Use of GnRH superagonist implants for longterm reversible contraception and its effect on oestrus occurrence and hormonal status in prepuberal bitches

[V. Al Daghistani]

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Veterinarska medicina - Ginekologija sa andrologijom / Veterinary Medicine - Gynecology and andrology

Ovariektomija, ovariohisterektomija i orhidektomija su najčešće hirurške intervencije koje se rutinski izvode u veterinarskoj praksi kod malih životinja. Incidencija komplikacija nakon ovariektomije ili ovariohisterektomije je relativno visoka i kreće se između 12% i 32%. Komplikacije neposredno nakon ovariektomije ili ovariohisterektomije uključuju krvarenje, vaginalno krvarenje, infekciju ili dehiscenciju rane, formiranje seroma, komplikacije usled anestezije, apsces grlića materice, reakciju tkiva na materijal za šivenje što može dovesti i do stvaranja granuloma ili fistula. Dugoročne komplikacije uključuju sindrom zaostalog jajnika, piometru, piometru zaostalog dela cerviksa "patrljka", fistule ili granulom patrljka, ozlede uretera, opstipaciju, uretro-, veziko-, enterovaginalne, kao i vaginoperitonalne fistule, opstrukcije kolona, pijelonefritis, urinarnu inkontinenciju, pararenalne pseudociste, hidronefrozu, a neretko i preteranu gojaznost. Poslednjih godina, na tržištu se pojavio veliki broj preparata, od kojih mnogi imaju više od jedne indikacije i mogućnosti primene. Kod potrebe za dugotrajnim ili permanentnim sprečavanjem polnog žara preporučuje se hirurška sterilizacija ženki i mužjaka, kao metod izbora, međutim sve više se govori o negativnim efektima rane (prepubertalne) sterilizacije i njihovim mogućim komplikacijama. Osnova za efikasnost u izazivanju infertilnosti kod određene vrste je razumevanje reproduktivnog ponašanja i fiziologije date vrste, i korišćenje tog znanja za odabir najpodesnije metode kontracepcije. Kontraceptivno sredstvo mora biti efikasno u izazivanju infertilnosti. Supresija estrusa kod kuja se postiže aplikacijom, uglavnom, progesteronskih preparata (gestagena), mada se mogu koristiti i sintetski anabolički steroidi (miboleron), međutim, sa navedenim sredstvima nisu postignuti zadovoljavajući rezultati. Deslorelin preparati, GnRH agonisti imaju veliku perspektivu u menadžmentu i kontroli estrusa kuja. Implantati GnRH agonista su subkutane insercije sporo-otpuštajućeg GnRH, kao što su implanti sa 4,7 mg i 9,4 mg deslorelin acetata, i predstavljaju odličnu alternativu reverzibilne kontrole ovarijalne aktivnosti. Ubacivanjem implantata sporo-otpuštajućeg GnRH agoniste, prirodno pulsativno otpuštanje hormona hipotalamusa i hipofize je blokirano. Posledično dolazi do bazičnog otpuštanja gonadotropina, koje se reperkutuje na smanjenu sintezu i otpuštanje folikulostimulirajućeg i luteinizirajućeg hormona prevenirajući folikularno razviće, odnosno dovodi do privremenog dugotrajnog odlaganja polnog ciklusa i problema koji su vezani za polni ciklus. Vrlo malo studija je opisalo odlaganje puberteta korišćenjem deslorelin implantata kod kuja, ali postoje literaturni navodi koji su potvrdili efikasnost ove metode kontracepcije. Starost kuja igra važnu ulogu u odgovoru na implantat . Cilj ovog istraživanja jeste određivanje dužine kontraceptivnog perioda nakon aplikacije agoniste GnRH kod juvenilnih kuja u prepubertetnom periodu i utvrđivanje efekata na hormonski status (estrogen, progesteron, melatonin), kao i na pojavu normalnog fiziološkog estrusa nakon perioda supresije...

Ovariectomy, ovariohysterectomy and orchidectomy are the most common surgical interventions routinely performed in small animal practice. The incidence of complications after ovariectomy and ovariohysterectomy is relatively high and ranges between 12% and 32%.. Complications immediately after ovariectomy or ovariohysterectomy include bleeding, vaginal bleeding, wound infection or dehiscence, seroma formation, complications from anesthesia, cervical abscess, tissue reaction to suture materials that can lead to granuloma or fistula formation. Long-term complications include residual ovary syndrome, pyometra, "stump" cervical residual pyometra, fistula or granuloma of the stump, ureteral injuries, constipation, urethro-, vesico-, enterovaginal, as well as vaginoperitoneal fistulas, colonic obstruction, urination, paralysis, hydronephrosis, and often excessive obesity. In recent years, a large number of contraceptive medications have appeared on the market, many of which have more than one indication and possibility of application. When there is a need for long-term or permanent prevention of sexual behavior in dogs, surgical castration is recommended as the method of choice, however, the negative effects of early (prepubertal) castration and their possible complications are being discussed. The basis of effectiveness in inducing infertility in certain species is understanding the reproductive behavior and physiology of a given species, and using that knowledge to select the most suitable method of contraception. The contraceptive must be effective in causing infertility. Suppression of estrus in bitches is achieved by the application, mainly, of progesterone preparations (gestagen), although synthetic anabolic steroids (mibolerone) can also be used, but satisfactory results have not been achieved. Deslorelin, a GnRH agonist, have a great perspective in the management and control of estrus in bitches. GnRH agonist implants are subcutaneous insertions of slow-release GnRH, such as the 4,7 mg and 9,4 mg deslorelin acetate implants, and are an excellent alternative for reversible control of ovarian activity. By inserting a slow-release GnRH agonist implant, the natural pulsatile release of hormones from the hypothalamus and pituitary gland is blocked. This leads to a basal release of gonadotropins, after which there is a reduced synthesis and release of follicle-stimulating hormone and luteinizing hormone preventing follicular development, therefore, it leads to a temporary long-term delay of the sexual cycle and problems related to the sexual cycle. Very few studies have described the delay of puberty using the deslorelin implant in bitches, but there are literature reports that have confirmed the effectiveness of this method of contraception in adult bitches. Age plays an important role in implant response. The aim of this study was to determine the length of the contraceptive period after the application of deslorelin implant (4,7 mg) in juvenile, prepubertal bitches and assess the effects on the hormonal status (etrogen, progesterone and melatonin), as well as on the occurrence of normal physiological estrus...

deslorelin, estrus, hormonski status, melatonin, juvenilne kuje

deslorelin, estrus, hormonal status, melatonin, prepubertal bitches

636.7.09(043.3)

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