ISSN 2398-2969      

Testicular degeneration

icanis
Contributor(s):

Introduction

  • Common, especially in show dogs.
  • Many causes, idiopathic most common in UK.

Pathogenesis

Etiology

  • Pyrexia.
  • Local inflammation.
  • Testicular tumors (especially sertoli cell tumors).
  • Infectious agents (Brucella canisand distemper)
  • Trauma.
  • Infection.
  • Endocrinopthay.
  • Ionizing radiation such as x-rays and gamma-rays).
  • Testosterone and other androgens.
  • Estrogens.
  • Glucocorticoids.
  • Cytotoxic agents.

Pathophysiology

  • Temporary suppression of spermatogenesis may follow many insults especially steroid therapy.
  • Permanent degeneration will only result if very severe insult or prolonged exposure.
  • Seminiferous epithelium is acutely sensitive to temperature. The scrotum is usually a few degrees cooler than body temperature. Elevations in body temperature translate into higher scrotal temperatures. This results in almost immediate sloughing of germinal epithelium with ejaculation of immature cells, abnormal cells and conjoined, 'giant' cells. The effect of ionising radiation is similar. There is little or no effect on libido. The effect of other agents on testicular degeneration can be more subtle. Considering that the total time taken for the formation of sperms and their transport through the epididymis is approximately 70-75 days, a dog should be re-evaluated for fertility about 75-90 days after an acute febrile or other damaging episode.
  • The effect of ionization and other degenerative influences on the genetic stability of preformed spermatozoa is unknown but should be considered harmful.
  • Whether sex steroids originate exogenously or from adrenal or testicular tumors (Leydig or Sertoli cell tumors) they have a negative feedback effect on the hypothalamus, inhibiting GnRH secretion. In some cases (especially with progestagens and corticosteroids), the effect of GnRH on the adenohypophysis is also inhibited.
  • Senile testicular atrophy of old dogs (>10 years) is described but poorly understood. It may be related to vascular lesions or inefficient function of the hypothalamic-pituitary-gonadal axis.

Timecourse

  • A dog can become infertile within 48 hours of an acute febrile episode. Some agents may take longer to render the animal infertile and some may only cause slight suppression of fertiltiy.

Diagnosis

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Treatment

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Prevention

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Outcomes

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Pugh C R & Konde L J (1991) Sonographic evaluation of testicular and scrotal abnormalities - a review of 26 case histories. Vet Radiol 32 (5), 243-250 VetMedResource.

Other sources of information

  • Roberts S JInfertility in male animals.In:Veterinary Obstetrics and Genital diseases.North Pomfret: Published by the author and distributed by David and Charles Inc. pp 826. (A good basic review of testicular degeneration in all animals.)

Can’t find what you’re looking for?

We have an ever growing content library on Vetlexicon so if you ever find we haven't covered something that you need please fill in the form below and let us know!

 
 
 
 

To show you are not a Bot please can you enter the number showing adjacent to this field

 Security code