Cryptorchidism in stallions

  • Eduardo Arroyo Comparative Theriogenology, Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
  • Ahmed Tibary Comparative Theriogenology, Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA, USA; and Center for Reproductive Biology, Washington State University, Pullman, WA, USA
Keywords: Equine, testis, sexual disorders, cryptorchid, male

Abstract

Cryptorchidism is the most common disorder of sexual development in the male. The etiopathogenesis of cryptorchidism remains poorly understood and may involve genetic and environmental factors. The condition is obvious in horses with a good history, but diagnosis of cryptorchidism can be challenging in an apparently gelded horse presenting with stallion-like behavior and hemicastrated horses. Determination of the location of the retained testis is important for the selection of the surgical approach for cryptorchidectomy. The objective of this paper is to review current knowledge regarding pathogenesis of cryptorchidism in the equine, and methods for diagnosis including ultrasonographic determination of the location of the retained testis. A discussion of cryptorchidectomy approaches and possible complications is presented.

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References

1. Amann RP, Veeramachaneni DNR: Cryptorchidism in common eutherian mammals. Reproduction (Cambridge) 2007;133:541–561. doi: 10.1530/REP-06-0272

2. Hayes HM: Epidemiological features of 5009 cases of equine cryptorchism. Equine Vet J 1986;18:467–471. doi: 10.1111/j.2042-3306.1986.tb03692.x

3. Ortved KF, Stewaart AW, Fubini SL, et al: Castration of 4 stallions with cryptorchidism caused by failure of regression of the front gonad cords. Pferdeheilkunde 2014;30:697–698.

4. Schumacher J: Surgical disorders of the testicle and associated structures. In: Auer J: editor. Equine surgery. Philadelphia, PA; W.B. Saunders Co.: 1992:676–696.

5. Bladon B: Surgical management of cryptorchidism in the horse. In Pract 2002;24:126–134. doi: 10.1136/inpract.24.3.126

6. Cattelan JW, Macoris DG, Barnabe PA, et al: Cryptorchism in horses: clinical and surgical aspects and serum testosterone determination. Arq Bras Med Vet Zoo 2004;56:150–156. doi: 10.1590/S0102-09352004000200003

7. Ribeiro MG, Ribeiro LVP, Silva JRd, et al: A retrospective study of surgical cases of equine cryptorchidism in northwestern Paraná. Rev Brasil Ciênc Vet 2014;21:160–162. doi: 10.4322/rbcv.2014.377

8. Huppes T, Stout TAE, Ensink JM: Decision making for cryptorchid castration; a retrospective analysis of 280 cases. Equine Vet Sci 2017;48:73–81. doi: 10.1016/j.jevs.2016.08.004

9. Eriksson S, Jaderkvist K, Dalin AM, et al: Prevalence and genetic parameters for cryptorchidism in Swedish-born Icelandic horses. Livest Sci 2015;180:1–5. doi: 10.1016/j.livsci.2015.06.022

10. Maxwell JAL: Equine hemi-castration: review of the condition, prevalence, aetiology, diagnosis and surgical management. Aust Vet J 2005;83:203–207. doi: 10.1111/j.1751-0813.2005.tb11648.x

11. Gough SL, Fraser BSL, Rendle DI, et al: Renal dysplasia, ectopic ureter, septic ureterectasia and cryptorchidism in an 11-month-old cob colt presenting with ascending pyoureter and pyocystis. Equine Vet Educ 2020;33:397–397. doi: 10.1111/eve.13296

12. Cox JE: The castration of horses: or castration of half a horse? Vet Rec 1973;93:425–426. doi: 10.1136/vr.93.15.425-a

13. Cox JE, Edwards GB, Neal PA: An analysis of 500 cases of equine cryptorchidism. Equine Vet J 1979;11:113–116. doi: 10.1111/j.2042-3306.1979.tb01321.x

14. Marshall JF, Moorman VJ, Moll HD: Comparison of the diagnosis and management of unilaterally castrated and cryptorchid horses at a referral hospital: 60 cases (2002–2006). J Am Vet Med Assoc 2007;231:931–934. doi: 10.2460/javma.231.6.931

15. Brendemuehl JP: Effects of repeated HCG administration on serum testosterone and testicular descent in prepubertal Thoroughbred colts with cryptorchid testicles. Lexington; American Association of Equine Practitioners (AAEP): 2006:381–383.

