Effect of the Combination of Synthetic Anthelmintics with Carvacryl Acetate in Emulsions with and without a Sodium Alginate Matrix on IHaemonchus contortus/I

One of the biggest problems with sheep and goat farming is worms. These parasites impede the development of these animals and even lead to death. Currently, the dewormers used to control these parasites do not have the desired effect because worms have developed resistance. This study aimed to evaluate the effect of nanoemulsions that combine synthetic anthelmintics with carvacryl acetate on the worm Haemonchus contortus. Assessments were performed on the hatching of worm eggs and the development of larvae. Photomicrographs of the eggs were taken to show the effect of the different treatments. The best results were obtained with the combination of carvacryl acetate and thiabendazole and carvacryl acetate and thiabendazole encapsulated in sodium alginate. The results of this study allowed the reuse of anthelmintics such as benzimidazoles whose use was discontinued due to the development of anthelmintic resistance, when combined with natural and nanoencapsulated products. The present study aimed to evaluate the effect of nanoemulsions using combined synthetic anthelmintics, thiabendazole (TBZ), levamisole (LEV), and ivermectin (IVM), with carvacryl acetate (CA) against Haemonchus contortus, and also tested the presence and absence of alginate (ALG). The anthelmintic effect of the CA/TBZ nanoemulsion was evaluated in the egg hatch test (EHT). The effects of CA/IVM and CA/LEV nanoemulsions were evaluated in the larval development test (LDT). The emulsions CA/TBZ/ALG and CA/TBZ showed a multimodal profile, with most particles on the nanometric scale. The encapsulation efficiency in CA/TBZ/ALG was 80.25%, and that in CA/LEV/ALG was 89.73%. In the EHT, CA/TBZ and CA/TBZ/ALG showed mean combination indices (CIs) of 0.55 and 0.36, respectively, demonstrating synergism in both. In LDT, CA/IVM had an average CI of 0.75, and CA/LEV and CA/LEV/ALG showed CI values of 0.4 and 0.93, respectively. It was concluded that CA/TBZ showed a synergistic interaction, and CA/TBZ/ALG showed an enhanced effect. In addition, the matrix brought stability to the product, encouraging its improvement to obtain higher efficacy.