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Journal of the American Association For... Nov 2023Sterility in male NHP has long been achieved through surgical castration or vasectomy. However, these techniques are irreversible, require a surgical procedure, and have...
Sterility in male NHP has long been achieved through surgical castration or vasectomy. However, these techniques are irreversible, require a surgical procedure, and have potential consequences such as sperm granulomas and long recovery time. Deslorelin is a gonadotropin-releasing hormone agonist that temporarily and reversibly suppresses sex hormone secretion. Our goal in this study was to investigate the effects of deslorelin on testosterone secretion and testicular volume in male rhesus macaques (). Male macaques ( = 4) each received two, 4.7-mg deslorelin implants subcutaneously in the interscapular region. Serum testosterone and testicular volume were then monitored at specific time points until 10 mo after treatment. Testosterone suppression was defined as testosterone levels lower than 0.6 ng/mL for a sustained period of at least 30 d. After implantation, mean testicular volume was significantly reduced by day 121. Testosterone suppression was observed in all subjects. However, the time from implantation to testosterone suppression and duration of suppression varied. Two macaques were hormonally suppressed by day 26 after implantation and remained suppressed for at least 6 mo. The other 2 macaques were hormonally suppressed by 2 mo after implantation; of these two, one remained suppressed for 70 days while the other was suppressed for at least 245 days. We conclude that deslorelin can safely suppress testosterone secretion in male rhesus macaques, but individual variation in onset and duration of action should be considered when establishing reimplantation time points and potential return to reproductive activity.
Topics: Male; Animals; Testis; Gonadotropin-Releasing Hormone; Macaca mulatta; Testosterone; Semen; Drug Implants; Triptorelin Pamoate
PubMed: 37844997
DOI: 10.30802/AALAS-JAALAS-22-000116 -
Journal of the American Association For... Nov 2023Hormonal contraception is an effective, reversible tool for managing birth rates in humans and nonhuman animals alike. However, manipulating reproductive hormones has...
Hormonal contraception is an effective, reversible tool for managing birth rates in humans and nonhuman animals alike. However, manipulating reproductive hormones has behavioral consequences that can impact social and sexual behavior between conspecifics. First, we studied 18 pairs of nonreproductive titi monkeys () to test the efficacy of a novel method of hormonal contraception (deslorelin acetate implants) on reproductive hormone cycling in females and found significant reductions in urinary estrogens and progestagens among treated females compared to untreated controls. We then studied 35 nonreproductive pairs of coppery titi monkeys () to ascertain whether treating females with one of 2 different forms of hormonal contraception (deslorelin acetate implants ( = 17) or medroxyprogesterone acetate injections ( = 9)) would influence the relationship between pair mates compared to the relationship between untreated females and their vasectomized male mates ( = 9). Over a 5-month period, we found no differences in affiliative behaviors between pairs containing untreated females compared to pairs in which the female was treated with either deslorelin acetate or medroxyprogesterone acetate. Similarly, we found no differences in affiliation between pairs in the 2 treatment groups. This study is the first to examine behavioral consequences of hormonal contraception in a pair-bonding species. The results are encouraging for captive, managed breeding colonies of such social animals, especially those used in behavioral research.
Topics: Humans; Male; Female; Animals; Contraceptive Agents; Callicebus; Medroxyprogesterone Acetate; Social Behavior
PubMed: 37973152
DOI: 10.30802/AALAS-JAALAS-23-000017 -
Journal of Equine Veterinary Science Aug 2023To successfully inseminate mares, precise detection of ovulation time is crucial, especially when using frozen-thawed semen. Monitoring body temperature, as has been...
To successfully inseminate mares, precise detection of ovulation time is crucial, especially when using frozen-thawed semen. Monitoring body temperature, as has been described in women, could be a noninvasive way to detect ovulation. The objective of this study was to investigate the relationship between the time of ovulation and the variation of body temperature in mares based on automatic continuous measurements during estrus. The experimental group included 21 mares for 70 analyzed estrous cycles. When the mares showed estrous behavior, they were administered intramuscular deslorelin acetate (2.25 mg) in the evening. At the same time, monitoring of body temperature using a sensor device fixed at the left lateral thorax was started and continued for over 60 hours. In 2-hour intervals, transrectal ultrasonography was performed to detect ovulation. Estimated body temperature in the 6 hours following ovulation detection was on average 0.06°C +/- 0.05°C (mean +/- SD) significantly higher when compared with body temperature at the same time on the preceding day (P = .01). In addition, a significant effect of PGF administration for estrus induction on the body temperature was found, being significantly higher until 6 hours before ovulation compared to that of uninduced cycles (P = .005). In conclusion, changes in body temperature during estrus in mares were related to ovulation. The increase in body temperature immediately after ovulation might be used in the future to establish automatized and noninvasive systems to detect ovulation. However, the identified temperature rise is relatively small on average and hardly identifiable in the individual mares.
Topics: Female; Horses; Animals; Body Temperature; Ovulation; Estrus; Estrous Cycle; Semen Preservation
PubMed: 37209788
DOI: 10.1016/j.jevs.2023.104565 -
JFMS Open Reports 2023The aim of this clinical case presentation was to describe the effect of a 4.7 mg deslorelin implant placement in a pregnant queen during the second half of gestation,...
CASE SUMMARY
The aim of this clinical case presentation was to describe the effect of a 4.7 mg deslorelin implant placement in a pregnant queen during the second half of gestation, and the consequences of its removal on the pregnancy and parturition. A 5-year-old female cat exhibiting nesting behaviour and weight gain 10 days after placement of a deslorelin implant was presented for examination. Gestation was confirmed on ultrasound, with two well-formed kittens of a gestational age of approximately 7 weeks. The deslorelin implant placed on the umbilicus was removed 1 week later. No change in the pregnancy was observed after removal of the implant. The fetuses showed no signs of distress on ultrasound and radiography examination 4 days after removal of the implant. One week after implant removal, the queen naturally delivered two healthy kittens. The queen showed maternal behaviour with normal milk production.
