Epididymitis is a disease of sheep. It is characterized by both acute and chronic inflammation of the testicle and epididymis. The disease results in economic losses for producers because of reduced fertility, shortened breeding life, necessary inspection, expensive immunization and increased labor. The most significant economic impact is a lowered conception rate, extended duration of the lambing period, failure of a high percentage of ewes to conceive, occasional abortions and weak lambs. (1)

Ram Epididymitis occurs in most of the sheep producing countries of the world. Here in the United States, it occurs mostly in the western states. However, it may become more prevalent in the mid western and eastern state flocks as more testing is completed.

A causative agent for Ram Epididymitis and the first organism identified was Brucella ovis. This was thought to be the only bacteria involved. Then, around 1975, researchers in Idaho were attempting to produce a B. ovis vaccine but found two other bacteria from cultures of active epididymitis. They were Actinobacillus seminis and Histophilus ovis (Hemophilus somnus). These later two organisms are more often associated with epididymitis of young rams and appear to be normal inhabitants of the prepuce and penis of young rams. (2)

Examination for ram epididymitis is by manual palpation of the testicles and epididymis. It is important to handle the scrotum and contents with both hands to compare the size, firmness and especially pay attention to scar tissue at the tail of the epididymitis where it attaches to the testicle. Semen samples showing spermatozoa with detached heads and leukocytes, especially neutrophils, would indicate a problem. Because a ram might be infected months before lesions appear, the serum ELISA, or enzyme linked immunosorbent assay test on serum is an important tool in controlling this disease. ELISA testing is now required in most ram sales. Another method of diagnosis is by semen culture. Follow up ELISA tests and a semen culture could confirm the diagnosis. Early work by McGowan and others used a Brucella ovis bacterin along with routing palpitation. This vaccination interfered with the C.F. (complement fixation) tests, and with eradication of the disease. Through routine palpation and raising ram lambs separately from adult rams, the incidence of epididymitis has been markedly reduced.

The transmission of epididymitis occurs by different ways. Some of the most common are: homosexual behavior of rams, ram breeding ewes following breeding by an infected ram and contamination of feed and water.

Clinical signs of epididymitis are confined to contents of the scrotal sac. Acute cases start with swelling of the epididymis (unilateral) without testicular involvement. Later the induration and fibrosis of the tail of the epididymitis leave a hard, fibrous mass. The demarcation between the testicle and tail of the epididymis is obliterated. Abscesses may develop at any time during this disease process. Eventually, the testicle on the same side as the infected epididymis atrophies and becomes soft.

It is important to distinguish between lamb epididymitis and ram epididymitis. Although handling clinical cases is the same in both age groups, (ex. culling infected rams) the prognosis for the rest of the ram flock differs markedly. Lamb epididymitis is not highly contagious and the ELISA test is of no value in the control of this disease. Adult ram epididymitis is extremely contagious, and the ELISA testing and culling is very effective. Another difference between lamb and adult ram epididymitis is that Brucella ovis is a venereally-transmitted disease which leads to high incidence of dry ewes (20 percent and up), abortions, still births and weak lambs. (2)

There are other causes of pathologic changes of the testicles and accessory sex glands. The large pendulous scrotum in adult rams is easily injured. Other conditions such as abscesses, wounds, hernias, resolved urolithiasis, varicocele and spermatoceles can be confused with epididymitis.

There is no effective treatment for rams with clinical epididymitis. These rams should be culled. A virgin ram lamb should be separated from older and potentially infected rams. Never mix infected rams with clean rams. Test all rams following the breeding program and during the period of low sexual activity using the ELISA test for Brucella ovis. Identify and eliminate all positive rams. Repeat this procedure at 45 to 60 day intervals during the period of low sexual activity, until the ram flock is free of the Brucella ovis. Palpation of the testis and epididymis should be done simultaneously with blood testing. Eliminate rams with gross lesions. Transfer the clean rams to a clean environment. In each subsequent year, repeat the blood test and clinical examination during the season of low sexual activity to determine the herd status. Add newly purchased rams to the clean herd only after their clean status has been established (two negative ELISA tests 45-60 days apart.) (2)

Ram epididymitis is an important disease to consider in sheep production. It is an insidious, chronic drain on profitable sheep raising. It attacks the very basis of the industry, which is reproductions. It increases the number of rams needed, decreases the lambing percentages, lengthens the lambing season, and increases the number of dry ewes. The problem is that many producers do not know that they have this disease in their rams and continue to look at and blame the ewes for lowered production. The disease can be eradicated by test and slaughter. The industry needs to be encouraged to instigate control and work toward an eradication program.

(1) Kimberling, Cleon V., "Diseases of Sheep", third edition, 1988, page 7-11.

(2) Bulgin, M., "Lamb Epididymitis" a review, Symposium on Diseases of Small Ruminants, 1989, pages 88-91.