16. Schofield WA: Use of acupuncture in equine reproduction. Theriogenology 2008;70:430–434. doi: 10.1016/j.theriogenology.2008.05.001

17. Bergin WC, Gier HT, Marion GB, et al: A developmental concept of equine cryptorchism. Biol Reprod 1970;3:82–92. doi: 10.1093/biolreprod/3.1.82

18. Smith JA: The development and descent of the testis in the horse. Vet Annu 1975;15:156–161.

19. Arighi M: Testicular descent. In: McKinnon AM, Squires EL, Vaala WE, Varner DD: editors. Equine reproduction. Voume 1, Ames; Wiley-Blackwell: 2011:1099–1106.

20. Hannan MA, Murase H, Sato F, et al: Age related and seasonal changes of plasma concentrations of insulin-like peptide 3 and testosterone from birth to early-puberty in Thoroughbred male horses. Theriogenology 2019;132:212–217. doi: 10.1016/j.theriogenology.2019.04.014

21. Tsogtgerel M, Komyo N, Murase H, et al: Serum concentrations and testicular expressions of insulin-like peptide 3 and Anti-Mullerian hormone in normal and cryptorchid male horses. Theriogenology 2020;154:135–142. doi: 10.1016/j.theriogenology.2020.05.026

22. Diribarne M, Vaiman A, Péchayre M, et al: Polymorphism analysis of microsatellites associated with seven candidate genes for equine cryptorchidism. J Equine Vet Sci 2009;29:37–41. doi: 10.1016/j.jevs.2008.11.003

23. Han H, Dong H, Chen Q, et al: Transcriptomic analysis of testicular gene expression in normal and cryptorchid horses. Animals 2020;10:102. doi: 10.3390/ani10010102

24. Wilson DG, Nixon AJ: Case of equine cryptorchidism resulting from persistence of the suspensory ligament of the gonad. Equine Vet J 1986;18:412–413. doi: 10.1111/j.2042-3306.1986.tb03670.x

25. Barrett EJ, Hanson RR: Cystic rete testis in a 3-Year-Old Gypsy Vanner Colt: a case report. J Equine Vet Sci 2013;33:127–129. doi: 10.1016/j.jevs.2012.05.003

26. Klonisch T, Steger K, Kehlen A, et al: INSL3 ligand-receptor system in the equine testis. Biol Reprod 2003;68:1975–1981.

27. Pujar S, Meyers-Wallen VN: Sequence variations in equine candidate genes for XX and XY inherited disorders of sexual development. Reprod Domest Anim 2012;47:827–834. doi: 10.1111/j.1439-0531.2011.01976.x

28. Hámori D: Heredity of equine cryptorchism. Allatorvosi Lapok 1940;63:130–131.

29. Flechsig J: Erblicher Kryptorchismus bei einem Landbeschäler. Tierzucht 1950;4:208.

30. Schurink A, de Jong A, de Nooij HR, et al: Genetic parameters of cryptorchidism and testis size in Friesian colts. Livest Sci 2016;190:136–140. doi: 10.1016/j.livsci.2016.06.012

31. Raudsepp T: Genetics of equine reproductive diseases. Vet Clin North Am Equine Pract 2020;36:395–409. doi: 10.1016/j.cveq.2020.03.013

32. Castaneda C, Radovic L, Felkel S, et al: Copy number variation of horse Y chromosome genes in normal equine populations and in horses with abnormal sex development and subfertility: relationship of copy number variations with Y haplogroups. G3-Genes Genom Genet 2022;12:jkac278. doi: 10.1093/g3journal/jkac278

33. Edwards JF: Pathologic conditions of the stallion reproductive tract. Anim Reprod Sci 2008;107:197–207. doi: 10.1016/j.anireprosci.2008.05.002

34. Constant SB, Larsen RE, Asbury AC, et al: XX-male-syndrome in a cryptorchid stallion. J Am Vet Med Assoc 1994;205:83–85.

