Effect of deslorelin on testicular function, serum dihydrotestosterone and oestradiol concentrations during and after suppression of sexual activity in tom cats

Objectives The aim of the study was to evaluate the efficacy of a 4.7 mg deslorelin implant in tom cats. Methods Nine mature male cats were included in the deslorelin group and five cats in the control group. Before the study started, all cats were confirmed to have distinct sexually dimorphic behaviour. Blood samples were taken on the implantation day, at day 7 and at day 15, then monthly, in order to measure serum dihydrotestosterone (DHT) and 17beta(β)-oestradiol concentrations. The deslorelin group (n = 9) was divided into two subgroups: five cats (cats 1–5) were neutered in the postimplantation period during suppression of sexually dimorphic behaviour, and four cats (cats 6–9) were neutered after re-expression of sexually dimorphic behaviour. The control group cats (n = 5) were castrated without administration of the implant. Results Sexually dimorphic behaviours ceased within a mean ± SD of 13–58 days (23.30 ± 14.17) after implantation. DHT concentration decreased within 30 days. The mean duration of suppression was 26.5 ± 7.42 months and reactivation coincided with increased DHT values reaching preimplantation concentrations within 1 month. 17β-oestradiol concentrations significantly correlated with DHT concentrations (P <0.01). For cats castrated during suppression of sexual behaviour, the length of the long axes of the nuclei of Leydig cells, the diameter of seminiferous tubules and the height of the epithelium of the seminiferous tubules did not change until 3–6 months after implantation, whereas at 12 and 32 months the measured values were even lower than in the control group. For cats castrasted after reactivation, the length of long axes of the nuclei of Leydig cells and the diameter of seminiferous tubules approached the values of the control group between 4 and 6 months after reactivation. Conclusions and relevance A deslorelin implant (4.7 mg) suppresses sexually dimorphic behaviour in tom cats without any side effects and with full reversibility; however, duration of suppression is highly individual.

[1]  P. Čížek,et al.  Azoospermia with variable testicular histology after 7 months of treatment with a deslorelin implant in toms. , 2015, Theriogenology.

[2]  S. Kaya,et al.  Clinical use of deslorelin implants for the long-term contraception in prepubertal bitches: effects on epiphyseal closure, body development, and time to puberty. , 2015, Theriogenology.

[3]  M. Merlo,et al.  Effect of GnRH analogs in postnatal domestic cats. , 2014, Theriogenology.

[4]  A. Wehrend,et al.  Suppression of fertility in adult cats. , 2014, Reproduction in domestic animals = Zuchthygiene.

[5]  A. Wehrend,et al.  Reversibility of germinative and endocrine testicular function after long-term contraception with a GnRH-agonist implant in the tom-a follow-up study. , 2014, Theriogenology.

[6]  S. Cristarella,et al.  Deslorelin implants in pre-pubertal female dogs: short- and long-term effects on the genital tract. , 2014, Reproduction in domestic animals = Zuchthygiene.

[7]  A. Wehrend,et al.  Basal testosterone concentrations after the application of a slow-release GnRH agonist implant are associated with a loss of response to buserelin, a short-term GnRH agonist, in the tom cat. , 2013, Theriogenology.

[8]  C. Barbeito,et al.  Long-term-release GnRH agonists postpone puberty in domestic cats. , 2012, Reproduction in domestic animals = Zuchthygiene.

[9]  P. Čížek,et al.  Reversible suppression of sexual activity in tomcats with deslorelin implant. , 2012, Theriogenology.

[10]  V. Olgac,et al.  Effects of the GnRH analogue deslorelin implants on reproduction in female domestic cats. , 2012, Theriogenology.

[11]  A. Wehrend,et al.  Clinical efficacy of a GnRH-agonist implant containing 4.7 mg deslorelin, Suprelorin, regarding suppression of reproductive function in tomcats. Sandra.Pesch@vetmed.uni-giessen.de. , 2011, Theriogenology.

[12]  G. Martin,et al.  Dose-response studies for pituitary and testicular function in male dogs treated with the GnRH superagonist, deslorelin. , 2009, Reproduction in domestic animals = Zuchthygiene.

[13]  G. Martin,et al.  Morphological study of the effects of the GnRH superagonist deslorelin on the canine testis and prostate gland. , 2009, Reproduction in domestic animals = Zuchthygiene.

[14]  C. Gobello.  Dopamine agonists, anti-progestins, anti-androgens, long-term-release GnRH agonists and anti-estrogens in canine reproduction: a review. , 2006, Theriogenology.

[15]  M. Kutzler,et al.  Non-surgical methods of contraception and sterilization. , 2006, Theriogenology.

[16]  L. Howe.  Surgical methods of contraception and sterilization. , 2006, Theriogenology.

[17]  L. Munson.  Contraception in felids. , 2006, Theriogenology.

[18]  S. Lambard,et al.  Aromatase and estrogen receptors in male reproduction , 2006, Molecular and Cellular Endocrinology.

[19]  M. Kustritz.  Reproductive behavior of small animals. , 2005 .

[20]  J. M. de las Mulas,et al.  Clinical, pathological and immunohistochemical study of feline mammary fibroepithelial hyperplasia following a single injection of depot medroxyprogesterone acetate , 2005, Journal of feline medicine and surgery.

[21]  R. Hess.  Estrogen in the adult male reproductive tract: A review , 2003, Reproductive biology and endocrinology : RB&E.

[22]  C. Agudelo.  Cystic endometrial hyperplasia‐pyometra complex in cats. A review , 2005, The Veterinary quarterly.

[23]  M. V. Kustritz,et al.  Canine and feline theriogenology , 2001 .

[24]  T. O. Abney.  The potential roles of estrogens in regulating Leydig cell development and function: A review , 1999, Steroids.

[25]  E. Kawakami,et al.  Androgen concentration in the blood and spermatogenic function of tom cats during the breeding season. , 1990, Nihon juigaku zasshi. The Japanese journal of veterinary science.

[26]  D. W. Hayden,et al.  Morphologic Changes in the Mammary Gland of Megestrol Acetate-treated and Untreated Cats: A Retrospective Study , 1989, Veterinary pathology.

[27]  A. Bartke,et al.  Effects of diethylstilboestrol on testicular function and luteinizing hormone receptors. , 1989, Revista espanola de fisiologia.

[28]  M. Peterson.  Effects of megestrol acetate on glucose tolerance and growth hormone secretion in the cat. , 1987, Research in veterinary science.

[29]  R. Rosychuk,et al.  Progestogen therapy in cats , 1985 .

[30]  J. Vreeburg,et al.  Copulation in Castrated Male Rats following Combined Treatment with Estradiol and Dihydrotestosterone , 1973, Science.