title: Environmental chemicals impact dog semen quality in vitro and may be associated with a temporal decline in sperm motility and increased cryptorchidism.
abstract: 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.
authors: School of Veterinary Medicine and Science, University of Nottingham, UK.|School of Animal Rural and Environmental Sciences, Nottingham Trent University, UK.
authors: Richard G
authors: RG
authors: Lea
authors: School of Veterinary Medicine and Science, University of Nottingham, UK.
authors: Andrew S
authors: AS
authors: Byers
authors: School of Veterinary Medicine and Science, University of Nottingham, UK.
authors: Rebecca N
authors: RN
authors: Sumner
authors: Environmental and Biochemical Sciences, The James Hutton Institute, UK.
authors: Stewart M
authors: SM
authors: Rhind
authors: Environmental and Biochemical Sciences, The James Hutton Institute, UK.
authors: Zulin
authors: Z
authors: Zhang
authors: School of Veterinary Medicine and Science, University of Nottingham, UK.
authors: Sarah L
authors: SL
authors: Freeman
authors: National Breeding Centre, Guide Dogs for the Blind Association, UK.
authors: Rachel
authors: R
authors: Moxon
authors: School of Veterinary Medicine and Science, University of Nottingham, UK.
authors: Holly M
authors: HM
authors: Richardson
authors: School of Veterinary Medicine and Science, University of Nottingham, UK.
authors: Martin
authors: M
authors: Green
authors: School of Biosciences, University of Nottingham, UK.
authors: Jim
authors: J
authors: Craigon
authors: School of Veterinary Medicine and Science, University of Nottingham, UK.
authors: Gary C W
authors: GC
authors: England
mesh_terms: D000818:Animals; D003456:Cryptorchidism; D004051:Diethylhexyl Phthalate / Q000737:chemistry; D004285:Dogs; D004781:Environmental Exposure; D005260:Female; D008297:Male; D011078:Polychlorinated Biphenyls / Q000737:chemistry; D012098:Reproduction / Q000187:drug effects; D012661:Semen / Q000187:drug effects*; D055101:Semen Analysis; D013081:Sperm Motility / Q000187:drug effects*; D013094:Spermatozoa / Q000187:drug effects*; D013737:Testis / Q000187:drug effects*; D013739:Testosterone / Q000378:metabolism
chemical_list: D013739:Testosterone; D004051:Diethylhexyl Phthalate; D011078:Polychlorinated Biphenyls; C014024:2,4,5,2',4',5'-hexachlorobiphenyl