Sunset Yellow FCF (SY), used frequently in ready-made foods, cosmetics, and the pharmaceutical industry, may cause many health problems. This study is intended to evaluate the morphological and cellular effects of SY on the embryonic chicken immune system throughout incubation. Babcock white leghorn eggs were randomly divided into four groups. Besides a control group, there were three treatment groups which received a single injection of 200, 1,000, or 2,000 ng of SY into the air sac just before incubation. The eggs were opened on the 10ᵗʰ, 13ᵗʰ, 16ᵗʰ, and 21ˢᵗ days of incubation. Samples of the bursa of Fabricius, thymus, and spleen were taken from embryos. Serial sections of 5 μm thickness were stained with histological methods and routine histological procedures were performed. An increase in the spleen volume was determined as the hatching time of the chicks approached. The highest eosinophil ratio was found in the SY₁,₀₀₀ and SY₂,₀₀₀ groups (P < 0.05), where the most significant change was developmental retardation in the thymus. In the bursa of Fabricius, there was less lymphocyte accumulation and eosinophilic cell infiltration with increasing doses. It was concluded that in ovo administered SY has undesired effects on embryonic development of the bursa of Fabricius, spleen, and thymus, and on spleen volume.

The industrial manufacturing of natural products for veterinary use represents a major weakness in the veterinary sector despite increased interest and the traditional ancestral knowledge that supports them. A cross-sectional, descriptive observational study was conducted to characterize the veterinary herbal products marketed worldwide during 2018 and 2019. A comprehensive thematic search limited to the 2018-2019 period was performed in the ScienceDirect, Scopus, PubMed, Web of Science, ResearchGate, and Academic Search Complete databases. The investigation identified 487 products registered in the global market manufactured by 54 companies, led by India, The Netherlands, and the United Kingdom. The market segments of animal production and phytomedicines were dominant with 73.7% and 53.0% of products, respectively. Cattle (22.2%), sheep-goats (16.2%), and canines (16.2%) were the most favored species. The most represented therapeutic indications were those intended to treat gastrointestinal disorders (30.47%), antimicrobials (16.66%), and antiparasitic agents (10.47%). The families Fabaceae, Lamiaceae, Asteraceae, Apiaceae, Malvaceae, and Rutaceae stood out because of their frequent use, encompassing 35.0% of the 137 declared species. Andrographis paniculata (Burm.f.) Nees and Withania somnifera (Lin) Dunal were the most important species. Oral formulations for internal use (72%) and liquids (51%) in 100 mL, 500 mL, and 1 L presentations showed the highest prevalence on the market. The global market for veterinary herbal products during the 2018-2019 period was relevant in the productive and medical animal sector. No differences were found between medicinal plant species used to formulate herbal products for human and animal use.