Bovis ISSN 2398-2993

Orchitis and epididymitis

Synonym(s): Swelling of testicle and/or epididymis

Contributor(s): Jonathan Statham , Mike Reynolds

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  • Cause: trauma or infection.
  • Signs: swelling of the testicle (orchitis) often concurrent with swelling of the epididymis (epididymitis). Usually unilateral.
  • Diagnosis: by clinical examination, ultrasound and semen evaluation/cytology/culture.
  • Treatment: antibiotics usually ineffective; unless administered very early in disease pathogenesis. Surgical removal may be considered.
  • Prognosis: normal sperm output from the other testis can also be affected, resulting in permanent subfertility or infertility.



  • Bacteria:
    • Trueperella pyogenes Trueperella pyogenes is often isolated from the affected testis but may not always be the original pathogen. 
    • Brucella abortus Brucella abortus is a well-documented infectious cause of orchitis/epididymitis.
  • Histophilus (Haemophilus) somni has also been implicated along with Mannheimia haemolytica Mannheimia haemolytica, Escherichia coli Escherichia coli, and other enterobacteriacea. 
  • Trauma. Testicular trauma
  • Ascending infection from opportunistic temporary infection of the prepuce (sheath). 
  • Bacteremia following episodes of Rumen acidosis Rumen acidosis associated with high cereal feeding.

Predisposing factors

  • Puberty associated with endocrine changes and opportunistic infections of the sheath eg with H somni or E. Coli.
  • High cereal feeding associated with rumen acidosis leading to rumenitis and bacteremia.


  • Spermatogenesis Spermatogenesis is very delicate and can be easily impaired.
  • Meiosis is affected first but after removal of an insult, regeneration within 6 weeks is to be expected providing the Sertoli cells are unaffected.
  •  It is proposed that damage to the spermatogenic epithelium interferes with androgen binding protein (ABP) and inhibin release leading to an increased FSH concentration.
    • This alters the balance of testosterone-oestradiol synthesis towards the latter and subsequently alters LH concentration.
    • LH can directly affect the Leydig cell, testosterone release and so ABP release by the Sertoli cell.
    • Therefore if events are prolonged or extreme, the accumulation of these effects could cause permanent derangement.
  • The process of spermatogenesis is influenced by temperature and may not proceed normally at the core temperature of the body. In the bull the testes are attuned to function at 3-4 C below core temperature.
  • Disruption of any thermoregulatory homeostatic mechanisms may therefore disrupt normal spermatogenesis in the bull.


  • There may be a slow progression of disease from an initial infection of mucosal surface to colonisation of regional lymph nodes over 1-2 months before bacteremia often lasting 1-2 months and pathology in genital organs.
  • However, there may be different presentations of disease depending on initial etiology and so timecourse may appear to be more acute.


  • Although individual disease risk in many cases, transmission of Brucella and H somus may result in multiple cases associated with close contact or newly purchased animals.


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Further Reading


Refereed Papers

  • Recent references from PubMed and VetMed Resource.
  • Statham J M E (2010) Differential diagnosis of scrotal enlargement in bulls. In Practice 32 p 2-9.
  • Penny C (2009) The development of a UK bull breeding soundness evaluation certificate. Cattle Practice 17, p 64-70.
  • Eppink E (2006) A survey of bull breeding soundness evaluations in the south east of Scotland. Cattle Practice 13 p 205-209.
  • Penny C (2005) Practical semen collection and examination techniques for breeding soundness evaluation of bulls. Cattle Practice 13, p 199-204.
  • McGowan M (2004) Approach to conducting bull breeding soundness evaluations. In Practice 26 p 485-491.

Other sources of information

  • Aiello S E & Moses M A (2016) Reproductive System. In: Merck Veterinary Manual. 11th Edn. Merck & Co Inc. Kenilworth, USA. pp1321-1408.
  • Foster R A (2016) Male Genital System. In: Jubb, Kennedy & Palmer's Pathology of Domestic Animals. 6th Edn. pp 465-510.
  • Chenoweth P (2015) Bull Health and Breeding Soundness. Bovine Medicine, 3rd Edition, Wiley-Blackwell Publishing, Oxford, pp 246-26.
  • Laws D (2014) Fit for purpose bulls. EBLEX (AHDB Beef and Lamb). [online] Available at:
  • Logue D N & Crawshaw W M (2004) Bull infertility. In: Bovine Medicine – Diseases and Husbandry of Cattle. 2nd Edn. Wiley-Blackwell Publishing, Oxford. pp 594-626.
  • Entwistle K & Fordyce G (2003) Evaluating and reporting bull fertility. Australian Association of Cattle Veterinarians, Brisbane, Australia.