Anatomical and histological study of intrainguinal testis in adult donkey (Equus asinus)

Document Type : Basic Sciences


1 Department of Basic Sciences, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran

2 Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran

3 Department of Basic Science, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran


BACKGROUND: Cryptorchidism is a congenital anomaly in which one (unilateral cryptorchidism) or both (bilateral cryptorchidism) testes fail to descend into the scrotum.                  OBJECTIVE: The aim of this study was to describe the anatomical and histological structure of the inguinal testis in the adult donkey. METHODS: In this study, after examination of the 59 donkeys, three of them with unilateral cryptorchidism in inguinal region were identified. These animals were euthanized, and their testicles were removed and evaluated biometrically. Then, the samples were fixated in 10% formalin solution and after sectioning, were stained with Hematoxylin-eosin and PAS, and examined under a light microscope. RESULTS: The results showed that the inguinal testes were stiff, epididymis was not determined and their size and weight were less than scrotal testes. The difference between the weight of cryptorchid and healthy testicles was statistically significant (p<0.05). Seminiferous tubules had lost their natural shape and inner cavity tubes did not have germ cells, and only a limited number of Sertoli cells could be seen. Remaining seminiferous tubules were only visible in the mediastinum. The cortical and subcapsular regions were without tubes and were occupied by loose connective tissues. CONCLUSIONS: Results indicated that the inguinal testes in adult donkeys lost their natural structure and more connective tissues and blood vessels are substituted.


