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 increasing resistance of head lice Pediculus humanus capitis to many drugs has highlighted the need for new alternatives to control head lice in adults. The effect of two types of extracts (aqueous and alcoholic) of Citrullus colocynthis fruit on adult lice was tested in vitro. The results showed that the alcoholic extract with a concentration of 20% showed similar efficacy in killing adult lice to that of Natroba 9% w/w, with values ranging between 87% to 98% within 18 minutes, followed by a 20% aqueous extract with a 44% to 79% death rate. A 10% concentration of both types of extracts had moderate lethality for lice, while a 5% concentration did not show strong lethality for adult lice. These results revealed significant differences between the control group and those treated with alcoholic and aqueous extract concentrations of C. colocynthis fruits at the probability level p ≤ 0.05.

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.