35. Nogueira PPO, Amorim GBAG, Oliveira OM, et al: Sex reversal syndrome in an Egyptian Arabian horse detected using genomic data – a case report. J Equine Vet Sci 2021;104:103692. doi: 10.1016/j.jevs.2021.103692

36. Peer M, Neuhauser S, Klaus C, et al: Laparoscopic gonadectomy in two intersex warmblood horses. J Equine Vet Sci 2012;32:117–122. doi: 10.1016/j.jevs.2011.08.011

37. Bannasch D, Rinaldo C, Millon L, et al: SRY negative 64,XX intersex phenotype in an American saddlebred horse. Vet J 2007;173:437–439. doi: 10.1016/j.tvjl.2005.11.008

38. Moreno Millán M, Demyda SE, Saleno DR: Sex chromosomes abnormalities in purebred Spanish horses with reproductive problems: cases report. Bull Univ Agric Sci Vet Med Cluj-Napoca Vet Med 2012;69:1–7.

39. Jaszczak K, Sysa P, Sacharczuk M, et al: SRY-negative, 64,XX sex reversal in a Konik Polski horse: a case report. Anim Sci Papers Rep 2010;28:381–388.

40. Buoen LC, Zhang TQ, Weber AF, et al: SRY-negative, XX intersex horses: the need for pedigree studies to examine the mode of inheritance of the condition. Equine Vet J 2000;32:78–81. doi: 10.2746/042516400777612071

41. Brito LFC, Sertich PL, Durkin K, et al: Autosomic 27 trisomy in a Standardbred colt. J Equine Vet Sci 2008;28:431–436. doi: 10.1016/j.jevs.2008.06.003

42. Dietze K, Kampmann C, Kuiper H, et al: Sex reversal syndrom bei einem fünfjährigen Friesenpferd. Pferdeheilkunde 2011;27:49–54. doi: 10.21836/PEM20110106

43. McIlwraith CW, Owen RAR: An equine cryptorchid with testicular and ovarian tissue. Equine Vet J 1976;8:156–160. doi: 10.1111/j.2042-3306.1976.tb03329.x

44. Vaughan L, Schofield W, Ennis S: SRY-negative XX sex reversal in a pony: a case report. Theriogenology 2001;55:1051–1057. doi: 10.1016/S0093-691X(01)00465-4

45. Ciotola F, Albarella S, Pasolini MP, et al: Molecular and cytogenetic studies in a case of XX SRY-negative sex reversal in an Arabian horse. Sex Dev 2012;6:104–107. doi: 10.1159/000331480

46. MeyersWallen VN, Hurtgen J, Schlafer D, et al: Sry-negative XX true hermaphroditism in a Pasa Fino horse. Equine Vet J 1997;29:404–408. doi: 10.1111/j.2042-3306.1997.tb03148.x

47. Bartmann CP, Klug E: Diagnosis, surgical management and forensic aspects of equine cryptorchidism. Tierarztl Prax G N 2001;29:175–182.

48. Hartman R, Hawkins JF, Adams SB, et al: Cryptorchidectomy in equids: 604 cases (1977–2010). J Am Vet Med Assoc 2015;246:777–784.

49. Leipold HW, DeBowes RM, Bennett S, et al: Cryptorchidism in the horse: genetic implications. Proc Ann Convention Am Assoc Equine Pract 1986;31:579–589.

50. Straticò P, Varasano V, Guerri G, et al: A retrospective study of cryptorchidectomy in horses: diagnosis, treatment, outcome and complications in 70 cases. Animals 2020;10:2446. doi: 10.3390/ani10122446

51. Rodgerson DH, Hanson RR: Cryptorchidism in horses 1. Anatomy, causes, and diagnosis. Comp Cont Educ Pract 1997;19:1280–1288.

52. Freidman R, Scott M, Heath SE, et al: The effects of increase testicular temperature on spermatogenesis in the stallion. J Reprod Fertil 1991;44:127–134.

