{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,18]],"date-time":"2026-03-18T20:53:29Z","timestamp":1773867209563,"version":"3.50.1"},"reference-count":6,"publisher":"Polish Academy of Sciences Chancellery","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<jats:p>For South American camelids (SAC) and, to a lesser extent, Old World camels (OWC), an increasing demand for veterinary services has developed in Central Europe in recent years, with specific knowledge of the reproductive endocrinology of this species being particularly in demand for the management of breeding farms. Compared to many other domestic animal species, relatively little reliable information is available on the endocrine control of pregnancy and parturition in camelids. However, some significant differences to other domestic ungulate species are evident. Knowledge of pregnancy-associated endocrine changes forms the basis for hormonal pregnancy diagnostics. Even though clinical pregnancy diagnostics using sonography is also of primary importance in camelids, hormonal methods, especially non-invasive methods, are potentially of considerable interest as they represent a less stressful or stress-free alternative. Non-invasive methods of pregnancy diagnostics are of particular interest in untrained OWC, where clinical diagnostics or blood sampling without sedation can be associated with unacceptable risks for the personnel involved. Experience with hormonal pregnancy diagnostics in camelids has so far only been published sporadically, with mostly progesterone, pregnancy-associated estrogens or relaxin being measured in the blood. Non-invasive measurement of progesterone or estrogen metabolites in feces and urine has also rarely been reported. The aim of this article is to summarize the current state of knowledge on the hormonal control of pregnancy and parturition in SAC and OWC and based on this, to show the possibilities for hormonal pregnancy diagnostics. Essential prerequisites for broader application, particularly of non-invasive methods in routine diagnostics, are the optimization of previously pursued methodological approaches, the commercial availability of the necessary reagents at reasonable cost, and the establishment of reliable reference values.<\/jats:p>","DOI":"10.24425\/pjvs.2026.158505","type":"journal-article","created":{"date-parts":[[2026,3,18]],"date-time":"2026-03-18T13:01:56Z","timestamp":1773838916000},"page":"133-133","source":"Crossref","is-referenced-by-count":0,"title":["Endocrine control of pregnancy and parturition in South American camelids and Old World camels and the resulting possibilities for hormonal pregnancy diagnostics"],"prefix":"10.24425","author":[{"given":"G.","family":"Schuler","sequence":"first","affiliation":[{"name":"Veterinary Clinic for Reproductive Medicine and Neonatology, Faculty of Veterinary Medicine, Justus Liebig University, Frankfurter Strasse 106, 35392 Giessen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"H.","family":"Wagner","sequence":"additional","affiliation":[{"name":"Veterinary Clinic for Reproductive Medicine and Neonatology, Faculty of Veterinary Medicine, Justus Liebig University, Frankfurter Strasse 106, 35392 Giessen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"U.","family":"Westerh\u00fcs","sequence":"additional","affiliation":[{"name":"Opel-Zoo, Opel Hessian Zoo Foundation, Am Opel-Zoo 3, 61476 Kronberg im Taunus, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"P.","family":"Pohlscheid","sequence":"additional","affiliation":[{"name":"Veterinary Clinic for Reproductive Medicine and Neonatology, Faculty of Veterinary Medicine, Justus Liebig University, Frankfurter Strasse 106, 35392 Giessen, Germany"},{"name":"Opel-Zoo, Opel Hessian Zoo Foundation, Am Opel-Zoo 3, 61476 Kronberg im Taunus, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"37468","published-online":{"date-parts":[[2026,3,17]]},"reference":[{"key":"#cr-split#-ref0.1","unstructured":"Aba MA, Bravo PW, Forsberg M, Kindahl H (1997) Endocrine changes during early pregnancy in the alpaca. Anim Reprod Sci 47: 273-279. Aba MA, Forsberg M, Kindahl H, Sumar J, Edqvist LE (1995) Endocrine changes after mating in pregnant and non-pregnant llamas and alpacas. Acta Vet Scand 36: 489-498. Aba MA, Kindahl H, Forsberg M, Quiroga M, Auza N (2000) Levels of progesterone and changes in prostaglandin F(2alpha) release during luteolysis and early pregnancy in llamas and the effect