiferous epithelium was examined histologically. This section was difficult to interpret but the author believes that the remnants of seminiferous tubules could be seen, together with numerous necrotic inflammatory cells. Remarkably, spermatogenesis appeared to be progressing normally in the left testis despite its proximity to this inflammatory process.

Selected references:

Chhalgari M.U. 2017. Caseous lymphadenitis in small ruminants: An overview on reproductive implications. https://www.researchgate.net/publication/316582742

Lacasta D.I. et al. 2009. Unilateral scrotal pyocele in ram caused by Staphylococcus capitis. Aust Vet J. 87:484-486.

Williamson P. and Nairn M E. 1980. Lesions caused by Corynebacterium pseudotuberculosis in the scrotum of rams. Aust Vet J. 56:496-498.