53. Arns MJ, Neck KF, Evans JW, et al: Ultrastructural abnormalities in equine spermatozoa from a cryptorchid stallion. J Equine Vet Sci 1988;8:122–124. doi: 10.1016/S0737-0806(88)80032-7

54. Veeramachaneni DNR, Sawyer HR: Carcinoma in situ and seminoma in equine testis. Apmis 1998;106:183–185. doi: 10.1111/j.1699-0463.1998.tb01334.x

55. Almeida J, Conley AJ, Ball BA: Expression of anti-Mullerian hormone, CDKN1B, connexin 43, androgen receptor and steroidogenic enzymes in the equine cryptorchid testis. Equine Vet J 2013;45:538–545. doi: 10.1111/evj.12013

56. Bogh IB, Baltsen M, Byskov AG, et al: Testicular concentration of meiosis-activating sterol is associated with normal testicular descent. Theriogenology 2001;55:983–992. doi: 10.1016/S0093-691X(01)00459-9

57. Cattelan JW, Boleli IC, Malheiros EB, et al: Morfometria de testículos escrotais, abdominais e inguinais de eqüinos criptórquios unilaterais. Arq Bras Med Vet Zoo 2005;57:217–222. doi: 10.1590/S0102-09352005000200013

58. Coryn M, De Morr A, Bouters R, et al: Clinical, morphological and endocrinological aspects of cryptorchidism in the horse. Theriogenology 1981;16:489–496.

59. Stickle RL, Fessler JF: Retrospective study of 350 cases of equine cryptorchidism. J Am Vet Med Assoc 1978;172:343–346.

60. Aupperle H, Gerlach K, Bartmann CP, et al: Histopathological findings in the cryptorchid testes of stallions. Pferdeheilkunde 1999;15:515–522. doi: 10.21836/PEM19990606

61. Vilar JM, Batista M, Carrillo JM, et al: Histological, cytogenetic and endocrine evaluation in twenty-five unilateral cryptorchid horses. J Appl Anim Res 2018;46:441–444. doi: 10.1080/09712119.2017.1333435

62. Hunt RJ, Hay W, Collatos C, et al: Testicular seminoma associated with torsion of the spermatic cord in 2 cryptorchid stallions. J Am Vet Med Assoc 1990;197:1484–1486.

63. Parker JE, Rakestraw PC: Intra-abdominal testicular torsion in a horse without signs of colic. J Am Vet Med Assoc 1997;210:375–377.

64. Smith LJ, Perkins JD: Laparoscopic-assisted castration of a monorchid male pseudohermaphrodite pony. Equine Vet Educ 2009;21:295–299. doi: 10.2746/095777309X422979

65. Santschi EM, Juzwiak JS, Slone DE: Monorchidism in three colts. J Am Vet Med Assoc 1989;94:265–266.

66. Rakestraw P: The value of laparoscopy in equine cryptorchidism and monorchidism. Equine Vet Educ 2006;18:88–89. doi: 10.1111/j.2042-3292.2006.tb00422.x

67. Petrizzi L, Varasano V, Robbe D, et al: Monorchidism in an Appaloosa stallion. Vet Rec 2004;155:424–425. doi: 10.1136/vr.155.14.424

68. de Magalhaes JF, Costa GMJ, de Oliveira CA, et al: Monorchidism in a four-beat gaited horse. Cienc Rural 2015;45:1058–1061.

69. Loose H, Aupperle H, Schnurrbusch U, et al: Morphologische und immunhistochemische Untersuchungen am Hoden des normalen und kryptorchiden Ebers. Berl Munch Tierarztl 2002;115:407–411.

70. Lydka M, Kotula-Balak M, Kopera-Sobota I, et al: Vimentin expression in testes of Arabian stallions. Equine Vet J 2011;43:184–189. doi: 10.1111/j.2042-3306.2010.00135.x

71. Tnibar A, Tibary A, Boulouha L, et al: Ultrasonograhic and histopathological features of atypical interstitial (Leydig) cell tumors in two cryptorchid horses. J Equine Vet Sci 2006;26:370–375. doi: 10.1016/j.jevs.2006.06.009

72. De Lange V, Chiers K, Lefere L, et al: Malignant seminoma in two unilaterally cryptorchid stallions. Reprod Domest Anim 2015;50:510–513. doi: 10.1111/rda.12488

73. Smith BL, Morton LD, Watkins JP, et al: Malignant seminoma in a cryptorchid stallion. J Am Vet Med Assoc 1989;195:775–776.

