Semen quality and interval to sterility in tom cats treated with a 9.4 mg deslorelin implant

Abstract

Objectives Gonadotropin-releasing hormone (GnRH) agonists like deslorelin are being increasingly used in tom cats for their efficacy in controlling reproductive behaviour and fertility. Deslorelin implants have been widely available in Europe since 2008. Little, if anything, is known about the interval between treatment and onset of sterility, as well as semen quality, after treatment in tom cats. The purpose of this study was to investigate semen quality and interval to sterility in tom cats treated with a 9.4 mg deslorelin implant. Methods Fifteen healthy adult tom cats were treated with a 9.4 mg deslorelin implant (Suprelorin 12). For each cat, semen collection and a GnRH stimulation test (intramuscular administration of 50 μg gonadorelin [Fertagyl], followed by blood sampling 1 h later, to assay serum testosterone) were performed on the first consultation and then repeated every 15 days until complete sterility was achieved. Semen collection was performed by introducing a 14 cm, open-end feline catheter (Argyle) 9 cm into the distal urethra 10 mins after sedation by intramuscular injection of 100 μg/kg medetomidine (Domitor). Results Semen collection was not successful in all cats at each attempt. In the first month after treatment, the semen of only four cats could be evaluated, while the semen of eight cats could be evaluated during the second and third months of the study. Semen quality (ejaculate volume, progressive motility and morphological abnormalities) improved slightly during the first 19-25 days in 2/4 cats, and in 1/4 cats motility was still very high (80%) 25 days post-treatment (PT), but we have no data regarding fertility prior to treatment in this cat. The last cat never produced spermatozoa. Subsequently, semen quality gradually worsened in all cats from 30 days onwards. At 70 days PT, one cat was still potentially fertile. After 72 days all cats were sterile. Conclusions and relevance Semen quality increased slightly in treated cats during the first month after treatment, and then gradually decreased over the following months. Complete sterility was reached within 40-72 days following implantation.

Long‐term effects of GnRH agonists on fertility and behaviour

“…Independent of the licensed indications, these deslorelin slow‐release implants (SRI) are also among others used off‐label in bitches (Fontaine & Fontbonne, ; Körber, Wehrend, Hoffmann, & Goericke‐Pesch, ; Maenhoudt, Santos, & Fontbonne, ; Maenhoudt et al., ; Palm & Reichler, ; Trigg, Doyle, Walsh, & Swangchan‐uthai, ; Trigg et al., ) as well as male and female cats (Goericke‐Pesch, Georgiev, Antonov, Albouy, & Wehrend, ; Goericke‐Pesch, Wehrend, & Georgiev, ; Goericke‐Pesch, Georgiev, Atanasov, Albouy, et al. ; Goericke‐Pesch, Georgiev, et al., ; Munson, Bauman, Asa, Jochle, & Trigg, ; Novotny et al., , ; Romagnoli et al., ). The aim of this review was to summarize the present knowledge about the effect of GnRH A‐SRI, especially those with deslorelin, on fertility and behaviour in male and female dogs and cats.…”

Captive ring‐tailed lemur breeding in semi‐free ranging conditions and genetic parentage analysis

“…Eight males were still living in the study institution when this publication was written (Table ). The temporary contraception implants used in 2015 were effective but not fully reliable, because one implanted female did in fact breed (FZ#2, Table ) due to a dysfunctional implant, a failed implantation, or the documented fact that the implant could lead to LH surge and ovulation before the complete inhibition of pituitary hormones (Romagnoli et al, ).…”

GnRH‐agonist deslorelin implant alters the progesterone release pattern during early pregnancy in gilts

“…The GnRH-agonist used as a slow-release pellet (containing 4.7 mg deslorelin) and was reported to have a long-term suppressive effect on reproductive steroids in dogs (Borges et al, 2015;Junaidi et al, 2009;Kaya et al, 2015;Trigg et al 2001) and cats (Camila et al, 2016;Fontaine, 2015;Romagnoli et al, 2017). These treatment properties are usually applied for time-limited sterilization and contraception or for postponing oestrus, which is of high relevance in other species such as the horse.…”

“…Deslorelin is a GnRH analogue, and has been developed in a slow-release formulation to prevent oestrus and pregnancy in the bitch and to suppress testosterone chronically (thereby sexual behaviour) in the male dog (Borges et al, 2015;Junaidi et al, 2007;Kaya et al 2015;Trigg et al, 2001) and the tomcat (Camila et al, 2016;Fontaine, 2015;Romagnoli et al, 2017). In the male dog, insertion of a deslorelin implant led to a peak in LH within an hour of treatment (Junaidi et al, 2009); the vertex was over within 3 hr and LH returned to the basal level by Day 3 after treatment.…”