Equis ISSN 2398-2977

Testis: orchitis - bacterial

Contributor(s): Annalisa Barrelet, Graham Munroe

Introduction

  • Orchitis is an inflammation of the testis.
  • Cause: trauma, infection, parasite migration, auto-immune.
  • Signs: testicular edema and pain. Pyrexia, anorexia and hindlimb lameness in bacterial infections; scrotal swelling and edema.
  • Diagnosis: history, clinical signs, semen evaluation, ultrasonography, testicular biopsy.
  • Treatment: cold water bathing, antimicrobials, NSAIDs.
  • Prognosis: good to guarded.

Pathogenesis

Etiology

Trauma
  • A kick to the scrotal area around coitus or teasing. If there is no skin penetration, the orchitis will normally remain non-septic.
    Infection
  • Hematogenous spread from a systemic infection.
  • Local penetrating wound (Streptococcusspp   Streptococcus spp  ,Staphylococcusspp   Staphylococcus spp  andE. coli  Escherichia coli  ).
  • Spread from infectious peritonitis via inguinal canal.
  • Retrograde infection is rare but accompanying epididymitis can occur.
  • Bacterial causes:Streptococcusequi (Strangles),Streptococcus zooepidemicus  Streptococcus spp  , and less frequently (not in UK)Pseudomonas mallei  Pseudomonas spp  (glanders),Salmonella abortus equi  Salmonella spp  (rare), andKlebsiella pneumoniae  Klebsiella pneumoniae  .
  • Viral causes: equine viral arteritis   Equine viral arteritis virus  , equine influenza virus   Equine influenza virus  , and (not in UK) equine infectious anemia virus   Equine infectious anemia virus  .
  • May lead to localized vascular lesions.
    Other causes
  • Parasite migration (Strongylus edentatus  Strongylus spp  ) has been implicated occasionally as a cause of orchitis.
  • An anti-sperm autoimmune response may cause an orchitis or non-inflammatory degeneration (trauma   →   damage to the blood-testis barrier) ie testicular lacerations, biopsies, neoplasms, trauma.

Pathophysiology

  • Mechanical injury or infection   →   inflammation.
  • Acute cases may have increased intra-testicular pressure due to edematous (engorgement) swelling confined by the tunica albuginea.
  • Intra-testicular pressure and increased testicular temperature   →   testicular degeneration.
  • Chronic cases will have irreversible atrophy of the seminiferous epithelium, fibrotic scarring and degeneration of the testis.
  • Fibrinous to sheet-like adhesions form between the testicular tunics as well as the epididymis.
  • The affected testis becomes small and firm in consistency.
  • Granuloma formation results from leakage of spermatozoa from seminiferous tubules and from associated epididymitis   →   epididymal obstruction   →   extravasation of sperm.
  • If prompt vigorous treatment is not given it is unlikely that total restoration of sperm production will occur.

Diagnosis

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Treatment

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Prevention

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Outcomes

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Gonzalez M, Tibary A, Sellon D C & Daniels J (2008)Unilateral orchitis and epididymitis caused by Corynebacterium pseudotuberculosis in a stallion.Equine Vet Educ20(1), 30-36 VetMedResource.
  • Wilson K E, Dascanio J J, Duncan R, Delling U & Ladd S M (2007)Orchitis, epididymitis and pampiniform phlebitis in a stallion.Equine Vet Educ19(5), 239-243 VetMedResource.


ADDED