74. Smith RA, Pearson LK, Wise LN, et al: Colic associated with bilateral seminoma in a cryptorchid American Miniature Horse stallion. In: SFT/ACT Annual Conference & Symposia, Milwaukee, WI, 2011. Clinical Theriogenology 3:691.

75. Hejmej A, Gorazd M, Kosiniak-Kamysz K, et al: Expression of aromatase and oestrogen receptors in reproductive tissues of the stallion and a single cryptorchid visualised by means of immunohistochemistry. Domest Anim Endocrinol 2005;29:534–547. doi: 10.1016/j.domaniend.2005.03.002

76. Lange Vd, Chiers K, Lefère L, et al: Malignant seminoma in two unilaterally cryptorchid stallions. Reprod Domest Anim 2015;50:510–513. doi: 10.1111/rda.12488

77. Cribb NC, Bouré LP: Laparoscopic removal of a large abdominal testicular teratoma in a standing horse. Vet Surg 2010;39:131–135. doi: 10.1111/j.1532-950X.2009.00618.x

78. Czimber GE: Cryptorchid testicular teratoma in a horse. Magy Allatorvosok 2021;143:579–583.

79. Leonardi L, Bertoletti A, Bellezza E, et al: Dentigerous equine teratoma in a stallion: surgical management and clinicopathology. Vet Sci 2021;8:84. doi: 10.3390/vetsci8050084

80. Pentek G, Albert M, Lukacs Z, et al: Equine testicular teratoma. Case report. Magy Allatorvosok 2001;123:529–533.

81. Ugolini LW, dos Santos FCC, da Costa GV, et al: Testicular teratoma in a unilateral right-sided abdominal cryptorchid horse. Acta Sci Vet 2019;47:409. doi: 10.22456/1679-9216.93609

82. Watkins M: Cryptorchid investigation of an adult cob pony with unknown history. Vet Rec Case Rep 2022;10:e235. doi: 10.1002/vrc2.235

83. Pasolini MP, Della Valle G, Pagano B, et al: Mature teratoma arising from an undescended testis in a horse: comparison between ultrasonographic and morphological features. Folia Morphol 2016;75:211–215. doi: 10.5603/FM.a2015.0088

84. Rijkenhuizen ABM, Lichtenberg D, Weitkamp K: Cystic intra-abdominal testicles: standing laparoscopic removal in two colts. Equine Vet Educ 2020;32:E130–E135. doi: 10.1111/eve.13030

85. Hay WP, Baskett A, Gregory CR: Testicular interstitial cell tumour and aplasia of the head of the epididymis in a cryptorchid stallion. Equine Vet Educ 1997;9:240–241. doi: 10.1111/j.2042-3292.1997.tb01316.x

86. Pratt SM, Stacy BA, Whitcomb B, et al: Malignant Sertoli cell tumor in the retained abdominal testis of a unilaterally cryptorchid horse. J Am Vet Med Assoc 2003;222:486–490. doi: 10.2460/javma.2003.222.486

87. Allison N, Moeller RB: Bilateral testicular leiomyosarcoma in a stallion. J Vet Diagn Invest 1999;11:179–182. doi: 10.1177/104063879901100214

88. Haider W, Brehm W, Keller H: Colic due to jejunal strangulation in a cryptorchid stallion. Tierärztliche Praxis 1996;24:476–478.

89. Tibary A, Ragle CA: Approach to diagnosis of cryptorchidim in the stallion. In: Proceeding of the Conference of the Moroccan Association of Equine Practictioners, Rabat, Morocco, 2017;1:1–17.

90. Pozor M: Application of various techniques in localizing retained testes in horses before cryptorchidectomy. J Equine Vet Sci 2016;43:S45–S48. doi: 10.1016/j.jevs.2016.06.076

91. Palme R, Holzmann A, Mitterer T: Measuring fecal estrogens for the diagnosis of cryptorchidism in horses. Theriogenology 1994;42:1381–1387. doi: 10.1016/0093-691X(94)90258-K

92. Cox JE, Williams JH, Rowe PH, et al: Testosterone in normal, cryptorchid and castrated male horses. Equine Vet J 1973;5:85–90. doi: 10.1111/j.2042-3306.1973.tb03200.x

93. Berndtson WE, Pickett BW, Nett TM: Reproductive physiology of the stallion. IV. Seasonal changes in the testosterone concentration of peripheral plasma. J Reprod Fertil 1974;39:115–118.

