title: Spermatozoal head defect as a cause of infertility in a stallion.
abstract: A 9-year-old Arabian stallion with a 3-year history of infertility was evaluated for breeding soundness. Both testes were small. Ultrasonography revealed a small amount of free fluid between the tunics of both testes. Results of cytologic examination of the fluid were unremarkable. On semen examination, progressive motility was 10%, and total number of spermatozoa in the ejaculate was 6.6 x 10(9), of which 92% were abnormal. Predominant abnormalities were head defects (75%): 57% of the heads had single or multiple vacuoles, and 60% also had midpiece swelling or bending.
authors.affiliation: Department of Rural Practice, College of Veterinary Medicine, University of Tennessee, Knoxville 37901.
authors.forename: J P
authors.initials: JP
authors.lastname: Held
authors.forename: P
authors.initials: P
authors.lastname: Prater
authors.forename: M
authors.initials: M
authors.lastname: Stettler
mesh_terms: D000818:Animals; D006734:Horse Diseases / Q000209:etiology*; D006736:Horses; D007248:Infertility, Male / Q000209:etiology / Q000662:veterinary*; D008297:Male; D008854:Microscopy, Electron; D013077:Sperm Head / Q000648:ultrastructure*; D013081:Sperm Motility; D013737:Testis / Q000473:pathology; D014617:Vacuoles / Q000648:ultrastructure