Proceeding of Veterinary and Animal Science Days 2018, 6th- 8th June, Milan, Italy HAF © 2013 Vol. V, No. 1s ISSN: 2283-3927 l The current 30% of canine perinatal mortality (Tonnessen et al., 2012) claims the need to deepen the knowledge about this phase, characterized by long-term hormonal and metabolic changes, that could benefit of long time-frame methods of investigation, reducing the quantity of samplings and thus respecting animal welfare (Veronesi et al., 2015). Indeed, apart from the well- known invasiveness of blood samplings, the necessary repeated collection of feces, urine and saliva, providing punctual information, could be stressful for the newborns and their mothers with negative effects on health status and maternal behavior. Given that sexual steroid hormones were reported to have an influence on health outcomes and development already from the perinatal period (Frey et al., 2017), in this work 17-β-Estradiol (E2) and Testosterone (T) concentrations were assessed from the claws of dogs up to 60 days of age, to identify possible endogenous biomarkers. Ten male and 10 female puppies, viable and healthy, born by elective cesarean section, were enrolled. Samplings were performed by trimming claws at birth, and the regrowth at 30 and 60 days of age after the breeder or the owner signed an informed consent. Then, E2 and T concentrations were analyzed by RIA (Veronesi et al., 2015) and a possible effect of gender evaluated by ANOVA. All the hormonal claws concentrations showed a significant (p<0.001) drop from birth to 30 and 60 days of age, while no significant changes were observed between 30 and at 60 days of age (Table 1). No influence of the newborns’ gender was found. Because of the higher levels of E2 and T observed at birth and at 30 days of age, it could be supposed that a source of production could be the placental and maternal compartments. However, the direct involvement of the fetus itself could not be excluded, given the reported accumulation from the nail capillary bed of those hormones (de Berker et al., 2007) and the production of sexual steroid hormones by feline fetal gonads (Braun and Jewgenow, 2017). Keywords Dog, Puppy, Claws, 17-ß- Estradiol, Testosterone. CORRESPONDING AUTHOR Jasmine Fusi jasmine.fusi@unimi.it JOURNAL HOME PAGE riviste.unimi.it/index.php/haf 17-ß-Estradiol and Testosterone concentrations in claws of puppies up to 60 days of age. J. Fusi1,*, T. Peric2, C. Bergamin3, M.C Veronesi1 1 Department of Veterinary Medicine, Università degli Studi di Milano, Via Celoria 10, Milan, Italy. 2 Laboratory for Environmental and Life Sciences, Univerza v Novi Gorici, Vipavska cesta, 5000, Nova Gorica, Slovenia. 3 Department of AgriFood, Environmental and Animal Sciences, University of Udine, Via Sondrio, 2, Udine, Italy. http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en Proceeding of Veterinary and Animal Science Days 2018, 6th- 8th June, Milan, Italy 2 HAF © 2013 Vol. V, No. 1s ISSN: 2283-3927 References Braun, B.C., Jewgenow, K., 2017. Expression of steroidogenic enzymes and steroid receptors in foetal gonads of domestic cat-Sex similarities and differences. Reproduction in Domestic Animals. 52, 130-136. de Berker, D.A., André, J., Baran, R., 2007. Nail biology and nail science. International Journal of Cosmetic Science. 29, 241-75. Frey, A.J., Park, B.Y., Schriver, E.R., Feldman, D.R., Parry, S., Croen, L.A., Fallin, D.M., Hertz-Picciotto, I., Newschaffer, C.J., Snyder, N.W., 2017. Differences in testosterone and its precursors by sex of the offspring in meconium. The Journal of Steroid Biochemistry and Molecular Biology. 167, 78-85. Tønnessen, R., Borge, K.S., Nødtvedt, A., Indrebø, A., 2012. Canine perinatal mortality: a cohort study of 224 breeds. Theriogenology. 77, 1788-801. Veronesi, M.C., Comin, A., Meloni, T., Faustini, M., Rota, A., Prandi, A., 2015. Coat and claws as new matrices for noninvasive long-term cortisol assessment in dogs from birth up to 30 days of age. Theriogenology. 84, 791-6. Table 1: Claws concentrations of 17- β-Estradiol (E2), and Testosterone (T) at birth, 30 and 60 days of age in the 20 puppies enrolled in the study. FEMALES (n=10) Birth 30 days 60 days E2 (pg/mg) 9.2 ± 3.87a 3.3 ± 1.75b 1.9 ± 0.67b T (pg/mg) 11.2 ± 6.66a 4.3 ± 2.44b 2.3 ± 0.78b MALES (n=10) Birth 30 days 60 days E2 (pg/mg) 8.3 ± 2.91a 2.4 ± 0.60b 1.7 ± 0.54b T (pg/mg) 8.7 ± 3.12a 3.7 ± 0.98b 1.9 ± 0.75b a, b within rows denotes a significant difference with p<0.001. http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en