94. Cox JE, Williams JH: Some aspects of the reproductive endocrinology of the stallion and cryptorchid. J Reprod Fertil Suppl 1975;75–79.

95. Claes A, Ball BA, Corbin CJ, et al: Anti-mullerian hormone as a diagnostic marker for equine cryptorchidism in three cases with equivocal testosterone concentrations. J Equine Vet Sci 2014;34:442–445. doi: 10.1016/j.jevs.2013.09.001

96. Claes A, Ball BA, Corbin CJ, et al: Age and season affect serum testosterone concentrations in cryptorchid stallions. Vet Rec 2013;173:168. doi: 10.1136/vr.101706

97. Tsunoda N, Ito M, Koyago M, et al: Dynamic changes in endogenous hormones from the testes and pituitary in response to a single injection of human chorionic gonadotrophin (HCG) in the thoroughbred stallion. Anim Reprod Sci 2010;121S:S165–S167.

98. Cox JE, Redhead PH, Dawso FE: Comparison of the measurement of plasma testosterone and plasma oestrogens for the diagnosis of cryptorchidism in the horse. Equine Vet J 1986;18:179–182.

99. Esteller-Vico A, Ball BA, Bridges JW, et al: Changes in circulating concentrations of testosterone and estrone sulfate after human chorionic gonadotropin administration and subsequent to castration of 2-year-old stallions. Anim Reprod Sci 2021;225. doi: 10.1016/j.anireprosci.2020.106670

100. Illera JC, Silvan G, Munro CJ, et al: Amplified androstenedione enzymeimmunoassay for the diagnosis of cryptorchidism in the male horse: comparison with testosterone and estrone sulphate methods. J Steroid Biochem 2003;84:377–382. doi: 10.1016/S0960-0760(03)00057-8

101. Claes A, Ball BA, Almeida J, et al: Serum anti-Mullerian hormone concentrations in stallions: Developmental changes, seasonal variation, and differences between intact stallions, cryptorchid stallions, and geldings. Theriogenology 2013;79:1229–1235. doi: 10.1016/j.theriogenology.2013.03.019

102. Claes ANJ, Ball BA: Biological functions and clinical applications of anti-mullerian hormone in stallions and mares. Vet Clin North Am Equine Pract 2016;32:451–464.

103. Murase H, Ochi A, Tozaki T, et al: A case of equine cryptorchidism with undetectable serum anti-Mullerian hormone. J Vet Med Sci 2020;82:209–211. doi: 10.1292/jvms.18-0057

104. Röcken M, Mosel G, Litzke LF: Evaluation of diagnostic and therapeutic possibilities of laparoscopic cryptorchidectomy in the standing horse. Pferdeheilkunde 2004;20:423–431.

105. Schambourg MA, Farley JA, Marcoux M, et al: Use of transabdominal ultrasonography to determine the location of cryptorchid testes in the horse. Equine Vet J 2006;38:242–245. doi: 10.2746/042516406776866354

106. Schumcher J: Chapter 60. Testis. In Auer JA, Stick J, Kümmerle J, Prange T: editors. Equine surgery. 5th edition, St. Louis; WB Saunders: 2019:996–1034.

107. Wohlsein P, Wissdorf H, Bartmann CP: Anatomische, klinische und forensische Aspekte zur angeblichen Rückwanderung des Hodens vom Skrotum in die Bauchhöhle beim Warm- und Vollblutfohlen. Pferdeheilkunde 2018;34:327–332. doi: 10.21836/PEM20180402

108. Pozor MA, Macpherson ML, Kelleman AA: How to determine location of cryptorchid testes in stallions, using ultrasonography. Lexington; American Association of Equine Practitioners (AAEP): 2018:230–235.

109. Ras A, Rapacz A, Ras-Norynska M, et al: Clinical, hormonal and ultrasonograph approaches to diagnosing cryptorchidism in horses. Pol J Vet Sci 2010;13:473–477.

