Seminal Vesiculitis in Animals: Causes, Types, Diagnosis, Prognosis, and Treatment

Seminal vesiculitis is an inflammation of the seminal vesicles. It is most common condition affecting the gland of bulls, stallions and boars. It is rare in bucks and rams.

Gross inflammatory lesions are found most commonly in the vesicular gland of all the accessory sex glands, and the ampullae.

Etiology

Seminal vesiculitis may be caused by a variety of pathogenic organisms. The most common cause is C. pyogenes. This organism may localize in the seminal vesicle from other primary, pyogenic, infective foci such as rumenitis, liver abscesses, traumatic gastritis, lung abscess or from a navel infection in young calf.

It may possibly enter as an ascending or descending infection from the prepuce or from an ampulitis, epididymitis or orchitis.

Infection may be spread in groups of young bulls by homosexual activities and contact of the penis and prepuce to the rear part of a bull that another had recently mounted.

It is possible that certain organisms as C. pyogenes may invade the seminal vesicle secondary to a temporary infection with a virus or other agent.

B. abortus is the most common cause for a seminal vesiculitis. B. abortus causes seminal vesiculitis in bulls.

B. suis commonly localizes in the seminal vesicles in boars.

Other organism found in infected seminal vesicles include: streptococci and staphylococci in bulls and boars. Pseudomonas aeruginosa, Mycoplasma bovigenitalium, E.coli, Mycobacterium tuberculosis, epivag virus, IBR-IPV, P.L.T.agent or Chlamydia.

The antibiotics used in extended semen had no effect on Mycoplasma bovigenitalium.

Seminal vesiculitis affects males of all ages. In bulls it has been reported as early as 10 months to 1 and 1.5 years of age.

Usually there are no external signs of the disease. However, some males will show signs of mild peritonitis with an arched back, reduced appetite, pain on defecation or on rectal examination and hesitation in mounting and thrusting.

These occasional signs are observed usually in bulls having abscesses of the seminal vesicle caused by C. pyogenes infection adjacent to the peritoneum.

On rectal examination seminal vesiculitis, especially bovine cases due to the C. pyogenes are characterized by irregular enlargement of the gland, fibrosis, peritoneal adhesions, loss of lobulations, fluctuation, and abscessation.

In rare cases, fistulas occur due to rupture of an abscess into the rectum.

Types

Types of seminal vesiculitis (Galloway’s classification) include:

1. Bovine seminal vesiculitis
2. Seminal vesiculitis

1. Bovine Seminal Vesiculitis

Bovine seminal vesiculitis was usually unilateral and due to chronic purulent inflammatory lesions with chronic interstitial changes and was commonly caused by C. pyogenes. Large clots or flocculi were commonly observed in the semen.

2. Seminal Vesiculitis

Seminal vesiculitis was usually bilateral and characterized by degenerative changes in the epithelium and inflammatory changes were variable. Culture of these vesicular glands were frequently negative for bacteria. Large amounts of feulgen positive chromatin masses were found in the lumen of affected glands and in the semen of the latter degenerative type of seminal vesiculitis. Semen may be viscid or “ropy ”.

Leucocytes in the semen may also come from other portions of the urogenital tract including the prepuce so their presence is not diagnostic of seminal vesiculitis.

Semen quality will vary between affected bulls with a lowered motility of the sperm cells, an elevated pH, a higher catalase activity and a lowered fructose content.

Although lowered fertility has been associated with seminal vesiculitis, many affected bulls breeding cows naturally have a good conception rate.

Frequently bull with a seminal vesiculitis will have another focus of infection in the testes, epididymitis or ampulla.

Diagnosis

Diagnosis is based on the clinical signs noted above.

Culture of the semen is usually an unsatisfactory method for diagnosing the causative bacterial agent because of the contamination from the sheath.

A new technique based on Galloway’s procedure, was developed to collect non-contaminated urethral samples from the bulls.

A tranquilizer was administered to quite the bull and allow withdrawal of the penis.

Rectal massage aided the protrusion of the penis from the sheath.

The penis was washed with an antiseptic solution and the urethra was irrigated with sterile saline.

A 25 cm sterile silastic tube was inserted up the urethra leaving about 4 cm protruding.

Rectal massage of the seminal vesicles, prostate and ampullae resulted in the collection of their secretions in to sterile vials for cultural purposes.

Prognosis

Prognosis in seminal vesiculitis is fair to poor depending upon the causative agent, the presence of other foci of infection in the reproductive tract, the duration and severity of the infection and value of the male.

Males with brucella infections, tuberculosis or mycoplasmosis of the seminal vesicles, or those with secondary lesions of the testes, epididymides, ampullae or prostate should be slaughtered.

Many young bulls with the seminal vesiculitis syndrome with catarrahal or degenerative seminal vesiculitis overcome the infections spontaneously in a few months.

During this period their use for breeding purposes is questionable.

Bulls with active acute lesions of seminal vesiculitis with a discharge of pus in the semen should not be used for artificial insemination as only rarely will the antibiotics used in extended semen destroy the organisms present.

Many bulls with seminal vesiculitis caused by organisms other than brucella or mycobacterium may be used naturally or even artificially with quite satisfactory conception rates especially if a large amount of mucopurulent material is not present in the ejaculate.

In C.pyogenes infection, the gland is usually left severely indurated and largely destroyed.

Acute cases of seminal vesiculitis tend to become chronic and chronic cases, if abscessation does not occur, tend to become fibrotic and indurated similar to the mammary gland following a severe infection.

In long-standing chronic cases, pus or high leucocytes numbers are seldom observed in the semen.

Treatment

Treatment with high doses of broad spectrum antibiotics, or antibiotics to which the causative agent is sensitive, for two weeks or longer together with mild massage of the vesicular gland to remove its contents may result in recovery or elimination of the infection in some males after 2 to 6 months.

In recent years surgical removal of the affected vesicular gland has been recommended for selected bulls in artificial insemination studs. Following surgery heavy prolonged antibiotic therapy was recommended.

Regular and frequent examination of the genital tract and semen for a year or more should be followed after treatment.