eprintid: 1559 rev_number: 7 eprint_status: archive userid: 5 dir: disk0/00/00/15/59 datestamp: 2025-12-26 09:20:21 lastmod: 2025-12-26 09:20:21 status_changed: 2025-12-26 09:20:21 type: article metadata_visibility: show creators_name: Zhelavskyi, Mykola creators_name: Kernychny, Serhii creators_name: Tsvilikhovsky, Valerii creators_id: nicoladoctor@gmail.com title: Fertility Restoration in Progestogen-Treated Hungarian Wirehaired Vizslas: Effects of GnRH Agonist on Reproductive Activity ispublished: pub subjects: SF divisions: j13 full_text_status: public keywords: Deslorelin, Estrus induction, Hormonal sterilization, Luteinizing hormone, Progesterone, Reproductive management abstract: Deslorelin implants are increasingly utilized in veterinary reproductive management as a reversible alternative to surgical sterilization in dogs. The present study evaluated the biphasic response to deslorelin (Suprelorin®, 4.7 mg; Virbac®, France) in Hungarian Wirehaired Vizsla bitches after long-term progestogen-induced estrus suppression and assessed its efficacy for estrus induction and hormonal response sterilization. Thirty healthy bitches, aged 2-3 years and weighing from 19.8 to 23.7 kg, were enrolled in the study, which was divided into three groups, including a control group (C1) and two experimental groups (E1 and E2), each comprising 10 bitches. All of these dogs received subcutaneous deslorelin implants during anestrus. In E1, bitches previously treated with medroxyprogesterone acetate for 18 to 24 months received the implant for estrus induction, which was surgically removed on day 7. In E2, the implant was used for prolonged estrus suppression. Cytology and hormone analysis samples (progesterone, luteinizing hormone) were collected from the cephalic vein at specific time points; during anestrus (day 160), before implantation in controls, proestrus (day 3), estrus (days 1-3), the flare-up phase (72 hours post-implantation), and post-removal (day 7, group E1). Diestrus was monitored on days 7, 9, 11, 14, 15, 30, and 60 for the E2 group under suppression. Cytological assessment was performed using Diff-Quik™ staining, and hormone levels were measured via chemiluminescent immunoassay and ELISA. Ultrasonography and physical examination were used to monitor reproductive tract status. The present study confirmed a biphasic response to deslorelin, characterized by an initial flare-up phase, during which luteinizing hormone (LH) levels and estrous behavior were elevated, peaking on days 3 or 4, followed by effective suppression from day 14 through day 60. Implant removal in group E1 successfully induced fertile estrus, demonstrating Suprelorin's utility for fertility restoration in progestogen-treated bitches. In group E2, the implant provided sustained reproductive suppression for up to 12 months without adverse effects. These results highlighted the dual role of deslorelin in inducing or suppressing estrus, providing a valuable, evidence-based pharmacological option for managing canine reproduction. date: 2025-06-25 publication: World’s Veterinary Journal volume: 15 number: 2 publisher: Scienceline Publication pagerange: 407-420 id_number: 10.54203/scil.2025.wvj41 refereed: TRUE issn: 2322-4568 official_url: https://wvj.science-line.com/attachments/article/86/WVJ15(2)407-420,2025.pdf j_index: scopus citation: (2025) Fertility Restoration in Progestogen-Treated Hungarian Wirehaired Vizslas: Effects of GnRH Agonist on Reproductive Activity. World’s Veterinary Journal. pp. 407-420. ISSN 2322-4568 document_url: http://eprints.science-line.com/id/eprint/1559/1/WVJ15%282%29407-420%2C2025%20%281%29.pdf