110. Braxmaier U, Litzke LF: Die transkutane Sonographie – eine zuverlässige Methode zur Diagnose des Kryptorchismus beim Pferd?. Tieraerztl Prax G N 2005;33:48–54. doi: 10.1055/s-0038-1624102

111. Coomer RPC, Gorvy DA, McKane SA, et al: Inguinal percutaneous ultrasound to locate cryptorchid testes. Equine Vet Educ 2016;28:150–154. doi: 10.1111/eve.12419

112. Beyer NF, Troillet A, Winter K, et al: Diagnostik und Therapie des Kryptorchismus – eine retrospektive Analyse von 86 Fällen. Pferdeheilkunde 2020;36:210–219. doi: 10.21836/PEM20200303

113. Jann HW, Rains JR: Diagnostic ultrasonography for evaluation of cryptorchidism in horses. J Am Vet Med Assoc 1990;196:297–300.

114. Brommer H, Grinwis GCM, Loon VV, et al: Laparoscopic-assisted diagnosis of anomalous unilateral abdominal cryptorchidism. Equine Vet Educ 2011;23:391–395. doi: 10.1111/j.2042-3292.2011.00243.x

115. Clements PE, Coomer RPC, McKane SA, et al: Clinical findings in 10 horses diagnosed with monorchidism following exploratory laparotomy or standing laparoscopic surgery. Equine Vet Educ 2020;32:431–436. doi: 10.1111/eve.13074

116. Magalhães JFd, Costa GMJ, Oliveira CAd, et al: Monorchidism in a four-beat gaited horse. Cienc Rural 2015;45:1058–1061.

117. Gardner AK, Santschi EM, Aeffner F, et al: Testicular ischaemic necrosis as a cause of equine cryptorchidism. Equine Vet Educ 2017;29:314–317. doi: 10.1111/eve.12544

118. Rijkenhuizen ABM, Harst MRvd: Castration in the standing horse combining laparoscopic and conventional techniques. Equine Vet J 2017;49:776–779.

119. Trumble TN, Hendrickson DA: Standing male equine urogenital endoscopic surgery. Vet Clin North Am Equine Pract 2000;16:269–284. doi: 10.1016/S0749-0739(17)30104-9

120. Hendrickson D: Laparoscopic cryptorchidectomy and ovariectomy in horses. Vet Clin North Am Equine Pract 2006;22:777–798. doi: 10.1016/j.cveq.2006.08.006

121. Hendrickson DA: A review of equine laparoscopy. ISRN Vet Sci 2012;2012:492650. doi: 10.5402/2012/492650

122. Sassot LN, Ragle CA, Farnsworth KD, et al: Morcellation for testes extraction in horses undergoing standing laparoscopic cryptorchidectomy. Can Vet J 2017;58:1215–1220.

123. Seabaugh KA, Goodrich LR, Morley PS, et al: Comparison of peritoneal fluid values after laparoscopic cryptorchidectomy using a vessel-sealing device (Ligasure) versus a ligating loop and removal of the descended testis. Vet Surg 2013;42:600–606. doi: 10.1111/j.1532-950X.2012.01065.x

124. Vigani A, Garcia-Pereira FL: Anesthesia and analgesia for standing equine surgery. Vet Clin North Am Equine Pract 2014;30:1–17.

125. Gaynor JS, Hubbell JA: Perineural and spinal anesthesia. Vet Clin North Am Equine Pract 1991;7:501–519. doi: 10.1016/S0749-0739(17)30483-2

126. Wittern C, Hendrickson DA, Trumble T, et al: Complications associated with administration of detomidine into the caudal epidural space in a horse. J Am Vet Med Assoc 1998;213:516–518.

127. Hendrickson DA, Wilson DG: Laparoscopic cryptorchid castration in standing horses. Vet Surg 1997;26:335–339. doi: 10.1111/j.1532-950X.1997.tb01507.x

128. Ragle CA, Southwood LL, Howlett MR: Ventral abdominal approach for laparoscopic cryptorchidectomy in horses. Vet Surg 1998;27:138–142.

