Spermatogenesis and testicular tumours in ageing dogs

• Published in: Journal of reproduction & fertility Vol. 120; no. 2; pp. 443 - 452
• Main Authors: Peters, M A, de Rooij, D G, Teerds, K J, van Der Gaag, I, van Sluijs, F J
• Format: Journal Article
• Language: English
• Published: England Society for Reproduction and Fertility 01-11-2000
• Subjects: Aging - physiology; Animals; Dog Diseases - pathology; Dogs - physiology; Leydig Cell Tumor - pathology; Male; Seminiferous Epithelium - pathology; Seminiferous Tubules - anatomy & histology; Seminoma - pathology; Sertoli Cell Tumor - pathology; Species Specificity; Sperm Count; Spermatogenesis - physiology; Testicular Neoplasms - pathology
• ISSN: 1470-1626; 0022-4251; 1741-7899
• DOI: 10.1530/jrf.0.1200443

Spermatogenesis was examined in testes from 74 dogs of various breeds without clinically detected testicular disease. A modified
Johnsen score system was used to determine whether spermatogenesis deteriorates with ageing. The diameter of seminiferous
tubules was measured in dogs without testicular disease to examine other possible effects of ageing on tubular performance.
There appeared to be no relation between age and these variables. The influence of testicular tumours on spermatogenesis was
also investigated in both affected and unaffected testes. The testes of 28 dogs with clinically palpable tumours and 21 dogs
with clinically non-palpable tumours were investigated. In cases of unilateral occurrence of a tumour, impairment of spermatogenesis
was observed only in the affected testis of dogs with clinically detected tumours. Bilateral occurrence of tumours, whether
detected clinically or non-clinically, was associated with severe impairment of spermatogenesis. The prevalence of tumours
increased during ageing. Eighty-six per cent of the clinically detected and 57% of the non-clinically detected tumours were
found in old dogs. Multiple types of tumour and bilateral occurrence were very common. Seminomas and Leydig cell tumours were
more frequent than Sertoli cell tumours. It was concluded that spermatogenesis per se did not decrease during ageing in dogs
but the occurrence of testicular tumours increased with ageing and affected spermatogenesis significantly, as reflected by
a lower Johnsen score.