Environmental chemicals impact dog semen quality in vitro and may be associated with a temporal decline in sperm motility and increased cryptorchidism

• Published in: Scientific reports Vol. 6; no. 1; p. 31281
• Main Authors: Lea, Richard G., Byers, Andrew S., Sumner, Rebecca N., Rhind, Stewart M., Zhang, Zulin, Freeman, Sarah L., Moxon, Rachel, Richardson, Holly M., Green, Martin, Craigon, Jim, England, Gary C. W.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 09-08-2016; Nature Publishing Group
• Subjects: 13/106; 14; 631/136/1425; 631/601/1737; 692/699/2732/1577; Animals; Biphenyl; Chemicals; Cryptorchidism; Deoxyribonucleic acid; Diethylhexyl Phthalate - chemistry; DNA; Dogs; Environmental Exposure; Explants; Female; Food; Humanities and Social Sciences; Infants; Male; Motility; multidisciplinary; Offspring; PCB; Polychlorinated biphenyls; Polychlorinated Biphenyls - chemistry; Reproduction - drug effects; Science; Secretion; Semen; Semen - drug effects; Semen Analysis; Sperm; Sperm Motility - drug effects; Spermatozoa - drug effects; Testes; Testis - drug effects; Testosterone; Testosterone - metabolism
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep31281

Adverse temporal trends in human semen quality and cryptorchidism in infants have been associated with exposure to environmental chemicals (ECs) during development. Here we report that a population of breeding dogs exhibit a 26 year (1988–2014) decline in sperm quality and a concurrent increased incidence of cryptorchidism in male offspring (1995–2014). A decline in the number of males born relative to the number of females was also observed. ECs, including diethylhexyl phthalate (DEHP) and polychlorinated biphenyl 153 (PCB153), were detected in adult dog testes and commercial dog foods at concentrations reported to perturb reproductive function in other species. Testicular concentrations of DEHP and PCB153 perturbed sperm viability, motility and DNA integrity
in vitro
but did not affect LH stimulated testosterone secretion from adult testis explants. The direct effects of chemicals on sperm may therefore contribute to the decline in canine semen quality that parallels that reported in the human.