Novo protocolo utilizando ocitocina para induzir a ejaculação em garanhão penectomizado

Authors

  • Thaís Mendes Sanches Cavalero Departmento de Reprodução Animal e Radiologia Veterinária, Faculdade de Medicina Veterinária e Zootecnia (FMVZ), UNESP, Botucatu, SP, Brazil.
  • Verônica Flores da Cunha Scheeren Departmento de Reprodução Animal e Radiologia Veterinária, Faculdade de Medicina Veterinária e Zootecnia (FMVZ), UNESP, Botucatu, SP, Brazil.
  • Lucas Emanuel Ferreira Canuto Departmento de Reprodução Animal e Radiologia Veterinária, Faculdade de Medicina Veterinária e Zootecnia (FMVZ), UNESP, Botucatu, SP, Brazil.
  • Lucas Troncarelli Rodrigues Departmento de Reprodução Animal e Radiologia Veterinária, Faculdade de Medicina Veterinária e Zootecnia (FMVZ), UNESP, Botucatu, SP, Brazil.
  • Frederico Ozanam Papa Departmento de Reprodução Animal e Radiologia Veterinária, Faculdade de Medicina Veterinária e Zootecnia (FMVZ), UNESP, Botucatu, SP, Brazil.

DOI:

https://doi.org/10.22456/1679-9216.88217

Abstract

Background: Several reproductive diseases can prevent ejaculation by the traditional method of collection. Neoplasias as squamous cell carcinoma is the most common tumor of the external genitalia of horses and its lesions usually prevent copulation. The pharmacological induction of ejaculation is an important alternative technique to obtain and preserve the genetic material of stallions incapable of ejaculating by traditional methods of semen collection. However, the protocols currently used have shown questionable results and new protocols are needed in order to increase the success rates. The aim of this study is to report the success of a new protocol in inducing ejaculation when oral imipramine and intravenous oxytocin and detomidine were administrated in a Crioulo stallion.

Case: A 9-year-old Crioulo stallion was admitted at the Veterinary Hospital of the São Paulo State University, FMVZUNESP, Botucatu, Brazil, with a history of a mass located on the glans and body of the penis. The histopathological exam confirmed the diagnostic of Squamous cell carcinoma and penectomy was performed. After 10 days of surgery the stallion was submitted to 5 different protocols with 3 days interval between the follow protocols: Imipramine+Xylazine; Imipramine+ Xylazine+Oxytocin; Imipramine+Detomidine and Imipramine+Detomidine+Oxytocin.

Discussion: The traditional protocol of pharmacologically-induced ejaculation with imipramine hydrochloride (3 mg/kg/v.o) and xylazine hydrochloride (0.66 mg/kg/iv) was not successful even when oxytocin (20 UI/iv) was added to this protocol. Administration of imipramine hydrochloride (3 mg/kg/v.o) two hours prior to administration of detomidine hydrochloride (0.02 mg/kg/i.v) also did not result in ejaculation. However, administration of imipramine hydrochloride (3 mg/kg/v.o) 2 h prior to administration of detomidine hydrochloride (0.02 mg/kg/i.v) associated with oxytocin (20 U.I/i.v) resulted in ejaculation. The stallion was submitted to three seminal collections with a three-day interval between administration of the protocol and ejaculated in all the attempts after approximately 5 min of detomidine and oxytocin injection, presenting mean values of 50 mL of total volume (TV) and concentration of 80x106 spermatozoa/mL. The VT was higher and concentration was lower when compared to ejaculates obtained by pharmacological induction in previous studies, probably due to daily stimulation with estrus mare to induce penile exposure in order to allow antisepsis of the surgical wound. Thus, it is believed that the large amount of total volume of this stallion is due to the high production of gel by the accessory sex glands, with consequent reduction of ejaculate concentration. The sperm kinetics were evaluated by the computerized method CASA (HTMA-IVOS-12) with total motility (MT) of 84% and progressive (MP) of 38%, with 70% of rapid spermatozoa (RAP), being considered normal to the equine specie and similar to those observed by other authors in pharmacolocally-induced ejaculates. Post-thaw sperm kinetics presented 42% of MT, 21% of MP and 28% of RAP probably due to an intrinsic sensitivity of the stallion to the freezing process. Thus, this report concludes that the protocol associating imipramine, detomidine and oxytocin was efficient in the pharmacological induction of ejaculation, presenting normal and characteristic sperm parameters of the specie. Fresh and refrigerated semen presented good parameters for use in conventional artificial inseminations while frozen semen is indicated for deep horn inseminations or for use in intracytoplasmic sperm injection (ICSI) programs.

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References

Corona G., Jannini E.A., Vignozzi L., Rastrelli G. & Maggi M. 2012. The hormonal control of ejaculation. Nature Reviews Urology. 9(9): 508-519.

Feary D.J., Moffet P.D., Bruemmer J.E., Southwood L., McCue P., Niswender K.D., Dickinson C. & Traub-dargatz J. 2005. Chemical ejaculation and cryopreservation of semen from a breeding stallion with paraphimosis secondary to priapism and haemorrhagic colitis - Case Report. Equine Veterinary Education. 17: 299-304.

Johnston P.F. & DeLuca J.L. 1998. Chemical ejaculation of stallions after administration of oral imipramine followed by intravenous xylazine. In: Proceedings of the 44th AAEP Annual Convention (Baltimore, U.S.A.). pp.59-62.

Love C.C. 1992. Semen collection techniques. Veterinary Clinics of North America: Equine Practice. 8(1): 111-128.

McDonnell S.M. 2001. Oral imipramine and intravenous xylazine for pharmacologically-induced ex copula ejaculation in stallions. Animal Reproduction Science. 68: 153-159.

McDonnell S.M. 2011. Pharmacological Manipulation of Ejaculation. In: McKinnon A.O., Squires E.L., Vaala W.E. & Varner D.D. (Eds). Equine Reproduction. 2nd edn. Ames: Wiley-Blackwell, pp.1413-1414.

McDonnell S.M. & Love C.C. 1991. Xylazine-induced ex copula ejaculation in stallions. Theriogenology. 36: 73-76.

McDonnell S.M. & Odian M.J. 1994. Imipramine and xylazine-induced ex copula ejaculation in stallions. Theriogenology. 41: 1005-1010.

Miroslava-Mrackova D.V.M., Blahova Z. & Marketa-Sedlinska D.V.M. 2013. The Realibility of two different protocols for pharmacologically induced ejaculation in donkeys (Equus asinus). Journal of Equine Veterinary Science. 33: 1121-1123.

Rowley D.D., Lock T.F. & Shipley C.F. 1999. Fertility of detomidine HCl induced ex copula ejaculated stallion semen. In: Proceedings of the 45th AAEPAnnual Convention (Albuquerque, U.S.A.). pp.221-223.

Von Den Top J.G.B., Heer N., Klein W.R. & Ensink J.M. 2008. Penile and prepucial tumours in the horse: a retrospective study of 144 affected horses. Equine Veterinary Journal. 40(6): 528-532.

Published

2018-01-01

How to Cite

Cavalero, T. M. S., Scheeren, V. F. da C., Canuto, L. E. F., Rodrigues, L. T., & Papa, F. O. (2018). Novo protocolo utilizando ocitocina para induzir a ejaculação em garanhão penectomizado. Acta Scientiae Veterinariae, 46, 4. https://doi.org/10.22456/1679-9216.88217