of treatment with flunixin meglumine. Anim Reprod Sci 59: 87-97. Aba MA, Sumar J, Kindahl H, Forsberg M, Edqvist LE (1998) Plasma concentrations of 15-ketodihydro-PGF2 alpha, progesterone, oestrone sulphate, oestradiol-17 beta and cortisol during late gestation, parturition and the early post partum period in llamas and alpacas. Anim Reprod Sci 50: 111-121. Abdel Rahim SE, el-Nazier AE (1987) Estimation of progesterone level in camels' (Camelus dromedarius) milk and its application in pregnancy diagnosis. Br Vet J 143: 555-559. Adams GP, Griffin PG, Ginther OJ (1989) In situ morphologic dynamics of ovaries, uterus, and cervix in llamas. Biol Reprod 41: 551-558. Adams GP, Sumar J, Ginther OJ (1990) Effects of lactational and reproductive status on ovarian follicular waves in llamas (Lama glama). J Reprod Fertil 90: 535-545. Adams GP, Sumar J, Ginther OJ (1991) Form and function of the corpus luteum in llamas. Anim Reprod Sci 24: 127-138. Agarwal SP, Khanna ND, Agarwal VK, Dwaraknath PK (1987) Circulating levels of estrogen and progesterone in female camel during pregnancy. Theriogenology 28: 849-859. Ainani H, Chhaibi H, Acha\u00e2ban MR, Piro M, Ouassat M, Tibary A, El Allali K, Simonneaux V (2022) Induced-ovulation in female dromedary camel involves kisspeptin neuron activation by \u03b2 nerve growth factor. Biol Reprod 107: 1490-1502. Almushawwah KS, Derar DR, Ali A (2025) Pseudopregnancy in dromedary camels: Characterization, prevalence, and clinical and hormonal properties. Theriogenology 235: 196-202. 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Bianchi CP, Gallelli MF, Herrera JM, Benavente MA, Rossetto L, Aba MA (2023) Current knowledge about the processes of luteolysis and maternal recognition of pregnancy in camelids. Reprod Domest Anim 58: 3-9. Bravo PW (1994) Reproductive endocrinology of llamas and alpacas. Vet Clin North Am Food Anim Pract 10: 265-279. Bravo PW, Bazan PJ, Troedsson MH, Villalta PR, Garnica JP (1996a) Induction of parturition in alpacas and subsequent survival of neonates. J Am Vet Med Assoc 209: 1760-1762. Bravo PW, Stewart DR, Lasley BL, Fowler ME (1996b) Hormonal indicators of pregnancy in llamas and alpacas. J Am Vet Med Assoc 208: 2027-2030. Bravo PW, Stabenfeldt GH, Fowler ME, Lasley BL (1991) Urinary steroids in the periparturient and postpartum periods through early pregnancy in llamas. Theriogenology 36: 267-278. Braz HB, Barreto RD, Silva-J\u00fanior LN, Horvath-Pereira BO, Silva TS, Silva MD, Acu\u00f1a F, Miglino MA (2024) Evolutionary patterns of maternal recognition of pregnancy and implantation in Eutherian mammals. Animals (Basel) 14: 2077. Brown BW (2000) A review on reproduction in South American camelids. Anim Reprod Sci 58: 169-195. Carter AM (2024) Genomics, the diversification of mammals, and the evolution of placentation. Dev Biol 516: 167-182. Chen BX, Yuen ZX (1984) Reproductive pattern of the Bactrian camel. In: Cockrill WR (ed) The Camelid. An All-purpose Animal"},{"key":"#cr-split#-ref0.2","unstructured":"The Scandinavian Institute of African Studies, Uppsala, Sweden, pp 364-396. Cobb ML, Iskandarani K, Chinchilli VM, Dreschel NA (2016) A systematic review and meta-analysis of salivary cortisol measurement in domestic canines. Domest Anim Endocrinol 57: 31-42. 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Aba MA, Sumar J, Kindahl H, Forsberg M, Edqvist LE (1998) Plasma concentrations of 15-ketodihydro-PGF2 alpha, progesterone, oestrone sulphate, oestradiol-17 beta and cortisol during late gestation, parturition and the early post partum period in llamas and alpacas. Anim Reprod Sci 50: 111-121. Abdel Rahim SE, el-Nazier AE (1987) Estimation of progesterone level in camels' (Camelus dromedarius) milk and its application in pregnancy diagnosis. Br Vet J 143: 555-559. Adams GP, Griffin PG, Ginther OJ (1989) In situ morphologic dynamics of ovaries, uterus, and cervix in llamas. Biol Reprod 41: 551-558. Adams GP, Sumar J, Ginther OJ (1990) Effects of lactational and reproductive status on ovarian follicular waves in llamas (Lama glama). J Reprod Fertil 90: 535-545. Adams GP, Sumar J, Ginther OJ (1991) Form and function of the corpus luteum in llamas. Anim Reprod Sci 24: 127-138. Agarwal SP, Khanna ND, Agarwal VK, Dwaraknath PK (1987) Circulating levels of estrogen and progesterone in female camel during pregnancy. Theriogenology 28: 849-859. Ainani H, Chhaibi H, Acha\u00e2ban MR, Piro M, Ouassat M, Tibary A, El Allali