The effectiveness of zinc oxide nanoparticles (ZnO-NPs) on Cryptosporidium parvum was investigated by infecting laboratory mice with a dose of 1 × 103 oocysts/mouse. Each group was given 1 mL of the specified dose and then administered ZnO-NPs at concentrations of 5, 15, and 20 mg/kg. The nested-polymerase chain reaction revealed the amplification of the heat shock protein gene of C. parvum in all samples that were identified microscopically using Ziehl–Neelsen staining. The current study indicated the use of ZnO-NPs as a treatment for mice infected with C. parvum oocysts for a week. The effects of the three concentrations varied in reducing the number of oocysts excreted in the feces of experimentally infected mice. The 20 mg/kg concentration was the best concentration becauseit completely reduced the oocysts on the fifth day, with a therapeutic efficiency of 100%. At this concentration, the mice completely stopped shedding oocysts compared to the positive control group, which continued to shed oocysts until the seventh day. This was also the closest concentration to the group treated with nitazoxanid, which achieved a therapeutic efficiency of 100% on the fourth day of treatment. At 15 mg/kg, therapeutic efficacy was achieved on the sixth and seventh days of treatment at a rate of 96.31% and 100% respectively. By contrast, 5 mg/kg showed low efficacy because the treated mice continued to produce oocysts until the seventh day of treatment.

The current study aimed to determine the effect of silver and chitosan nanoparticles of size 10 to 30 nm on the dead of lice in vitro and in vivo to determine the optimal time and concentration to combat chicken lice. 100 local chickens Gallus gallus domesticus were collected from Al-Diwaniyah province and 6 species of local chicken lice were isolated: Menacanthus stramineus, Menacanthus pallidullus, Menacanthus cornutus, Goniodes gigas, Cuclotogaster heterographus and Bonomiella columbae. The results of treating lice with chitosan and silver nanoparticles at concentrations (40, 60, and 80) mg/mL in vitro and at different periods (5, 10, 15, and 30) minutes after treatment showed that chitosan and silver nanoparticles at a concentration of 80 mg/mL are the most effective in killing lice. The dead rate of lice reached 100% after 15 minutes of treatment with chitosan nanoparticles and 100% in the case of silver nanoparticles after 30 minutes. The results of spraying chitosan and silver nanoparticles on the body of chickens infected with lice experimentally, based on the relative therapeutic efficacy within 30 minutes, indicated that silver nanoparticles were the most effective in completely killing lice in the group treated with a concentration of 80 mg/kg after 30 minutes, where the percentage of therapeutic efficacy was 96.7%. This was followed by chitosan nanoparticles at a concentration of 80 mg/kg, and the percentage of therapeutic efficiency was 91.5%. Chitosan and silver nanocomposite have a promising effect in the elimination of lice infestation in chickens.

Many scolicidal agents have been used to destroy fertile protoscolices, but these scolicidal agents have side effects, highlighting the need for research on effective and non-toxic replacement scolicidal agents. Gold nanoparticles are biocompatible and non-toxic. The current study examined the effects of AuNPs in killing the protoscolices of Echinococcus granulosus in vitro using eosin staining. The protoscolices were treated with 0.2, 0.4, 0.8, or 1.0 mg/mL of gold nanoparticles (AuNPs) for 15, 30, 45, or 60 minutes. A concentration of 1.0 mg/mL was the most efficient in killing the protoscolices after 60 minutes exposure, reaching 96%, followed by 0.8 mg/mL (84.5%), whereas 0.4 and 0.2 mg/mL of AuNPs achieved a death rate of 76.8% and 68.5%, respectively. The loss of the protoscolices was lower at shorter exposure times with the same concentration of AuNPs and increased as the AuNP concentration was increased at the same exposure time. Significant differences were found between the different groups compared to the control group.

In the study, zinc oxide nanoparticles (ZNOPs) at concentrations of 20, 40, and 60 mg/kg were tested for their antimicrobial action against the oocysts of Eimeria tenella. The oocysts of E. tenella were isolated from the feces of broilers received at the veterinary hospital in Diwaniyah Province and initially diagnosed by compound optical microscopy. The oocysts were confirmed molecularly by polymerase chain reaction targeting the ITS1 gene with a molecular weight of 409 bp. The results in the first week showed that ZNOP concentrations of 20 and 40 mg/kg possess various activities against E. tenella, while 60 mg/kg was the most effective in reducing excreted oocysts compared to the positive control and amprolium group, along with the appearance of mild symptoms and a mortality rate of 0.8%. In the second week of infection, excreted oocysts and mortality rates generally decreased in all treated groups. A comparison of all groups showed that the 60 mg/kg ZNOP-treated group had a significantly lower number of excreted oocysts, and all birds in this group recovered during the second week of infection. These findings revealed the prospect of using ZNOPs against E. tenella in challenging situations of the appearance of resistance to anticoccidial agents.