129. Searle D, Dart AJ, Dart CM, et al: Equine castration: review of anatomy, approaches, techniques and complications in normal, cryptorchid and monorchid horses. Aust Vet J 1999;77:428–434. doi: 10.1111/j.1751-0813.1999.tb12083.x

130. Staffieri F, Driessen B: Field Anesthesia in the Equine. Clin Tech Equine Pract 2007;6:111–119. doi: 10.1053/j.ctep.2007.05.003

131. Mueller P: Cryptorchidim. In: Wolf DF, Moll HD: editors. Large animal urogenital surgery. 2nd edition, Philadelphia, PA; Willams and Wilkins: 1999:37–45.

132. Rodgerson DH, Hanson RR: Cryptorchidism in horses 2. Treatment. Comp Cont Educ Pract 1997;19:1372–1379.

133. Wilson DG, Reinertson EL: A modified parainguinal approach for cryptorchidectomy in horses. An evaluation in 107 horses. Vet Surg 1987;16:1–4.

134. Adams S: Cryptorchidectomy. In: N, J:editors. Current practice of equine surgery. Philadelphia, PA: J.B. Lippincott: 1990:722–726.

135. Mueller POE, Parks AH: Cryptorchidism in horses. Equine Vet Educ 1999;11:77–86. doi: 10.1111/j.2042-3292.1999.tb00926.x

136. Swift PN: Castration of a stallion with bilateral abdominal cryptorchidism by flank laparotomy. Aust Vet J 1972;48:472–473.

137. Adams A, Hendrickson DA: Standing male equine urogenital surgery. Vet Clin North Am Equine Pract 2014;30:169–190. doi: 10.1016/j.cveq.2013.11.005

138. Lowe JE, Higginbotham R: Castration of abdominal cryptorchid horses by a paramedian laparotomy approach. Cornell Vet 1969;59:121–126.

139. Fischer AT, Vachon AM: Laparoscopic intra-abdominal ligation and removal of cryptorchid testes in horses. Equine Vet J 1998;30:105–108. doi: 10.1111/j.2042-3306.1998.tb04468.x

140. Joyce J: A review of laparoscopic cryptorchidectomy. J Equine Vet Sci 2008;28:112–117. doi: 10.1016/j.jevs.2008.01.009

141. Rodgerson DH: Cryptorchidectomy. In: Ragle CA: editor. Advances in equine laparoscopy. 1st edition, Chichester; John Wiley & Sons: 2012:139–147.

142. Hand R, Rakestraw P, Taylor T: Evaluation of a vessel-sealing device for use in laparoscopic ovariectomy in mares. Vet Surg 2002;31:240–244. doi: 10.1053/jvet.2002.33482

143. Bracamonte JL, Thomas KL: Laparoscopic cryptorchidectomy with a vessel-sealing device in dorsal recumbent horses: 43 cases. Vet Surg 2017;46:559–565. doi: 10.1111/vsu.12624

144. Voermans M, Rijkenhuizen ABM, van der Velden MA: The complex blood supply to the equine testis as a cause of failure in laparoscopic castration. Equine Vet J 2006;38:35–39.

145. Voermans M, Van der Velden MA: Unsuccessful laparoscopic castration in a cryptorchid Frisian stallion. Tijdschr Diergeneesk 2006;131:774–777.

146. Rijkenhuizen A, Dijk P: Diagnostic and therapeutic laparoscopy in the horse: experiences in 236 cases. Pferdeheilkunde 2002;18:12–20.

147. Cribb NC, Koenig J, Sorge U: Comparison of laparoscopic versus conventional open cryptorchidectomies on intraoperative and postoperative complications and duration of surgery, anesthesia, and hospital stay in horses. J Am Vet Med Assoc 2015;246:885–892. doi: 10.2460/javma.246.8.885

148. Kramer J: Atypical cryptorchid castrations. Equine Vet Educ 2017;29:318–320. doi: 10.1111/eve.12575

149. Hendrickson DA: Complications of laparoscopic surgery. Vet Clin North Am Equine Pract 2008;24:557–571. doi: 10.1016/j.cveq.2008.09.003
Published
2023-07-07
How to Cite
Arroyo E., & Tibary A. (2023). Cryptorchidism in stallions. Clinical Theriogenology, 15, 31-51. https://doi.org/10.58292/ct.v15.9648