K, Simonneaux V (2022) Induced-ovulation in female dromedary camel involves kisspeptin neuron activation by \u03b2 nerve growth factor. Biol Reprod 107: 1490-1502. Almushawwah KS, Derar DR, Ali A (2025) Pseudopregnancy in dromedary camels: Characterization, prevalence, and clinical and hormonal properties. Theriogenology 235: 196-202. Barbato O, Menchetti L, Brecchia G, Barile VL (2022) Using pregnancy-associated glycoproteins (PAGs) to improve reproductive management: from dairy cows to other dairy livestock. Animals (Basel) 12: 2033. Bathgate RA, Halls ML, van der Westhuizen ET, Callander GE, Kocan M, Summers RJ (2013) Relaxin family peptides and their receptors. Physiol Rev 93: 405-480. Bazer FW, Thatcher WW (1977) Theory of maternal recognition of pregnancy in swine based on estrogen controlled endocrine versus exocrine secretion of prostaglandin F2alpha by the uterine endometrium. Prostaglandins 14: 397-400. Bella A, Sousa NM, Dehimi ML, Watts J, Beckers JF (2007) Western analyses of pregnancy-associated glycoprotein family (PAG) in placental extracts of various mammals. Theriogenology 68: 1055-1066. Bene S, Szab\u00f3 F, Polg\u00e1r PJ, Juh\u00e1sz J, Nagy P (2021) Genetic parameters of gestation length trait in dromedary camels (Camelus dromedarius). Acta Vet Hung 69: 249-255. Bianchi CP, Gallelli MF, Herrera JM, Benavente MA, Rossetto L, Aba MA (2023) Current knowledge about the processes of luteolysis and maternal recognition of pregnancy in camelids. Reprod Domest Anim 58: 3-9. Bravo PW (1994) Reproductive endocrinology of llamas and alpacas. Vet Clin North Am Food Anim Pract 10: 265-279. Bravo PW, Bazan PJ, Troedsson MH, Villalta PR, Garnica JP (1996a) Induction of parturition in alpacas and subsequent survival of neonates. J Am Vet Med Assoc 209: 1760-1762. Bravo PW, Stewart DR, Lasley BL, Fowler ME (1996b) Hormonal indicators of pregnancy in llamas and alpacas. J Am Vet Med Assoc 208: 2027-2030. Bravo PW, Stabenfeldt GH, Fowler ME, Lasley BL (1991) Urinary steroids in the periparturient and postpartum periods through early pregnancy in llamas. Theriogenology 36: 267-278. Braz HB, Barreto RD, Silva-J\u00fanior LN, Horvath-Pereira BO, Silva TS, Silva MD, Acu\u00f1a F, Miglino MA (2024) Evolutionary patterns of maternal recognition of pregnancy and implantation in Eutherian mammals. Animals (Basel) 14: 2077. Brown BW (2000) A review on reproduction in South American camelids. Anim Reprod Sci 58: 169-195. Carter AM (2024) Genomics, the diversification of mammals, and the evolution of placentation. Dev Biol 516: 167-182. Chen BX, Yuen ZX (1984) Reproductive pattern of the Bactrian camel. In: Cockrill WR"},{"key":"#cr-split#-ref0.5","unstructured":"(ed) The Camelid. An All-purpose Animal; The Scandinavian Institute of African Studies, Uppsala, Sweden, pp 364-396. Cobb ML, Iskandarani K, Chinchilli VM, Dreschel NA (2016) A systematic review and meta-analysis of salivary cortisol measurement in domestic canines. Domest Anim Endocrinol 57: 31-42. Cui P, Ji R, Ding F, Qi D, Gao H, Meng H, Yu J, Hu S, Zhang H (2007) A complete mitochondrial genome sequence of the wild two-humped camel (Camelus bactrianus ferus): an evolutionary history of camelidae. BMC Genomics 8: 241. Egi T, Hanada M, Tokura Y, Flores AB, Acosta T (2024) Possibility of early pregnancy detection in alpacas (Vicugna pacos) based on fecal steroid hormone concentrations. Anim Sci J 95: e70000. El-Belely MS (1994) Endocrine changes, with emphasis on 13, 14-dihydro-15-keto-prostaglandin F 2\u03b1 and corticosteroids, before and during parturition in dromedary camels (Camelus dromedarius). J Agric Sci 122: 315-323. Elias E, Bedrak E, Yagil R (1984) Peripheral blood levels of progesterone in female camels during various reproductive stages. Gen Comp Endocrinol 53: 235-240. Elias E, Degen AA, Kam M (1991) Effect of conception date on length of gestation in the dromedary camel (Camelus dromedarius) in the Negev Desert. Anim Reprod Sci 25: 173-177. Elwishy AB, Hemeida NA, Omar MA, Mobarak AM, El Sayed MA (1981) Functional changes in the pregnant camel with special reference to foetal growth. Br Vet J 137: 527-537. Fernandez-Baca S, Hansel W, Novoa C (1970) Corpus luteum function in the alpaca. Biol Reprod 3: 252-261. Fernandez-Baca S, Hansel W, Saatman R, Sumar J, Novoa C (1979) Differential luteolytic effects of right and left uterine horns in the alpaca. Biol Reprod 20: 586-595. 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