Absalan, F., Movahedin, M., Mowla, S.J. (2008) Assessment of testis histological changes and sperm parameters in experimentally-induced unilateral and bilateral cryptorchid mouse model. Iran J Reprod Med. 6(3): 143-148.##
Amann, R.P., Veeramachaneni, D.N. (2006) Cryptorchism and associated problems in animals. Anim Reprod. 3:108- 120.##
Arighi, M. (2011) Testicular descent. In: Equine Reproduction, Vol. 1, 2nd Edn. Blackwell Publishing, West Sussex, UK. p. 1099-1106.##
Arighi, M., Bosu, W.T.K., Raeside, J.I. (1986) Hormonal diagnosis of equine cryptorchidism and histology of the retained testes. ProcAAEP. 31: 591-602.##
Aupperlel, H., Gerlach, K.C.P., Sabine, B., Schoonl, H.A. (1999) Histopathologicail flindings in the cryptorchidism testes of stallions. Pferdeheilkunde. 6: 515-522. ##
Baishya, S.K., Anubrata, D., Khargharia, G., Bardoloi, R.K. (2003) Studies on certain aspects of epididymal spermatozoa of unilateral cryptorchid indigenous boar of Meghalaya. Indian J Hill Fmg. 16: 86-88.##
Claes, A., Barry, B.A., Corbin, C.J., Conley, A.J. (2014) Anti-Müllerian Hormone as a Diagnostic Marker for Equine Cryptorchidism in Three Cases with Equivocal Testosterone Concentrations. J Equine Vet Sci. 34: 442-445.##
Coryn, M., Moor, A., Bouters, R. (1981) Clinical, morphological and endocrinological aspects of cryptorchidism in the horse. Theriogenology. 16: 489-496.##
Cox, J.E. (1982) Factors affecting testis weight in normal and cryptorchid horses. J Reprod Fertil. 32: 129-134.##
Eriksson, E., Jäderkvist, K., Dalin, A.M., Axelsson, J., Lindgren, G. (2015) Prevalence and genetic parameters for cryptorchidism in Swedish-born Icelandic horses. Liv Sci.180: 1-5.##
Harutaka, M., Shigeaki, S., Tomohiko, A., Fumio, S., Barry, A.B., Yasuo, N. (2015) Anti-Müllerian hormone as an indicator of hemi-castrated unilateral cryptorchid horses. J Equine Sci. 26(1): 15-20.##
Hayes, H.M. (1986) Epidemiological features of 5009 cases of equine cryptorchidism. Equine Vet J. 18(6): 467-471.##
Hejmej, A., Biliñska, B. (2008) The effects of cryptorchidism on the regulation of steroidogenesis and gap junctional communication in equine testes. Endokrynol Pol. 59(2): 112-118.##
Huff, D.S., Fenig, D.M., Canning, D.A. (2001) Abnormal germ cell development in cryptorchidism. Horm Res. 55: 11-17.##
Igbokwe, I.O., Grema, H.A., Ikpo, A.E., Mshelbwala, F.M., Igbokwe, N.A. (2009) Unilateral Cryptorchidism In Nigerian Sahel Bucks. Int J Morphol. 27(3): 805-810. ##
Kafi, M., Oryan, A., Morgan-Azghadi, N. (2007) Pathology of testis and epididymes in native goats in southern Iran. Comp Clin Path. 16: 201-205.##
Kaleva, M., Toppari, J. (2005) Cryptorchidism: an indicator of testicular dysgenesis. Cell Tissue Res. 322: 167-172.##
Kollin, C., Stukenborg, J.B., Nurmio, M., Sundqvist, E., Gustafsson, T., Söder, O., Toppari, J., Nordenskjöld, A., Ritzén, E.M. (2012) Boys with undescended testes: endocrine, volumetric and morphometric studies on testicular function before and after orchidopexy at nine months or three years of age. J Clin Endocrinol Metab. 97(12): 4588-4595.##
Kraft, K.H., Mucksavage, P., Cunning, D.A., Snyder, H.M., Kolon, T.F. (2011) Histological findings in patients with cryptorchidism and testis-epididymis nonfusion. J Urol. 186: 2045-2049.##
Lu, K.G. (2005) Clinical diagnosis of the cryptorchid stallion. Clin Tech Equine Prac. doi:10.1053/j.ctep.2005.07.006 ##
Morel, M.C.G.D. (2015) Equine Reproductive Physiology, Breeding and Stud Management, United Kingdom, (4th ed.) CABI, Wallingford, Oxfordshire, UK.##
Mueller, P.O.E., Parks, A.H. (1999) Cryptorchidism in horses. Equine Vet Educ. 11: 77-86.##
Narasimha, V.K., Madhuri, E., Sadak, B.S., Radha, M.Y.R., Guru, S.M., Bhaskar, M. (2009) Alterations in carbohydrate metabolism under cryptorchid condition in albino rats. J Appl Nat Sci. 1(1): 62-65.##
Noakes, D.E., Parkinson, T.J., England, G.C.W. (2001) Arthur’s Veterinary Reproduction and Obstetrics. 8th Edn. Saunders, Philadelphia, USA. p. 551-552. ##
Peng, J., Shen, L., Chen, J., Cao, X., Zhou, Y., Weng, H., Long, C., Zhang, D., Tu, S., Zhang, Y., He, D., Lin, T., Wei, G. (2016) New discovery of cryptorchidism: Decreased retinoic acid in testicle, Saudi Pharm J. doi: 10.1016/j.jsps.2016.04.020##
Saalu, L.C., Adesanya, A.O., Oyewopo, A.O., Raji, Y. (2007) An evaluation of the deleterious effect of unilateral cryptorchidism on the contralateral normally descended testis. Sci Res Essays. 2 (3): 074-078.##
Searle, D., Dart, A.J., Dart, C.M., Hodgson, D.R. (1999) Equine castration: review of anatomy, approaches, techniques and complications in normal, cryptorchid and monorchid horses. Aus Vet J. 77(7): 428-34.##
Stickle, R.L., Fessler, J.F. (1978) Retrospective study of 350 cases of equine cryptorchidism. J Am Vet Med Assoc. 172: 343-346.##
Virtanen, H.E., Bjerknes, R., Cortes, D. (2007) Cryptorchidism: classification, prevalence and long-term consequences. Acta Paediatrica. 96: 611-616.##
Virtanen, H.E., Toppari, J. (2015) Cryptorchodism and fertility. Endocrinol Metab Clin N Am. doi:10.1016/j.ecl.2015.07.013##
Zaidi, M.T., Khan, A.A., Faruqi, N.A. (2005) Microstructure of the spermatic system in a fertile unilateral crypyorchid male- A case report. J Anat Soc India. 54: 1-9.##