doi:10.3390/ani11010146engde Miguel, R.Asín, J.Rodríguez-Largo, A.Echeverría, I.Lacasta, D.Pinczowski, P.Gimeno, M.Molín, J.Fernández, A.de Blas, I.de Andrés, D.Pérez, M.Reina, R.Luján, L.Growth performance and clinicopathological analyses in lambs repetitively inoculated with aluminum-hydroxide containing vaccines or aluminum-hydroxide onlyART-2021-122625Aluminum (Al) hydroxide is an effective adjuvant used in sheep vaccines. However, Al-adjuvants have been implicated as potential contributors to a severe wasting syndrome in sheep— the so-called ovine autoimmune-inflammatory syndrome induced by adjuvants (ASIA syndrome). This work aimed to characterize the effects of the repetitive injection of Al-hydroxide containing products in lambs. Four flocks (Flocks 1–4; n = 21 each) kept under different conditions were studied. Three groups of seven lambs (Vaccine, Adjuvant-only, and Control) were established in each flock. Mild differences in average daily gain and fattening index were observed, indicating a reduced growth performance in Vaccine groups, likely related to short-term episodes of pyrexia and decreased daily intake. Clinical and hematological parameters remained within normal limits. Histology showed no significant differences between groups, although there was a tendency to present a higher frequency of hyperchromatic, shrunken neurons in the lumbar spinal cord in the Adjuvant-only group. Although Al-hydroxide was linked to granulomas at the injection site and behavioral changes in sheep, the results of the present experimental work indicate that injected Al-hydroxide is not enough to fully reproduce the wasting presentation of the ASIA syndrome. Other factors such as sex, breed, age, production system, diet or climate conditions could play a role.2021http://zaguan.unizar.es/record/9915410.3390/ani11010146http://zaguan.unizar.es/record/99154oai:zaguan.unizar.es:99154info:eu-repo/grantAgreement/ES/DGA/A17-17Rinfo:eu-repo/grantAgreement/ES/MCIU/RTI2018-096172-B-C31info:eu-repo/grantAgreement/ES/MCIU/RTI2018-096172-B-C33info:eu-repo/grantAgreement/ES/MINECO/AGL2013-49137-C3-1-Rinfo:eu-repo/grantAgreement/ES/MINECO/AGL2013-49137-C3-2-RAnimals 11, 1 (2021), 146 [18 pp]byhttp://creativecommons.org/licenses/by/3.0/es/info:eu-repo/semantics/openAccess