Felis ISSN 2398-2950

Testicular degeneration

Contributor(s): Rob Lofstedt

Introduction

  • Most frequent cause of true infertility in males.
  • Management, taking male to female, seasonal anestrus in female and testicular inactivity may be more important causes of infertility.

Pathogenesis

Etiology

  • Systemic infection, eg panleukopenia virus Feline panleucopenia (parvo) / feline calicivirus infection Feline calicivirus / feline rhinopneumonitis.
  • High thermal environment (cryptorchidism Testicle: cryptorchid, adipose tissue, high environmental temperature).
  • Local inflammation (scrotal dermatitis, periorchitis).
  • Testicular tumors (especially Sertoli cell tumors) Testis: neoplasia.
  • Trauma.
  • Endocrinopathy.
  • Ionizing radiation (such as x-rays and gamma-rays).
  • Testosterone and other androgens.
  • Estrogens.
  • Glucocorticoids.
  • Cytotoxic agents.
  • Malnutrition or vitamin A, phosphorus or protein deficiencies.

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   →   almost immediate sloughing of germinal epithelium with ejaculation of immature cells, abnormal cells and conjoined, 'giant' cells.
  • The effect of ionizing radiation is similar. There is little or no effect on libido.
  • The effect of otherz 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   Testis: normal spermatogenesis - histology  , a cat 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.

Timecourse

  • A cat 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 fertility.

Diagnosis

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Treatment

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Prevention

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Elcock L H, Schoning P (1984) Age-related changes in the cat testis and epididymis. Am J Vet Res 45 (11), 2380-2384 PubMed.


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