RELEVANCE AND NOVEL INFORMATION
In the light of the lack of literature on implant injection and removal in the pregnant queen, this case report showcases a successful birth of healthy kittens without any subsequent adverse effect on the queen. Further study is needed to assess the safety of implant removal during pregnancy and potential use as a means to induce fertile oestrus in the queen.
PubMed: 37873522
DOI: 10.1177/20551169231201606 -
Animals : An Open Access Journal From... Aug 2023Deslorelin implant use in cats is a medical alternative to surgical sterilization, and due to its prolonged efficacy, its use has shown growing interest in the...
Deslorelin implant use in cats is a medical alternative to surgical sterilization, and due to its prolonged efficacy, its use has shown growing interest in the veterinary community. In the case of breeding facilities, its removal is often requested for the early restoration of testicular function. As anti-Müllerian hormones (AMH) in males is dependent of testosterone secretion, its assay may determine the restoration of testicular steroid secretion. An average of 3 weeks has been already described for tomcats' testicular function resumption after implant removal, but information about AMH concentrations in deslorelin-treated tomcats is lacking. Fourteen tomcats were treated for temporary suppression of fertility with a 4.7 mg deslorelin implant, which was surgically removed after 3, 6 or 9 months (n = 6, 4 and 4 tomcats, respectively). A general clinical and reproductive check with a gonadorelin stimulation test for testosterone determination was performed before deslorelin implant administration. After implant removal, tomcats' testicles were ultrasonographically checked for volume determination every 1-2 weeks with observation of the glans penis (presence or absence of spikes) and blood collection to assay both testosterone and AMH concentrations. AMH concentrations increased significantly during the deslorelin treatment from 20.95 ± 4.97 ng/mL to 82.41 ± 14.59 ng/mL ( < 0.05). Following implant removal, AMH concentrations progressively decreased to pre-treatment levels, with a value of 28.42 ± 7.98 ng/mL on the third week post-removal where testosterone secretion was again detected. Even if a big variability of AMH concentrations exists between male individuals, resumption of tomcats' testicular function following a deslorelin treatment can be determined by AMH assay.
PubMed: 37627341
DOI: 10.3390/ani13162552 -
Veterinary Research Communications Dec 2023Deslorelin acetate is a gonadotropin-releasing hormone agonist formulated in a controlled-release subcutaneous implant and designed for reversible suppression of...
Effect of a subcutaneous implant of deslorelin acetate on serum testosterone concentrations in male Hermann's (Testudo hermanni sp.) and Greek (Testudo graeca sp.) tortoises.
Deslorelin acetate is a gonadotropin-releasing hormone agonist formulated in a controlled-release subcutaneous implant and designed for reversible suppression of testosterone production in dogs. It has also been demonstrated to be effective in other animal species, but no data on its effectiveness in male land tortoises are available. This study aimed to evaluate the effect of a 4.7-mg deslorelin acetate implant on serum testosterone concentrations in male Hermann's (Testudo hermanni sp.) and Greek (Testudo graeca sp.) tortoises. Twenty adult male tortoises housed under the same environmental conditions were enrolled for the study and randomly assigned to a treatment (D, n = 10) or a control (C, n = 10) group. Starting in May, males from the D group were implanted with a 4.7-mg deslorelin acetate device, whereas males from the C group did not receive any treatment. Blood samples were collected once immediately before implant application (S0-May) and at 15 days (S1-June), 2 (S2-July), and 5 (S3-October) months after application. Serum testosterone at each sampling time was measured through a solid-phase, enzyme-labeled, competitive chemiluminescent immunoassay. Median serum testosterone concentrations were not significantly different between the two groups in all sampling times, and no interaction between treatment and sampling time was observed. The present study, therefore, suggests that a single treatment with a 4.7-mg deslorelin acetate implant has no effect on testosterone circulation in male Hermann's and Greek tortoises during the following 5 months.
Topics: Animals; Male; Dogs; Turtles; Greece
PubMed: 37173553
DOI: 10.1007/s11259-023-10138-6 -
Effect of GnRH agonist (deslorelin) on reproductive activity in captive female veiled chameleons ().Veterinarni Medicina Jul 2023Eighteen 5 months old veiled chameleon females () were used in the study. Seven females received subcutaneous implants with gonadotropin-releasing hormone agonist...
Eighteen 5 months old veiled chameleon females () were used in the study. Seven females received subcutaneous implants with gonadotropin-releasing hormone agonist (GnRH) deslorelin acetate whereas eleven females were used as control animals without any implants. Females were kept in five terraria, in groups of four females (in 3 terraria) and groups of three females (in 2 terraria), respectively. A minimum of one female with GnRH implants was present in each terrarium. They were kept under standard husbandry conditions. Females of both groups (females with GnRH and controls, respectively) were monitored for three years. No differences between females with GnRH implants and females without GnRH implants were observed with respect to the presence of large ovarian follicles, number of eggs/female, or number of clutches/female. GnRH implants did not prevent spontaneous reproductive activity in any of the 7 females with implants. Ovariectomy was performed in 8 females (4 females with GnRH implants and 4 control females). Ten females (3 females with GnRH implants and 7 control females) had to be euthanised. In 17 of 18 female veiled chameleons of this study histologic examination revealed heterophilic granulomatous oophoritis. The use of GnRH agonist implants did not prove to be an appropriate method for the control of reproductive function in captive female veiled chameleons.
PubMed: 37982053
DOI: 10.17221/31/2023-VETMED